The Key Role of Akt Protein Kinase in Metabolic-Inflammatory Pathways Cross-Talk: TNF-α Down-Regulation and Improving of Insulin Resistance in HepG2 Cell Line

Low-intensity Pulsed Ultrasound Stimulation of the Intestine Improves Insulin Resistance in Type 2 Diabetes

OBJECTIVE

Ultrasound stimulation of internal organs and peripheral nerves has demonstrated promising potential in regulating blood glucose metabolism. This study aims to assess the effectiveness of low-intensity pulsed ultrasound stimulation (LIPUS) on intestine in improving insulin resistance with type 2 diabetes mellitus (T2DM).

METHODS

C57BL/6J mice, both normal and T2DM, were randomly divided into three groups: Control, T2D-sham, and T2D-LIPUS. The T2D-LIPUS group received LIPUS stimulation in the intestine. The parameters were as follows: 1 MHz frequency, 1.0 kHz pulse repetition frequency (PRF), 20% duty cycle, 100 mW/cm² intensity spatial average temporal average (ISATA), for 20 minutes per session, five days per week, over four weeks.

RESULTS

Blood glucose analysis indicated that mice in the T2D-LIPUS group displayed significantly lower area under the curve (AUC) of glucose tolerance tests (GTT) and insulin tolerance tests (ITT) (p < 0.001), HOMA-IR (p < 0.001), and fasting serum insulin levels (p < 0.01) compared to the T2D-sham group. LIPUS treatment effectively lowered serum levels of IL-1β (p < 0.001) and TNF-α (p < 0.01) along with mRNA expression levels of IL-1β (p < 0.01) and IL-18 (p < 0.001) in the intestines of T2DM mice. Additionally, Western blot analysis revealed a reduction in the protein levels of NLRP3, caspase-1, and GSDMD-N in the intestinal tissues of mice treated with LIPUS.

CONCLUSION

These findings suggest that LIPUS can reduce inflammation and cellular apoptosis, while improving insulin resistance by inhibiting the NLRP3/Caspase-1/GSDMD signaling pathway. This research introduces a novel, non-pharmacological approach for managing T2DM.

The reciprocal effects of autophagy and the Warburg effect in pancreatic ductal adenocarcinoma: an in vitro study

Autophagy and the Warburg effect are two common pathways in pancreatic ductal adenocarcinoma (PDAC). To date, the reciprocal effects of these pathways have not yet been elucidated. Therefore, this study was designed to investigate the relationship between these factors in vitro and may provide therapeutic targets in the future. The Mia-Paca-2 and AsPc-1 cell lines were cultured under normal conditions. To achieve autophagy, starvation was induced by Hank's balanced salt solution (HBSS), whereas autophagy was inhibited by 3-methyladenine (3-MA). The Warburg effect is mimicked by lactic acid, and the Warburg effect is inhibited by oxamate, the main inhibitor of lactate dehydrogenase. Cell viability was checked through the MTT assay method. Autophagy was checked via evaluation of Beclin-1 via western blotting. The amount of lactic acid was also measured with a lactate dehydrogenase (LDH) assay kit. The cells were incubated with different concentrations of 3-MA, lactic acid and oxamate. The viability of AsPc-1 cells decreased, and the IC50 values were 1195 µM, 23.06 mM and 8.617 mM for 3-MA, lactic acid and oxamate, respectively. Similarly, the IC50 values of Mia-Paca-2 were 873.9 µM, 35.9 mM and 26.74 mM for 3-MA, lactic acid and oxamate, respectively. Our data revealed that starvation increased the expression of the autophagy-related protein Beclin-1 (P value < 0.05); however, 3-MA significantly reduced its expression (P value < 0.05). In addition, lactic acid alone did not affect the expression level of Beclin-1 (P value > 0.05), but oxamate treatment increased its expression (P value < 0.05). We also showed that starvation reduced lactic acid levels, but an autophagy inhibitor, 3MA, significantly increased lactic acid production (P value < 0.05). Our findings showed that lactic acid alone has no significant effect on autophagy and that oxamate induces autophagy, possibly because of caloric restriction. On the other hand, autophagy inhibits lactic acid production, whereas the inhibition of autophagy leads to increased lactic acid production.

Research progress on the potential correlation between polycystic ovary syndrome and periodontal disease

Over the past few years, the correlation between periodontal disease (PD) and polycystic ovary syndrome (PCOS) has attracted widespread attention owing to the increased incidence of these diseases. Several studies have suggested a possible link between the two. In this narrative review, we examined the epidemiology, common risk factors, and pathological mechanisms of PCOS and PD to investigate the potential association between these diseases. Evidence from the literature indicates that PCOS and PD can interact with each other. Common risk factors, such as microbial homeostasis imbalance owing to dysbiosis, along with multiple hormone and inflammatory mediators, as well as inflammatory responses owing to oxidative stress and oxidative responses owing to ferroptosis, are all associated with the pathogenesis of both diseases. Further studies are needed to clarify the specific mechanisms of interaction between PCOS and PD, which could clarify future directions in disease management and combined multidisciplinary treatment.

SIRT1 activation attenuates palmitate induced apoptosis in C2C12 muscle cells

BACKGROUND

Type 2 diabetes is characterized by insulin resistance, which manifests mainly in skeletal muscles. SIRT1 has been found to play a role in the insulin signaling pathway. However, the molecular underpinnings of SIRT1's function in palmitate fatty acid-induced apoptosis still need to be better understood.

METHODS

In this research, skeletal muscle cells are treated with palmitate to be insulin resistant. It is approached that SIRT1 is downregulated in C2C12 muscle cells during palmitate-induced apoptosis and that activating SIRT1 mitigates this effect.

RESULTS

Based on these findings, palmitate-induced apoptosis suppressed mitochondrial biogenesis by lowering PGC-1 expression, while SIRT1 overexpression boosted. The SIRT1 inhibitor sirtinol, on the other hand, decreased mitochondrial biogenesis under the same conditions. This research also shows that ROS levels rise in the conditions necessary for apoptosis induction by palmitate, and ROS inhibitors can mitigate this effect. This work demonstrated that lowering ROS levels by boosting SIRT1 expression inhibited apoptotic induction in skeletal muscle cells.

CONCLUSION

This study's findings suggested that SIRT1 can improve insulin resistance in type 2 diabetes by slowing the rate of lipo-apoptosis and boosting mitochondrial biogenesis, among other benefits.

Hub genes, key miRNAs and interaction analyses in type 2 diabetes mellitus: an integrative in silico approach

Diabetes is a rising global metabolic disorder and leads to long-term consequences. As a multifactorial disease, the gene-associated mechanisms are important to know. This study applied a bioinformatics approach to explore the molecular underpinning of type 2 diabetes mellitus through differential gene expression analysis. We used microarray datasets GSE16415 and GSE29226 to identify differentially expressed genes between type 2 diabetes and normal samples using R software. Following that, using the STRING database, the protein-protein interaction network was constructed and further analyzed by Cytoscape software. The EnrichR database was used for Gene Ontology and pathway enrichment analysis to explore key pathways and functional annotations of hub genes. We also used miRTarBase and TargetScan databases to predict miRNAs targeting hub genes. We identified 21 hub genes in type 2 diabetes, some showing more significant changes in the PPI network. Our results revealed that GLUL, SLC32A1, PC, MAPK10, MAPT, and POSTN genes are more important in the PPI network and can be experimentally investigated as therapeutic targets. Hsa-miR-492 and hsa-miR-16-5p are suggested for diagnosis and prognosis by targeting GLUL, SLC32A1, PC, MAPK10, and MAPT genes involved in the insulin signaling pathway. Insight: Type 2 diabetes, as a rising global and multifactorial disorder, is important to know the gene-associated mechanisms. In an integrative bioinformatics analysis, we integrated different finding datasets to put together and find valuable diagnostic and prognostic hub genes and miRNAs. In contrast, genes, RNAs, and enzymes interact systematically in pathways. Using multiple databases and software, we identified differential expression between hub genes of diabetes and normal samples. We explored different protein-protein interaction networks, gene ontology, key pathway analysis, and predicted miRNAs that target hub genes. This study reported 21 significant hub genes and some miRNAs in the insulin signaling pathway for innovative and potential diagnostic and therapeutic purposes.

Recent Advances in the Treatment of Insulin Resistance Targeting Molecular and Metabolic Pathways: Fighting a Losing Battle?

Diabetes Mellitus (DM) is amongst the most notable causes of years of life lost worldwide and its prevalence increases perpetually. The disease is characterized as multisystemic dysfunctions attributed to hyperglycemia resulting directly from insulin resistance (IR), inadequate insulin secretion, or enormous glucagon secretion. Insulin is a highly anabolic peptide hormone that regulates blood glucose levels by hastening cellular glucose uptake as well as controlling carbohydrate, protein, and lipid metabolism. In the course of Type 2 Diabetes Mellitus (T2DM), which accounts for nearly 90% of all cases of diabetes, the insulin response is inadequate, and this condition is defined as Insulin Resistance. IR sequela include, but are not limited to, hyperglycemia, cardiovascular system impairment, chronic inflammation, disbalance in oxidative stress status, and metabolic syndrome occurrence. Despite the substantial progress in understanding the molecular and metabolic pathways accounting for injurious effects of IR towards multiple body organs, IR still is recognized as a ferocious enigma. The number of widely available therapeutic approaches is growing, however, the demand for precise, safe, and effective therapy is also increasing. A literature search was carried out using the MEDLINE/PubMed, Google Scholar, SCOPUS and Clinical Trials Registry databases with a combination of keywords and MeSH terms, and papers published from February 2021 to March 2022 were selected as recently published papers. This review paper aims to provide critical, concise, but comprehensive insights into the advances in the treatment of IR that were achieved in the last months.

Analysis of WDFY4 rs7097397 and PHLDB1 rs7389 polymorphisms in Chinese patients with systemic lupus erythematosus

OBJECTIVES

To explore the relationship among patient-specific SNPs from one SLE family, lupus susceptibility, and laboratory indicators in a western Chinese population.

METHODS

We previously performed whole exome sequencing in one SLE family and screened 5 SLE candidate SNPs. In this study, we verified them in 634 SLE patients and 400 healthy controls and analyzed the relationship between SNPs and laboratory indicators.

RESULTS

Among the 5 candidate SNPs, PHLDB1 rs7389T/G (dominant model, OR = 0.627, 95%CI = 0.480-0.820, P = 0.001) and WDFY4 rs7097397G/A (dominant model, OR = 0.653, 95%CI = 0.438-0.973, P = 0.035) were associated with SLE susceptibility. In addition, the G allele of rs7389 was related to an increased level of TNF-α (q = 0.013). The A allele of rs7097397 was related to reduced levels of IL-1β (q = 0.033) and IL-6 (q = 0.039) and high positive rate of antinuclear antibodies (q = 0.021).

CONCLUSIONS

Our study indicated that both the rs7389T/G and rs7097397G/A polymorphisms were related to SLE susceptibility in western China. rs7389T/G was related to increased TNF-α content, while rs7097397G/A was associated with reduced IL-1β and IL-6 content and increased antinuclear antibody positive rate. Key Points • The G allele of rs7389 was related to reduced susceptibility to SLE. • The A allele of rs7097397 was associated with reduced susceptibility to SLE. • The G allele of rs7389 was related to increased levels of TNF-α. • The A allele of rs7097397 was related to decreased concentrations of IL-1β and IL-6, as well as an increased positive rate of antinuclear antibody.

Pseudo-ginsenoside Rh2 Induces Protective Autophagy in Hepatocellular Carcinoma HepG2 Cells

BACKGROUND

Pseudo-ginsenoside-Rh2 (pseudo-G-Rh2), a novel derivative of ginsenoside Rh2, is reported to exert a pro-apoptotic effect on various malignancies. However, whether this anti-cancer action of pseudo-G-Rh2 involves autophagy remains to be determined and explored.

OBJECTIVES

Investigation of pseudo-G-Rh2-induced apoptosis and autophagy and the underlying mechanism.

METHODS

In the present study, the MTT assay was used for evaluating cell viability and the lactate dehydrogenase (LDH) assay was performed to assess cell toxicity. Autophagy evaluation was performed using monodansylcadaverine (MDC) staining and transmission electron microscopy (TEM). The levels of autophagy-associated and apoptosis-associated proteins were determined using Western blotting. The Annexin V FITC/propidium iodide (PI) assay was used to assess apoptosis.

RESULTS

The Annexin V FITC/PI assay revealed that the percentage of apoptotic cells in HepG2 cells at concentrations 0, 20, 40, and 60 μM was 3.75%±1.37%, 5.70%±1.04%, 12.30%±2.10%, and 34.26%±4.73%, respectively. Pseudo-G-Rh2 was observed to significantly increase the expressions of BAX, cleaved-caspase-3, and cleaved-caspase-9, while it decreased the Bcl-2 expression. MDC and TEM analyses revealed that pseudo-G-Rh2 at concentrations 20, 40, and 60 μM significantly facilitated the accumulation of autophagosomes and autolysosomes within the HepG2 cells. Moreover, pseudo-G-Rh2 significantly increased the expressions of LC3 Ⅱ/LC3 Ⅰ, and Beclin-1 and decreased the expression of p62. The Annexin V FITC/PI assay also revealed that in comparison to the pseudo-G-Rh2 group, the concurrent treatment with pseudo-G-Rh2 and an autophagy inhibitor (CQ or 3-MA) significantly induced distinct apoptosis. In addition, pseudo-G-Rh2 activated AMPK and inhibited the PI3K/Akt/mTOR pathway in a concentration-dependent manner. Pseudo-G-Rh2 is similar to the current patents, which enhanced its anti-cancer activity by combining with autophagy inhibitors.

CONCLUSION

Pseudo-G-Rh2 could induce protective autophagy in HepG2 cells, at least in part, via AMPK and the PI3K/Akt/mTOR pathway.