RESUMO
Insulin resistance and pancreatic ß-cell dysfunction are the main pathogenesis of type 2 diabetes mellitus (T2DM). However, insulin therapy and diabetes medications do not effectively solve the two problems simultaneously. In this study, a biomimetic oral hydrogen nanogenerator that leverages the benefits of edible plant-derived exosomes and hydrogen therapy was constructed to overcome this dilemma by modulating gut microbiota and ameliorating oxidative stress and inflammatory responses. Hollow mesoporous silica (HMS) nanoparticles encapsulating ammonia borane (A) were used to overcome the inefficiency of H2 delivery in traditional hydrogen therapy, and exosomes originating from ginger (GE) were employed to enhance biocompatibility and regulate intestinal flora. Our study showed that HMS/A@GE not only considerably ameliorated insulin resistance and liver steatosis, but inhibited the dedifferentiation of islet ß-cell and enhanced pancreatic ß-cell proportion in T2DM model mice. In addition to its antioxidant and anti-inflammatory effects, HMS/A@GE augmented the abundance of Lactobacilli spp. and tryptophan metabolites, such as indole and indole acetic acid, which further activated the AhR/IL-22 pathway to improve intestinal-barrier function and metabolic impairments. This study offers a potentially viable strategy for addressing the current limitations of diabetes treatment by integrating gut-microbiota remodelling with antioxidant therapies.
Assuntos
Antioxidantes , Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Resistência à Insulina , Células Secretoras de Insulina , Nanopartículas , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Animais , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Antioxidantes/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Nanopartículas/química , Camundongos , Masculino , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Camundongos Endogâmicos C57BL , Zingiber officinale/química , Dióxido de Silício/química , Exossomos/metabolismo , Biomimética/métodos , Estresse Oxidativo/efeitos dos fármacosRESUMO
Introduction: We reported that Ca2+-independent phospholipase A2ß (iPLA2ß)-derived lipids (iDLs) contribute to type 1 diabetes (T1D) onset. As CD4+ and CD8+ T cells are critical in promoting ß-cell death, we tested the hypothesis that iDL signaling from these cells participates in T1D development. Methods: CD4+ and CD8+ T cells from wild-type non-obese diabetic (NOD) and NOD.iPLA2ß+/- (NOD.HET) mice were administered in different combinations to immunodeficient NOD.scid. Results: In mice receiving only NOD T cells, T1D onset was rapid (5 weeks), incidence 100% by 20 weeks, and islets absent. In contrast, onset was delayed 1 week and incidence reduced 40%-50% in mice receiving combinations that included NOD.HET T cells. Consistently, islets from these non-diabetic mice were devoid of infiltrate and contained insulin-positive ß-cells. Reduced iPLA2ß led to decreased production of proinflammatory lipids from CD4+ T cells including prostaglandins and dihydroxyeicosatrienoic acids (DHETs), products of soluble epoxide hydrolase (sEH), and inhibition of their signaling decreased (by 82%) IFNγ+CD4+ cells abundance. However, only DHETs production was reduced from CD8+ T cells and was accompanied by decreases in sEH and granzyme B. Discussion: These findings suggest that differential select iDL signaling in CD4+ and CD8+ T cells contributes to T1D development, and that therapeutics targeting such signaling might be considered to counter T1D.
Assuntos
Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Diabetes Mellitus Tipo 1 , Camundongos Endogâmicos NOD , Transdução de Sinais , Animais , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Camundongos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/imunologia , Fosfolipases A2 do Grupo VI/metabolismo , Fosfolipases A2 do Grupo VI/genética , Metabolismo dos Lipídeos , Camundongos SCID , FemininoRESUMO
Type 2 diabetes (T2D) is a disease characterized by heterogeneously progressive loss of islet ß cell insulin secretion usually occurring after the presence of insulin resistance (IR) and it is one component of metabolic syndrome (MS), and we named it metabolic dysfunction syndrome (MDS). The pathogenesis of T2D is not fully understood, with IR and ß cell dysfunction playing central roles in its pathophysiology. Dyslipidemia, hyperglycemia, along with other metabolic disorders, results in IR and/or islet ß cell dysfunction via some shared pathways, such as inflammation, endoplasmic reticulum stress (ERS), oxidative stress, and ectopic lipid deposition. There is currently no cure for T2D, but it can be prevented or in remission by lifestyle intervention and/or some medication. If prevention fails, holistic and personalized management should be taken as soon as possible through timely detection and diagnosis, considering target organ protection, comorbidities, treatment goals, and other factors in reality. T2D is often accompanied by other components of MDS, such as preobesity/obesity, metabolic dysfunction associated steatotic liver disease, dyslipidemia, which usually occurs before it, and they are considered as the upstream diseases of T2D. It is more appropriate to call "diabetic complications" as "MDS-related target organ damage (TOD)", since their development involves not only hyperglycemia but also other metabolic disorders of MDS, promoting an up-to-date management philosophy. In this review, we aim to summarize the underlying mechanism, screening, diagnosis, prevention, and treatment of T2D, especially regarding the personalized selection of hypoglycemic agents and holistic management based on the concept of "MDS-related TOD".
Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/patologia , Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina/genética , Estresse do Retículo Endoplasmático/genética , Adulto , Síndrome Metabólica/terapia , Síndrome Metabólica/genética , Síndrome Metabólica/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Dislipidemias/genética , Dislipidemias/terapia , Dislipidemias/patologia , Dislipidemias/metabolismo , Obesidade/genética , Obesidade/terapia , Obesidade/patologia , Estresse OxidativoRESUMO
BACKGROUND: Autophagy plays a crucial role in modulating the proliferation of cancer diseases. However, the application of Naringenin (Nar), a compound with potential benefits against these diseases, has been limited due to its poor solubility and bioavailability. OBJECTIVE: This study aimed to develop solid lipid nanoparticles (Nar-SLNs) loaded with Nar to enhance their therapeutic impact. METHODS: In vitro experiments using Rin-5F cells exposed to Nar and Nar-SLNs were carried out to investigate the protective effects of Nar and its nanoformulation against the pancreatic cancer cell line of Rin-5F. RESULTS: Treatment with Nar and Nar-SLN led to an increase in autophagic markers (Akt, LC3, Beclin1, and ATG genes) and a decrease in the level of miR-21. Both Nar and Nar-SLN treatments inhibited cell proliferation and reduced the expression of autophagic markers. Notably, Nar-SLNs exhibited greater efficacy compared to free Nar. CONCLUSION: These findings suggest that SLNs effectively enhance the cytotoxic impact of Nar, making Nar-SLNs a promising candidate for suppressing or preventing Rin-5F cell growth.
Assuntos
Autofagia , Proliferação de Células , Flavanonas , Nanopartículas , Flavanonas/farmacologia , Flavanonas/administração & dosagem , Flavanonas/química , Autofagia/efeitos dos fármacos , Nanopartículas/química , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Animais , Ratos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Lipídeos/química , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Humanos , Portadores de Fármacos/química , LipossomosRESUMO
BACKGROUND: Type 2 diabetes mellitus (T2DM) is a chronic condition characterized by insulin resistance and impaired insulin production, leading to elevated blood glucose levels. Curcumin, a polyphenolic compound from Curcuma longa, has shown potential in improving insulin sensitivity and reducing blood glucose levels, which may help mitigate type 2 diabetes progression. OBJECTIVE: To assess the efficacy of improving type 2 diabetes (T2DM). STUDY DESIGN: This randomized, double-blind, placebo-controlled trial included subjects (n = 272) with criteria for type 2 diabetes. METHODS: All subjects were randomly assigned to receive curcumin (1500 mg/day) or placebo with blind labels for 12 months. To assess the improvement of T2DM after curcumin treatments body weight and body mass index, fasting plasma glucose, glycosylated hemoglobin A1c, ß-cell function (homeostasis model assessment [HOMA-ß]), insulin resistance (HOMA-IR), insulin, adiponectin, and leptin were monitored at the baseline and at 3-, 6-, 9-, and 12-month visits during the course of intervention. RESULTS: After 12 months of treatment, the curcumin-treated group showed a significant decrease in fasting blood glucose (115.49 vs.130.71; P < 0.05), HbA1c (6.12 vs. 6.47; P < 0.05). In addition, the curcumin-treated group showed a better overall function of ß-cells, with higher HOMA-ß (136.20 vs. 105.19; P < 0.01) The curcumin-treated group showed a lower level of HOMA-IR (4.86 vs. 6.04; P < 0.001) and higher adiponectin (14.51 vs. 10.36; P < 0.001) when compared to the placebo group. The curcumin-treated group also showed a lower level of leptin (9.42 vs. 20.66; P < 0.001). Additionally, body mass index was lowered (25.9 4 vs.29.34), with a P value of 0.001. CONCLUSIONS: A 12-month curcumin intervention in type 2 diabetes patients shows a significant glucose-lowering effect. Curcumin treatment appeared to improve the overall function of ß-cells and reduce both insulin resistance and body weight, with very minor adverse effects. Curcumin intervention in obese patients with type 2 diabetes may be beneficial. TRIAL REGISTRATION: Thai clinical trials regentrify no.20140303003.
Assuntos
Glicemia , Índice de Massa Corporal , Curcumina , Diabetes Mellitus Tipo 2 , Hemoglobinas Glicadas , Resistência à Insulina , Células Secretoras de Insulina , Insulina , Obesidade , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/complicações , Curcumina/farmacologia , Curcumina/administração & dosagem , Masculino , Feminino , Método Duplo-Cego , Pessoa de Meia-Idade , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Obesidade/tratamento farmacológico , Obesidade/complicações , Insulina/sangue , Adiponectina/sangue , Extratos Vegetais/farmacologia , Extratos Vegetais/administração & dosagem , Leptina/sangue , Adulto , Curcuma , Peso Corporal/efeitos dos fármacosRESUMO
Type 1 Diabetes (T1D) is a chronic metabolic disease resulting from insulin deficiency due to autoimmune loss of pancreatic ß cells. In addition to ß cell destruction, it is now accepted that ß cell stress and dysfunction, such as senescence, plays a crucial role in the development of the disease. Accumulation of senescent ß cells occurs during development of T1D in humans and contributes to the progression of T1D in the nonobese diabetic (NOD) mouse model. Senescent ß cells are thought to exacerbate the inflammatory response within the islets by production and secretion of senescence-associated secretory phenotype (SASP). Extracellular vesicles (EVs) from ß cells have been shown to carry protein and microRNAs (miRNAs), influencing cellular signaling and may contribute to the development of T1D but it remains to be addressed how senescence impacts ß cell EV cargo. In this minireview, we discuss emerging evidence that EV cargo proteins and miRNAs associated with senescence could contribute to the development of T1D and could suggest potential biomarkers and therapeutic targets for the regulation of SASP and elimination of senescent ß cells in T1D. Future investigation exploring the intricate relationship between ß cell senescence, EVs and miRNAs could pave the way for the development of novel diagnostic techniques and therapeutic interventions.
Assuntos
Senescência Celular , Diabetes Mellitus Tipo 1 , Vesículas Extracelulares , Células Secretoras de Insulina , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Humanos , Vesículas Extracelulares/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Animais , MicroRNAs/metabolismo , MicroRNAs/genética , Fenótipo Secretor Associado à SenescênciaRESUMO
Insulin resistance is the primary contributor to the disruption in glucose homeostasis in the body, playing a significant causative role in many metabolic diseases. Insulin resistance is characterized by compensatory insulin secretion and reduced insulin responsiveness in target organs. Dysregulation of the interaction between insulin-secreting cells and insulin-responsive target organs is an important factor driving the progression of insulin resistance. Circulating endocrine hormones are important mediators mediating the interaction between insulin-secreting cells and insulin-responsive target organs. In addition to the classical hormones secreted by endocrine glands and organ-specific hormones secreted by metabolism-related organs (adipose tissue, muscle, liver, etc.), extracellular vesicles have been recognized as a novel class of endocrine hormones with a complex composition. Extracellular vesicles can transport signaling molecules, such as miRNAs and LncRNAs, to vital organs related to insulin resistance, in a manner akin to conventional hormones. The significant role in regulating the development of insulin resistance underscores the increasing interest in extracellular vesicles as essential contributors to this process. In this review, we summarize the three types of hormones (classical hormones, organokines and extracellular vesicles) that play a regulatory role in insulin resistance, and focus on the novel endocrine hormones, extracellular vesicles, to elaborate the mechanism of extracellular vesicles' regulation of insulin resistance progress from two aspects: the impact on insulin-secreting cells and the influence on insulin-responsive target organs. In addition, this paper outlines the clinical applications of extracellular vesicles in insulin resistance. A comprehensive understanding of the regulatory mechanisms and diagnostic status of the inter-organ network in insulin resistance has great potential to advance targeted therapeutic interventions and diagnostic markers, thereby benefiting both the prevention and treatment of insulin resistance.
Assuntos
Vesículas Extracelulares , Resistência à Insulina , Humanos , Vesículas Extracelulares/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/fisiologia , Insulina/metabolismo , Hormônios/metabolismo , Animais , Tecido Adiposo/metabolismo , MicroRNAs/metabolismo , MicroRNAs/genéticaRESUMO
Type 2 diabetes (T2D) is associated with a systemic increase in the pro-inflammatory cytokine IL-1ß. While transient exposure to low IL-1ß concentrations improves insulin secretion and ß-cell proliferation in pancreatic islets, prolonged exposure leads to impaired insulin secretion and collective ß-cell death. IL-1 is secreted locally by islet-resident macrophages and ß-cells; however, it is unknown if and how the two opposing modes may emerge at single islet level. We investigated the duality of IL-1ß with a quantitative in silico model of the IL-1 regulatory network in pancreatic islets. We find that the network can produce either transient or persistent IL-1 responses when induced by pro-inflammatory and metabolic cues. This suggests that the duality of IL-1 may be regulated at the single islet level. We use two core feedbacks in the IL-1 regulation to explain both modes: First, a fast positive feedback in which IL-1 induces its own production through the IL-1R/IKK/NF-κB pathway. Second, a slow negative feedback where NF-κB upregulates inhibitors acting at different levels along the IL-1R/IKK/NF-κB pathway-IL-1 receptor antagonist and A20, among others. A transient response ensues when the two feedbacks are balanced. When the positive feedback dominates over the negative, islets transit into the persistent inflammation mode. Consistent with several observations, where the size of islets was implicated in its inflammatory state, we find that large islets and islets with high density of IL-1ß amplifying cells are more prone to transit into persistent IL-1ß mode. Our results are likely not limited to IL-1ß but are general for the combined effect of multiple pro-inflammatory cytokines and chemokines. Generalizing complex regulations in terms of two feedback mechanisms of opposing nature and acting on different time scales provides a number of testable predictions. Taking islet architecture and cellular heterogeneity into consideration, further dynamic monitoring and experimental validation in actual islet samples will be crucial to verify the model predictions and enhance its utility in clinical applications.
Assuntos
Diabetes Mellitus Tipo 2 , Inflamação , Interleucina-1beta , Ilhotas Pancreáticas , Ilhotas Pancreáticas/metabolismo , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Modelos Biológicos , Transdução de Sinais/fisiologia , NF-kappa B/metabolismo , Animais , Simulação por Computador , Retroalimentação Fisiológica/fisiologia , Células Secretoras de Insulina/metabolismoRESUMO
AIMS/HYPOTHESIS: Apart from its fibrinolytic activity, the tissue plasminogen activator (tPA)/plasmin system has been reported to cleave the peptide amyloid beta, attenuating brain amyloid deposition in Alzheimer's disease. As aggregation of human islet amyloid polypeptide (hIAPP) is toxic to beta cells, we sought to determine whether activation of the fibrinolytic system can also reduce islet amyloid deposition and its cytotoxic effects, which are both observed in type 2 diabetes. METHODS: The expression of Plat (encoding tPA) and plasmin activity were measured in isolated islets from amyloid-prone hIAPP transgenic mice or non-transgenic control islets expressing non-amyloidogenic mouse islet amyloid polypeptide cultured in the absence or presence of the amyloid inhibitor Congo Red. Plat expression was also determined in hIAPP-treated primary islet endothelial cells, bone marrow-derived macrophages (BMDM) and INS-1 cells, in order to determine the islet cell type(s) producing tPA in response to hIAPP aggregation. Cell-free thioflavin-T assays and MS were used to respectively monitor hIAPP aggregation kinetics and investigate plasmin cleavage of hIAPP. Cell viability was assessed in INS-1 beta cells treated with hIAPP with or without plasmin. Finally, to confirm the findings in human samples, PLAT expression was measured in freshly isolated islets from donors with and without type 2 diabetes. RESULTS: In isolated islets from transgenic mice, islet Plat expression and plasmin activity increased significantly with the process of amyloid deposition (p≤0.01, n=5); these effects were not observed in islets from non-transgenic mice and were blocked by Congo Red (p≤0.01, n=4). In response to hIAPP exposure, Plat expression increased in BMDM and INS-1 cells vs vehicle-treated cells (p≤0.05, n=4), but not in islet endothelial cells. Plasmin reduced hIAPP fibril formation in a dose-dependent manner in a cell-free system, and restored hIAPP-induced loss of cell viability in INS-1 beta cells (p≤0.01, n=5). Plasmin cleaved monomeric hIAPP, inducing a rapid decrease in the abundance of full-length hIAPP and the appearance of hIAPP 1-11 and 12-37 fragments. hIAPP 12-37, which contains the critical amyloidogenic region, was not toxic to INS-1 cells. Finally, PLAT expression was significantly increased by 2.4-fold in islets from donors with type 2 diabetes (n=4) vs islets from donors without type 2 diabetes (n=7) (p≤0.05). CONCLUSIONS/INTERPRETATION: The fibrinolytic system is upregulated in islets with hIAPP aggregation. Plasmin rapidly degrades hIAPP, limiting its aggregation into amyloid and thus protecting beta cells from hIAPP-induced toxicity. Thus, increasing islet plasmin activity might be a strategy to limit beta cell loss in type 2 diabetes.
Assuntos
Fibrinolisina , Células Secretoras de Insulina , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Camundongos Transgênicos , Ativador de Plasminogênio Tecidual , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Animais , Humanos , Fibrinolisina/metabolismo , Camundongos , Ativador de Plasminogênio Tecidual/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Diabetes Mellitus Tipo 2/metabolismo , Regulação para Cima/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacosRESUMO
Amylin promoter and transcriptional factors are well-established, inducible factors in the production of the main amyloidogenic pancreatic hormone, human islet amyloid peptide (hIAPP) or amylin. However, posttranscriptional mechanisms driving hIAPP expression in pancreas remain enigmatic, and hence were explored here. The translational assay revealed that both 5' and 3' untranslated regions (UTRs) of hIAPP restricted expression of the luciferase constructs only in constructs driven by the hIAPP promoter. Bioinformatics analysis revealed several putative seed sequences for a dozen micro RNAs (miRNAs) in hIAPP's 3' UTR. miR-182, miR-335, and miR-495 were the most downregulated miRNAs in stressed human islets exposed to endoplasmic reticulum (ER) or metabolic stressors, thapsigargin (TG) or high glucose (HG). Correspondingly, miR-335 mimics alone or in combination with miR-495 and miR-182 mimics significantly and potently (>3-fold) reduced hIAPP protein expression in HG-treated cultured human islets. siRNA-mediated silencing of Ago2 but not Ago1 significantly stimulated hIAPP expression and secretion from transfected, HG-treated human islets. Conversely, ectopic expression of Ago2 in hIAPP-expressing RIN-m5F cell line driven by CMV promoter reduced hIAPP intracellular protein levels. Collectively, the results point to a novel and synergistic role for hIAPP promoter, 5/3' UTRs and Ago-2/miR-335 complex in post-transcriptional regulation of hIAPP gene expression in normal and metabolically active ß-cells.
Assuntos
Proteínas Argonautas , Células Secretoras de Insulina , Insulinoma , Polipeptídeo Amiloide das Ilhotas Pancreáticas , MicroRNAs , Humanos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Células Secretoras de Insulina/metabolismo , Insulinoma/metabolismo , Insulinoma/genética , Insulinoma/patologia , Proteínas Argonautas/metabolismo , Proteínas Argonautas/genética , Biossíntese de Proteínas , Regiões 3' não Traduzidas , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Linhagem Celular Tumoral , Animais , Glucose/metabolismoRESUMO
Background: Endogenous insulin supplementation is essential for individuals with type 1 diabetes (T1D). However, current treatments, including pancreas transplantation, insulin injections, and oral medications, have significant limitations. The development of engineered cells that can secrete endogenous insulin offers a promising new therapeutic strategy for type 1 diabetes (T1D). This approach could potentially circumvent autoimmune responses associated with the transplantation of differentiated ß-cells or systemic delivery of viral vectors. Methods: We utilized CRISPR/Cas9 gene editing coupled with homology-directed repair (HDR) to precisely integrate a promoter-free EMCVIRES-insulin cassette into the 3' untranslated region (UTR) of the GAPDH gene in human HEK-293T cells. Subsequently quantified insulin expression levels in these engineered cells, the viability and functionality of the engineered cells when seeded on different cell vectors (GelMA and Cytopore I) were also assessed. Finally, we investigated the therapeutic potential of EMCVIRES-based insulin secretion circuits in reversing Hyperglycaemia in T1D mice. Result: Our results demonstrate that HDR-mediated gene editing successfully integrated the IRES-insulin loop into the genome of HEK-293T cells, a non-endocrine cell line, enabling the expression of human-derived insulin. Furthermore, Cytopore I microcarriers facilitated cell attachment and proliferation during in vitro culture and enhanced cell survival post-transplantation. Transplantation of these cell-laden microcarriers into mice led to the development of a stable, fat-encapsulated structure. This structure exhibited the expression of the platelet-endothelial cell adhesion molecule CD31, and no significant immune rejection was observed throughout the experiment. Diabetic mice that received the cell carriers reversed hyperglycemia, and blood glucose fluctuations under simulated feeding stimuli were very similar to those of healthy mice. Conclusion: In summary, our study demonstrates that Cytopore I microcarriers are biocompatible and promote long-term cell survival in vivo. The promoter-free EMCVIRES-insulin loop enables non-endocrine cells to secrete mature insulin, leading to a rapid reduction in glucose levels. We have presented a novel promoter-free genetic engineering strategy for insulin secretion and proposed an efficient cell transplantation method. Our findings suggest the potential to expand the range of cell sources available for the treatment of diabetes, offering new avenues for therapeutic interventions.
Assuntos
Diabetes Mellitus Tipo 1 , Edição de Genes , Hiperglicemia , Células Secretoras de Insulina , Insulina , Humanos , Animais , Hiperglicemia/terapia , Hiperglicemia/metabolismo , Camundongos , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Insulina/genética , Células HEK293 , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/genética , Edição de Genes/métodos , Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/genética , Sítios Internos de Entrada Ribossomal/genética , Regiões Promotoras Genéticas , Sistemas CRISPR-CasRESUMO
The existence of functionally diverse and plastic ß cells in islets of Langerhans has been reported since the 1980s. Recently, high-resolution technologies have advanced our understanding of ß-cell heterogeneity and plasticity. Here, we define plasticity broadly as dynamic changes in cellular phenotypes and heterogeneity as differences in cellular behaviors. Individual ß cells react differently to environmental challenges and act together to maintain ß-cell mass and glucose homeostasis within a narrow range of 70-140 mg/dL. During the progress of diabetes, this elaborate balance is disrupted, and a lack of ß-cell compensation leads to dysregulated blood glucose. In this chapter, we assess ß-cell stress that instigates increased ß-cell heterogeneity and adaptive ß-cell responses such as proliferation, dedifferentiation, maturity, and insulin secretion. We also discuss the maturity, electrical activity, and insulin secretion of well-characterized ß-cell subgroups. Finally, we touch upon the plasticity of other non-ß pancreatic cells and their cooperation with ß cells to maintain homeostasis.
Assuntos
Plasticidade Celular , Células Secretoras de Insulina , Células Secretoras de Insulina/fisiologia , Células Secretoras de Insulina/metabolismo , Humanos , Animais , Secreção de Insulina , Insulina/metabolismo , HomeostaseRESUMO
Maternal nutrition and metabolic health status during pregnancy are critical factors that shape the life-long health trajectory of offspring. Altered nutrition during specific times of development in utero can lead to functional changes in tissues such as the pancreatic ß-cells, predisposing those tissues to metabolic diseases and Type 2 diabetes that manifest later in life. This chapter will focus on the role of pregnancy complications with altered nutrition during gestation in the maladaptive programming of ß-cell mass and function in the offspring.
Assuntos
Células Secretoras de Insulina , Feminino , Gravidez , Células Secretoras de Insulina/metabolismo , Humanos , Fenômenos Fisiológicos da Nutrição Materna , Animais , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Estado Nutricional , Complicações na Gravidez , Diabetes Mellitus Tipo 2/metabolismoRESUMO
The pancreatic ß cells are at the hub of myriad signals to regulate the secretion of an adequate amount of insulin needed to re-establish postprandial euglycemia. The ß cell possesses sophisticated metabolic enzymes and a variety of extracellular receptors and channels that amplify insulin secretion in response to autocrine, paracrine, and neurohormonal signals. Considerable research has been undertaken to decipher the mechanisms regulating insulin secretion. While the triggering pathway induced by glucose is needed to initiate the exocytosis process, multiple other stimuli modulate the insulin secretion response. This chapter will discuss the recent advances in understanding the role of the diverse glucose- and fatty acid-metabolic coupling factors in amplifying insulin secretion. It will also highlight the intracellular events linking the extracellular receptors and channels to insulin secretion amplification. Understanding these mechanisms provides new insights into learning more about the etiology of ß-cell failure and paves the way for developing new therapeutic strategies for type 2 diabetes.
Assuntos
Secreção de Insulina , Células Secretoras de Insulina , Insulina , Humanos , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Animais , Glucose/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/genética , Transdução de Sinais , Ácidos Graxos/metabolismoRESUMO
Dysfunction or loss of pancreatic ß cells can cause insulin deficiency and impaired glucose regulation, resulting in conditions like type 2 diabetes. The ATP-binding cassette transporter A1 (ABCA1) plays a key role in the reverse cholesterol transport system, and its decreased expression is associated with pancreatic ß cell lipotoxicity, resulting in abnormal insulin synthesis and secretion. Increased glutamate release can cause glucotoxicity in ß cells, though the detailed mechanisms remain unclear. This study investigated the effect of N-methyl-D-aspartic acid (NMDA) on ABCA1 expression in INS-1 cells and primary pancreatic islets to elucidate the signaling mechanisms that suppress insulin secretion. Using Western blotting, microscopy, and biochemical analyses, we found that NMDA activated the mitogen-activated protein kinase (MEK)-dependent pathway, suppressing ABCA1 protein and mRNA expression. The MEK-specific inhibitor PD98059 restored ABCA1 promoter activity, indicating the involvement of the extracellular signal-regulated kinase (MEK/ERK) pathway. Furthermore, we identified the liver X receptor (LXR) as an effector transcription factor in NMDA regulation of ABCA1 transcription. NMDA treatment increased cholesterol and triglyceride levels while decreasing insulin secretion, even under high-glucose conditions. These effects were abrogated by treatment with PD98059. This study reveals that NMDA suppresses ABCA1 expression via the MEK/ERK/LXR pathway, providing new insights into the pathological suppression of insulin secretion in pancreatic ß cells and emphasizing the importance of investigating the role of NMDA in ß cell dysfunction.
Assuntos
Transportador 1 de Cassete de Ligação de ATP , Células Secretoras de Insulina , Receptores X do Fígado , Sistema de Sinalização das MAP Quinases , N-Metilaspartato , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Animais , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Transportador 1 de Cassete de Ligação de ATP/genética , N-Metilaspartato/farmacologia , Ratos , Receptores X do Fígado/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Colesterol/metabolismo , Insulina/metabolismo , Secreção de Insulina/efeitos dos fármacos , Masculino , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Linhagem CelularRESUMO
BACKGROUND/AIMS: There are evidences that a decrease in the functional activity of pancreatic ß-cells under type 2 diabetes conditions may be associated with their senescence, therefore, senotherapy may be a prospective strategy for the diabetes treatment. METHODS: The senotherapeutic potential of peroxiredoxin 6 (PRDX6) was studied in RIN-m5F pancreatic ß-cells with streptozotocin-induced senescence by measuring markers, associated with senescence. RESULTS: Exposure to streptozotocin (STZ) resulted in the senescence of the ß-cells. The addition of PRDX6 to the culture medium of RIN-m5F ß-cells before treatment with STZ decreased the levels of the following senescence markers: the percentage of SA-ß-Gal-positive cells, the phosphorylation of histone H2AX and p21 proteins, and the secretion of the proinflammatory cytokine IL-6 but not the anti-inflammatory cytokine IL-10. These effects were accompanied by a decrease in the production of reactive oxygen species (ROS) and the restoration of impaired NF-κB activation. In addition, PRDX6 altered the production of the heat shock protein HSP90: the production of the constitutive form of HSP90-beta decreased, while the level of inducible HSP90-alpha increased. CONCLUSION: PRDX6 prevented the senescence of RIN-m5F cells in response to the DNA damage-inducing agent streptozotocin, indicating a potential protective role of PRDX6 in type 2 diabetes mellitus.
Assuntos
Senescência Celular , Proteínas de Choque Térmico HSP90 , Células Secretoras de Insulina , Interleucina-6 , Peroxirredoxina VI , Espécies Reativas de Oxigênio , Estreptozocina , Animais , Estreptozocina/toxicidade , Ratos , Senescência Celular/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/citologia , Espécies Reativas de Oxigênio/metabolismo , Peroxirredoxina VI/metabolismo , Interleucina-6/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , NF-kappa B/metabolismo , Linhagem Celular , Interleucina-10/metabolismo , Histonas/metabolismoRESUMO
Type 1 diabetes (T1D) is a T lymphocyte-mediated autoimmune disease caused by pancreatic ß|-cell destruction, which eventually leads to reduced insulin level and increased blood glucose level (Syed, 2022). As a multifactorial disease, T1D is characterized by a genetic predisposition associated with various environmental and cellular elements (Syed, 2022). Pancreatic ß cells have long been considered the "innocent victims" in T1D pathogenesis since the pancreas is attacked by the immune cells, resulting in a process known as insulitis, in which the immune cells infiltrate pancreatic islets and secrete pro-inflammatory cytokines. However, growing evidence suggests that various ß|-cell stresses, dysfunction, and death contribute to T1D pathogenesis, as it has been observed that ß|-cell dysfunction in autoantibody-positive (Aab+) individuals exists long before T1D diagnosis (Evans-Molina et al., 2018).
Assuntos
Senescência Celular , Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Resposta a Proteínas não Dobradas , Diabetes Mellitus Tipo 1/imunologia , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Animais , Camundongos , Humanos , Autoanticorpos/imunologiaRESUMO
Long-lived PFKFB3-expressing ß-cells are dysfunctional partly because of prevailing glycolysis that compromises metabolic coupling of insulin secretion. Their accumulation in type 2 diabetes (T2D) appears to be related to the loss of apoptotic competency of cell fitness competition that maintains islet function by favoring constant selection of healthy "winner" cells. To investigate how PFKFB3 can disguise the competitive traits of dysfunctional "loser" ß-cells, we analyzed the overlap between human ß-cells with bona fide "loser signature" across diabetes pathologies using the HPAP scRNA-seq and spatial transcriptomics of PFKFB3-positive ß-cells from nPOD T2D pancreata. The overlapping transcriptional profile of "loser" ß-cells was represented by down-regulated ribosomal biosynthesis and genes encoding for mitochondrial respiration. PFKFB3-positive "loser" ß-cells had the reduced expression of HLA class I and II genes. Gene-gene interaction analysis revealed that PFKFB3 rs1983890 can interact with the anti-apoptotic gene MAIP1 implicating positive epistasis as a mechanism for prolonged survival of "loser" ß-cells in T2D. Inhibition of PFKFB3 resulted in the clearance of dysfunctional "loser" ß-cells leading to restored glucose tolerance in the mouse model of T2D.
Assuntos
Diabetes Mellitus Tipo 2 , Metabolismo Energético , Epistasia Genética , Células Secretoras de Insulina , Fosfofrutoquinase-2 , Células Secretoras de Insulina/metabolismo , Animais , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Camundongos , Fosfofrutoquinase-2/genética , Fosfofrutoquinase-2/metabolismo , Metabolismo Energético/genética , Masculino , Transcriptoma/genética , Apoptose/genética , Camundongos Endogâmicos C57BLRESUMO
The field of epigenetics broadly seeks to define heritable phenotypic modifications that occur within cells without changes to the underlying DNA sequence. These modifications allow for precise control and specificity of function between cell types-ultimately creating complex organ systems that all contain the same DNA but only have access to the genes and sequences necessary for their cell-type-specific functions. The pancreas is an organ that contains varied cellular compartments with functions ranging from highly regulated glucose-stimulated insulin secretion in the ß-cell to the pancreatic ductal cells that form a tight epithelial lining for the delivery of digestive enzymes. With diabetes cases on the rise worldwide, understanding the epigenetic mechanisms driving ß-cell identity, function, and even disease is particularly valuable. In this chapter, we will discuss the known epigenetic modifications in pancreatic islet cells, how they are deposited, and the environmental and metabolic contributions to epigenetic mechanisms. We will also explore how a deeper understanding of epigenetic effectors can be used as a tool for diabetes therapeutic strategies.