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result(s) for
"Irs1"
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LncIRS1 controls muscle atrophy via sponging miR‐15 family to activate IGF1‐PI3K/AKT pathway
2019
Background Recent studies indicate important roles for long noncoding RNAs (lncRNAs) in the regulation of gene expression by acting as competing endogenous RNAs (ceRNAs). However, the specific role of lncRNAs in skeletal muscle atrophy is still unclear. Our study aimed to identify the function of lncRNAs that control skeletal muscle myogenesis and atrophy. Methods RNA sequencing was performed to identify the skeletal muscle transcriptome (lncRNA and messenger RNA) between hypertrophic broilers and leaner broilers. To study the ‘sponge’ function of lncRNA, we constructed a lncRNA‐microRNA (miRNA)‐gene interaction network by integrated our previous submitted skeletal muscle miRNA sequencing data. The primary myoblast cells and animal model were used to assess the biological function of the lncIRS1 in vitro or in vivo. Results We constructed a myogenesis‐associated lncRNA‐miRNA‐gene network and identified a novel ceRNA lncRNA named lncIRS1 that is specifically enriched in skeletal muscle. LncIRS1 could regulate myoblast proliferation and differentiation in vitro, and muscle mass and mean muscle fibre in vivo. LncIRS1 increases gradually during myogenic differentiation. Mechanistically, lncIRS1 acts as a ceRNA for miR‐15a, miR‐15b‐5p, and miR‐15c‐5p to regulate IRS1 expression, which is the downstream of the IGF1 receptor. Overexpression of lncIRS1 not only increased the protein abundance of IRS1 but also promoted phosphorylation level of AKT (p‐AKT) a central component of insulin‐like growth factor‐1 pathway. Furthermore, lncIRS1 regulates the expression of atrophy‐related genes and can rescue muscle atrophy. Conclusions The newly identified lncIRS1 acts as a sponge for miR‐15 family to regulate IRS1 expression, resulting in promoting skeletal muscle myogenesis and controlling atrophy.
Journal Article
Evaluation of Antidiabetic Activity of Biogenic Silver Nanoparticles Using Thymus serpyllum on Streptozotocin-Induced Diabetic BALB/c Mice
2022
Type 2 Diabetes Mellitus is one of the most common metabolic disorders, and is characterized by abnormal blood sugar level due to impaired insulin secretion or impaired insulin action—or both. Metformin is the most commonly used drug for the treatment of Type 2 Diabetes Mellitus, but due to its slow mode of action and various side effects it shows poor and slow therapeutic response in patients. Currently, scientists are trying to tackle these limitations by developing nanomedicine. This research reports novel synthesis of silver nanoparticles using aqueous extract of Thymus serpyllum and aims to elucidate its therapeutic potential as an antidiabetic agent on streptozotocin induced diabetic BALB/c mice. Thymus serpyllum mediated silver nanoparticles were characterized through UV, SEM, XRD, and FTIR. The alpha amylase inhibition and antioxidant activity were checked through α amylase and DPPH radical scavenging assay, respectively. To check the effect of silver nanoparticles on blood glucose levels FBG, IPGTT, ITT tests were employed on STZ induced BALB/c mice. To assess the morphological changes in the anatomy of liver, pancreas, and kidney of BALB/c mice due to silver nanoparticles, histological analysis was done through H&E staining system. Finally, AMPK and IRS1 genes expression analysis was carried out via real time PCR. Silver nanoparticles were found to be spherical in shape with an average size of 42 nm. They showed an IC50 of 8 μg/mL and 10 μg/mL for α amylase and DPPH assay, respectively. Our study suggests that silver nanoparticles—specifically 10 mg/kg—cause a significant increase in the expression of AMPK and IRS1, which ultimately increase the glucose uptake in cells. Thymus serpyllum mediated silver nanoparticles possess strong antioxidant and antidiabetic potential and can further be explored as an effective and cheaper alternative option for treatment of Type 2 Diabetes Mellitus.
Journal Article
Danggui Shaoyao San Alleviates Early Cognitive Impairment in Alzheimer's Disease Mice Through IRS1/GSK3β/Wnt3a‐β‐Catenin Pathway
by
Xu, Xiang‐Qing
,
Ding, Peng‐Li
,
Zhang, Kai‐Xin
in
Alzheimer Disease - drug therapy
,
Alzheimer Disease - metabolism
,
Alzheimer's disease
2024
Introduction Alzheimer's disease (AD) is a neurodegenerative disease characterized by Amyloid plaques and neurofibrillary tangles. We explored the potential mechanism by which Danggui Shaoyao San (DSS) modulates central glucose metabolism via the insulin receptor substrate 1 (IRS1)/glycogen synthase kinase‐3β (GSK3β)/Wnt3a‐β‐catenin pathway, thereby exerting protective effects on cognitive functions. Methods In vitro, HT22 cells were induced with streptozotocin (STZ) to investigate the impact of GSK3β on pathway transduction. The active components in the DSS stock solution were validated using mass spectrometry. Subsequently, an AD model in C57BL/6J mice was established through STZ injection into both ventricles. The success of the model was validated behaviorally and pathologically. The Morris Water Maze (MWM) test, immunohistochemistry, Western blotting, quantitative reverse transcription‐PCR, and 18F‐fluorodeoxyglucose‐positron emission tomography (FDG‐PET) were employed to evaluate the influence of DSS on memory and pathological changes in AD. Results The DSS stock solution, rich in active components, ameliorated the memory deficits in AD mice in the MWM. In vitro, GSK3β exhibited regulatory control over Wnt and β‐catenin, with GSK3β inhibition mitigating β‐amyloid and tau redundancies at protein and gene levels, facilitating signal transduction. In vivo, DSS impacted key targets in the IRS1/GSK3β/Wnt3a‐β‐catenin pathway, mitigated senile plaques resulting from amyloid β (Aβ) deposition and neurofiber tangles induced by tau hyperphosphorylation, and alleviated the decline in central glucose metabolism observed in FDG‐PET. Conclusions Our findings suggest that DSS potentially confers cognitive protection by alleviating central hypoglycemia through the IRS1/GSK3β/Wnt3a‐β‐catenin pathway. This may serve as a promising therapeutic avenue for AD. In vitro, HT22 cells were induced with streptozotocin to investigate the impact of GSK3β on pathway transduction. The active components in the DSS stock solution were validated using mass spectrometry. Subsequently, an AD model in C57BL/6J mice was established through streptozotocin injection into both ventricles. The success of the model was validated behaviorally and pathologically. The Morris Water Maze test, immunohistochemistry, Western blotting, quantitative reverse transcription‐PCR, and 18F‐fluorodeoxyglucose‐positron emission tomography (FDG‐PET) were employed to evaluate the influence of DSS on memory and pathological changes in AD. DSS potentially confers cognitive protection by alleviating central hypoglycemia through the IRS1/GSK3β/Wnt3a‐β‐catenin pathway.
Journal Article
H19 inhibition increases HDAC6 and regulates IRS1 levels and insulin signaling in the skeletal muscle during diabetes
2022
Background
Histone deacetylases (HDACs) that catalyze removal of acetyl groups from histone proteins, are strongly associated with several diseases including diabetes, yet the precise regulatory events that control the levels and activity of the HDACs are not yet well elucidated.
Methods
Levels of H19 and HDACs were evaluated in skeletal muscles of normal and diabetic db/db mice by Western Blot analysis. C2C12 cells were differentiated and transfected with either the scramble or H19 siRNA and the levels of HDACs and
Prkab2
,
Pfkfb3
,
Srebf1
,
Socs2
,
Irs1
and
Ppp2r5b
were assessed by Western Blot analysis and qRT-PCR, respectively. Levels of H9, HDAC6 and IRS1 were evaluated in skeletal muscles of scramble/ H19 siRNA injected mice and chow/HFD-fed mice.
Results
Our data show that the lncRNA H19 and HDAC6 exhibit inverse patterns of expression in the skeletal muscle of diabetic db/db mice and in C2C12 cells, H19 inhibition led to significant increase in HDAC activity and in the levels of HDAC6, both at the transcript and protein levels. This was associated with downregulation of IRS1 levels that were prevented in the presence of the HDAC inhibitor, SAHA, and HDAC6 siRNA suggesting the lncRNA H19-HDAC6 axis possibly regulates cellular IRS1 levels. Such patterns of H19, HDAC6 and IRS1 expression were also validated and confirmed in high fat diet-fed mice where as compared to normal chow-fed mice, H19 levels were significantly inhibited in the skeletal muscle of these mice and this was accompanied with elevated HDAC6 levels and decreased IRS1 levels. In-vivo inhibition of H19 led to significant increase in HDAC6 levels and this was associated with a decrease in IRS1 levels in the skeletal muscle.
Conclusions
Our results suggest a critical role for the lncRNA H19-HDAC6 axis in regulating IRS1 levels in the skeletal muscle during diabetes and therefore restoring normal H19 levels might hold a therapeutic potential for the management of aberrant skeletal muscle physiology during insulin resistance and type 2 diabetes.
Journal Article
Exosome-shuttled miR-150–5p from LPS-preconditioned mesenchymal stem cells down-regulate PI3K/Akt/mTOR pathway via Irs1 to enhance M2 macrophage polarization and confer protection against sepsis
by
He, Yuxin
,
Zhang, Teng
,
Liu, Shuchang
in
1-Phosphatidylinositol 3-kinase
,
AKT protein
,
Animals
2024
Sepsis is a life-threatening organ dysfunction and lack of effective measures in the current. Exosomes from mesenchymal stem cells (MSCs) reported to alleviate inflammation during sepsis, and the preconditioning of MSCs could enhance their paracrine potential. Therefore, this study investigated whether exosomes secreted by lipopolysaccharide (LPS)-pretreated MSCs exert superior antiseptic effects, and explored the underlying molecular mechanisms.
Exosomes were isolated and characterized from the supernatants of MSCs. The therapeutic efficacy of normal exosomes (Exo) and LPS-pretreated exosomes (LPS-Exo) were evaluated in terms of survival rates, inflammatory response, and organ damage in an LPS-induced sepsis model. Macrophages were stimulated with LPS and treated with Exo or LPS-Exo to confirm the results of the
studies, and to explain the potential mechanisms.
LPS-Exo were shown to inhibit aberrant pro-inflammatory cytokines, prevent organ damages, and improve survival rates of the septic mice to a greater extent than Exo.
, LPS-Exo significantly promoted the M2 polarization of macrophages exposed to inflammation. miRNA sequencing and qRT-PCR analysis identified the remarkable expression of miR-150-5p in LPS-Exo compared to that in Exo, and exosomal miR-150-5p was transferred into recipient macrophages and mediated macrophage polarization. Further investigation demonstrated that miR-150-5p targets Irs1 in recipient macrophages and subsequently modulates macrophage plasticity by down-regulating the PI3K/Akt/mTOR pathway.
The current findings highly suggest that exosomes derived from LPS pre-conditioned MSCs represent a promising cell-free therapeutic method and highlight miR-150-5p as a novel molecular target for regulating immune hyperactivation during sepsis.
Journal Article
1,25(OH)2-vitamin D3 upregulates glucose uptake mediated by SIRT1/IRS1/GLUT4 signaling cascade in C2C12 myotubes
by
Jain, Sushil K.
,
Manna, Prasenjit
,
Achari, Arunkumar E.
in
Biochemistry
,
Biomedical and Life Sciences
,
Calcitriol
2018
This study examined the hypothesis that 1,25-dihydroxyvitamin D
3
(1,25(OH)
2
D
3
) upregulates the insulin-independent signaling cascade of glucose metabolism. C2C12 myotubes were treated with high glucose (HG, 25 mM) and 1,25(OH)
2
D
3
(0–50 nM). 1,25(OH)
2
D
3
supplementation upregulated both insulin-independent (SIRT1) and insulin-dependent (p-IRS) signaling molecules, and stimulated the GLUT4 translocation, and glucose uptake in HG-treated myotubes. The effect of 1,25(OH)
2
D
3
on IRS1 phosphorylation, GLUT4 translocation, and glucose uptake was attenuated in SIRT1-knockdown myotubes. Treatment with 1,25(OH)
2
D
3
, coupled with insulin, enhanced GLUT4 translocation and glucose uptake compared to treatment with either insulin or 1,25(OH)
2
D
3
alone in HG-treated myotubes, which suggests that insulin-independent signaling molecules can contribute to the higher glucose metabolism observed in 1,25(OH)
2
D
3
and insulin-treated cells. The data, therefore, suggest that 1,25(OH)
2
D
3
increases glucose consumption by inducing SIRT1 activation, which in turn increases IRS1 phosphorylation and GLUT4 translocation in myotubes.
Journal Article
Hesperidin ameliorates signs of the metabolic syndrome and cardiac dysfunction via IRS/Akt/GLUT4 signaling pathway in a rat model of diet-induced metabolic syndrome
by
Prachaney, Parichat
,
Maneesai, Putcharawipa
,
Rattanakanokchai, Siwayu
in
AKT protein
,
animal models
,
Antihypertensives
2021
Background
Hesperidin has been reported to have biological activities such as antihypertensive, hypoglycemic, and antioxidant effects. This study investigated whether hesperidin could improve signs of the metabolic syndrome and cardiac function in a high-fat diet (HFD) induced metabolic syndrome (MS) in rats.
Methods
Male Sprague–Dawley rats were fed HFD and 15% fructose for 16 weeks and treated with hesperidin (15 or 30 mg/kg, based on signs of MS from a preliminary study) or metformin, a positive control agent, (100 mg/kg) for the final four weeks. Cardiac function, blood pressure, fasting blood glucose, oral glucose tolerance, serum insulin, and lipid profiles were measured. Histomorphometrics of left ventricles, epidydimal fat pads and liver were evaluated. Expressions of phosphorylate insulin receptor substrate1(p-IRS1), p-Akt and GLUT4 in cardiac tissue were determined.
Results
Hesperidin and metformin attenuated MS in HFD rats (
p
< 0.05). The accumulation of visceral fat pads and fatty liver associated with increases in liver lipid contents and liver enzymes were found in MS rats that were alleviated in hesperidin or metformin-treated groups (
p
< 0.05). Hesperidin and metformin improved cardiac dysfunction and hypertrophy observed in MS rats (
p
< 0.05). Restoration of the insulin signaling pathway, IRS/Akt/GLUT4 protein expression, was demonstrated in hesperidin and metformin-treated groups (
p
< 0.05). Hesperidin (30 mg/kg) was more effective than the lower dose.
Conclusion
Hesperidin was effective in reducing signs of MS and alterations of LV hypertrophy and function. These beneficial effects on the heart were associated with the restoration of the cardiac insulin signaling pathway in MS rats.
Journal Article
Plant-derived cell-penetrating microprotein α-astratide aM1 targets Akt signaling and alleviates insulin resistance
by
Dutta, Bamaprasad
,
Kam, Antony
,
Tam, James P.
in
1-Phosphatidylinositol 3-kinase
,
Accumulation
,
Adipocytes
2023
Insulin-resistant diabetes is a common metabolic disease with serious complications. Treatments directly addressing the underlying molecular mechanisms involving insulin resistance would be desirable. Our laboratory recently identified a proteolytic-resistant cystine-dense microprotein from huáng qí (
Astragalus membranaceus
) called α-astratide aM1, which shares high sequence homology to leginsulins. Here we show that aM1 is a cell-penetrating insulin mimetic, enters cells by endocytosis, and activates the PI3K/Akt signaling pathway independent of the insulin receptor leading to translocation of glucose transporter GLUT4 to the cell surface to promote glucose uptake. We also showed that aM1 alters gene expression, suppresses lipid synthesis and uptake, and inhibits intracellular lipid accumulation in myotubes and adipocytes. By reducing intracellular lipid accumulation and preventing lipid-induced, PKCθ-mediated degradation of IRS1/2, aM1 restores glucose uptake to overcome insulin resistance. These findings highlight the potential of aM1 as a lead for developing orally bioavailable insulin mimetics to expand options for treating diabetes.
Journal Article
PYCR1 promotes liver cancer cell growth and metastasis by regulating IRS1 expression through lactylation modification
by
Gao, Chenzi
,
Wang, Haoyu
,
Zhang, Xu
in
Animals
,
Carcinoma, Hepatocellular - genetics
,
Carcinoma, Hepatocellular - metabolism
2024
Background Liver cancer (LC) is among the deadliest cancers worldwide, with existing treatments showing limited efficacy. This study aimed to elucidate the role and underlying mechanisms of pyrroline‐5‐carboxylate reductase 1 (PYCR1) as a potential therapeutic target in LC. Methods Immunohistochemistry and Western blot were used to analyse the expression of PYCR1 in LC cells and tissues. EdU assays, colony‐forming assays, scratch wound healing assays, Transwell assays, nude mouse xenograft models and nude mouse lung metastasis models were used to detect the growth and metastasis abilities of LC cells. Transcriptome sequencing was used to search for downstream target genes regulated by PYCR1, and metabolomics was used to identify the downstream metabolites regulated by PYCR1. ChIP assays were used to analyse the enrichment of H3K18 lactylation in the IRS1 promoter region. Results We found that the expression of PYCR1 was significantly increased in HCC and that this high expression was associated with poor prognosis in HCC patients. Knockout or inhibition of PYCR1 inhibited HCC cell proliferation, migration and invasion both in vivo and in vitro. In addition, we revealed that knocking out or inhibiting PYCR1 could inhibit glycolysis in HCC cells and reduce H3K18 lactylation of the IRS1 histone, thereby inhibiting IRS1 expression. Conclusions Our findings identify PYCR1 as a pivotal regulator of LC progression that influences tumour cell metabolism and gene expression. By demonstrating the potential of targeting PYCR1 to inhibit LC cell proliferation and metastasis, this study identified PYCR1 as a promising therapeutic target for LC. Highlights Pyrroline‐5‐carboxylate reductase 1 (PYCR1) promotes the proliferation and metastasis of liver cancer (LC) cells. The expression of PYCR1 in LC is regulated by DNA methylation. Knocking down or inhibiting PYCR1 inhibits glycolysis as well as the PI3K/AKT/mTOR and MAPK/ERK pathways in LC cells. PYCR1 regulates the transcriptional activity of IRS1 by affecting H3K18 lactylation in its promoter region. Schematic diagram illustrating the mechanism by which PYCR1 knockout/inhibition hinders liver cancer (LC) progression by regulating IRS1 expression through lactylation. Upon PYCR1 knockout/inhibition, LC glycolysis is inhibited, and the intracellular lactate level decreases. As a result, the enrichment of H3K18la in the promoter region of IRS1 is lost, leading to a reduction in IRS1 expression. Immediately afterward, the downstream activation of the PI3K/AKT/mTOR and MAPK/ERK pathways was weakened, resulting in a failure to promote the growth and metastasis of LC cells.
Journal Article
Valorization of Winemaking By-Products: White and Red Grape Seed Oils Improve Glucose Consumption and Uptake In Vitro
by
Mauro, Manuela
,
Arizza, Vincenzo
,
Longo, Francesco
in
Antidiabetics
,
Backup software
,
Carotenoids
2025
The rising demand for alternative solutions to diabetes mellitus has prompted significant interest in the exploration of plant-derived anti-diabetic compounds, especially within a circular economy framework that seeks sustainable and profitable reuse options. In this context, red (RSGO) and white (WGSO) grape seed oils, by-products of Sicilian vineyards, were prepared, analyzed for their fatty acid, polyphenol, carotenoid, and chlorophyll content, and evaluated for their glucose-lowering ability on HepG2 cells. Utilizing cytochemical techniques, flow cytometry, and protein blotting, we explored the effects of non-toxic oil dilutions on (i) glycogen storage, (ii) glucose consumption/uptake, (iii) GLUT-2, GLUT-4, and hepatocyte nuclear factor-1α (HNF1α) expression levels, and (iv) AMP-activated protein kinase (AMPK), insulin receptor substrate-1 (IRS-1), AKT, and PKCζ phosphorylation states, which are involved in insulin-mediated and -independent regulation of GLUT-4 membrane exposure. RGSO and WGSO, despite adopting slightly varying molecular strategies, were both proven to be effective stimulators of glucose absorption and glycogenesis. Specifically, RSGO promoted GLUT-2 and GLUT-4 up-regulation, whereas the WGSO-induced effect was associated with an increase in GLUT-4 levels alone. Moreover, the oils activated both pathways responsible for GLUT-4 translocation. Therefore, these wine-making residues have substantial potential as anti-diabetic solutions, holding promise for integration into the biomedical and food sectors.
Journal Article