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1.
Nutrients ; 16(17)2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39275180

RESUMEN

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.


Asunto(s)
Transportador 1 de Casete de Unión a ATP , Células Secretoras de Insulina , Receptores X del Hígado , Sistema de Señalización de MAP Quinasas , N-Metilaspartato , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/efectos de los fármacos , Animales , Transportador 1 de Casete de Unión a ATP/metabolismo , Transportador 1 de Casete de Unión a ATP/genética , N-Metilaspartato/farmacología , Ratas , Receptores X del Hígado/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Colesterol/metabolismo , Insulina/metabolismo , Secreción de Insulina/efectos de los fármacos , Masculino , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Línea Celular
2.
Artículo en Inglés | MEDLINE | ID: mdl-39196800

RESUMEN

Type 1 Diabetes (T1D) is a chronic metabolic disease resulting from autoimmune destruction of pancreatic beta cells. Beta cells activate a variety of stress responses during the development of T1D, including senescence, which involves cell cycle arrest, prosurvival signaling and a proinflammatory secretome termed the senescence-associated secretory phenotype (SASP). We previously identified growth and differentiation factor 15 (GDF15) as a major SASP factor in human islets and human EndoC-ßH5 beta cells in a model of DNA damage-mediated senescence that recapitulates features of senescent beta cells in T1D. Soluble GDF15 has been shown to exert protective effects on human and mouse beta cells during various forms of stress relevant to T1D, therefore we hypothesized that secreted GDF15 may play a prosurvival role during DNA damage-mediated senescence in human beta cells. We found that elevated GDF15 secretion was associated with endogenous senescent beta cells in an islet preparation from a T1D donor, supporting the validity of our DNA damage model. Using antibody-based neutralization, we found that secreted endogenous GDF15 was not required for senescent human islet or EndoC cell viability. Rather, neutralization of GDF15 led to reduced expression of specific senescence-associated genes, including GDF15 itself and the prosurvival gene BCL2L1. Taken together, these data suggest that SASP factor GDF15 is not required to sustain senescent human islet viability, but it is required to maintain senescence-associated transcriptional responses.

3.
Mol Cell Endocrinol ; 592: 112294, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38838763

RESUMEN

The aim of the present research was to explore the mechanisms underlying the role of dopamine in the regulation of insulin secretion in beta cells. The effect of dopamine on insulin secretion was investigated on INS 832/13 cell line upon glucose and other secretagogues stimulation. Results show that dopamine significantly inhibits insulin secretion stimulated by both glucose and other secretagogues, while it has no effect on the basal secretion. This effect requires the presence of dopamine during incubation with the various secretagogues. Both electron microscopy and immunohistochemistry indicate that in beta cells the D2 dopamine receptor is localized within the insulin granules. Blocking dopamine entry into the insulin granules by inhibiting the VMAT2 transporter with tetrabenazine causes a significant increase in ROS production. Our results confirm that dopamine plays an important role in the regulation of insulin secretion by pancreatic beta cells through a regulated and precise compartmentalization mechanisms.


Asunto(s)
Comunicación Autocrina , Dopamina , Glucosa , Secreción de Insulina , Células Secretoras de Insulina , Insulina , Proteínas de Transporte Vesicular de Monoaminas , Insulina/metabolismo , Secreción de Insulina/efectos de los fármacos , Dopamina/metabolismo , Animales , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/efectos de los fármacos , Ratas , Glucosa/metabolismo , Comunicación Autocrina/efectos de los fármacos , Proteínas de Transporte Vesicular de Monoaminas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Receptores de Dopamina D2/metabolismo , Línea Celular , Tetrabenazina/farmacología , Tetrabenazina/análogos & derivados
4.
Biogerontology ; 25(5): 819-836, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38748336

RESUMEN

An over-activation of the mechanistic target of rapamycin (mTOR) pathway promotes senescence and age-related diseases like type 2 diabetes. Besides, the regenerative potential of pancreatic islets deteriorates with aging. Nevertheless, the role of mTOR on senescence promoted by metabolic stress in islet cells as well as its relevance for electrophysiological aspects is not yet known. Here, we investigated whether parameters suggested to be indicative for senescence are induced in vitro in mouse islet cells by glucotoxicity and if mTOR inhibition plays a protective role against this. Islet cells exhibit a significant increase (~ 76%) in senescence-associated beta-galactosidase (SA-beta-gal) activity after exposure to glucotoxicity for 72 h. Glucotoxicity does not markedly influence p16INK4a protein within 72 h, but p16INK4a levels increase significantly after a 7-days incubation period. mTOR inhibition with a low rapamycin concentration (1 nM) entirely prevents the glucotoxicity-mediated increase of SA-beta-gal and p16INK4a. At the functional level, reactive oxygen species, calcium homeostasis, and electrical activity are disturbed by glucotoxicity, and rapamycin fails to prevent this. In contrast, rapamycin significantly attenuates the insulin hypersecretion promoted by glucotoxicity by modifying the mRNA levels of Vamp2 and Snap25 genes, related to insulin exocytosis. Our data indicate an influence of glucotoxicity on pancreatic islet-cell senescence and a reduction of the senescence markers by mTOR inhibition, which is relevant to preserve the regenerative potential of the islets. Decreasing the influence of mTOR on islet cells exposed to glucotoxicity attenuates insulin hypersecretion, but is not sufficient to prevent electrophysiological disturbances, indicating the involvement of mTOR-independent mechanisms.


Asunto(s)
Senescencia Celular , Inhibidor p16 de la Quinasa Dependiente de Ciclina , Islotes Pancreáticos , Serina-Treonina Quinasas TOR , Animales , Serina-Treonina Quinasas TOR/metabolismo , Ratones , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Senescencia Celular/efectos de los fármacos , Insulina/metabolismo , Sirolimus/farmacología , beta-Galactosidasa/metabolismo , Secreción de Insulina/efectos de los fármacos , Glucosa/metabolismo , Masculino , Ratones Endogámicos C57BL , Células Cultivadas , Especies Reactivas de Oxígeno/metabolismo
5.
Curr Diabetes Rev ; 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38747221

RESUMEN

The epidemic of diabetes continues to be an increasing problem, and there is a need for new therapeutic strategies. There are several promising drugs and molecules in synthetic medicinal chemistry that are developing for diabetes. In addition to this approach, extensive studies with gene and cell therapies are being conducted. Gene therapy is an existing approach in treating several diseases, such as cancer, autoimmune diseases, heart disease and diabetes. Several reports have also suggested that stem cells have the differentiation capability to functional pancreatic beta cell development in vitro and in vivo, with the utility to treat diabetes and prevent the progression of diabetes-related complications. In this current review, we have focused on the different types of cell therapies and vector-based gene therapy in treating or preventing diabetes.

6.
Discov Med ; 36(184): 865-873, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38798247

RESUMEN

Insulin plays a central role in blood glucose regulation, with insulin resistance contributing to the progression of prediabetes to diabetes, underscoring the importance of early intervention. Androgens, primarily synthesized in the testis under pituitary gland influence, impact male reproductive function. Testosterone, crucial for sexual development and secondary male characteristics, declines with age, leading to issues like anemia, sexual dysfunction, and reduced bone density. Sex-specific differences in glucose metabolism highlight males' lower insulin sensitivity and less effective glucose utilization compared to females due to androgenic effects. Testosterone's intricate role extends to potential benefits in glycemic control, fat mass reduction, and muscle strength increase in men with diabetes. However, cautious consideration of testosterone therapy is crucial, especially in the presence of underlying health conditions, warranting further research for clear guidelines in managing hyperglycemia.


Asunto(s)
Homeostasis , Testosterona , Humanos , Masculino , Testosterona/uso terapéutico , Testosterona/metabolismo , Glucosa/metabolismo , Glucemia/metabolismo , Adulto , Resistencia a la Insulina
7.
Front Endocrinol (Lausanne) ; 15: 1399741, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38572475

RESUMEN

[This corrects the article DOI: 10.3389/fendo.2023.1221520.].

8.
Islets ; 16(1): 2344622, 2024 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-38652652

RESUMEN

Chronically elevated levels of glucose are deleterious to pancreatic ß cells and contribute to ß cell dysfunction, which is characterized by decreased insulin production and a loss of ß cell identity. The Krüppel-like transcription factor, Glis3 has previously been shown to positively regulate insulin transcription and mutations within the Glis3 locus have been associated with the development of several pathologies including type 2 diabetes mellitus. In this report, we show that Glis3 is significantly downregulated at the transcriptional level in INS1 832/13 cells within hours of being subjected to high glucose concentrations and that diminished expression of Glis3 is at least partly attributable to increased oxidative stress. CRISPR/Cas9-mediated knockdown of Glis3 indicated that the transcription factor was required to maintain normal levels of both insulin and MafA expression and reduced Glis3 expression was concomitant with an upregulation of ß cell disallowed genes. We provide evidence that Glis3 acts similarly to a pioneer factor at the insulin promoter where it permissively remodels the chromatin to allow access to a transcriptional regulatory complex including Pdx1 and MafA. Finally, evidence is presented that Glis3 can positively regulate MafA transcription through its pancreas-specific promoter and that MafA reciprocally regulates Glis3 expression. Collectively, these results suggest that decreased Glis3 expression in ß cells exposed to chronic hyperglycemia may contribute significantly to reduced insulin transcription and a loss of ß cell identity.


Asunto(s)
Regulación hacia Abajo , Glucosa , Células Secretoras de Insulina , Insulina , Proteínas Represoras , Animales , Ratas , Línea Celular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Glucosa/metabolismo , Glucosa/farmacología , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Factores de Transcripción Maf de Gran Tamaño/genética , Factores de Transcripción Maf de Gran Tamaño/metabolismo , Estrés Oxidativo/genética , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Transactivadores/genética , Transactivadores/metabolismo
9.
Cell Calcium ; 120: 102883, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38643716

RESUMEN

The basal and glucose-induced insulin secretion from pancreatic beta cells is a tightly regulated process that is triggered in a Ca2+-dependent fashion and further positively modulated by substances that raise intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or by certain antidiabetic drugs. In a previous study, we have temporally resolved the subplasmalemmal [Ca2+]i dynamics in beta cells that are characterized by trains of sharply delimited spikes, reaching peak values up to 5 µM. Applying total internal reflection fluorescence (TIRF) microscopy and synaptopHluorin to visualize fusion events of individual granules, we found that several fusion events can coincide within 50 to 150 ms. To test whether subplasmalemmal [Ca2+]i microdomains around single or clustered Ca2+ channels may cause a synchronized release of insulin-containing vesicles, we applied simultaneous dual-color TIRF microscopy and monitored Ca2+ fluctuations and exocytotic events in INS-1 cells at high frame rates. The results indicate that fusions can be triggered by subplasmalemmal Ca2+ spiking. This, however, does account for a minority of fusion events. About 90 %-95 % of fusion events either happen between Ca2+ spikes or incidentally overlap with subplasmalemmal Ca2+ spikes. We conclude that only a fraction of exocytotic events in glucose-induced and tolbutamide- or forskolin-enhanced insulin release from INS-1 cells is tightly coupled to Ca2+ microdomains around voltage-gated Ca2+ channels.


Asunto(s)
Calcio , Exocitosis , Células Secretoras de Insulina , Insulina , Microscopía Fluorescente , Células Secretoras de Insulina/metabolismo , Calcio/metabolismo , Animales , Ratas , Insulina/metabolismo , Exocitosis/efectos de los fármacos , Señalización del Calcio , Secreción de Insulina/efectos de los fármacos , Glucosa/metabolismo , Vesículas Secretoras/metabolismo
10.
Aquat Toxicol ; 271: 106923, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38669778

RESUMEN

Perfluorooctanesulfonic acid (PFOS) is a ubiquitous legacy environmental contaminant detected broadly in human samples and water supplies. PFOS can cross the placenta and has been detected in cord blood and breastmilk samples, underscoring the importance of understanding the impacts of maternal PFOS exposure during early development. This study aimed to investigate the effects of a preconception exposure to PFOS on developmental endpoints in offspring, as well as examine the role of the transcription factor Nuclear factor erythroid-2-related factor (Nrf2a) in mediating these effects. This transcription factor regulates the expression of several genes that protect cells against oxidative stress including during embryonic development. Adult female zebrafish were exposed to 0.02, 0.08 or 0.14 mg/L PFOS for 1 week (duration of one cycle of oocyte maturation) and then paired with unexposed males from Nrf2a mutant or wildtype strains. Embryos were collected for two weeks or until completion of 5 breeding events. PFOS was maternally transferred to offspring independent of genotype throughout all breeding events in a dose-dependent manner, ranging from 2.77 to 23.72 ng/embryo in Nrf2a wildtype and 2.40 to 15.80 ng/embryo in Nrf2a mutants. Although embryo viability at collection was not impacted by maternal PFOS exposure, developmental effects related to nutrient uptake, growth and pancreatic ß-cell morphology were observed and differed based on genotype. Triglyceride levels were increased in Nrf2a wildtype eggs from the highest PFOS group. In Nrf2a wildtype larvae there was a decrease in yolk sac uptake while in Nrf2a mutants there was an increase. Additionally, there was a significant decrease in pancreatic ß-cell (islet) area in wildtype larvae from the 0.14 mg/L PFOS accompanied by an increase in the prevalence of abnormal islet morphologies compared to controls. Abnormal morphology was also observed in the 0.02 and 0.08 mg/L PFOS groups. Interestingly, in Nrf2a mutants there was a significant increase in the pancreatic ß-cell area in the 0.02 and 0.08 mg/L PFOS groups and no changes in the prevalence of abnormal islet morphologies. These results suggest that the regulation of processes like nutrient consumption, growth and pancreatic ß-cell development are at least partially modulated by the presence of a functional Nrf2a transcriptomic response. Overall, preconception exposure to environmental pollutants, such as PFOS, may impact the maturing oocyte and cause subtle changes that can ultimately impact offspring health and development.


Asunto(s)
Ácidos Alcanesulfónicos , Fluorocarburos , Exposición Materna , Factor 2 Relacionado con NF-E2 , Contaminantes Químicos del Agua , Pez Cebra , Animales , Fluorocarburos/toxicidad , Ácidos Alcanesulfónicos/toxicidad , Femenino , Contaminantes Químicos del Agua/toxicidad , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Masculino , Embrión no Mamífero/efectos de los fármacos , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Desarrollo Embrionario/efectos de los fármacos
11.
Assay Drug Dev Technol ; 22(3): 148-159, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38526231

RESUMEN

The progression of type II diabetes (T2D) is characterized by a complex and highly variable loss of beta-cell mass, resulting in impaired insulin secretion. Many T2D drug discovery efforts aimed at discovering molecules that can protect or restore beta-cell mass and function have been developed using limited beta-cell lines and primary rodent/human pancreatic islets. Various high-throughput screening methods have been used in the context of drug discovery, including luciferase-based reporter assays, glucose-stimulated insulin secretion, and high-content screening. In this context, a cornerstone of small molecule discovery has been the use of immortalized rodent beta-cell lines. Although insightful, this usage has led to a more comprehensive understanding of rodent beta-cell proliferation pathways rather than their human counterparts. Advantages gained in enhanced physiological relevance are offered by three-dimensional (3D) primary islets and pseudoislets in contrast to monolayer cultures, but these approaches have been limited to use in low-throughput experiments. Emerging methods, such as high-throughput 3D islet imaging coupled with machine learning, aim to increase the feasibility of integrating 3D microtissue structures into high-throughput screening. This review explores the current methods used in high-throughput screening for small molecule modulators of beta-cell mass and function, a potentially pivotal strategy for diabetes drug discovery.


Asunto(s)
Descubrimiento de Drogas , Ensayos Analíticos de Alto Rendimiento , Células Secretoras de Insulina , Bibliotecas de Moléculas Pequeñas , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Humanos , Animales , Bibliotecas de Moléculas Pequeñas/farmacología , Bibliotecas de Moléculas Pequeñas/química , Regeneración/efectos de los fármacos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo
12.
J Ethnopharmacol ; 327: 118045, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38479546

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Yunvjian (YNJ), a traditional Chinese herbal formula first reported in Jing Yue Quan Shu, is commonly used in the clinical treatment of type 2 diabetes mellitus (T2DM). However, the mechanism by which YNJ affects T2DM remains unclear. AIM OF THE STUDY: This study aimed to assess the therapeutic effects of YNJ on T2DM and explore the potential mechanism involved. MATERIALS AND METHODS: High-performance liquid chromatography (HPLC) was used to identify the chemical compounds of YNJ. The anti-T2DM effects of YNJ were observed in a high-fat diet/streptozotocin induced rat model. The type 2 diabetic rats were prepared as follows: rats were fed a high-fat diet for four weeks and then intraperitoneally injected with a low dose (30 mg/kg) of streptozotocin. YNJ and the positive control metformin were used in these experiments. Biochemical assays were implemented to determine the fasting blood glucose, glucose tolerance, insulin sensitivity, serum lipid levels, and oxidative stress index of the pancreas. Hematoxylin-eosin (H&E) staining was used to assess histopathological alterations in the pancreas. The mechanism by which YNJ affects T2DM was evaluated in INS-1 cells treated with glucose and high sodium palmitate. YNJ-supplemented serum was used in these experiments. Methyl thiazolyl tetrazolium assays, enzyme-linked immunosorbent assays, Nile red staining, flow cytometric analysis, and Western blotting were used to assess apoptosis, insulin secretion, lipid accumulation, reactive oxygen species production, and protein levels. RESULTS: Five major compounds were identified in YNJ. In high-fat diet/streptozotocin-induced diabetic rats, YNJ-M notably decreased fasting blood glucose and lipid levels; ameliorated glucose tolerance, insulin sensitivity, and islet morphology; reduced Malondialdehyde levels; and restored superoxide dismutase activity in the pancreatic islets. Furthermore, the effect of YNJ-M was significantly greater than that of YNJ-L, and YNJ-H had little effect on diabetic rats. In vitro experiments revealed that YNJ-supplemented serum (10%, 15%, and 20%) dramatically suppressed apoptosis, mitigated intracellular lipid accumulation and reduced intracellular oxidative stress levels in a dose-dependent manner. Additionally, YNJ-supplemented serum increased the protein expression of Nuclear factor erythroid 2-related factor 2, Heme oxygenase-1, and superoxide dismutase 1 and inhibited the protein expression of Kelch-like ECH-associated protein 1. CONCLUSION: YNJ ameliorates high-fat diet/streptozotocin induced experimental T2DM. The underlying mechanism involves reducing oxidative stress in pancreatic beta cells. The findings of this study provide scientific justification for the application of the traditional medicine YNJ in treating T2DM.


Asunto(s)
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Hiperglucemia , Resistencia a la Insulina , Células Secretoras de Insulina , Ratas , Animales , Diabetes Mellitus Tipo 2/inducido químicamente , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Estreptozocina/farmacología , Dieta Alta en Grasa/efectos adversos , Glucemia , Diabetes Mellitus Experimental/metabolismo , Estrés Oxidativo , Hiperglucemia/tratamiento farmacológico , Glucosa/metabolismo , Lípidos
13.
Epigenomes ; 8(1)2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38534794

RESUMEN

Type 1 diabetes (T1D) is a metabolic disease resulting from progressive autoimmune destruction of insulin-producing pancreatic beta cells. Although the majority of beta cells are lost in T1D, a small subset undergoes senescence, a stress response involving growth arrest, DNA damage response, and activation of a senescence-associated secretory phenotype (SASP). SASP in beta cells of the nonobese diabetic (NOD) mouse model of T1D and primary human islets is regulated at the level of transcription by bromodomain extra-terminal (BET) proteins, but the mechanisms remain unclear. To explore how SASP is transcriptionally regulated in beta cells, we used the NOD beta cell line NIT-1 to model beta cell SASP and identified binding partners of BET protein Brd4 and explored the role of the cyclin-dependent kinase inhibitor p21. Brd4 interacted with a variety of proteins in senescent NIT-1 cells including subunits of the Ino80 chromatin remodeling complex, which was expressed in beta cells during T1D progression in NOD mice and in human beta cells of control, autoantibody-positive, and T1D donors as determined from single-cell RNA-seq data. RNAi knockdown of p21 during senescence in NIT-1 cells did not significantly impact viability or SASP. Taken together, these results suggest that Brd4 interacts with several protein partners during senescence in NIT-1 cells, some of which may play roles in SASP gene activation and that p21 is dispensable for the SASP in this beta cell model.

14.
Int J Mol Sci ; 25(3)2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38339098

RESUMEN

Diabetes mellitus is clinically defined by chronic hyperglycemia. Sex differences in the presentation and outcome of diabetes exist with premenopausal women having a reduced risk of developing diabetes, relative to men, or women after menopause. Accumulating evidence shows a protective role of estrogens, specifically 17-beta estradiol, in the maintenance of pancreatic beta cell health; however, the mechanisms underlying this protection are still unknown. To elucidate these potential mechanisms, we used a pancreatic beta cell line (BTC6) and a mouse model of hyperglycemia-induced atherosclerosis, the ApoE-/-:Ins2+/Akita mouse, exhibiting sexual dimorphism in glucose regulation. In this study we hypothesize that 17-beta estradiol protects pancreatic beta cells by modulating the unfolded protein response (UPR) in response to endoplasmic reticulum (ER) stress. We observed that ovariectomized female and male ApoE-/-:Ins2+/Akita mice show significantly increased expression of apoptotic UPR markers. Sham operated female and ovariectomized female ApoE-/-:Ins2+/Akita mice supplemented with exogenous 17-beta estradiol increased the expression of adaptive UPR markers compared to non-supplemented ovariectomized female ApoE-/-:Ins2+/Akita mice. These findings were consistent to what was observed in cultured BTC6 cells, suggesting that 17-beta estradiol may protect pancreatic beta cells by repressing the apoptotic UPR and enhancing the adaptive UPR activation in response to pancreatic ER stress.


Asunto(s)
Diabetes Mellitus , Hiperglucemia , Células Secretoras de Insulina , Humanos , Femenino , Ratones , Masculino , Animales , Células Secretoras de Insulina/metabolismo , Estradiol/farmacología , Estradiol/metabolismo , Respuesta de Proteína Desplegada , Diabetes Mellitus/metabolismo , Estrés del Retículo Endoplásmico , Hiperglucemia/metabolismo , Apolipoproteínas E/metabolismo
15.
Trends Endocrinol Metab ; 35(7): 576-585, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38307810

RESUMEN

Cellular senescence is a programmed state of cell cycle arrest that involves a complex immunogenic secretome, eliciting immune surveillance and senescent cell clearance. Recent work has shown that a subpopulation of pancreatic ß-cells becomes senescent in the context of diabetes; however, it is not known whether these cells are normally subject to immune surveillance. In this opinion article, we advance the hypothesis that immune surveillance of ß-cells undergoing a senescence stress response normally limits their accumulation during aging and that the breakdown of these mechanisms is a driver of senescent ß-cell accumulation in diabetes. Elucidation and therapeutic activation of immune surveillance mechanisms in the pancreas holds promise for the improvement of approaches to target stressed senescent ß-cells in the treatment of diabetes.


Asunto(s)
Senescencia Celular , Vigilancia Inmunológica , Células Secretoras de Insulina , Células Secretoras de Insulina/inmunología , Células Secretoras de Insulina/metabolismo , Senescencia Celular/inmunología , Senescencia Celular/fisiología , Humanos , Animales , Diabetes Mellitus/inmunología
16.
J Extracell Vesicles ; 13(2): e12410, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38320981

RESUMEN

Extracellular vesicles (EVs) exert a significant influence not only on the pathogenesis of diseases but also on their therapeutic interventions, contingent upon the variances observed in their originating cells. Mitochondria can be transported between cells via EVs to promote pathological changes. In this study, we found that EVs derived from M1 macrophages (M1-EVs), which encapsulate inflammatory mitochondria, can penetrate pancreatic beta cells. Inflammatory mitochondria fuse with the mitochondria of pancreatic beta cells, resulting in lipid peroxidation and mitochondrial disruption. Furthermore, fragments of mitochondrial DNA (mtDNA) are released into the cytosol, activating the STING pathway and ultimately inducing apoptosis. The potential of adipose-derived stem cell (ADSC)-released EVs in suppressing M1 macrophage reactions shows promise. Subsequently, ADSC-EVs were utilized and modified with an F4/80 antibody to specifically target macrophages, aiming to treat ferroptosis of pancreatic beta cells in vivo. In summary, our data further demonstrate that EVs secreted from M1 phenotype macrophages play major roles in beta cell ferroptosis, and the modified ADSC-EVs exhibit considerable potential for development as a vehicle for targeted delivery to macrophages.


Asunto(s)
Vesículas Extracelulares , Ferroptosis , Células Secretoras de Insulina , Pancreatitis , Humanos , Enfermedad Aguda , Células Secretoras de Insulina/metabolismo , Pancreatitis/metabolismo , Vesículas Extracelulares/metabolismo , Macrófagos/metabolismo , Mitocondrias
17.
Diabetologia ; 67(5): 908-927, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38409439

RESUMEN

AIMS/HYPOTHESIS: The proinflammatory cytokines IFN-α, IFN-γ, IL-1ß and TNF-α may contribute to innate and adaptive immune responses during insulitis in type 1 diabetes and therefore represent attractive therapeutic targets to protect beta cells. However, the specific role of each of these cytokines individually on pancreatic beta cells remains unknown. METHODS: We used deep RNA-seq analysis, followed by extensive confirmation experiments based on reverse transcription-quantitative PCR (RT-qPCR), western blot, histology and use of siRNAs, to characterise the response of human pancreatic beta cells to each cytokine individually and compared the signatures obtained with those present in islets of individuals affected by type 1 diabetes. RESULTS: IFN-α and IFN-γ had a greater impact on the beta cell transcriptome when compared with IL-1ß and TNF-α. The IFN-induced gene signatures have a strong correlation with those observed in beta cells from individuals with type 1 diabetes, and the level of expression of specific IFN-stimulated genes is positively correlated with proteins present in islets of these individuals, regulating beta cell responses to 'danger signals' such as viral infections. Zinc finger NFX1-type containing 1 (ZNFX1), a double-stranded RNA sensor, was identified as highly induced by IFNs and shown to play a key role in the antiviral response in beta cells. CONCLUSIONS/INTERPRETATION: These data suggest that IFN-α and IFN-γ are key cytokines at the islet level in human type 1 diabetes, contributing to the triggering and amplification of autoimmunity.


Asunto(s)
Diabetes Mellitus Tipo 1 , Islotes Pancreáticos , Humanos , Citocinas/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Interferones/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Interferón gamma/metabolismo , Islotes Pancreáticos/metabolismo
18.
Front Mol Biosci ; 11: 1354199, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38404962

RESUMEN

In Type 1 and Type 2 diabetes, pancreatic ß-cell survival and function are impaired. Additional etiologies of diabetes include dysfunction in insulin-sensing hepatic, muscle, and adipose tissues as well as immune cells. An important determinant of metabolic health across these various tissues is mitochondria function and structure. This review focuses on the role of mitochondria in diabetes pathogenesis, with a specific emphasis on pancreatic ß-cells. These dynamic organelles are obligate for ß-cell survival, function, replication, insulin production, and control over insulin release. Therefore, it is not surprising that mitochondria are severely defective in diabetic contexts. Mitochondrial dysfunction poses challenges to assess in cause-effect studies, prompting us to assemble and deliberate the evidence for mitochondria dysfunction as a cause or consequence of diabetes. Understanding the precise molecular mechanisms underlying mitochondrial dysfunction in diabetes and identifying therapeutic strategies to restore mitochondrial homeostasis and enhance ß-cell function are active and expanding areas of research. In summary, this review examines the multidimensional role of mitochondria in diabetes, focusing on pancreatic ß-cells and highlighting the significance of mitochondrial metabolism, bioenergetics, calcium, dynamics, and mitophagy in the pathophysiology of diabetes. We describe the effects of diabetes-related gluco/lipotoxic, oxidative and inflammation stress on ß-cell mitochondria, as well as the role played by mitochondria on the pathologic outcomes of these stress paradigms. By examining these aspects, we provide updated insights and highlight areas where further research is required for a deeper molecular understanding of the role of mitochondria in ß-cells and diabetes.

19.
Curr Res Transl Med ; 72(2): 103437, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38244275

RESUMEN

BACKGROUND: Type 2 diabetes (T2D) is a progressive disease. Many drugs currently being used for the management of T2D have minimal effect on pancreatic beta cells regeneration. Cell-based therapies might provide potential benefits in this aspect. METHODS: A pilot study in five T2D patients with 12 months follow-up was performed to evaluate the effect of autologous bone marrow mononuclear stem cells (BM-MNCs) infusion into pancreatic arteries on the insulin requirement, beta-cell function, insulin resistance, and systemic inflammatory marker (CRP). RESULTS: The primary endpoint, a 50 % reduction of total insulin doses from baseline, was not achieved in this study. However, a trend of increasing fasting C-peptide (p = 0.07) and C-peptide 60' (p = 0.07) and 90' (p = 0.07) after a mixed-meal tolerance test was observed 12 months post-infusion compared to baseline levels. A similar result was observed for the homeostatic model assessment of beta cell function (HOMA1-B), an index for beta cell function. No improvement was observed for insulin resistance measured by homeostasis model assessment of insulin resistance (HOMA1-IR) and systemic inflammatory parameter. CONCLUSION: Intraarterial pancreatic autologous BM-MNCs infusion might potentially improve beta cell function in T2D patients, although further study is needed to confirm this finding.


Asunto(s)
Trasplante de Médula Ósea , Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Células Secretoras de Insulina , Trasplante Autólogo , Humanos , Células Secretoras de Insulina/fisiología , Células Secretoras de Insulina/efectos de los fármacos , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/sangre , Masculino , Persona de Mediana Edad , Femenino , Trasplante de Médula Ósea/métodos , Proyectos Piloto , Biomarcadores , Insulina/administración & dosificación , Infusiones Intraarteriales , Páncreas , Adulto , Inflamación , Péptido C/sangre , Péptido C/análisis , Anciano , Leucocitos Mononucleares/trasplante , Leucocitos Mononucleares/metabolismo
20.
Ther Deliv ; 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38180003

RESUMEN

Aim: The aim of this study is to test the biocompatibility of hydrogels with polysaccharides and bile acids on three murine cell lines. Materials & methods: Novel hydrogels containing poloxamer 407, polysaccharides (starch, pectin, acacia, carboxymethyl and methyl 2-hydroxyethyl cellulose) and deoxycholic acid were prepared using cold method, sterilized and used in biological assays to determine effects on hepatic, muscle, and pancreatic beta cells. Results and conclusion: Hydrogels with deoxycholic acid had tissue-depending effects on cellular survival and bioenergetics, resulting in the best cellular viability and bioenergetics within pancreatic beta cells. Further research is needed as proposed hydrogels may be beneficial for cell delivery systems of pancreatic beta cells.


In this study, we made gels using different materials, including five types of sugar and an acid found in bile. We investigated whether these gels would harm cells and their respiration. Muscle cells responded poorly to gels, as gels harmed their natural processes. Liver cells responded slightly better to gels, but gels still harmed them a lot. Cells found in the pancreas were not especially affected by gels, and these gels may be good candidates for further research with pancreatic cells. The gels could potentially be used to deliver drugs to the cells.

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