IGF-1 ameliorates streptozotocin-induced pancreatic β cell dysfunction and apoptosis via activating IRS1/PI3K/Akt/FOXO1 pathway

Expression and clinical significance of IGF-1 and PDGF in aqueous humor and serum of diabetic patients with visually significant cataract

This study aimed to analyze the expression and clinical significance of IGF-1 and PDGF in the aqueous humor and serum of diabetic patients with visually significant cataract. A retrospective study was conducted on 136 diabetic patients with visually significant cataract who underwent phacoemulsification. Patients were divided into non-complication (n = 82) and complication groups (n = 54) based on postoperative outcomes. Clinical baseline data, as well as IGF-1 and PDGF levels in aqueous humor and serum, were compared between groups. ROC curve analysis was utilized to evaluate the predictive value of IGF-1 and PDGF for postoperative complications. Logistic regression was employed to identify risk factors, and Kaplan-Meier analysis was adopted to assess the impact of IGF-1 and PDGF levels on postoperative complications. No significant differences were found between the two groups in terms of gender, age, BMI, intraocular pressure, surgical eye, phacoemulsification time, phacoemulsification energy, axial length, smoking, drinking history, hypertension, hyperlipidemia, FINS, HbA1C, CRP, or FPG. However, significant differences were observed in disease duration, presence of retinopathy, and IL-6 levels. Patients with complications had significantly higher IGF-1 and PDGF levels in both aqueous humor and serum compared to those without complications. Elevated IGF-1 and PDGF levels were independent risk factors for complications and increased the risk of postoperative complications. Elevated IGF-1 and PDGF levels in aqueous humor and serum are significant independent risk factors for postoperative complications in diabetic patients with visually significant cataract. Both markers can assist in predicting adverse outcomes and are associated with an increased risk of complications.

Mediating effect of osteocalcin underlying the link between insulin-like growth factor-I and gestational diabetes mellitus

PURPOSE

To investigate the associations of serum insulin like growth factor I (IGF-I) and Osteocalcin (OC) concentrations with gestational diabetes mellitus (GDM) risk among Chinese women.

METHODS

A case-control study was conducted in China, involving 125 GDM and 153 healthy pregnant women at 24-28 gestational weeks from 2019 to 2022. The study was approved by the Clinical Trial Ethics Committee of the Third Afliated Hospital of Zhengzhou University in January 04, 2020, and the study had been registered with the Chinese Clinical Trial Registry (ChiCTR2000028811). Maternal serum IGF-I and OC levels were measured in the second trimester. Logistic regression models and restricted cubic spline (RCS) were employed to calculate the association of IGF-I and OC levels with the risk of GDM, and and receiver operating characteristic (ROC) curves were generated to evaluate the predictive capacity of IGF-I and OC for GDM. Mediation analyses were used to investigate the mediation effect of OC on the association between IGF-I and the risk of GDM.

RESULTS

Both serum IGF-I and undercarboxylated Osteocalcin (ucOC) concentration were positively associated with the risk of GDM. The relationship between serum IGF-I and the risk of GDM is not linear (P-value < 0.001, P-Nonlinear < 0.001). Mediation analyses suggested that 48.61% of the associations between IGF-I and GDM might be mediated by ucOC. The areas under the ROC curves for IGF-I and integrated model were 74.5% and 76.2%.

CONCLUSIONS

Serum IGF-I might provide a new dimension in the diagnosis of GDM for clinical application, and ucOC might serve as a mediator between IGF-I and GDM.

Exercise training benefits pancreatic islet by modulating the insulin-like growth factor 1/phosphatidylinositol 3-kinase/protein kinase B pathway

BACKGROUND

Diabetes is characterized by insulin resistance as well as impaired insulin production, with β-cell dysfunction playing a critical role in disease progression. Exercise is known to improve insulin sensitivity, but its effects on pancreatic islet quality and function remain poorly understood. This work hypothesized that swimming training enhances glycemic control and insulin secretion by upregulating the insulin-like growth factor 1 (IGF-1)/phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway in streptozotocin (STZ)-induced diabetic rats.

AIM

To investigate the effects of swimming on pancreatic islet quality and function in STZ-induced diabetic rats via the IGF-1/PI3K/AKT pathway.

METHODS

Twenty-six Sprague-Dawley rats were grouped into diabetic and control groups, with each group further split into exercise and sedentary subgroups. Diabetic rats were induced with STZ. The exercise groups underwent swimming training for 60 minutes/day, 5 days/week, for 8 weeks. Body weight, food intake, blood glucose, insulin, lipids, and muscle glycogen were measured. Pancreatic islet morphology and the protein expression levels of IGF-1, PI3K, and AKT were analyzed. Data were analyzed using two-way repeated-measure ANOVA, followed by Tukey’s post-hoc test.

RESULTS

Exercise training significantly improved body weight [diabetic exercise group (D-Ex): 390.66 ± 50.14 g vs diabetic sedentary group (D-Sed): 315.89 ± 50.12 g, P < 0.05], reduced blood glucose (D-Ex: 12.21 ± 4.43 mmol/L vs D-Sed: 17.79 ± 2.05 mmol/L, P < 0.05), and increased insulin levels (D-Ex: 53.50 ± 15.31 pmol/L vs D-Sed: 25.31 ± 10.23 pmol/L, P < 0.05) in diabetic rats. It also enhanced islet morphology, increased IGF-1 expression, and activated the PI3K/AKT pathway (P < 0.05). In-vitro experiments confirmed that IGF-1 positively regulated insulin expression and inhibited β-cell apoptosis via the PI3K/AKT pathway.

CONCLUSION

Exercise training improves pancreatic islet quality and function in diabetic rats by modulating the IGF-1/PI3K/AKT pathway, highlighting its therapeutic potential for diabetes management.

The multifaceted function of FoxO1 in pancreatic β-cell dysfunction and insulin resistance: Therapeutic potential for type 2 diabetes

The forkhead box O1 (FoxO1), the first discovered member of the FoxO family, is a critical transcription factor predominantly found in insulin-secreting and insulin-sensitive tissues. In the pancreas of adults, FoxO1 expression is restricted to islet β cells. We determined that in human islet microarray datasets, FoxO1 expression is higher than other FoxO transcription factors. Our analyses of three human islet datasets revealed that FoxO1 expression tends to shows a negative correlation with type 2 diabetes and no correlation with body mass index (BMI) between individuals with low levels of HbA1C (or ND, non-diabetic) and high levels of HbA1C (or T2D, type 2 diabetes). However, FoxO1 function is multifaceted and mainly regulated by post-translational modifications including phosphorylation and deacetylation that involved in pancreatic β cell function and insulin sensitivity. This study summarized the molecular mechanisms underlying the role of FoxO1 activity in pancreatic β-cell dysfunction and insulin resistance in T2D. In addition, we collected the clinical trials of FoxO1 inhibitor and agonist in diabetes, and discussed the therapeutic potential of FoxO1 activity in diabetes treatment.

The impact of a high-carbohydrate diet on the cognitive behavior of mice in a low-pressure, low-oxygen environment

The effectiveness of high-carbohydrate diets (HCD) on cognitive impairment is still being debated. To clarify the impact of HCD on the cognitive behavior of mice under low-pressure hypoxic conditions, we studied 24 mice in different environments while subjecting them to dietary intervention for 5 weeks, and conducting behavioral tests. Under low-pressure hypoxic conditions, HCD intervention reversed the decline in spatial learning and memory abilities in mice caused by hypoxia, ameliorated pathological brain damage, and restored the integrity of the intestinal mucosa. We also identified differences in the microbial community. Under low-pressure hypoxic conditions, the intestinal abundance of Parasutterella in mice decreased, the abundance of harmful bacteria such as Desulfovibrio increased, and apoptosis was more prevalent, possibly explaining the observed decreases in glutathione peroxidase activity and brain-derived neurotrophic factor (BDNF) expression in the brain. HCD intervention increased the intestinal abundance of Bifidobacterium in hypoxic mice, reduced the abundances of Desulfovibrio and Faecalibaculum, and played antioxidant roles by lowering malondialdehyde levels and increasing superoxide dismutase activity in the brain by metabolizing amino acids and lipids. HCD also upregulated hippocampal BDNF levels and downregulated caspase 3. Collectively, these results are important because they help explain how HCD intervention can reduce hypoxia-induced damage to brain function.

SEP-363856 attenuates CUMS-induced depression-like behaviours and reverses hippocampal neuronal injuries

OBJECTIVES

This study employed a chronic unpredictable mild stress (CUMS) model to examine the antidepressant properties of SEP-363856.

METHODS

The sucrose preference test (SPT) was employed to evaluate anhedonia, the open field test (OFT) to measure locomotor activity and exploratory behaviour, the elevated plus-maze (EPM) to assess anxiety-like behaviour, and the tail suspension test (TST) and forced swimming test (FST) to determine despair behaviour. qRT-PCR was implemented to evaluate gene expression levels in the hippocampus. Western blot, and ELISA were implemented to evaluate hippocampal protein expression, and Nissl staining was implemented to identify hippocampal neuronal injury.

RESULTS

The 10 mg/kg dosage of SEP-363856 and fluoxetine significantly improved depressive-like behaviours as assessed by the SPT, OFT, EPM, TST, and FST. This was associated with improved hippocampal neuronal damage, enhanced mRNA expression of brain-derived neurotrophic factor, synaptophysin, and postsynaptic density 95. SEP-363856 increased the levels of insulin-like growth factor-1 (IGF-1), IGF-1 receptor β, phospho-phosphatidylinositide 3-kinase, and phospho-protein kinase B in the brain.

CONCLUSIONS

The antidepressant-like effects of SEP-363856 are linked to increased hippocampal neurotrophic factors, decreased hippocampus neuronal lesions, and activation of the IGF-1Rβ/PI3K/AKT signalling pathway. The latter may serve as a novel drug target for the treatment of depression.

Carboxymethylation of paramylon derived from Euglena gracilis and its hypoglycemic mechanism in diabetic mice

Paramylon is a polysaccharide primarily composed of β-1,3-glucan, characterized by its high crystallinity and insolubility in water. Enhancing its water solubility through structural modifications presents an effective strategy to unlock its biological activity. In this study, carboxymethylation was employed to produce carboxymethylated paramylon (CEP) with varying carboxyl concentrations. The successful introduction of carboxyl groups led to a notable improvement in water solubility. In vivo experiments demonstrated that CEP reduced fasting blood glucose levels by 24.42 %, improved oral glucose tolerance, and enhanced insulin sensitivity in diabetic mice. Additionally, CEP regulated lipid homeostasis and ameliorated liver damage. Through modulation of the adenosine monophosphate-activated protein kinase/phosphoinositide 3-kinase/protein kinase B pathway and the glucose-6-phosphatase/phosphoenolpyruvate carboxykinase pathway, CEP effectively regulated hepatic glucose absorption and production. Furthermore, CEP mitigated diabetes-induced lipid metabolism disorders. These findings suggest that CEP holds significant promise in ameliorating glucose metabolism disorder, indicating its potential as a novel hypoglycemic functional food.

Hinokione: an abietene diterpene with pancreatic β cells regeneration and hypoglycemic activity, and other derivatives with novel structures from the woods of Agathis dammara

In this study, 14 abietene and pimarene diterpenoids were isolated from the woods of Agathis dammara. Among them, 4 new compounds, dammarone A-C and dammaric acid A (1-4), were firstly reported, respectively. The structure of the new compounds was determined by HR ESI-MS and 1D/2D NMR spectroscopy, and their absolute configuration was determined by electronic circular dichroism (ECD) exciton chirality method. The hypoglycemic effect of all compounds was evaluated by transgenic zebrafish model, and the structure-activity relationship was discussed. Hinokione (7, HO) has low toxicity and significant hypoglycemic effects on zebrafish, the mechanism is mainly by promoting the differentiation of zebrafish pancreatic endocrine precursor cells (PEP cells) into β cells, thereby promoting the regeneration of pancreatic β cells.

Exploring the mechanism of Jinlida granules against type 2 diabetes mellitus by an integrative pharmacology strategy

Jinlida granule (JLD) is a Traditional Chinese Medicine (TCM) formula used for the treatment of type 2 diabetes mellitus (T2DM). However, the mechanism of JLD treatment for T2DM is not fully revealed. In this study, we explored the mechanism of JLD against T2DM by an integrative pharmacology strategy. Active components and corresponding targets were retrieved from Traditional Chinese Medicine System Pharmacology (TCMSP), SwissADME and Bioinformatics Analysis Tool for Molecular Mechanisms of Traditional Chinese Medicine Database (BATMAN-TCM) database. T2DM-related targets were obtained from Drugbank and Genecards databases. The protein-protein interaction (PPI) network was constructed and analyzed with STRING (Search Toll for the Retrieval of Interacting Genes/proteins) and Cytoscape to get the key targets. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) enrichment analyses were performed with the Database for Annotation, Visualization and Integrated Discovery (DAVID). Lastly, the binding capacities and reliability between potential active components and the targets were verified with molecular docking and molecular dynamics simulation. In total, 185 active components and 337 targets of JLD were obtained. 317 targets overlapped with T2DM-related targets. RAC-alpha serine/threonine-protein kinase (AKT1), tumor necrosis factor (TNF), interleukin-6 (IL-6), cellular tumor antigen p53 (TP53), prostaglandin G/H synthase 2 (PTGS2), Caspase-3 (CASP3) and signal transducer and activator of transcription 3 (STAT3) were identified as seven key targets by the topological analysis of the PPI network. GO and KEGG enrichment analyses showed that the effects were primarily associated with gene expression, signal transduction, apoptosis and inflammation. The pathways were mainly enriched in PI3K-AKT signaling pathway and AGE-RAGE signaling pathway in diabetic complications. Molecular docking and molecular dynamics simulation verified the good binding affinity between the key components and targets. The predicted results may provide a theoretical basis for drug screening of JLD and a new insight for the therapeutic effect of JLD on T2DM.

FGF19 Promotes the Proliferation and Insulin Secretion from Human Pancreatic β Cells Via the IRS1/GLUT4 Pathway

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a commonly observed complication associated with obesity. The effect of fibroblast growth factor 19 (FGF19), a promising therapeutic agent for metabolic disorders, on pancreatic β cells in obesity-associated T2DM remains poorly understood.

METHODS

Human pancreatic β cells were cultured with high glucose (HG) and palmitic acid (PA), followed by treatment with FGF19. The cell proliferation, apoptosis, and insulin secretion were evaluated by CCK-8, qRT-PCR, ELISA, flow cytometry, and western blotting. The expression of the insulin receptor substrate (IRS)/glucose transporter (GLUT) pathway was evaluated. The interaction between FGF19 and IRS1 was predicted using the STRING database and verified by co-immunoprecipitation and immunofluorescence. The regulatory effects of the IRS1/GLUT4 pathway on human pancreatic β cells were assessed by overexpressing IRS1 and silencing IRS1 and GLUT4.

RESULTS

HG+PA treatment reduced the human pancreatic β cell proliferation and insulin secretion and promoted cell apoptosis. However, FGF19 treatment restored these alterations and significantly increased the expressions of IRS1, GLUT1, and GLUT4 in the IRS/GLUT pathway. Furthermore, FGF19 and IRS1 were found to interact. IRS1 overexpression partially promoted the proliferation of pancreatic β cells and insulin secretion through GLUT4. Additionally, the silencing of IRS1 or GLUT4 attenuated the therapeutic effects of FGF19.

CONCLUSION

In conclusion, FGF19 partly promoted the proliferation and insulin secretion of human pancreatic β cells and inhibited apoptosis by upregulating the IRS1/GLUT4 pathway. These findings establish a theoretical framework for the clinical utilization of FGF19 in the treatment of obesity-associated T2DM.

Long non‑coding RNA PEG13 regulates endothelial cell senescence through the microRNA‑195/IRS1 axis

Atherosclerosis is a chronic inflammatory disease characterized by endothelial dysfunction and plaque formation. The present study aimed to elucidate the pathological role of the long non-coding RNA (lncRNA) paternally expressed 13 (PEG13) in the onset and progression of atherosclerosis. Specifically, its effects on human umbilical vein endothelial cell (HUVEC) proliferation, angiogenesis, senescence and senescence-associated secretory phenotype (SASP)-related factors were investigated using cell proliferation, cellular angiogenesis, β-galactosidase staining, reverse transcription-quantitative PCR and enzyme-linked immunosorbent assays. The results showed that oxidized low-density lipoprotein (ox-LDL) inhibited lncRNA PEG13 expression and HUVEC viability in a dose-dependent manner and PEG13 overexpression partially reversed these effects. Additionally, PEG13 overexpression ameliorated the ox-LDL-induced impairment of angiogenesis, cellular senescence and SASP. Furthermore, lncRNA PEG13 directly targeted microRNA (miR/miRNA)-195-5p, suppressing the ox-LDL-induced upregulation of the miRNA. The gene coding for insulin receptor substrate 1 (IRS1), an activator of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, was confirmed as a direct target of miR-195. PEG13 overexpression attenuated the ox-LDL-induced inhibition of IRS1 expression and PI3K/AKT signaling and its protective effects on HUVEC viability, angiogenesis and senescence were partially reversed by small interfering RNAs targeting IRS1. The present study demonstrated that lncRNA PEG13 attenuates ox-LDL-induced senescence in HUVECs by modulating the miR-195/IRS1/PI3K/AKT signaling pathway, suggesting a potential therapeutic target for the treatment of atherosclerosis.

Impact of type 2 diabetes mellitus on short-term and long-term outcomes of stage iv colorectal cancer patients after primary surgery: a propensity score matching analysis

PURPOSE

This study aims to investigate the influence of type 2 diabetes mellitus (T2DM) on stage IV colorectal cancer (CRC) patients performed primary surgery in terms of short-term and long-term outcomes.

METHODS

Patients diagnosed with stage IV CRC and received primary CRC surgery at a single clinical center from Jan, 2013 to Jan, 2020 were included in this study. Baseline characteristics, short-term and long-term outcomes were compared between the T2DM group and the Non-T2DM group. Univariate and multivariate analysis were used to find risk factors for overall survival (OS). Propensity score matching (PSM) using a 1:1 ratio was used to minimize selective bias between the two groups. Statistical analysis was performed using SPSS (version 22.0) software.

RESULTS

A total of 302 eligible patients were enrolled, and there were 54 (17.9%) patients with T2DM, and 248 (82.1%) patients without T2DM. The T2DM group had more older patients (P < 0.01), higher body mass index (BMI) (P < 0.01), and a higher proportion of hypertension (P < 0.01) than the Non-T2DM group. After PSM, there were 48 patients in each group. There were no significant differences in short-term outcomes or OS between the two groups, either before or after PSM (P > 0.05). In multivariate analysis, older age (P < 0.01, HR = 1.032, 95% CI = 1.014-1.051) and larger tumor size (P < 0.01, HR = 1.760, 95% CI = 1.179-2.626) were independent factors for OS.

CONCLUSION

Although T2DM did not influence short-term outcomes or OS in stage IV CRC patients after primary surgery, age and tumor size might have predictive value for OS.