PICK1 attenuates high glucose-induced pancreatic β-cell death through the PI3K/Akt pathway and is negatively regulated by miR-139-5p

Crosstalk between MiRNAs/lncRNAs and PI3K/AKT signaling pathway in diabetes mellitus: Mechanistic and therapeutic perspectives

Diabetes as a fastest growing diseases worldwide is characterized by elevated blood glucose levels. There's an enormous financial burden associated with this endocrine disorder, with unequal access to health care between developed and developing countries. PI3Ks (phosphoinositide 3-kinases) have been demonstrated to be crucial for glucose homeostasis, and malfunctioning of these molecules can contribute to an increase in glucose serum levels, the main pathophysiological feature of diabetes. Additionally, recent evidence suggests that miRNAs and lncRNAs are reciprocally interacting with this signaling pathway. It is therefore evident that abnormal regulation of miRNAs/lncRNAs in the lncRNAs/miRNAs/PI3K/AKT axis is related to clinicopathological characteristics and plays a crucial role in the regulation of biological processes. It has therefore been attempted in this review to describe the interaction between PI3K/AKT signaling pathway and various miRNAs/lncRNAs and their importance in DM biology. We also presented the clinical applications of PI3K/AKT-related ncRNAs/herbal medicine in patients with DM.

Targeting postsynaptic glutamate receptor scaffolding proteins PSD-95 and PICK1 for obesity treatment

Human genome-wide association studies (GWAS) suggest a functional role for central glutamate receptor signaling and plasticity in body weight regulation. Here, we use UK Biobank GWAS summary statistics of body mass index (BMI) and body fat percentage (BF%) to identify genes encoding proteins known to interact with postsynaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-d-aspartate (NMDA) receptors. Loci in/near discs large homolog 4 (DLG4) and protein interacting with C kinase 1 (PICK1) reached genome-wide significance (P < 5 × 10-8) for BF% and/or BMI. To further evaluate the functional role of postsynaptic density protein-95 (PSD-95; gene name: DLG4) and PICK1 in energy homeostasis, we used dimeric PSD-95/disc large/ZO-1 (PDZ) domain-targeting peptides of PSD-95 and PICK1 to demonstrate that pharmacological inhibition of PSD-95 and PICK1 induces prolonged weight-lowering effects in obese mice. Collectively, these data demonstrate that the glutamate receptor scaffolding proteins, PICK1 and PSD-95, are genetically linked to obesity and that pharmacological targeting of their PDZ domains represents a promising therapeutic avenue for sustained weight loss.

Discussion on the mechanism of Danggui Sini decoction in treating diabetic foot based on network pharmacology and molecular docking and verification of the curative effect by meta-analysis

Objective

The main active components and mechanism of Danggui Sini decoction (DSD) in treating diabetic foot (DF) were studied and verified by network pharmacology and molecular docking. Evidence-based medicine was used to prove its efficacy.

Methods

The TCMSP systematic pharmacology platform screened out DSD's practical components and targets-screening disease targets in GeneCards database, using Cytoscape 3.7.2 to draw DSD-active ingredient-target network diagram, and drawing the protein interaction network diagram through STRING database. The Metascape platform was used to analyze the GO function enrichment and KEGG signal pathway. The molecular docking experiment was carried out by using Auto Dock vina 4.2. The related literature on DSD in treating DF in China Zhiwang, Wanfang, Weipu, and China Biomedical Literature Database was searched. The literature was screened, data was extracted, and quality was evaluated according to the inclusion and exclusion criteria. Then, a meta-analysis was performed using RevMan 5.3 software.

Results

A total of 256 targets of all effective components of DSD were obtained. Among 1,272 disease targets, there are 113 common targets. The GO analysis received 6,179 entries, and the KEGG pathway enrichment analysis found 251 related pathways. The molecular docking results of the main targets of diabetic foot and the active substances of DSD all showed a high docking activity. The meta-analysis included six literature, all of which were randomized controlled experiments. The quality grade of the literature was C, and the results showed that the total effective rate of clinical efficacy in the experimental group was significantly higher than that in the control group.

Conclusions

DSD may treat DF by participating in biological processes such as cell proliferation regulation, inflammatory reaction, oxidative stress reaction, and promotion of angiogenesis. DSD treats DF through AKT1, TP53, IL6, TNF, VEGFA, and other targets. DSD plays a role in treating DF mainly through the AGE-RAGE signaling pathway and PI3K-AKT signaling pathway. The molecular docking results of AKT1, TP53, IL-6, TNF, and VEGFA with the active substances of DSD show that they all have a high docking activity; among them, VEGFA has a higher docking activity. Compared with conventional treatment, DSD has a high effective rate, short wound healing time, large wound healing area, and high ABI index.

Hispidin Inhibits Ferroptosis Induced by High Glucose via the miR-15b-5p/GLS2 Axis in Pancreatic Beta Cells

Type 2 diabetes mellitus (T2DM) is a global health issue that lacks effective treatments. Dysfunction and/or death of pancreatic β-cells (PBCs) are considered a major cause of T2DM. Therefore, elucidating the mechanisms underlying the death of PBCs might be helpful to develop novel strategies to treat T2DM. Ferroptosis is a newly identified form of cell death that has distinct features. However, knowledge regarding the role of ferroptosis in the death of PBCs remains limited. In the current study, we used high glucose (10 mM) (HG) levels to induce ferroptosis in PBC. We also observed that hispidin, a polyphenol compound that can be isolated from Phellinus linteus, could attenuate ferroptosis induced by HG in PBCs. Mechanistic investigations showed that hispidin led to the upregulation of miR-15b-5p, which directly inhibits the expression of glutaminase (GLS2) which plays an essential role in the glutamine metabolism. In addition, we found that overexpression of GLS2 could abrogate the protective effect of hispidin against ferroptosis caused by HG in PBCs. Therefore, our study provides novel insights into the mechanisms that regulate the death of PBCs.

Older postmenopausal women with lower lean mass have hypermethylated sites in the PI3K-Akt pathway

Introduction: The decrease in lean mass is directly related to the loss of independence, muscle strength, and worse quality of life over the years. Although the genetic determinants of muscle mass were well recognized, recent literature has been uncovering new epigenetic factors affecting the state of muscular tissue. This study aimed to verify differences in the DNA methylation profile among Brazilian postmenopausal women aged 50-70 years according to the lean mass evaluation. Methods: A cross-sectional study comprised 40 women aged 50-70 years. After K-means cluster analysis the 40 participants were divided into two groups, the Lower Lean Mass group with 20 participants (61.1 ± 4.6 years) and the Higher Lean Mass group with 20 participants (60.7 ± 3.2 years). Lean mass was measured by dual-energy X-ray emission densitometry (DEXA). The participants' DNA was extracted using the Salting Out technique and subsequently, the Illumina 850k EPIC Infinium Methylation BeadChip was performed to obtain methylation data. Results: We obtained 1,913 differentially methylated sites (p ≤ 0.005 of β > 5% and β < -5%) in a total of 979 genes between groups (p ≤ 0.005; -5% > β > 5%). In addition, the PI3K-Akt pathway had the greatest power of significance with an FDR of 4.6 × 10^-3. Conclusion: Our results demonstrate a differentiation between specific sites of different genes, which have essential functions in body composition and energy metabolism, supporting future studies that aim to relate lean mass with epigenetics.

Aberrant messenger RNA expression in peripheral blood mononuclear cells is associated with gouty arthritis

AIM

Gouty arthritis (GA) is a type of self-limiting inflammatory arthritis caused by deposition of monosodium urate (MSU). This study aimed to analyze the expression variation of messenger RNAs (mRNAs) in GA patients and investigated the role of mRNAs in GA pathogenesis.

METHODS

Five patients with acute GA (AGA), 5 with non-acute GA (NAGA), and 5 healthy controls (HC) were recruited to examine differential mRNA expression profiles in peripheral blood mononuclear cells (PBMCs) and explore whether mRNA is involved in the pathogenesis of AGA. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used to study the biological functions of differentially expressed mRNA and the relationship between genes and signal pathways.

RESULTS

Compared with HC, the AGA group had 1456 differentially expressed mRNAs, while the NAGA group had 437 differentially expressed mRNAs and compared with the NAGA group, 115 differentially expressed mRNAs were found in the AGA group. GO analysis showed that the differentially expressed mRNA in the AGA group was mainly enriched in processes related to leukocyte activation and immune response, while KEGG analysis showed that "Staphylococcus aureus infection" and "Cytokine-cytokine receptor interaction" are enriched in the up-regulated mRNAs in the AGA group.

CONCLUSION

This study identified genes and pathways that are differentially expressed during the onset of AGA, which might reveal part of the pathogenesis of the disease and provide clues to explaining the severe pain associated with disease onset and the rapid development of inflammatory response that subsides by itself.

Targeting the PI3K/Akt signaling pathway in pancreatic β-cells to enhance their survival and function: An emerging therapeutic strategy for type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of the insulin-producing β-cells within the pancreas. Islet transplantation represents one cure; however, during islet preparation and post transplantation significant amounts of β-cell death occur. Therefore, prevention and cure of T1D is dependent upon the preservation of β-cell function and the prevention of β-cell death. Phosphoinositide 3-kinase (PI3K)/Akt signaling represents a promising therapeutic target for T1D due to its pronounced effects on cellular survival, proliferation, and metabolism. A growing amount of evidence indicates that PI3K/Akt signaling is a critical determinant of β-cell mass and function. Modulation of the PI3K/Akt pathway, directly (via the use of highly specific protein and peptide-based biologics, excretory/secretory products of parasitic worms, and complex constituents of plant extracts) or indirectly (through microRNA interactions) can regulate the β-cell processes to ultimately determine the fate of β-cell mass. An important consideration is the identification of the specific PI3K/Akt pathway modulators that enhance β-cell function and prevent β-cell death without inducing excessive β-cell proliferation, which may carry carcinogenic side effects. Among potential PI3K/Akt pathway agonists, we have identified a novel parasite-derived protein, termed FhHDM-1 (Fasciola hepatica helminth defense molecule 1), which efficiently stimulates the PI3K/Akt pathway in β-cells to enhance function and prevent death without concomitantly inducing proliferation unlike several other identified stimulators of PI3K/Akt signaling . As such, FhHDM-1 will inform the design of biologics aimed at targeting the PI3K/Akt pathway to prevent/ameliorate not only T1D but also T2D, which is now widely recognized as an inflammatory disease characterized by β-cell dysfunction and death. This review will explore the modulation of the PI3K/Akt signaling pathway as a novel strategy to enhance β-cell function and survival.

hMSCs Migrate under the Chemotaxis of CXCL-13 and Enhance Islet B Cell Activity through p-AKT Signaling Pathway in High-Glucose Environment

As a common clinical chronic disease, the incidence of diabetes is increasing year by year. According to the latest statistics from the International Diabetes Federation, as of 2019, the global prevalence of diabetes has reached 8.3%. This study aims to investigate the effect of CXCL-13 on the migration ability of human mesenchymal stem cells (hMSCs) and to clarify the specific molecular mechanism of the protective effect of hMSCs on islet B cells. The hMSCs were cultured in high-glucose environment, and the effect of CXCL-13 on the migration ability of hMSCs was determined by Transwell experiment. After coculture of hMSCs and islet B cells, the activity of cells was detected by CCK8 assay, the expression of Ki-67 in cells was detected by RT-PCR, and the expression of P53 was detected by Western blot to investigate the effect of hMSCs on the proliferation and apoptosis of islet B cells. The effect of hMSCs on the function of islet B cells was determined by glucose stimulated insulin secretion experiment. Transwell experiment results showed that CXCL-13 could promote the migration of hMSCs to islet B cells in high-glucose environment. The results of CCK-8 showed that the cell activity in the coculture group was significantly higher than that of the other groups, and RT-PCR showed that the expression of Ki-67 was significantly increased in the coculture group of hMSCs and islet B cells. The results of Western blot showed that the expression of P53 was significantly decreased in the coculture group, and the glucose stimulated insulin secretion test showed that insulin secretion was significantly increased. It was found that after the inhibition of ATK, cell activity was significantly reduced, and apoptosis was significantly increased. Meanwhile, the expression of Ki-67 was inhibited, the expression of P-53 was significantly increased, and insulin secretion was significantly reduced. To sum up, in a high-glucose environment, CXCL-13 effectively promoted the migration of hMSCs, and hMSCs protected the activity and function of islet B cells through Akt signaling pathway.

Molecular study of the proliferation process of beta cells derived from pluripotent stem cells

BACKGROUND

Diabetes mellitus (DM) is a chronic metabolic disorder, increasing in the number of patients and poses a severe threat to human health. Significant advances have been made in DM treatment; the most important of which is differentiation and proliferation of beta cells from IPSCs.

METHODS

Data were collected from PUBMED at various time points up to the academic year of 2020. The related keywords are listed as follows: "Induced pluripotent stem cell", "Proliferation", "Growth factor", "Small molecule", "cardiotoxicity" and "Scaffold."

RESULT

The use of growth factors along with small molecules can be a good strategy for beta-cell proliferation. Also, proliferation of beta cells on nanofibers scaffolds can create a similar in vivo environment, that leads to increased function of beta-cell. Some transcription factors that cause beta cells proliferation play an important role in inflammation; so, it is essential to monitor them to prevent inflammation.

CONCLUSION

Finally, the simultaneous use of growth factors, micronutrients and scaffolds can be an excellent strategy to increase the proliferation and function of beta cells derived from IPSCs.

MicroRNA-139-5p Alleviates High Glucose-Triggered Human Retinal Pigment Epithelial Cell Injury by Targeting LIM-Only Factor 4

Diabetic retinopathy (DR) is a type of diabetes complication, which can result in loss of vision in adults worldwide. Increasing evidence has revealed that microRNAs (miRs) can regulate DR progression. Thus, the present study was aimed at assessing the possible mechanism of miR-139-5p in high glucose- (HG-) incubated retinal pigment epithelial (ARPE-19) cells. The present results demonstrated that miR-139-5p expression was notably reduced in the serum samples of patients with DR, as well as in ARPE-19 cells treated with HG in a time-dependent manner. Moreover, miR-139-5p was markedly overexpressed by transfection of miR-139-5p mimics into ARPE-19 cells. Overexpression of miR-139-5p markedly induced cell viability and repressed HG-triggered apoptosis. Furthermore, overexpression of miR-139-5p relived HG-enhanced oxidative stress injury. It was found that HG induced malondialdehyde levels but decreased superoxide dismutase and glutathione peroxidase activities in ARPE-19 cells. In addition, overexpression of miR-139-5p could markedly decrease intracellular stress. The results demonstrated that overexpression of miR-139-5p effectively repressed HG-activated inflammation, as indicated by the upregulation of inflammation cytokines, including TNF-α, IL-6, and Cox-2, in ARPE-19 cells. Subsequently, it was identified that LIM-only factor 4 (LMO4) could act as a downstream target for miR-139-5p. LMO4 expression was significantly increased in patients with DR and HG-treated ARPE-19 cells. Mechanistically, knockdown of LMO4 reversed the biological role of miR-139-5p in proliferation, apoptosis, oxidative stress, and release of inflammation factors in vitro. Collectively, these results suggested that miR-139-5p significantly decreased ARPE-19 cell injury caused by HG by inducing proliferation and suppressing cell apoptosis, oxidant stress, and inflammation by modulating LMO4.

miR-139-5p mediates the palmitate-induced inhibition of insulin secretion by targeting neuronal pentraxin 1 in INS-1 cells

High fatty acid reduces insulin secretion in pancreatic β-cells and miR-139-5p is increased in diabetic pancreatic tissues and induces islet β-cell apoptosis. However, to date, there is no study exploring whether or not miR-139-5p is involved in high fatty acid-induced insulin secretion. In the present study, INS-1 cells were exposed to different concentrations (0.1, 0.2, and 0.4 mM) of palmitate for different time periods (12, 24, and 48 h). The expression levels of miR-139-5p and neuronal pentraxin 1 (NPTX1) were evaluated by real-time PCR and western blot analysis. The regulation of NPTX1 by miR-139-5p was examined by luciferase assay. Cell transfection was conducted using Lipo8000 or Lipofectamine RNAiMAX. Potassium or glucose-stimulated insulin secretion levels were used to verify the function of miR-139-5p or NPTX1 in insulin secretion. Insulin secretion levels were detected by radioimmunoassay. We found that miR-139-5p was increased in INS-1 cells stimulated with palmitate. In addition, miR-139-5p was also elevated in islets of high-fat diet-fed mice and db/db mice compared to those in islets of normal diet-fed mice and wild-type mice. Knockdown of miR-139-5p could reverse high fatty acid-induced insulin secretion defects in INS-1 cells. Furthermore, we demonstrated that NPTX1 is a target of miR-139-5p. miR-139-5p mediated palmitate-induced insulin secretion defects by targeting NPTX1. Moreover, palmitate treatment declined the expression of NPTX1 and the NPTX1 expression was also decreased in islets of high-fat diet-fed mice and db/db mice. Impaired NPTX1 expression is involved in fatty acid-induced insulin secretion defects. Collectively, our results illustrate that the induction of β-cell insulin secretion defects by fatty acids is mediated, at least in part, by miR-139-5p via downregulation of NPTX1 expression.

miR-139-5p promotes neovascularization in diabetic retinopathy by regulating the phosphatase and tensin homolog

Pathological retinal neovascularization is a driver of the progression of diabetic retinopathy (DR). The present study sought to identify the microRNAs (miRNAs) that are differentially expressed during the progression of DR as well as to explore the specific regulatory mechanism of those miRNAs in retinal neovascularization. Using a microarray data set and a diabetic mouse model, it was determined that miR-139-5p was significantly upregulated during the progression of DR. The in vitro investigation revealed an elevation in the miR-139-5p level in both the high glucose (HG)-treated mouse retinal microvascular endothelial cells (mRMECs) and the HG-treated human RMECs (hRMECs). The miR-139-5p overexpression elevated cell migration, facilitated tube formation, and increased vascular endothelial growth factor (VEGF) protein level in the hRMECs. While the angiogenic effect of miR-139-5p overexpression was halted by an anti-VEGF antibody. Meanwhile, the miR-139-5p knockdown eliminated the VEGF-induced cell migration and tube formation in the hRMECs. The phosphatase and tensin homolog (PTEN) was the target gene of the miR-139-5p. PTEN overexpression removed the angiogenic effect of miR-139-5p overexpression, which led to reduced cell migration and tube formation. In the diabetic mice, the miR-139-5p antagomir effectively decreased the acellular capillaries and suppressed the formation of aberrant blood vessels in the retinal tissues. Taken together, miR-139-5p promotes retinal neovascularization by repressing PTEN expression.