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The blast phase of BCR::ABL1-negative myeloproliferative neoplasm (MPN-BP) represents the final stage of the disease, which is complicated by complex genomic alterations. These alterations result from sequence changes in genetic material (DNA, RNA) and can lead to either a gain or loss of function of encoded proteins, such as adaptor proteins, enzymes, components of spliceosomes, cell cycle checkpoints regulators, transcription factors, or proteins in cell signaling pathways. Interference at various levels, including transcription, translation, and post-translational modification (such as methylation, dephosphorylation, or acetylation), can contribute to these alterations. Mutated genes such as ASXL1, EZH2, IDH1, IDH2, TET2, SRSF2, U2AF1, TP53, NRAS, KRAS, PTPN11, SH2B3/LNK, and RUNX1 play active roles at different stages of genetic material expression, modification, and protein function manipulation in MPNs. These mutations are also correlated with, and can contribute to, the progression of MPN-BP. In this review, we summarize their common mutational profiles, functions, and associations with progression of MPN-BP.
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Crisis Blástica , Trastornos Mieloproliferativos , Humanos , Crisis Blástica/genética , Trastornos Mieloproliferativos/genética , Mutación , GenómicaRESUMEN
Breast cancer remains the most frequently diagnosed cancer in women worldwide. Tumors that express hormone receptors account for 75% of all cases. Understanding alternative signaling cascades is important for finding new therapeutic targets for hormone receptor-positive breast cancer patients. JAK-STAT signaling is commonly activated in hormone receptor-positive breast tumors, inducing inflammation, proliferation, migration, and treatment resistance in cancer cells. In hormone receptor-positive breast cancer, the JAK-STAT cascade is stimulated by hormones and cytokines, such as prolactin and IL-6. In normal cells, JAK-STAT is inhibited by the action of the adaptor protein, LNK. However, the role of LNK in breast tumors is not fully understood. This review compiles published reports on the expression and activation of the JAK-STAT pathway by IL-6 and prolactin and potential inhibition of the cascade by LNK in hormone receptor-positive breast cancer. Additionally, it includes analyses of available datasets to determine the level of expression of LNK and various members of the JAK-STAT family for the purpose of establishing associations between expression and clinical outcomes. Together, experimental evidence and in silico studies provide a better understanding of the potential implications of the JAK-STAT-LNK loop in hormone receptor-positive breast cancer progression.
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Neoplasias de la Mama , Transducción de Señal , Humanos , Femenino , Transducción de Señal/fisiología , Quinasas Janus/metabolismo , Prolactina/metabolismo , Interleucina-6/metabolismo , Factores de Transcripción STAT/metabolismoRESUMEN
OBJECTIVE: tRNA-derived fragments (tRFs) play crucial roles in the progression of various diseases, and widely distribute in human tissues, including blood and urine. The diagnosis of enthesitis-related arthritis (ERA) is based on the observation of clinical manifestations. Therefore, we aimed to investigate whether serum tRFs can be used as diagnostic markers for ERA. METHODS: Serum was collected from children admitted to the Children's Hospital Affiliated with Nanjing Medical University between February 2022 to October 2022. The expression profiles of tRFs in the serum of ERA patients (n = 5) and healthy controls (HCs; n = 5) were investigated using small RNA high-throughput sequencing. The level and diagnostic value of tRF-21-LNK8KEP1B were evaluated by real-time quantitative PCR in serum samples from 30 ERA patients and 31 HCs. The specificity and sensitivity of tRFs were determined using receiver operating characteristic analyses. Bioinformatics analysis was performed to explore and identify the potential biological pathways induced by tRFs. RESULTS: Ninety-eight upregulated and 63 downregulated tRFs were identified in the serum. We selected tRF-21-LNK8KEP1B as a candidate marker using KEGG pathway enrichment and PCR validation. tRF-21-LNK8KEP1B was substantially increased in the serum of ERA patients compared with that in HCs. The area under the curve (AUC) for tRF-21-LNK8KEP1B in the ERA group was 0.7849. CONCLUSIONS: Collectively, we demonstrated the promising role of serum tRF-21-LNK8KEP1B -levels as a diagnostic biomarker for ERA.
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Artritis , ARN de Transferencia , Niño , Humanos , ARN de Transferencia/genética , ARN de Transferencia/metabolismo , BiomarcadoresRESUMEN
PURPOSE: To investigate the potential role of gut microbiota in obesity-induced insulin resistance (IR). METHODS: Four-week-old male C57BL/6 wild-type mice (n = 6) and whole-body SH2 domain-containing adaptor protein (LNK)-deficient in C57BL/6 genetic backgrounds mice (n = 7) were fed with a high-fat diet (HFD, 60% calories from fat) for 16 weeks. The gut microbiota of 13 mice feces samples was analyzed by using a 16 s rRNA sequencing analysis. RESULTS: The structure and composition of the gut microbiota community of WT mice were significantly different from those in the LNK-/- group. The abundance of the lipopolysaccharide (LPS)-producing genus Proteobacteria was increased in WT mice, while some short-chain fatty acid (SCFA)-producing genera in WT groups were significantly lower than in LNK-/- groups (p < 0.05). CONCLUSIONS: The structure and composition of the intestinal microbiota community of obese WT mice were significantly different from those in the LNK-/- group. The abnormality of the gut microbial structure and composition might interfere with glucolipid metabolism and exacerbate obesity-induced IR by increasing LPS-producing genera while reducing SCFA-producing probiotics.
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BACKGROUND: Polycystic ovary syndrome (PCOS), which is often accompanied by insulin resistance, is closely related to increased apoptosis of ovarian granulosa cells. LNK is an important regulator of the insulin signaling pathway. When insulin binds to the receptor, the PI3K/AKT/FOXO signaling pathway is activated, and FOXO translocates from the nucleus to the cytoplasm, thereby inhibiting the expression of pro-apoptotic genes. METHODS: Granulosa cells were collected from PCOS patients to investigate the relationship between LNK, cell apoptosis and insulin resistance. KGN cells underwent LNK overexpression/silence and insulin stimulation. The AKT/FOXO3 pathway was studied by western blot and immunofluorescence. LNK knockout mice were used to investigate the effect of LNK on the pathogenesis of PCOS. RESULTS: The level of LNK was higher in PCOS group than control group. LNK was positively correlated with granulosa cell apoptosis and insulin resistance, and negatively correlated with oocyte maturation rate. LNK overexpression in KGN cells inhibited insulin-induced AKT/FOXO3 signaling pathway, causing nucleus translocation of FOXO3 and promoting granulosa cell apoptosis. LNK knockout partially restored estrous cycle and improved glucose metabolism in PCOS mice. CONCLUSIONS: LNK was closely related to insulin resistance and apoptosis of granulosa cells via the AKT/FOXO3 pathway. LNK knockout partially restored estrous cycle and improved glucose metabolism in PCOS mice, suggesting LNK might become a potential biological target for the clinical treatment of PCOS.
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Proteínas Adaptadoras Transductoras de Señales/genética , Apoptosis/genética , Proteína Forkhead Box O3/metabolismo , Células de la Granulosa/metabolismo , Insulina/metabolismo , Síndrome del Ovario Poliquístico/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adulto , Animales , Femenino , Humanos , Técnicas In Vitro , Resistencia a la Insulina , Ratones , Ratones Noqueados , Síndrome del Ovario Poliquístico/metabolismo , Transducción de Señal , Adulto JovenRESUMEN
In recent years, LNK, an adapter protein, has been found to be associated with metabolic diseases, including hypertension and diabetes. We found that the expression of LNK in human adipose tissue was positively correlated with serum glucose and insulin in obese people. We examined the role of LNK in insulin resistance and systemic energy metabolism using LNK-deficient mice (LNK-/-). With consumption of a high-fat diet, wild type (WT) mice accumulated more intrahepatic triglyceride, higher serum triglyceride (TG), free fatty acid (FFA) and high sensitivity C-reactive protein (hsCRP) compared with LNK-/- mice. However, there was no significant difference between LNK-/- and WT mice under normal chow diet. Meanwhile, glucose transporter 4 (GLUT4) expression in adipose tissue and insulin-stimulated glucose uptake in adipocytes were increased in LNK-/- mice. LNK-/- adipose tissue showed activated reactivity for IRS1/PI3K/Akt/AS160 signaling, and administration of a PI3K inhibitor impaired glucose uptake. In conclusion, LNK plays a pivotal role in adipose glucose transport by regulating insulin-mediated IRS1/PI3K/Akt/AS160 signaling.
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BACKGROUND: LNK adaptor protein is a crucial regulator of normal hematopoiesis, which down-regulates activated tyrosine kinases at the cell surface resulting in an antitumor effect. To date, little studies have examined activities of LNK in solid tumors except ovarian cancer. METHODS: Clinical tissue chips were obtained from 16 clinical patients after surgery. Western blotting assay and quantitative real time PCR was performed to measure the expression of LNK. We investigate the in vivo and vitro effect of LNK in Triple Negative Breast Cancer by using cell proliferationãmigration assays and an in vivo murine xenograft model. Western blotting assay was performed to investigate the mechanism of LNK in triple negative breast cancer. RESULTS: We found that the levels of LNK expression were elevated in high grade triple-negative breast cancer through Clinical tissue chips. Remarkably, overexpression of LNK can promote breast cancer cell proliferation and migration in vivo and vitro, while silencing of LNK show the opposite phenomenon. We also found that LNK can promote breast cancer cell to proliferate and migrate via activating JAK/STAT3 and ERK1/2 pathway. CONCLUSIONS: Our results suggest that the adaptor protein LNK acts as a positive signal transduction modulator in TNBC.
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The circadian clock modulates immune responses in plants and animals; however, it is unclear how host-pathogen interactions affect the clock. Here we analyzed clock function in Arabidopsis thaliana mutants with defective immune responses and found that enhanced disease susceptibility 4 (eds4) displays alterations in several circadian rhythms. Mapping by sequencing revealed that EDS4 encodes the ortholog of NUCLEOPORIN 205, a core component of the inner ring of the nuclear pore complex (NPC). Consistent with the idea that the NPC specifically modulates clock function, we found a strong enrichment in core clock genes, as well as an increased nuclear to total mRNA accumulation, among genes that were differentially expressed in eds4 mutants. Interestingly, infection with Pseudomonas syringae in wild-type (WT) plants downregulated the expression of several morning core clock genes as early as 1 h post-infection, including all members of the NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED (LNK) gene family, and this effect was attenuated in eds4. Furthermore, lnk mutants were more susceptible than the WT to P. syringae infection. These results indicate that bacterial infection, acting in part through the NPC, alters core clock gene expression and/or mRNA accumulation in a way that favors bacterial growth and disease susceptibility.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/microbiología , Proteínas CLOCK/metabolismo , Regulación de la Expresión Génica de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Pseudomonas syringae/fisiología , Animales , Proteínas de Arabidopsis/genética , Proteínas CLOCK/genética , Mutación , Enfermedades de las Plantas/inmunologíaRESUMEN
BACKGROUND: Rapid progression contributes to treatment failure in anaplastic thyroid carcinoma (ATC) patients. In a preliminary study, we demonstrated that some hematopoietic factors may be involved in the progression of ATC. The adaptor protein LNK, which is a negative regulator of hematopoietic cytokine signalling, has been studied extensively in malignant hematopoietic cells. However, there are few studies on LNK in solid tumours. METHODS: Real-time PCR, immunohistochemistry (IHC) and western blot analysis of LNK were performed on ATC cells, differentiated thyroid cancer (DTC) cells and normal thyroid cells. In vitro assays (including pull-down, liquid chromatography-mass spectrometry (LC-MS), co-IP, MTT and colony formation) were performed to validate the effect of LNK on ATC progression and elucidate the molecular mechanisms. RESULTS: Compared with DTC cells and normal thyroid cells, ATC cells exhibit overexpression of LNK. In addition, LNK overexpression results in increased proliferation of ATC cells. Conversely, LNK knockdown significantly suppresses ATC cell proliferation. LC-MS identified the 14-3-3 ε/γ protein as a LNK binding partner. Finally, the results indicate that LNK overexpression significantly enhances the anti-apoptotic ability of ATC cells via the Akt-NFκB-Bcl-2/Bcl-xL pathway and that the oncogenic effect of LNK largely depends on 14-3-3 ε/γ binding. CONCLUSIONS: The present study elucidated the important role of LNK in the growth of ATC opposite to its behaviour in the hematopoietic system and indicates that LNK is a potential target for the treatment of ATC.
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OBJECTIVE: A large number of studies have explored the function of LNK in hematologic system disease, while that in solid tumors has been rarely investigated. In the present study, we attempted to explore the expression level of LNK in colorectal cancer (CRC) as well as the potential relationship between them. MATERIALS AND METHODS: The expression levels of LNK were examined using real-time PCR (RT-PCR) and immunohistochemistry (IHC) in cancer tissues and the matching adjacent normal tissues. Then, clinical data, including gender, age, tumor size, lymph node metastasis, parenteral invasion situation, distant metastasis, and TNM stage, from 32 patients were analyzed. Finally, we detected the effect of LNK on the invasion by performing a transwell assay in HCT 116 cells and HT29 cells. RESULTS: The RT-PCT results revealed that the expression level of LNK was significantly lower in colorectal cancer tissues than that in normal tissues. After analyzing the clinical pathological characteristics, we discovered that LNK had a negative expression in 56.3% patients with colorectal cancer. Moreover, the LNK negative expression was recorded in 83.3% patients with invasion, which was significantly higher than that in patients with positive LNK (42.9%,P < 0.05). A further study verified that the overexpression of LNK effectively reduced the invasion ability of the tumor cells in the transwell assay. CONCLUSION: Our present study reported that LNK as an adaptor protein had low expression in colorectal cancer and was related to tumor invasion, which provided a new potential therapeutic strategy for CRC treatment.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Metástasis Linfática/patología , Invasividad Neoplásica/patología , Línea Celular Tumoral , Movimiento Celular/fisiología , Femenino , Células HCT116 , Células HT29 , Humanos , Masculino , Persona de Mediana Edad , PronósticoRESUMEN
Myocardial ischemia/reperfusion (I/R) injury is the major limitation for the cardioprotective action of revascularization after myocardial infarction. Lymphocyte adapter protein (Lnk), an adapter protein, has a regulatory role in multiple signaling pathways by functioning as a scaffold for different substrates. However, the involvement of Lnk in myocardial I/R injury remains to be established. In this study, increased expression of Lnk was detected upon the development of myocardial I/R injury. Mice were genetically engineered to investigate the role of Lnk in this pathological process. Upon I/R, myocardial infarction, cardiac dysfunction, inflammation and apoptosis were increased in Lnk-deficient hearts. However, cardiomyocyte-specific overexpression of Lnk protected the hearts against myocardial I/R injury. Mechanistically, we observed that the activation of Akt, but neither ERK1/2 nor STAT3, was influenced by the expression of Lnk upon myocardial I/R injury. Furthermore, the requirement of PI3K-Akt activation for the cardioprotective effect of Lnk was confirmed in rescue experiments using the PI3K inhibitor LY294002. Taken together, our data provide a potential diagnostic and therapeutic strategy for myocardial I/R injury.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Linfocitos/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Miocitos Cardíacos/metabolismo , Animales , Apoptosis/fisiología , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación/fisiología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/fisiologíaAsunto(s)
Calreticulina/genética , Mutación , Policitemia/sangre , Policitemia/genética , Proteínas/genética , Trombocitemia Esencial/sangre , Trombocitemia Esencial/genética , Proteínas Adaptadoras Transductoras de Señales , Anciano de 80 o más Años , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Péptidos y Proteínas de Señalización Intracelular , Janus Quinasa 2/genética , Masculino , Policitemia/diagnóstico , Trombocitemia Esencial/diagnósticoAsunto(s)
Biomarcadores de Tumor/biosíntesis , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Proteínas/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Adolescente , Biomarcadores de Tumor/genética , Niño , Preescolar , Femenino , Expresión Génica , Humanos , Lactante , Péptidos y Proteínas de Señalización Intracelular , Estimación de Kaplan-Meier , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Pronóstico , Proteínas/genética , ARN Mensajero/genética , ARN Neoplásico/genéticaRESUMEN
OBJECTIVE: The phase III clinical trial PERFECT was designed to assess clinical safety and efficacy of intramyocardial CD133+ bone marrow stem cell treatment combined with CABG for induction of cardiac repair. DESIGN: Multicentre, double-blinded, randomised placebo controlled trial. SETTING: The study was conducted across six centres in Germany October 2009 through March 2016 and stopped due slow recruitment after positive interim analysis in March 2015. PARTICIPANTS: Post-infarction patients with chronic ischemia and reduced LVEF (25-50%). INTERVENTIONS: Eighty-two patients were randomised to two groups receiving intramyocardial application of 5ml placebo or a suspension of 0.5-5×106 CD133+. OUTCOME: Primary endpoint was delta (∆) LVEF at 180days (d) compared to baseline measured in MRI. FINDINGS (PRESPECIFIED): Safety (n=77): 180d survival was 100%, MACE n=2, SAE n=49, without difference between placebo and CD133+. Efficacy (n=58): The LVEF improved from baseline LVEF 33.5% by +9.6% at 180d, p=0.001 (n=58). Treatment groups were not different in ∆LVEF (ANCOVA: Placebo +8.8% vs. CD133+ +10.4%, ∆CD133+vs placebo +2.6%, p=0.4). FINDINGS (POST HOC): Responders (R) classified by ∆LVEF≥5% after 180d were 60% of the patients (35/58) in both treatment groups. ∆LVEF in ANCOVA was +17.1% in (R) vs. non-responders (NR) (∆LVEF 0%, n=23). NR were characterized by a preoperative response signature in peripheral blood with reduced CD133+ EPC (RvsNR: p=0.005) and thrombocytes (p=0.004) in contrast to increased Erythropoeitin (p=0.02), and SH2B3 mRNA expression (p=0.073). Actuarial computed mean survival time was 76.9±3.32months (R) vs. +72.3±5.0months (NR), HR 0.3 [Cl 0.07-1.2]; p=0.067.Using a machine learning 20 biomarker response parameters were identified allowing preoperative discrimination with an accuracy of 80% (R) and 84% (NR) after 10-fold cross-validation. INTERPRETATION: The PERFECT trial analysis demonstrates that the regulation of induced cardiac repair is linked to the circulating pool of CD133+ EPC and thrombocytes, associated with SH2B3 gene expression. Based on these findings, responders to cardiac functional improvement may be identified by a peripheral blood biomarker signature. TRIAL REGISTRATION: ClinicalTrials.govNCT00950274.
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Antígeno AC133/metabolismo , Células de la Médula Ósea/inmunología , Trasplante de Médula Ósea , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/terapia , Adulto , Anciano , Método Doble Ciego , Femenino , Humanos , Aprendizaje Automático , Masculino , Persona de Mediana Edad , Análisis de Supervivencia , Resultado del Tratamiento , Función Ventricular IzquierdaRESUMEN
LNK (SH2B3) is an intracellular adaptor protein that negatively regulates cellular proliferation or self-renewal of hematopoietic stem cells and some other progenitor cells. LNK is also recognized as a key regulator of insulin resistance and inflammatory responses in several tissues and organs. The function of LNK in adipose tissue is unknown. We previously demonstrated that type 2 diabetes mellitus (T2DM) mouse model had elevated serum free fatty acids (FFAs) levels and increased preadipocyte apoptosis in visceral fat tissue, showing the occurrence of lipotoxicity. Herein, when compared to control mice, the protein expression of LNK decreased in epididymal fat tissue from the high-sucrose/fat diet, low-dose streptozotocin induced T2DM mouse model. We thus investigated whether LNK could regulate palmitate-induced preadipocyte apoptosis in an in vitro apoptotic model in 3T3-L1 preadipocytes. LNK specific siRNA exacerbated palmitate-induced apoptosis and increased pro-apoptotic protein levels of cleaved caspase-3, Bax and cytochrome C; while overexpression of LNK cDNA exhibited significant anti-apoptotic effects. Consistently, LNK specific siRNA further decreased the Akt Ser-473 phosphorylation reduced by palmitate and located on upstream of Bax and cytochrome C. The siRNA-mediated LNK knockdown exacerbated mitochondrial membrane depolarization and mitochondrial-derived reactive oxygen species production induced by palmitate, whereas overexpression of LNK attenuated that. These results indicated that LNK plays a regulatory role in the palmitate-related preadipocyte apoptosis and might be involved in adipose tissue dysfunction.
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Adipocitos/citología , Adipocitos/efectos de los fármacos , Apoptosis/efectos de los fármacos , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Péptidos y Proteínas de Señalización Intracelular/deficiencia , Palmitatos/farmacología , Proteínas Adaptadoras Transductoras de Señales , Adipocitos/metabolismo , Animales , Diabetes Mellitus Tipo 2/inducido químicamente , Dieta Alta en Grasa , Sacarosa en la Dieta , Modelos Animales de Enfermedad , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Masculino , Proteínas de la Membrana , Ratones , Ratones Endogámicos C57BL , EstreptozocinaRESUMEN
This paper aims to present an overview of MICA and natural killer group 2 member D (NKG2D) genetic and functional interactions and their impact on kidney transplant outcome. Organ transplantation has gone from what can accurately be called a "clinical experiment" to a routine and reliable practice, which has proven to be clinically relevant, life-saving and cost-effective when compared with non-transplantation management strategies of both chronic and acute end-stage organ failures. The kidney is the most frequently transplanted organ in the world (transplant-observatory). The two treatment options for end-stage renal disease (ESRD) are dialysis and/or transplantation. Compared with dialysis, transplantation is associated with significant improvements in quality of life and overall longevity. A strong relationship exists between allograft loss and human leukocyte antigens (HLA) antibodies (Abs). HLA Abs are not the only factor involved in graft loss, as multiple studies have shown that non-HLA antigens are also involved, even when a patient has a good HLA matche and receives standard immunosuppressive therapy. A deeper understanding of other biomarkers is therefore important, as it is likely to lead to better monitoring (and consequent success) of organ transplants. The objective is to fill the void left by extensive reviews that do not often dive this deep into the importance of MICA and NKG2D in allograft acceptance and their partnership in the immune response. There are few papers that explore the relationship between these two protagonists when it comes to kidney transplantation. This is especially true for the role of NKG2D in kidney transplantation. These reasons give a special importance to this review, which aims to be a helpful tool in the hands of researchers in this field.
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The Lnk adapter protein negatively regulates the signaling of thrombopoietin (TPO), the main megakaryocyte (MK) growth factor. Lnk-deficient (-/-) mice have increased TPO signaling and increased MK number. Interestingly, several mouse models exist in which increased MK number leads to a high bone mass phenotype. Here we report the bone phenotype of these mice. MicroCT and static histomorphometric analyses at 20 weeks showed the distal femur of Lnk-/- mice to have significantly higher bone volume fraction and trabecular number compared to wild-type (WT) mice. Notably, despite a significant increase in the number of osteoclasts (OC), and decreased bone formation rate in Lnk-/- mice compared to WT mice, Lnk-/- mice demonstrated a 2.5-fold greater BV/TV suggesting impaired OC function in vivo. Additionally, Lnk-/- mouse femurs exhibited non-significant increases in mid-shaft cross-sectional area, yet increased periosteal BFR compared to WT femurs was observed. Lnk-/- femurs also had non-significant increases in polar moment of inertia and decreased cortical bone area and thickness, resulting in reduced bone stiffness, modulus, and strength compared to WT femurs. Of note, Lnk is expressed by OC lineage cells and when Lnk-/- OC progenitors are cultured in the presence of TPO, significantly more OC are observed than in WT cultures. Lnk is also expressed in osteoblast (OB) cells and in vitro reduced alkaline phosphatase activity was observed in Lnk-/- cultures. These data suggest that both direct effects on OB and OC as well as indirect effects of MK in regulating OB contributes to the observed high bone mass. J. Cell. Biochem. 118: 2231-2240, 2017. © 2017 Wiley Periodicals, Inc.
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Péptidos y Proteínas de Señalización Intracelular/metabolismo , Osteoclastos/citología , Osteoclastos/metabolismo , Trombopoyetina/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Fosfatasa Alcalina/genética , Fosfatasa Alcalina/metabolismo , Animales , Apoptosis/genética , Apoptosis/fisiología , Western Blotting , Células de la Médula Ósea/metabolismo , Ciclo Celular/genética , Ciclo Celular/fisiología , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Proliferación Celular/genética , Proliferación Celular/fisiología , Femenino , Inmunoprecipitación , Péptidos y Proteínas de Señalización Intracelular/deficiencia , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Megacariocitos/metabolismo , Proteínas de la Membrana , Ratones , Ratones Endogámicos C57BL , Osteoblastos/citología , Osteoblastos/metabolismo , Osteogénesis/genética , Osteogénesis/fisiología , Células RAW 264.7 , Trombopoyetina/genética , Microtomografía por Rayos XRESUMEN
Adipogenic differentiation of mesenchymal stem cells (MSCs) is critical for metabolic homeostasis and nutrient signaling during development. However, limited information is available on the pivotal modulators of adipogenic differentiation of MSCs. Adaptor protein Lnk (Src homology 2B3 [SH2B3]), which belongs to a family of SH2-containing proteins, modulates the bioactivities of different stem cells, including hematopoietic stem cells and endothelial progenitor cells. In this study, we investigated whether an interaction between insulin-like growth factor-1 receptor (IGF-1R) and Lnk regulated IGF-1-induced adipogenic differentiation of MSCs. We found that wild-type MSCs showed greater adipogenic differentiation potential than Lnk (-/-) MSCs. An ex vivo adipogenic differentiation assay showed that Lnk (-/-) MSCs had decreased adipogenic differentiation potential compared with wild-type MSCs. Interestingly, we found that Lnk formed a complex with IGF-1R and that IGF-1 induced the dissociation of this complex. In addition, we observed that IGF-1-induced increase in the phosphorylation of Akt and mammalian target of rapamycin was triggered by the dissociation of the IGF-1R-Lnk complex. Expression levels of a pivotal transcription factor peroxisome proliferator-activated receptor gamma (PPAR-γ) and its adipogenic target genes (LPL and FABP4) significantly decreased in Lnk (-/-) MSCs. These results suggested that Lnk adaptor protein regulated the adipogenesis of MSCs through the IGF-1/Akt/PPAR-γ pathway.
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Recent evidence indicates the adaptor protein SH2B3 has a major role in the progression of renal diseases. SH2B3 is highly expressed by hematopoietic cells and regulates cytokine signaling, inducing cell-specific effects. Additionally, its expression in other cell types suggests that SH2B3 may have a more extensive role within the kidney. Ex vivo studies have determined targets of SH2B3 cell-specific signaling, while in vivo studies have observed the SH2B3 overall affects in the progression of renal diseases. This mini-review covers the function of SH2B3-expressing cell types that contribute to renal pathologies and their regulation by SH2B3.
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Enfermedades Renales/metabolismo , Riñón/metabolismo , Proteínas/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Humanos , Péptidos y Proteínas de Señalización Intracelular , Transducción de Señal/fisiologíaRESUMEN
Adipogenic differentiation of mesenchymal stem cells (MSCs) is critical for metabolic homeostasis and nutrient signaling during development. However, limited information is available on the pivotal modulators of adipogenic differentiation of MSCs. Adaptor protein Lnk (Src homology 2B3 [SH2B3]), which belongs to a family of SH2-containing proteins, modulates the bioactivities of different stem cells, including hematopoietic stem cells and endothelial progenitor cells. In this study, we investigated whether an interaction between insulin-like growth factor-1 receptor (IGF-1R) and Lnk regulated IGF-1-induced adipogenic differentiation of MSCs. We found that wild-type MSCs showed greater adipogenic differentiation potential than Lnk(–/–) MSCs. An ex vivo adipogenic differentiation assay showed that Lnk(–/–) MSCs had decreased adipogenic differentiation potential compared with wild-type MSCs. Interestingly, we found that Lnk formed a complex with IGF-1R and that IGF-1 induced the dissociation of this complex. In addition, we observed that IGF-1-induced increase in the phosphorylation of Akt and mammalian target of rapamycin was triggered by the dissociation of the IGF-1R–Lnk complex. Expression levels of a pivotal transcription factor peroxisome proliferator-activated receptor gamma (PPAR-γ) and its adipogenic target genes (LPL and FABP4) significantly decreased in Lnk(–/–) MSCs. These results suggested that Lnk adaptor protein regulated the adipogenesis of MSCs through the IGF-1/Akt/PPAR-γ pathway.