PAR2 promotes impaired glucose uptake and insulin resistance in NAFLD through GLUT2 and Akt interference

Birthweight influences liver structure, function and disease risk: Evidence of a causal association

AIM

Low birthweight is an issue during pregnancy associated with an increased risk of developing liver disease later in life. Previous Mendelian randomisation (MR) studies which explored this issue have not isolated the direct impact of the foetus on birthweight. In the present study, MR was used to assess whether direct foetal effects on birthweight were causally associated with liver structure, function and disease risk independent of intrauterine effects.

MATERIALS AND METHODS

We extracted single nucleotide polymorphisms (SNPs) from genome-wide association studies (GWAS) about direct foetal-affected birthweight (321 223 cases) to conduct univariable and multivariable MR analyses to explore the relationships between birthweight and 4 liver structure measures, 9 liver function measures and 18 liver diseases. A two-step MR analysis was used to further assess and quantify the mediating effects of the mediators.

RESULTS

When isolating direct foetal effects, genetically predicted lower birthweight was associated with a higher risk of non-alcoholic fatty liver disease (NAFLD) (odds ratios [OR], 95% confidence interval [CI]: 1.61, 1.29-2.02, p < 0.001), higher magnetic resonance imaging [MRI] proton density fat fraction (PDFF) and higher serum gamma glutamyltransferase (GGT). Two-step MR identified two candidate mediators that partially mediate the direct foetal effect of lower birthweight on NAFLD, including fasting insulin (proportion mediated: 22.29%) and triglycerides (6.50%).

CONCLUSIONS

Our MR analysis reveals a direct causal association between lower birthweight and liver MRI PDFF, as well as the development of NAFLD, which persisted even after accounting for the potential influence of maternal factors. In addition, we identified fasting insulin and triglycerides as mediators linking birthweight and hepatic outcomes, providing insights for early clinical interventions.

Linagliptin's impact on lymphatic barrier and lymphangiogenesis in oral cancer with high glucose

OBJECTIVES

Uncertainties remain regarding the effect of elevated glucose levels on lymphatic metastasis of cancer cells. Our study elucidated the mechanisms linking high glucose to lymphangiogenesis and lymphatic barrier-related factors and investigated the protective role of linagliptin against lymphatic barrier dysfunction.

MATERIALS AND METHODS

A CAL-27-LEC co-culture system was established. Sodium fluorescein permeability assay observed lymphatic endothelial cell permeability. Western blotting and RT-qPCR detected protein and mRNA expression under different conditions, respectively. CCK-8, scratch wound healing, and transwell assays revealed cell migration and proliferation. Tube formation experiment tested capacity for endothelial tube formation. Immunohistochemical staining analyzed tissue sections from 43 oral cancer individuals with/without diabetes.

RESULTS

In high-glucose co-culture system, we observed increased lymphatic barrier permeability and decreased expression of ZO-1 and occludin, two tight-junction proteins; conversely, the expression of PAR2, a high permeability-related protein, was increased. Following linagliptin treatment, the expression levels of VEGF-C, VEGFR-3, and PAR2 decreased, while those of ZO-1 and occludin increased. Considerably higher levels of LYVE-1 expression in individuals with diabetes than in those without diabetes.

CONCLUSIONS

By ameliorating the high glucose-induced disruption of the lymphatic endothelial barrier, linagliptin may reduce lymphangiogenesis and exhibit an inhibitory effect on lymphatic metastasis in oral cancer patients with diabetes.

Multi-omics joint analysis reveals that the Miao medicine Yindanxinnaotong formula attenuates non-alcoholic fatty liver disease

BACKGROUD

Non-alcoholic fatty liver disease (NAFLD) is a growing chronic liver disease worldwide, and no effective agent is approved yet for this condition. Traditional Chinese Medicine (TCM), which has been practiced for thousands of years in China and other Asian countries, is considered an important source for identifying novel medicines for various diseases. Miao medicine Yindanxinnaotong formula (YDX) is a classical TCM for the treatment of hyperlipidemia disease by reducing blood lipid content, while the role of YDX have not been clarified in NAFLD.

PURPOSE

To investigate the protective effect of YDX on NAFLD in mice induced by high fat diet (HFD) and clarify the potential mechanism.

METHODS

NAFLD mice model was constructed by receiving HFD for 10-week period with or without YDX administration. Lipid profiles, biochemical indicators, and histopathological staining were performed to evaluate the extent of hepatic lipid accumulation and hepatic steatosis. 16S rRNA sequencing was used to determine the gut microbial composition. Serum metabolomics was further used to investigate the changes in plasma biomarkers for NAFLD-associated by UPLC-Q-TOF/MS analysis. Subsequently, liver transcriptomics was employed to identify differentially expressed genes and explore regulatory pathways. Then, lipid metabolism-related proteins and inflammation factors were examined by Western blot and ELISA.

RESULTS

YDX reduced body weight gain, liver index and inflammatory cytokines levels, along with improved hepatic steatosis, serum lipid profile, sensitivity to insulin and also tolerance to glucose, and enhanced oxidative defense system in HFD-induced mice. Also, YDX remarkedly affected gut microbiota diversity and community richness and decreased the ratio of Firmicutes/Bacteroidetes. Meanwhile, YDX also reduced the production of harmful lipid metabolites in the sera of NAFLD mice, such as LPC(18:0), LPC(18:1) and carnitine. Notably, consistent with liver transcriptomics results, YDX downregulated the expression of proteins implicated in de novo lipid synthesis (Srebp-1c, Acaca, Fasn, Scd-1, and Cd36) and pro-inflammatory cytokines (IL-6 and TNF-α), and increased the expression of proteins-related fatty acid β-oxidation (Ampkα, Ppar-α, and Cpt-1) in the liver by activating Ampk pathway.

CONCLUSION

YDX is promisingly an effective therapy for preventing NAFLD by modulating the Ampk pathway, inhibiting gut microbiota disorder, and reducing the production of harmful lipid metabolites.

Identification of novel targets associated with cholesterol metabolism in nonalcoholic fatty liver disease: a comprehensive study using Mendelian randomization combined with transcriptome analysis

Background

There is limited research on cholesterol metabolism-related genes (CM-RGs) in non-alcoholic fatty liver disease (NAFLD), despite hypercholesterolemia being a recognized risk factor. The role of CM-RGs in NAFLD remains unclear.

Methods

The differentially expressed genes (DEGs) between NAFLD and control were acquired by differential expression analysis. The differentially expressed genes associated with cholesterol metabolism (DE-CM-RGs) were identified and functional enrichment analyses were performed. Protein-protein interaction network analysis and a two-sample Mendelian randomization study were utilized for identifying hub genes. Nomogram model, competing endogenous RNA and messenger RNA-drug networks were established. In addition, immunoinfiltration analysis was performed.

Results

We identified four hub genes (MVK, HMGCS1, TM7SF2, and FDPS) linked to NAFLD risk. MVK and TM7SF2 were protective factors, HMGCS1 and FDPS were risk factors for NAFLD. The area under the curve values of nomograms in GSE135251 and GSE126848 were 0.79 and 0.848, respectively. The gene set enrichment analysis indicated that hub genes participated in calcium signaling pathways and biosynthesis of unsaturated fatty acids. NAFLD patients showed increased CD56dim NK cells and Th17. Tretinoin, alendronate, zoledronic acid, and quercetin are potential target agents in NAFLD.

Conclusion

Our study has linked cholesterol metabolism genes (MVK, HMGCS1, TM7SF2, and FDPS) to NAFLD, providing a promising diagnostic framework, identifying treatment targets, and offering novel perspectives into its mechanisms.

Endogenous electric field coupling Mxene sponge for diabetic wound management: haemostatic, antibacterial, and healing

Improper management of diabetic wound effusion and disruption of the endogenous electric field can lead to passive healing of damaged tissue, affecting the process of tissue cascade repair. This study developed an extracellular matrix sponge scaffold (K1P6@Mxene) by incorporating Mxene into an acellular dermal stroma-hydroxypropyl chitosan interpenetrating network structure. This scaffold is designed to couple with the endogenous electric field and promote precise tissue remodelling in diabetic wounds. The fibrous structure of the sponge closely resembles that of a natural extracellular matrix, providing a conducive microenvironment for cells to adhere grow, and exchange oxygen. Additionally, the inclusion of Mxene enhances antibacterial activity(98.89%) and electrical conductivity within the scaffold. Simultaneously, K1P6@Mxene exhibits excellent water absorption (39 times) and porosity (91%). It actively interacts with the endogenous electric field to guide cell migration and growth on the wound surface upon absorbing wound exudate. In in vivo experiments, the K1P6@Mxene sponge reduced the inflammatory response in diabetic wounds, increased collagen deposition and arrangement, promoted microvascular regeneration, Facilitate expedited re-epithelialization of wounds, minimize scar formation, and accelerate the healing process of diabetic wounds by 7 days. Therefore, this extracellular matrix sponge scaffold, combined with an endogenous electric field, presents an appealing approach for the comprehensive repair of diabetic wounds.

SerpinB3: A Multifaceted Player in Health and Disease-Review and Future Perspectives

SerpinB3, a member of the serine-protease inhibitor family, has emerged as a crucial player in various physiological and pathological processes. Initially identified as an oncogenic factor in squamous cell carcinomas, SerpinB3's intricate involvement extends from fibrosis progression and cancer to cell protection in acute oxidative stress conditions. This review explores the multifaceted roles of SerpinB3, focusing on its implications in fibrosis, metabolic syndrome, carcinogenesis and immune system impairment. Furthermore, its involvement in tissue protection from oxidative stress and wound healing underscores its potential as diagnostic and therapeutic tool. Recent studies have described the therapeutic potential of targeting SerpinB3 through its upstream regulators, offering novel strategies for cancer treatment development. Overall, this review underscores the importance of further research to fully elucidate the mechanisms of action of SerpinB3 and to exploit its therapeutic potential across various medical conditions.

Association of Obstructive Sleep Apnea with Nonalcoholic Fatty Liver Disease: Evidence, Mechanism, and Treatment

Obstructive sleep apnea (OSA), a common sleep-disordered breathing condition, is characterized by intermittent hypoxia (IH) and sleep fragmentation and has been implicated in the pathogenesis and severity of nonalcoholic fatty liver disease (NAFLD). Abnormal molecular changes mediated by IH, such as high expression of hypoxia-inducible factors, are reportedly involved in abnormal pathophysiological states, including insulin resistance, abnormal lipid metabolism, cell death, and inflammation, which mediate the development of NAFLD. However, the relationship between IH and NAFLD remains to be fully elucidated. In this review, we discuss the clinical correlation between OSA and NAFLD, focusing on the molecular mechanisms of IH in NAFLD progression. We meticulously summarize clinical studies evaluating the therapeutic efficacy of continuous positive airway pressure treatment for NAFLD in OSA. Additionally, we compile potential molecular biomarkers for the co-occurrence of OSA and NAFLD. Finally, we discuss the current research progress and challenges in the field of OSA and NAFLD and propose future directions and prospects.

Intermittent Fasting-Improved Glucose Homeostasis Is Not Entirely Dependent on Caloric Restriction in db/db Male Mice

Intermittent fasting (IF), which involves prolonged fasting intervals accompanied by caloric restriction (CR), is an effective dietary treatment for obesity and diabetes. Although IF offers many benefits, it is difficult to determine whether these benefits are the consequences of CR. Every-other-day feeding (EODF) is a commonly used IF research model. This study was designed to identify factors, in addition to CR, responsible for the effects of EODF and the possible underlying mechanisms. Diabetic db/db mice were divided into three groups: ad libitum (AL), meal feeding (MF), and EODF. The MF model was used to attain a level of CR comparable to that of EODF, with food distribution evenly divided between 10:00 a.m. and 6:00 p.m., thereby minimizing the fasting interval. EODF yielded greater improvements in glucose homeostasis than MF in db/db mice by reducing fasting glucose levels and enhancing glucose tolerance. However, these effects on glucose metabolism were less pronounced in lean mice. Furthermore, ubiquitination of the liver-specific glucocorticoid (GC) receptor (GR) facilitated its degradation and downregulation of Kruppel-like factor 9 (KLF9), which ultimately suppressed liver gluconeogenesis in diabetic EODF mice. Although GR and KLF9 might mediate the metabolic benefits of EODF, the potential benefits of EODF might be limited by elevated serum GC levels in diabetic EODF mice. Overall, this study suggests that the metabolic benefits of EODF in improving glucose homeostasis are independent of CR, possibly because of the downstream effects of liver-specific GR degradation.

ARTICLE HIGHLIGHTS

Pan-cancer analysis of SLC2A family genes as prognostic biomarkers and therapeutic targets

Background

The major facilitator superfamily glucose transporters (GLUTs), encoded by solute carrier 2A (SLC2A) genes, mediate the transmembrane movement and uptake of glucose. To satisfy the improved energy demands, glycolysis flux is increased in cancers compared with healthy tissues. Multiple diseases, including cancer, have been associated with GLUTs. Nevertheless, not much research has been done on the functions of SLC2As in pan-cancer prognosis or their clinical treatment potential.

Methods

The SLC2A family genes' level of expression and prognostic values were analyzed in relation to pan-cancer. We then examined the association among SLC2As expression and TME, Stemness score, clinical characteristics, immune subtypes, and drug sensitivity. We merged bioinformatics analysis techniques with up-to-date public databases. Additionally, SLC2As from the KOBAS database were subjected to enrichment analysis.

Results

We discovered that SLC2As' gene expression differed significantly between normal tissues and many malignancies. A number of tumors from various databases demonstrate a relationship between prognosis and SLC2A family gene expression. For instance, SLC2A2 and SLC2A5 were associated with the overall survival (OS) of hepatocellular carcinoma. SLC2A1 was associated with the OS of lung adenocarcinoma and pancreatic adenocarcinoma. Moreover, the SLC2A family gene expression is significantly correlated with the pan-cancer stromal and immune scores, and the RNA and DNA stemness scores. Furthermore, we found that the majority of SLC2As had a strong correlation with the tumor stages in KIRC. The immunological subtypes and all members of the SLC2A gene family exhibited a substantial correlation. Moreover, pathways containing insulin resistance and adipocytokine signaling pathway may influence the progression of some cancers. Finally, there is a significant positive or negative connection between drug sensitivity and SLC2A1 expression.

Conclusion

Our research highlights the significant promise of SLC2As as prognostic indicators and offers insightful approaches for upcoming exploration of SLC2As as putative therapeutic targets in malignancies.

Type 1 diabetes mellitus and non-alcoholic fatty liver disease: a two-sample Mendelian randomization study

Background

NAFLD (Nonalcoholic fatty liver disease) is becoming an increasingly common cause of chronic liver disease. Metabolic dysfunction, overweight/obesity, and diabetes are thought to be closely associated with increased NAFLD risk. However, few studies have focused on the mechanisms of NAFLD occurrence in T1DM.

Methods

We conducted a two-sample Mendelian randomization (MR) analysis to assess the causal association between T1DM and NAFLD with/without complications, such as coma, renal complications, ketoacidosis, neurological complications, and ophthalmic complications. Multiple Mendelian randomization methods, such as the inverse variance weighted (IVW) method, weighted median method, and MR-Egger test were performed to evaluate the causal association of T1DM and NAFLD using genome-wide association study summary data from different consortia, such as Finngen and UK biobank.

Results

We selected 37 SNPs strongly associated with NAFLD/LFC (at a significance level of p < 5 × 10-8) as instrumental variables from the Finnish database based on the T1DM phenotype (8,967 cases and 308,373 controls). We also selected 14/16 SNPs based on with or without complications. The results suggest that the genetic susceptibility of T1DM does not increase the risk of NAFLD (OR=1.005 [0.99, 1.02], IVW p=0.516, MR Egger p=0.344, Weighted median p=0.959, Weighted mode p=0.791), regardless of whether complications are present. A slight causal effect of T1DM without complications on LFC was observed (OR=1.025 [1.00, 1.03], MR Egger p=0.045). However, none of the causal relationships were significant in the IVW (p=0.317), Weighted median (p=0.076), and Weighted mode (p=0.163) methods.

Conclusion

Our study did not find conclusive evidence for a causal association between T1DM and NAFLD, although clinical observations indicate increasing abnormal transaminase prevalence and NAFLD progression in T1DM patients.

Examining the Pathogenesis of MAFLD and the Medicinal Properties of Natural Products from a Metabolic Perspective

Metabolic-associated fatty liver disease (MAFLD), characterized primarily by hepatic steatosis, has become the most prevalent liver disease worldwide, affecting approximately two-fifths of the global population. The pathogenesis of MAFLD is extremely complex, and to date, there are no approved therapeutic drugs for clinical use. Considerable evidence indicates that various metabolic disorders play a pivotal role in the progression of MAFLD, including lipids, carbohydrates, amino acids, and micronutrients. In recent years, the medicinal properties of natural products have attracted widespread attention, and numerous studies have reported their efficacy in ameliorating metabolic disorders and subsequently alleviating MAFLD. This review aims to summarize the metabolic-associated pathological mechanisms of MAFLD, as well as the natural products that regulate metabolic pathways to alleviate MAFLD.

Sinapine targeting PLCβ3 EF hands disrupts Gαq-PLCβ3 interaction and ameliorates cardiovascular diseases

BACKGROUND

The renin-angiotensin-aldosterone system (RAAS) over-activation is highly involved in cardiovascular diseases (CVDs), with the Gαq-PLCβ3 axis acting as a core node of RAAS. PLCβ3 is a potential target of CVDs, and the lack of inhibitors has limited its drug development.

PURPOSE

Sinapine (SP) is a potential leading compound for treating CVDs. Thus, we aimed to elucidate the regulation of SP towards the Gαq-PLCβ3 axis and its molecular mechanism.

STUDY DESIGN

Aldosteronism and hypertension animal models were employed to investigate SP's inhibitory effect on the abnormal activation of the RAAS through the Gαq-PLCβ3 axis. We used chemical biology methods to identify potential targets and elucidate the underlying molecular mechanisms.

METHODS

The effects of SP on aldosteronism and hypertension were evaluated using an established animal model in our laboratory. Target identification and underlying molecular mechanism research were performed using activity-based protein profiling with a bio-orthogonal click chemistry reaction and other biochemical methods.

RESULTS

SP alleviated aldosteronism and hypertension in animal models by targeting PLCβ3. The underlying mechanism for blocking the Gαq-PLCβ3 interaction involves targeting the EF hands through the Asn-260 amino acid residue. SP regulated the Gαq-PLCβ3 axis more precisely than the Gαq-GEFT or Gαq-PKCζ axis in the cardiovascular system.

CONCLUSION

SP alleviated RAAS over-activation via Gαq-PLCβ3 interaction blockade by targeting the PLCβ3 EF hands domain, which provided a novel PLC inhibitor for treating CVDs. Unlike selective Gαq inhibitors, SP reduced the risk of side effects compared to Gαq inhibitors in treating CVDs.

TF-FVIIa PAR2-β-Arrestin Signaling Sustains Organ Dysfunction in Coxsackievirus B3 Infection of Mice

BACKGROUND

Accumulating evidence implicates the activation of G-protein-coupled PARs (protease-activated receptors) by coagulation proteases in the regulation of innate immune responses.

METHODS

Using mouse models with genetic alterations of the PAR2 signaling platform, we have explored contributions of PAR2 signaling to infection with coxsackievirus B3, a single-stranded RNA virus provoking multiorgan tissue damage, including the heart.

RESULTS

We show that PAR2 activation sustains correlates of severe morbidity-hemodynamic compromise, aggravated hypothermia, and hypoglycemia-despite intact control of the virus. Following acute viral liver injury, canonical PAR2 signaling impairs the restoration process associated with exaggerated type I IFN (interferon) signatures in response to viral RNA recognition. Metabolic profiling in combination with proteomics of liver tissue shows PAR2-dependent reprogramming of liver metabolism, increased lipid droplet storage, and gluconeogenesis. PAR2-sustained hypodynamic compromise, reprograming of liver metabolism, as well as imbalanced IFN responses are prevented in β-arrestin coupling-deficient PAR2 C-terminal phosphorylation mutant mice. Thus, wiring between upstream proteases and immune-metabolic responses results from biased PAR2 signaling mediated by intracellular recruitment of β-arrestin. Importantly, blockade of the TF (tissue factor)-FVIIa (coagulation factor VIIa) complex capable of PAR2 proteolysis with the NAPc2 (nematode anticoagulant protein c2) mitigated virus-triggered pathology, recapitulating effects seen in protease cleavage-resistant PAR2 mice.

CONCLUSIONS

These data provide insights into a TF-FVIIa signaling axis through PAR2-β-arrestin coupling that is a regulator of inflammation-triggered tissue repair and hemodynamic compromise in coxsackievirus B3 infection and can potentially be targeted with selective coagulation inhibitors.

The protease activated receptor 2 - CCAAT/enhancer-binding protein beta - SerpinB3 axis inhibition as a novel strategy for the treatment of non-alcoholic steatohepatitis

OBJECTIVE

The serine protease inhibitor SerpinB3 has been described as critical mediator of liver fibrosis and it has been recently proposed as an additional hepatokine involved in NASH development and insulin resistance. Protease Activated Receptor 2 has been identified as a novel regulator of hepatic metabolism. A targeted therapeutic strategy for NASH has been investigated, using 1-Piperidine Propionic Acid (1-PPA), since this compound has been recently proposed as both Protease Activated Receptor 2 and SerpinB3 inhibitor.

METHODS

The effect of SerpinB3 on inflammation and fibrosis genes was assessed in human macrophage and stellate cell lines. Transgenic mice, either overexpressing SerpinB3 or carrying Serpinb3 deletion and their relative wild type strains, were used in experimental NASH models. Subgroups of SerpinB3 transgenic mice and their controls were also injected with 1-PPA to assess the efficacy of this compound in NASH inhibition.

RESULTS

1-PPA did not present significant cell and organ toxicity and was able to inhibit SerpinB3 and PAR2 in a dose-dependent manner. This effect was associated to a parallel reduction of the synthesis of the molecules induced by endogenous SerpinB3 or by its paracrine effects both in vitro and in vivo, leading to inhibition of lipid accumulation, inflammation and fibrosis in experimental NASH. At mechanistic level, the antiprotease activity of SerpinB3 was found essential for PAR2 activation, determining upregulation of the CCAAT Enhancer Binding Protein beta (C/EBP-β), another pivotal regulator of metabolism, inflammation and fibrosis, which in turn determined SerpinB3 synthesis.

CONCLUSIONS

1-PPA treatment was able to inhibit the PAR2 - C/EBP-β - SerpinB3 axis and to protect from NASH development and progression, supporting the potential use of a similar approach for a targeted therapy of NASH.

Physiological functions of glucose transporter-2: From cell physiology to links with diabetes mellitus

Glucose is a sugar crucial for human health since it participates in many biochemical reactions. It produces adenosine 5'-triphosphate (ATP) and nucleosides through glucose metabolic and pentose phosphate pathways. These processes require many transporter proteins to assist in transferring glucose across cells, and the most notable ones are glucose transporter-2 (GLUT-2) and sodium/glucose cotransporter 1 (SGLT1). Glucose enters small intestinal epithelial cells from the intestinal lumen by crossing the brush boundary membrane via the SGLT1 cotransporter. It exits the cells by traversing the basolateral membrane through the activity of the GLUT-2 transporter, supplying energy throughout the body. Dysregulation of these glucose transporters is involved in the pathogenesis of several metabolic diseases, such as diabetes. Natural loss of GLUT-2 or its downregulation causes abnormal blood glucose concentrations in the body, such as fasting hypoglycemia and glucose tolerance. Therefore, understanding GLUT-2 physiology is necessary for exploring the mechanisms of diabetes and targeted treatment development. This article reviews how the apical GLUT-2 transporter maintains normal physiological functions of the human body and the adaptive changes this transporter produces under pathological conditions such as diabetes.

Methylparaben induces hepatic glycolipid metabolism disorder by activating the IRE1α-XBP1 signaling pathway in male mice

Methylparaben (MP), a preservative widely used in daily supplies, exists in both the environment and the human body. However, the potential health risks posed by MP remain unclear. This study aimed to unravel the mechanisms by which MP disrupts glucose and lipid homeostasis. For this, we administered MP to mice and observed changes in glucose and lipid metabolism. MP exposure led to hyperglycemia, hyperlipidemia, visceral organ injury, and hepatic lipid accumulation. RNA sequencing results from mice livers indicated a close association between MP exposure and endoplasmic reticulum (ER) stress, inflammatory response, and glucose and lipid homeostasis. Western blotting and quantitative reverse transcription-polymerase chain reaction revealed that MP activated ER stress, particularly the inositol-requiring enzyme 1 (IRE1)/X-box binding protein 1 (XBP1) pathway, which further promoted the activation of the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. The activation of these pathways phosphorylated insulin receptor substrate-1 (IRS1) (ser 307), resulting in decreased phosphorylation of protein kinase B (Akt) (ser 473), leading to insulin resistance. Additionally, MP exposure promoted lipogenesis through ER stress. To explore potential remedies, we administered the ER stress inhibitor 4-phenylbutyric acid (4-PBA) and the IRE1α-XBP1 pathway inhibitor toyocamycin to mice, both of which protected against metabolic disorders and organ injury caused by MP. These findings suggest that MP induces disruptions in glucose and lipid metabolism through ER stress, primarily through the IRE1α-XBP1 pathway.

Comprehensive Strategy for Identifying Extracellular Vesicle Surface Proteins as Biomarkers for Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a liver disorder that has become a global health concern due to its increasing prevalence. There is a need for reliable biomarkers to aid in the diagnosis and prognosis of NAFLD. Extracellular vesicles (EVs) are promising candidates in biomarker discovery, as they carry proteins that reflect the pathophysiological state of the liver. In this review, we developed a list of EV proteins that could be used as diagnostic biomarkers for NAFLD. We employed a multi-step strategy that involved reviewing and comparing various sources of information. Firstly, we reviewed papers that have studied EVs proteins as biomarkers in NAFLD and papers that have studied circulating proteins as biomarkers in NAFLD. To further identify potential candidates, we utilized the EV database Vesiclepedia.org to qualify each protein. Finally, we consulted the Human Protein Atlas to search for candidates' localization, focusing on membrane proteins. By integrating these sources of information, we developed a comprehensive list of potential EVs membrane protein biomarkers that could aid in diagnosing and monitoring NAFLD. In conclusion, our multi-step strategy for identifying EV-based protein biomarkers for NAFLD provides a comprehensive approach that can also be applied to other diseases. The protein candidates identified through this approach could have significant implications for the development of non-invasive diagnostic tests for NAFLD and improve the management and treatment of this prevalent liver disorder.

Signaling pathways and intervention for therapy of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) represents one of the fastest growing epidemic metabolic disorders worldwide and is a strong contributor for a broad range of comorbidities, including vascular, visual, neurological, kidney, and liver diseases. Moreover, recent data suggest a mutual interplay between T2DM and Corona Virus Disease 2019 (COVID-19). T2DM is characterized by insulin resistance (IR) and pancreatic β cell dysfunction. Pioneering discoveries throughout the past few decades have established notable links between signaling pathways and T2DM pathogenesis and therapy. Importantly, a number of signaling pathways substantially control the advancement of core pathological changes in T2DM, including IR and β cell dysfunction, as well as additional pathogenic disturbances. Accordingly, an improved understanding of these signaling pathways sheds light on tractable targets and strategies for developing and repurposing critical therapies to treat T2DM and its complications. In this review, we provide a brief overview of the history of T2DM and signaling pathways, and offer a systematic update on the role and mechanism of key signaling pathways underlying the onset, development, and progression of T2DM. In this content, we also summarize current therapeutic drugs/agents associated with signaling pathways for the treatment of T2DM and its complications, and discuss some implications and directions to the future of this field.

Emerging novel targets for nonalcoholic fatty liver disease treatment: Evidence from recent basic studies

Nonalcoholic fatty liver disease (NAFLD), a leading chronic disease worldwide, affects approximately a quarter of the global population. Nonalcoholic steatohepatitis (NASH) is an advanced form of NAFLD and is more likely to progress to liver fibrosis than simple steatosis. NASH is also identified as the most rapidly growing cause of hepatocellular carcinoma. Although in the past decade, several phase II/III clinical trials have shown promising results in the use of novel drugs targeting lipid synthase, farnesoid X receptor signaling, peroxisome proliferator-activated receptor signaling, hepatocellular injury, and inflammatory signaling, proven pharmaceutical agents to treat NASH are still lacking. Thus, continuous exploration of the mechanism underlying the pathogenesis of NAFLD and the identification of novel therapeutic targets remain urgent tasks in the field. In the current review, we summarize studies reported in recent years that not only provide new insights into the mechanisms of NAFLD development but also explore the possibility of treating NAFLD by targeting newly identified signaling pathways. We also discuss evidence focusing on the intrahepatic targets involved in the pathogenesis of NAFLD as well as extrahepatic targets affecting liver metabolism and function.