Thbs1 induces lethal cardiac atrophy through PERK-ATF4 regulated autophagy

Wenshen Xiaozheng Tang alleviates fibrosis in endometriosis by regulating differentiation and paracrine signaling of endometrium-derived mesenchymal stem cells

ETHNOPHARMACOLOGICAL RELEVANCE

Wenshen Xiaozheng Tang (WXT), a traditional Chinese medicine (TCM) decoction, is effective for treating endometriosis. However, the effect of WXT on endometrium-derived mesenchymal stem cells (eMSCs) which play a key role in the fibrogenesis of endometriosis requires further elucidation.

AIMS OF THE STUDY

The aim of this study was to clarify the potential mechanism of WXT in improving fibrosis in endometriosis by investigating the regulation of WXT on differentiation and paracrine of eMSCs.

MATERIALS AND METHODS

The nude mice with endometriosis were randomly divided into model group, WXT group and mifepristone group. After 21 days of treatment, the lesion volume was calculated. Fibrosis in the lesions was evaluated by Masson staining and expression of fibrotic proteins. The differentiation of eMSCs in vivo was explored using a fate-tracking experiment. To further clarify the regulation of WXT on eMSCs, primary eMSCs from the ectopic lesions of endometriosis patients were isolated and characterized. The effect of WXT on the proliferation and differentiation of ectopic eMSCs was examined. To evaluate the role of WXT on the paracrine activity of ectopic eMSCs, the conditioned medium (CM) from ectopic eMSCs pretreated with WXT was collected and applied to treat ectopic endometrial stromal cells (ESCs), after which the expression of fibrotic proteins in ectopic ESCs was assessed. In addition, transcriptome sequencing was used to investigate the regulatory mechanism of WXT on ectopic eMSCs, and western blot and ELISA were employed to determine the key mediator.

RESULTS

WXT impeded the growth of ectopic lesions in nude mice with endometriosis and reduced collagen deposition and the expression of fibrotic proteins fibronectin, collagen I, α-SMA and CTGF in the endometriotic lesions. The fate-tracking experiment showed that WXT prevented human eMSCs from differentiating into myofibroblasts in the nude mice. We successfully isolated eMSCs from the lesions of patients with endometriosis and demonstrated that WXT suppressed proliferation and myofibroblast differentiation of ectopic eMSCs. Moreover, the expression of α-SMA, collagen I, fibronectin and CTGF in ectopic ESCs was significantly down-regulated by the CM of ectopic MSCs pretreated with WXT. Combining the results of RNA sequencing, western blot and ELISA, we found that WXT not only reduced thrombospondin 4 expression in ectopic eMSCs, but also decreased thrombospondin 4 secretion from ectopic eMSCs. Thrombospondin 4 concentration-dependently upregulated the expression of collagen I, fibronectin, α-SMA and CTGF in ectopic ESCs, indicating that thrombospondin 4 was a key mediator of WXT in inhibiting the fibrotic process in endometriosis.

CONCLUSION

WXT improved fibrosis in endometriosis by regulating differentiation and paracrine signaling of eMSCs. Thrombospondin 4, whose release from ectopic eMSCs is inhibited by WXT, may be a potential target for the treatment of endometriosis.

Endothelial Unfolded Protein Response-Mediated Cytoskeletal Effects

The endothelial semipermeable monolayers ensure tissue homeostasis, are subjected to a plethora of stimuli, and their function depends on cytoskeletal integrity and remodeling. The permeability of those membranes can fluctuate to maintain organ homeostasis. In cases of severe injury, inflammation or disease, barrier hyperpermeability can cause irreparable damage of endothelium-dependent issues, and eventually death. Elucidation of the signaling regulating cytoskeletal structure and barrier integrity promotes the development of targeted pharmacotherapies towards disorders related to the impaired endothelium (e.g., acute respiratory distress syndrome, sepsis). Recent reports investigate the role of unfolded protein response in barrier function. Herein we review the cytoskeletal components, the unfolded protein response function; and their interrelations on health and disorder. Moreover, we emphasize on unfolded protein response modulators, since they ameliorate illness related to endothelial leak.

A new strategy for the treatment of intracerebral hemorrhage: Ferroptosis

Intracerebral hemorrhage, is a cerebrovascular disease with high morbidity, mortality, and disability. Due to the lack of effective clinical treatments, the development of new drugs to treat intracerebral hemorrhage is necessary. In recent years, ferroptosis has been found to play an important role in the pathophysiological process of intracerebral hemorrhage, which can be treated by inhibiting ferroptosis and thus intracerebral hemorrhage. This article aims to explain the mechanism of ferroptosis and its relationship to intracerebral hemorrhage. In the meantime, it briefly discusses the molecules identified to alleviate intracerebral hemorrhage by inhibiting ferroptosis, along with other clinical agents that are expected to treat intracerebral hemorrhage through this mechanism. In addition, a brief overview of the morphological alterations of different forms of cell death and their role in ICH is provided. Finally, the challenges that may arise in translating ferroptosis inhibitors from basic research to clinical use are presented. This article serves as a reference and provides insights to aid in the treatment of intracerebral hemorrhage in the clinic.

Combined inhibition of histone methyltransferases EZH2 and DOT1L is an effective therapy for neuroblastoma

BACKGROUND

The child cancer, neuroblastoma (NB), is characterised by a low incidence of mutations and strong oncogenic embryonal driver signals. Many new targeted epigenetic modifier drugs have failed in human trials as monotherapy.

METHODS

We performed a high-throughput, combination chromatin-modifier drug screen against NB cells. We screened 13 drug candidates in 78 unique combinations.

RESULTS

We found that the combination of two histone methyltransferase (HMT) inhibitors: GSK343, targeting EZH2, and SGC0946, targeting DOT1L, demonstrated the strongest synergy across 8 NB cell lines, with low normal fibroblast toxicity. High mRNA expression of both EZH2 and DOT1L in NB tumour samples correlated with the poorest patient survival. Combination HMT inhibitor treatment caused activation of ATF4-mediated endoplasmic reticulum (ER) stress responses. In addition, glutathione and several amino acids were depleted by HMT inhibitor combination on mass spectrometry analysis. The combination of SGC0946 and GSK343 reduced tumour growth in comparison to single agents.

CONCLUSION

Our results support further investigation of HMT inhibitor combinations as a therapeutic approach in NB.

(-)-Epicatechin regulates endoplasmic reticulum stress and promotes ferroptosis in lung cancer cells via the PERK/eIF2α/ATF4 signaling pathway

OBJECTIVE

(-)-Epicatechin (EC) is an active ingredient of Fagopyrum dibtrys (D. Don) Hara and can regulate lung cancer progression. However, the specific regulatory mechanism is poorly understood. This study explored the specific mechanism of EC in the treatment of lung cancer.

METHODS

H460 cells were injected subcutaneously into the left dorsal sides of nude mice to establish an animal model of lung cancer. H460 and H1299 cells and nude mice were treated with different concentrations of EC. The expression levels of related proteins were detected by Western blotting. Cell proliferation, migration, and invasion were detected by CCK-8, colony formation, and Transwell assays. Flow cytometry was used to detect the Ca2+ level in lung cancer cells. Immunohistochemistry was used to detect the expression of Ki-67 in tumor tissues.

RESULTS

This study revealed that ferroptosis in lung cancer cells was inhibited during lung cancer development. EC treatment promotes ferroptosis, inhibits the proliferation, migration and invasion of lung cancer cells, and inhibits the formation of tumors in vivo. Ferroptosis inhibitors (Fer-1) weaken the effects of EC on lung cancer cells, whereas a ferroptosis inducer (erastin) further promotes the effects of EC. In addition, endoplasmic reticulum (ER) stress is involved in the EC-induced ferroptosis of lung cancer cells, and treatment with GSK, an inhibitor of the ER stress protein PERK, can reverse the effect of EC.

CONCLUSION

EC therapy activates the PERK-eIF2α-ATF4 signaling pathway to increase ER stress, thereby promoting ferroptosis in lung cancer cells and inhibiting the occurrence and development of lung cancer. Our research suggests that EC may become a drug candidate for treating lung cancer.

A potential coagulation-related diagnostic model associated with immune infiltration for acute myocardial infarction

The production of pro-coagulation factors can affect the development and prognosis of acute myocardial infarction (AMI). The clinical value of coagulation-related genes (CRGs) was investigated to discover new targets for diagnosing and treating AMI. We screened 335 differentially expressed genes (DEGs) between AMI and healthy individuals based on the GSE66360 dataset. We took the intersection of the obtained DEGs with 139 CRGs. Finally, 10 differentially expressed CEGs were screened out. The random forest algorithm was constructed to identify 6 signature CRGs (THBS1, SERPINA1, THBD, MMP9, MAFF, and PLAU). Subsequently, the established predictive model was found to have good diagnostic accuracy (AUC = 0.9694 in the training cohort [GSE66360 dataset] and 0.9076 in the external validation cohort [GSE48060 dataset]). Consensus clustering identified the CRG clusters, and the accuracy of the grouping was verified. We found that AMI patients can be divided into two distinct subgroups based on the differentially expressed CRGs. Immune cell infiltration level was consistent with the expression levels of CRGs based on single sample gene set enrichment analysis. These findings reveal the potential role of CRGs in AMI. Characterizing the coagulation features of AMI patients can help in the risk stratification of patients and provide personalized treatment strategies.

Unstressing the Reticulum: Nutritional Strategies for Modulating Endoplasmic Reticulum Stress in Obesity

The progression of obesity involves several molecular mechanisms that are closely associated with the pathophysiological response of the disease. Endoplasmic reticulum (ER) stress is one such factor. Lipotoxicity disrupts endoplasmic reticulum homeostasis in the context of obesity. Furthermore, it induces ER stress by activating several signaling pathways via inflammatory responses and oxidative stress. ER performs crucial functions in protein synthesis and lipid metabolism; thus, triggers such as lipotoxicity can promote the accumulation of misfolded proteins in the organelle. The accumulation of these proteins can lead to metabolic disorders and chronic inflammation, resulting in cell death. Thus, alternatives, such as flavonoids, amino acids, and polyphenols that are associated with antioxidant and anti-inflammatory responses have been proposed to attenuate this response by modulating ER stress via the administration of nutrients and bioactive compounds. Decreasing inflammation and oxidative stress can reduce the expression of several ER stress markers and improve clinical outcomes through the management of obesity, including the control of body weight, visceral fat, and lipid accumulation. This review explores the metabolic changes resulting from ER stress and discusses the role of nutritional interventions in modulating the ER stress pathway in obesity.

Identification of autophagy-related signatures in doxorubicin-induced cardiotoxicity

PURPOSE

Doxorubicin is an antibiotic drug used clinically to treat infectious diseases and tumors. Unfortunately, it is cardiotoxic. Autophagy is a cellular self-decomposition process that is essential for maintaining homeostasis in the internal environment. Accordingly, the present study was proposed to characterize the autophagy-related signatures of doxorubicin-induced cardiotoxicity.

METHODS

Datasets related to doxorubicin-induced cardiotoxicity were retrieved by searching the GEO database and differentially expressed genes (DEGs) were identified. DEGs were taken to intersect with autophagy-related genes to obtain autophagy-related signatures, and Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and protein-protein interaction (PPI) network were performed on them. Further, construction of miRNA-hub gene networks and identification of target drugs to reveal potential molecular mechanisms and therapeutic strategies. Animal models of doxorubicin-induced cardiotoxicity were constructed to validate differences in gene expression for autophagy-related signatures.

RESULTS

PBMC and heart samples from the GSE37260 dataset were selected for analysis. There were 995 and 2357 DEGs in PBMC and heart samples, respectively, and they had 23 intersecting genes with autophagy-related genes. RT-qPCR confirmed the differential expression of 23 intersecting genes in doxorubicin-induced cardiotoxicity animal models in general agreement with the bioinformatics results. An autophagy-related signatures consisting of 23 intersecting genes is involved in mediating processes and pathways such as autophagy, oxidative stress, apoptosis, protein ubiquitination and phosphorylation. Moreover, Akt1, Hif1a and Mapk3 are hub genes in autophagy-associated signatures and their upstream miRNAs are mainly rno-miR-1188-5p, rno-miR-150-3p and rno-miR-326-3p, and their drugs are mainly CHEMBL55802, Carboxyamidotriazole and 3-methyladenine.

CONCLUSION

This study identifies for the first-time autophagy-related signatures in doxorubicin's cardiotoxicity, which could provide potential molecular mechanisms and therapeutic strategies for doxorubicin-induced cardiotoxicity.

Analysis of joint protein expression profile in anterior disc displacement of TMJ with or without OA

OBJECTIVE

Anterior disc displacement (ADD) is a common clinical issue and may cause osteoarthritis (OA). However, the research of protein changes in synovial fluid as disease development marker and potential treatment clue is still insufficient.

MATERIALS AND METHODS

We conducted the high-resolution mass spectrometry (MS) of synovial fluid collected from 60 patients with normal disk position to ADD and ADD with osteoarthritis (OA). The proteins with significant changes among the 3 groups were analyzed by biological information and further validated by in primary rat condyle chondrocytes and OA animal model.

RESULTS

FGL2, THBS4, TNC, FN1, OMD etc. were significantly increased in ADD without OA (p < 0.05), which reflected the active extracellular matrix and collagen metabolism. FGFR1, FBLN2, GRB2 etc. were significantly increased in ADD with OA group (p < 0.05), which revealed an association with apoptosis and ferroptosis. Proteins such as P4HB, CBLN4, FHL1, VIM continuously increase in the whole disease progress (p < 0.05). Both the in vitro and in vivo results are consistent with protein changes detected in MS profile.

CONCLUSION

This study firstly provides the expression changes of proteins from normal disc condyle relationship toward ADD with OA, which can be selected and studied further as disease progress marker and potential treatment targets.

Thrombospondins: Conserved mediators and modulators of metazoan extracellular matrix

This review provides a personal overview of significant scientific developments in the thrombospondin field during the course of my career. Thrombospondins are multidomain, multimeric, calcium-binding extracellular glycoproteins with context-specific roles in tissue organisation. They act at cell surfaces and within ECM to regulate cell phenotype and signalling, differentiation and assembly of collagenous ECM, along with tissue-specific roles in cartilage, angiogenesis and synaptic function. More recently, intracellular, homeostatic roles have also been identified. Resolution of structures for the major domains of mammalian thrombospondins has facilitated major advances in understanding thrombospondin biology from molecule to tissue; for example, in illuminating molecular consequences of disease-causing coding mutations in human pseudoachrondroplasia. Although principally studied in vertebrates, thrombospondins are amongst the most ancient of animal ECM proteins, with many invertebrates encoding a single thrombospondin and the thrombospondin gene family of vertebrates originating through gene duplications. Moreover, thrombospondins form one branch of a thrombospondin superfamily that debuted at the origin of metazoans. The super-family includes additional sub-groups, present only in invertebrates, that differ in N-terminal domain organisation, share the distinctive TSP C-terminal region domain architecture and, to the limited extent studied to date, apparently contribute to tissue development and organisation. Finally, major lines of translational research are discussed, related to fibrosis; TSP1, TSP2 and inhibition of angiogenesis; and the alleviation of chronic cartilage tissue pathologies in pseudoachrondroplasia.

Hyperactivation of ATF4/TGF-β1 signaling contributes to the progressive cardiac fibrosis in Arrhythmogenic cardiomyopathy caused by DSG2 Variant

BACKGROUND

Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiomyopathy characterized with progressive cardiac fibrosis and heart failure. However, the exact mechanism driving the progression of cardiac fibrosis and heart failure in ACM remains elusive. This study aims to investigate the underlying mechanisms of progressive cardiac fibrosis in ACM caused by newly identified Desmoglein-2 (DSG2) variation.

METHODS

We identified homozygous DSG2F531C variant in a family with 8 ACM patients using whole-exome sequencing and generated Dsg2F536C knock-in mice. Neonatal and adult mouse ventricular myocytes isolated from Dsg2F536C knock-in mice were used. We performed functional, transcriptomic and mass spectrometry analyses to evaluate the mechanisms of ACM caused by DSG2F531C variant.

RESULTS

All eight patients with ACM were homozygous for DSG2F531C variant. Dsg2F536C/F536C mice displayed cardiac enlargement, dysfunction, and progressive cardiac fibrosis in both ventricles. Mechanistic investigations revealed that the variant DSG2-F536C protein underwent misfolding, leading to its recognition by BiP within the endoplasmic reticulum, which triggered endoplasmic reticulum stress, activated the PERK-ATF4 signaling pathway and increased ATF4 levels in cardiomyocytes. Increased ATF4 facilitated the expression of TGF-β1 in cardiomyocytes, thereby activating cardiac fibroblasts through paracrine signaling and ultimately promoting cardiac fibrosis in Dsg2F536C/F536C mice. Notably, inhibition of the PERK-ATF4 signaling attenuated progressive cardiac fibrosis and cardiac systolic dysfunction in Dsg2F536C/F536C mice.

CONCLUSIONS

Hyperactivation of the ATF4/TGF-β1 signaling in cardiomyocytes emerges as a novel mechanism underlying progressive cardiac fibrosis in ACM. Targeting the ATF4/TGF-β1 signaling may be a novel therapeutic target for managing ACM.

The role of lysosomal membrane proteins in autophagy and related diseases

As a self-degrading and highly conserved survival mechanism, autophagy plays an important role in maintaining cell survival and recycling. The discovery of autophagy-related (ATG) genes has revolutionized our understanding of autophagy. Lysosomal membrane proteins (LMPs) are important executors of lysosomal function, and increasing evidence has demonstrated their role in the induction and regulation of autophagy. In addition, the functional dysregulation of the process mediated by LMPs at all stages of autophagy is closely related to neurodegenerative diseases and cancer. Here, we review the role of LMPs in autophagy, focusing on their roles in vesicle nucleation, vesicle elongation and completion, the fusion of autophagosomes and lysosomes, and degradation, as well as their broad association with related diseases.

Targeting translocator protein protects against myocardial ischemia/reperfusion injury by alleviating mitochondrial dysfunction

Ischemic heart disease (IHD) remains a leading cause of mortalities worldwide, necessitating timely reperfusion to reduce acute mortality. Paradoxically, reperfusion can induce myocardial ischemia/reperfusion (I/R) injury, which is primarily characterized by mitochondrial dysfunction. Translocator protein (TSPO) participates in multiple cellular events; however, its role in IHD, especially in the process of myocardial I/R injury, has not been well determined. The aim of the present study was to investigate the functional role of TSPO in myocardial I/R injury and dissect the concomitant cellular events involved. This study utilized small interfering RNA (siRNA) technology to knock down TSPO expression. The I/R process was simulated using an anoxia/reoxygenation (A/R) model. The role of TSPO in H9c2 cardiomyocytes was assessed using various techniques, such as Western blotting, Flow cytometry, Reverse transcription-quantitative PCR (RT-qPCR), Immunofluorescence, Co-immunoprecipitation (co-IP) and similar methods. It was found that A/R markedly upregulated the expression of TSPO in cardiomyocytes. Inhibition of TSPO improved myocardial cell apoptosis and damage following A/R stimulation. Additionally, targeting TSPO alleviated mitochondrial damage, reduced mitochondrial ROS release and enhanced ATP synthesis following A/R stimulation. It was further confirmed that A/R stimulation induced a significant increase in the expression of pivotal markers [phosporylated-PKR-like ER kinase (PERK)/PERK, activating transcription factor 6 (ATF6) and inositol-requiring enzyme 1] involved in the adaptive unfolded protein response, which is accompanied by downstream signaling during endoplasmic reticulum (ER) stress. Notably, TSPO knockdown increased the expression of the aforementioned markers and, subsequently, TSPO was confirmed to interact with ATF6, suggesting that TSPO might play a role in ER stress during myocardial I/R injury. Finally, inhibition of TSPO upregulated mitophagy, as indicated by further decreases in P62 and increases in Parkin and PINK1 levels following A/R stimulation. Together, the results suggest that TSPO plays a multifaceted role in myocardial I/R injury. Understanding TSPO-induced cellular responses could inform targeted therapeutic strategies for patients with IHD.

Study on diagnostic-sensitive markers of primary immune thrombocytopaenia in children based on plasma proteomics

To use proteomic techniques to identify sensitive diagnostic biomarkers for paediatric immune thrombocytopenia (ITP). We selected children in ITP and control groups, using a four-dimensional data-independent acquisition approach (4D-DIA) to analyse its protein expression. The significantly differentially expressed proteins were selected for enzyme-linked immunosorbent assay (ELISA) validation in a cohort comprising 50 samples (13 healthy controls, 15 secondary thrombocytopenia controls and 22 children with ITP). Receiver operating characteristics (ROC) were generated to diagnose ITP and to assess the diagnostic effectiveness of this approach. Compared with the control group, 55 differentially expressed proteins (43 increased and 12 decreased) were determined in the ITP group. Matrix metalloproteinases-9 (MMP-9) and thrombospondin-1 (THBS1) were significantly expressed and selected for ELISA. The verification outcomes aligned with the findings from the proteomic examinations. In contrast to the control cohort, the ITP subjects exhibited markedly elevated plasma MMP-9 levels and reduced plasma THBS1 concentrations. Additionally, the ROC curves indicated the diagnostic value of these biomarkers. In conclusion, proteomics facilitates identifying the sensitive biomarkers for ITP diagnosis. We have preliminarily selected two differentially expressed proteins, MMP-9 and THBS1, whose potential role as biomarkers for diagnosing ITP requires further research.

Single-Cell Spatial Transcriptomics Unveils Platelet-Fueled Cycling Macrophages for Kidney Fibrosis

With the increasing incidence of kidney diseases, there is an urgent need to develop therapeutic strategies to combat post-injury fibrosis. Immune cells, including platelets, play a pivotal role in this repair process, primarily through their released cytokines. However, the specific role of platelets in kidney injury and subsequent repair remains underexplored. Here, the detrimental role of platelets in renal recovery following ischemia/reperfusion injury and its contribution to acute kidney injury  to chronic kidney disease transition is aimed to investigated. In this study, it is shown that depleting platelets accelerates injury resolution and significantly reduces fibrosis. Employing advanced single-cell and spatial transcriptomic techniques, macrophages as the primary mediators modulated by platelet signals is identified. A novel subset of macrophages, termed "cycling M2", which exhibit an M2 phenotype combined with enhanced proliferative activity is uncovered. This subset emerges in the injured kidney during the resolution phase and is modulated by platelet-derived thrombospondin 1 (THBS1) signaling, acquiring profibrotic characteristics. Conversely, targeted inhibition of THBS1 markedly downregulates the cycling M2 macrophage, thereby mitigating fibrotic progression. Overall, this findings highlight the adverse role of platelet THBS1-boosted cycling M2 macrophages in renal injury repair and suggest platelet THBS1 as a promising therapeutic target for alleviating inflammation and kidney fibrosis.

The long noncoding RNA lncMPD2 inhibits myogenesis by targeting the miR-34a-5p/THBS1 axis

Long noncoding RNAs (lncRNAs) participate in regulating skeletal muscle development. However, little is known about their role in regulating chicken myogenesis. In this study, we identified a novel lncRNA, lncMPD2, through transcriptome sequencing of chicken myoblasts at different developmental stages. Functionally, gain- and loss-of-function experiments showed that lncMPD2 inhibited myoblast proliferation and differentiation. Mechanistically, lncMPD2 directly bound to miR-34a-5p, and miR-34a-5p promoted myoblasts proliferation and differentiation and inhibited the mRNA and protein expression of its target gene THBS1. THBS1 inhibited myoblast proliferation and differentiation in vitro and delayed muscle regeneration in vivo. Furthermore, rescue experiments showed that lncMPD2 counteracted the inhibitory effects of miR-34a-5p on THBS1 and myogenesis-related gene mRNA and protein expression. In conclusion, lncMPD2 regulates the miR-34a-5p/THBS1 axis to inhibit the proliferation and differentiation of myoblasts and skeletal muscle regeneration. This study provides more insight into the molecular regulatory network of skeletal muscle development, identifying novel potential biomarkers for improving chicken quality and increasing chicken yield. In addition, this study provides a potential goal for breeding strategies that minimize muscle damage in chickens.

Implications of endoplasmic reticulum stress and autophagy in aging and cardiovascular diseases

The average lifespan of humans has been increasing, resulting in a rapidly rising percentage of older individuals and high morbidity of aging-associated diseases, especially cardiovascular diseases (CVDs). Diverse intracellular and extracellular factors that interrupt homeostatic functions in the endoplasmic reticulum (ER) induce ER stress. Cells employ a dynamic signaling pathway of unfolded protein response (UPR) to buffer ER stress. Recent studies have demonstrated that ER stress triggers various cellular processes associated with aging and many aging-associated diseases, including CVDs. Autophagy is a conserved process involving lysosomal degradation and recycling of cytoplasmic components, proteins, organelles, and pathogens that invade the cytoplasm. Autophagy is vital for combating the adverse influence of aging on the heart. The present report summarizes recent studies on the mechanism of ER stress and autophagy and their overlap in aging and on CVD pathogenesis in the context of aging. It also discusses possible therapeutic interventions targeting ER stress and autophagy that might delay aging and prevent or treat CVDs.

Identification of novel endoplasmic reticulum-related genes and their association with immune cell infiltration in major depressive disorder

BACKGROUND

Several lines of evidence point to an interaction between genetic predisposition and environmental factors in the onset of major depressive disorder (MDD). This study is aimed to investigate the pathogenesis of MDD by identifying key biomarkers, associated immune infiltration using bioinformatic analysis and human postmortem sample.

METHODS

The Gene Expression Omnibus (GEO) database of GSE98793 was adopted to identify hub genes linked to endoplasmic reticulum (ER) stress-related genes (ERGs) in MDD. Another GEO database of GSE76826 was employed to validate the novel target associated with ERGs and immune infiltration in MDD. Moreover, human postmortem sample from MDD patients was utilized to confirm the differential expression analysis of hub genes.

RESULTS

We discovered 12 ER stress-related differentially expressed genes (ERDEGs). A LASSO Cox regression analysis helped construct a diagnostic model for these ERDEGs, incorporating immune infiltration analysis revealed that three hub genes (ERLIN1, SEC61B, and USP13) show the significant and consistent expression differences between the two groups. Western blot analysis of postmortem brain samples indicated notably higher expression levels of ERLIN1 and SEC61B in the MDD group, with USP13 also tending to increase compared to control group.

LIMITATIONS

The utilization of the MDD gene chip in this analysis was sourced from the GEO database, which possesses a restricted number of pertinent gene chip samples.

CONCLUSIONS

These findings indicate that ERDEGs especially including ERLIN1, SEC61B, and USP13 associated the infiltration of immune cells may be potential diagnostic indicators for MDD.

Research progress on the role and mechanism of Sirtuin family in doxorubicin cardiotoxicity

BACKGROUND

Doxorubicin (DOX) is a widely utilized anthracycline chemotherapy drug in cancer treatment, yet its efficacy is hindered by both short-term and long-term cardiotoxicity. Although oxidative stress, inflammation and mitochondrial dysfunction are established factors in DOX-induced cardiotoxicity, the precise molecular pathways remain elusive. Further exploration of the pathogenesis and identification of novel molecular targets are imperative. Recent studies have implicated the Sirtuins family in various physiological and pathological processes, suggesting their potential in ameliorating DOX-induced cardiotoxicity. Moreover, research on Sirtuins has discovered small-molecule compounds or medicinal plants with regulatory effects, representing a notable advancement in preventing and treating DOX-induced cardiac injury.

PURPOSE

In this review, we delve into the pathogenesis of DOX-induced cardiotoxicity and explore the therapeutic effects of Sirtuins in mitigating this condition, along with the associated molecular mechanisms. Furthermore, we delineate the roles and mechanisms of small-molecule regulators of Sirtuins in the prevention and treatment of DOX-induced cardiotoxicity.

STUDY-DESIGN/METHODS

Data for this review were sourced from various scientific databases (such as Web of Science, PubMed and Science Direct) up to March 2024. Search terms included "Sirtuins," "DOX-induced cardiotoxicity," "DOX," "Sirtuins regulators," "histone deacetylation," among others, as well as several combinations thereof.

RESULTS

Members of the Sirtuins family regulate both the onset and progression of DOX-induced cardiotoxicity through anti-inflammatory, antioxidative stress and anti-apoptotic mechanisms, as well as by maintaining mitochondrial stability. Moreover, natural plant-derived active compounds such as Resveratrol (RES), curcumin, berberine, along with synthetic small-molecule compounds like EX527, modulate the expression and activity of Sirtuins.

CONCLUSION

The therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity represents a potential molecular target. However, further research is urgently needed to elucidate the relevant molecular mechanisms and to assess the safety and biological activity of Sirtuins regulators. This review offers an in-depth understanding of the therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity, providing a preliminary basis for the clinical application of Sirtuins regulators in this condition.

Ntsr1 contributes to pulmonary hypertension by enhancing endoplasmic reticulum stress via JAK2-STAT3-Thbs1 signaling

Pulmonary hypertension (PH) is a severe clinical syndrome with pulmonary vascular remodeling and poor long-term prognosis. Neurotensin receptor 1 (Ntsr1), serve as one of the G protein-coupled receptors (GPCRs), implicates in various biological processes, but the potential effects of Ntsr1 in PH development are unclear. The Sugen/Hypoxia (SuHx) or monocrotaline (MCT) induced rat PH model was used in our study and the PH rats showed aggravated pulmonary artery remodeling and increased right ventricular systolic pressure (RVSP). Our results revealed that Ntsr1 induced endoplasmic reticulum (ER) stress response via ATF6 activation contributed to the development of PH. Moreover, RNA-sequencing (RNA-seq) and phosphoproteomics were performed and the Ntsr1-JAK2-STAT3-thrombospondin 1 (Thbs1)-ATF6 signaling was distinguished as the key pathway. In vitro, pulmonary artery smooth muscle cells (PASMCs) under hypoxia condition showed enhanced proliferation and migration properties, which could be inhibited by Ntsr1 knockdown, JAK2 inhibitor (Fedratinib) treatment, STAT3 inhibitior (Stattic) treatment, Thbs1 knockdown or ATF6 knockdown. In addition, adeno-associated virus 1 (AAV1) were used to knockdown the expression of Ntsr1, Thbs1 or ATF6 in rats and reversed the phenotype of PH. In summary, our results reveal that Ntsr1-JAK2-STAT3-Thbs1 pathway can induce enhanced ER stress via ATF6 activation and increased PASMC proliferation and migration capacities, which can be mechanism of the pulmonary artery remodeling and PH. Targeting Ntsr1 might be a novel therapeutic strategy to ameliorate PH.

GADD45A: With or without you

The growth arrest and DNA damage inducible (GADD)45 family includes three small and ubiquitously distributed proteins (GADD45A, GADD45B, and GADD45G) that regulate numerous cellular processes associated with stress signaling and injury response. Here, we provide a comprehensive review of the current literature investigating GADD45A, the first discovered member of the family. We first depict how its levels are regulated by a myriad of genotoxic and non-genotoxic stressors, and through the combined action of intricate transcriptional, posttranscriptional, and even, posttranslational mechanisms. GADD45A is a recognized tumor suppressor and, for this reason, we next summarize its role in cancer, as well as the different mechanisms by which it regulates cell cycle, DNA repair, and apoptosis. Beyond these most well-known actions, GADD45A may also influence catabolic and anabolic pathways in the liver, adipose tissue and skeletal muscle, among others. Not surprisingly, GADD45A may trigger AMP-activated protein kinase activity, a master regulator of metabolism, and is known to act as a transcriptional coregulator of numerous nuclear receptors. GADD45A has also been reported to display a cytoprotective role by regulating inflammation, fibrosis and oxidative stress in several organs and tissues, and is regarded an important contributor for the development of heart failure. Overall data point to that GADD45A may play an important role in metabolic, neurodegenerative and cardiovascular diseases, and also autoimmune-related disorders. Thus, the potential mechanisms by which dysregulation of GADD45A activity may contribute to the progression of these diseases are also reviewed below.

MICU3 Regulates Mitochondrial Calcium and Cardiac Hypertrophy

BACKGROUND

Calcium (Ca2+) uptake by mitochondria occurs via the mitochondrial Ca2+ uniporter. Mitochondrial Ca2+ uniporter exists as a complex, regulated by 3 MICU (mitochondrial Ca2+ uptake) proteins localized in the intermembrane space: MICU1, MICU2, and MICU3. Although MICU3 is present in the heart, its role is largely unknown.

METHODS

We used CRISPR-Cas9 to generate a mouse with global deletion of MICU3 and an adeno-associated virus (AAV9) to overexpress MICU3 in wild-type mice. We examined the role of MICU3 in regulating mitochondrial calcium ([Ca2+]m) in ex vivo hearts using an optical method following adrenergic stimulation in perfused hearts loaded with a Ca2+-sensitive fluorophore. Additionally, we studied how deletion and overexpression of MICU3, respectively, impact cardiac function in vivo by echocardiography and the molecular composition of the mitochondrial Ca2+ uniporter complex via Western blot, immunoprecipitation, and Blue native-PAGE analysis. Finally, we measured MICU3 expression in failing human hearts.

RESULTS

MICU3 knock out hearts and cardiomyocytes exhibited a significantly smaller increase in [Ca2+]m than wild-type hearts following acute isoproterenol infusion. In contrast, heart with overexpression of MICU3 exhibited an enhanced increase in [Ca2+]m compared with control hearts. Echocardiography analysis showed no significant difference in cardiac function in knock out MICU3 mice relative to wild-type mice at baseline. However, mice with overexpression of MICU3 exhibited significantly reduced ejection fraction and fractional shortening compared with control mice. We observed a significant increase in the ratio of heart weight to tibia length in hearts with overexpression of MICU3 compared with controls, consistent with hypertrophy. We also found a significant decrease in MICU3 protein and expression in failing human hearts.

CONCLUSIONS

Our results indicate that increased and decreased expression of MICU3 enhances and reduces, respectively, the uptake of [Ca2+]m in the heart. We conclude that MICU3 plays an important role in regulating [Ca2+]m physiologically, and overexpression of MICU3 is sufficient to induce cardiac hypertrophy, making MICU3 a possible therapeutic target.

IKIP downregulates THBS1/FAK signaling to suppress migration and invasion by glioblastoma cells

Background

Inhibitor of NF-κB kinase-interacting protein (IKIP) is known to promote proliferation of glioblastoma (GBM) cells, but how it affects migration and invasion by those cells is unclear.

Methods

We compared levels of IKIP between glioma tissues and normal brain tissue in clinical samples and public databases. We examined the effects of IKIP overexpression and knockdown on the migration and invasion of GBM using transwell and wound healing assays, and we compared the transcriptomes under these different conditions to identify the molecular mechanisms involved.

Results

Based on data from our clinical samples and from public databases, IKIP was overexpressed in GBM tumors, and its expression level correlated inversely with survival. IKIP overexpression in GBM cells inhibited migration and invasion in transwell and wound healing assays, whereas IKIP knockdown exerted the opposite effects. IKIP overexpression in GBM cells that were injected into mouse brain promoted tumor growth but inhibited tumor invasion of surrounding tissue. The effects of IKIP were associated with downregulation of THBS1 mRNA and concomitant inhibition of THBS1/FAK signaling.

Conclusions

IKIP inhibits THBS1/FAK signaling to suppress migration and invasion of GBM cells.

Mammalian integrated stress responses in stressed organelles and their functions

The integrated stress response (ISR) triggered in response to various cellular stress enables mammalian cells to effectively cope with diverse stressful conditions while maintaining their normal functions. Four kinases (PERK, PKR, GCN2, and HRI) of ISR regulate ISR signaling and intracellular protein translation via mediating the phosphorylation of eukaryotic translation initiation factor 2 α (eIF2α) at Ser51. Early ISR creates an opportunity for cells to repair themselves and restore homeostasis. This effect, however, is reversed in the late stages of ISR. Currently, some studies have shown the non-negligible impact of ISR on diseases such as ischemic diseases, cognitive impairment, metabolic syndrome, cancer, vanishing white matter, etc. Hence, artificial regulation of ISR and its signaling with ISR modulators becomes a promising therapeutic strategy for relieving disease symptoms and improving clinical outcomes. Here, we provide an overview of the essential mechanisms of ISR and describe the ISR-related pathways in organelles including mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosomes. Meanwhile, the regulatory effects of ISR modulators and their potential application in various diseases are also enumerated.

Thbs1 regulates skeletal muscle mass in a TGFβ-Smad2/3-ATF4-dependent manner

Loss of muscle mass is a feature of chronic illness and aging. Here, we report that skeletal muscle-specific thrombospondin-1 transgenic mice (Thbs1 Tg) have profound muscle atrophy with age-dependent decreases in exercise capacity and premature lethality. Mechanistically, Thbs1 activates transforming growth factor β (TGFβ)-Smad2/3 signaling, which also induces activating transcription factor 4 (ATF4) expression that together modulates the autophagy-lysosomal pathway (ALP) and ubiquitin-proteasome system (UPS) to facilitate muscle atrophy. Indeed, myofiber-specific inhibition of TGFβ-receptor signaling represses the induction of ATF4, normalizes ALP and UPS, and partially restores muscle mass in Thbs1 Tg mice. Similarly, myofiber-specific deletion of Smad2 and Smad3 or the Atf4 gene antagonizes Thbs1-induced muscle atrophy. More importantly, Thbs1-/- mice show significantly reduced levels of denervation- and caloric restriction-mediated muscle atrophy, along with blunted TGFβ-Smad3-ATF4 signaling. Thus, Thbs1-mediated TGFβ-Smad3-ATF4 signaling in skeletal muscle regulates tissue rarefaction, suggesting a target for atrophy-based muscle diseases and sarcopenia with aging.

Potential targets for the treatment of MI: GRP75-mediated Ca2+ transfer in MAM

After myocardial infarction (MI), there is a notable disruption in cellular calcium ion homeostasis and mitochondrial function, which is believed to be intricately linked to endoplasmic reticulum (ER) stress. This research endeavors to elucidate the involvement of glucose regulated protein 75 (GRP75) in post-MI calcium ion homeostasis and mitochondrial function. In MI rats, symptoms of myocardial injury were accompanied by an increase in the activation of ER stress. Moreover, in oxygen-glucose deprivation (OGD)-induced cardiomyocytes, it was confirmed that inhibiting ER stress exacerbated intracellular Ca2+ disruption and cell apoptosis. Concurrently, the co-localization of GRP75 with IP3R and VDAC1 increased under ER stress in cardiomyocytes. In OGD-induced cardiomyocytes, knockdown of GRP75 not only reduced the Ca2+ levels in both the ER and mitochondria and improved the ultrastructure of cardiomyocytes, but it also increased the number of contact points between the ER and mitochondria, reducing mitochondria associated endoplasmic reticulum membrane (MAM) formation, and decreased cell apoptosis. Significantly, knockdown of GRP75 did not affect the protein expression of PERK and hypoxia-inducible factor 1α (HIF-1α). Transcriptome analysis of cardiomyocytes revealed that knockdown of GRP75 mainly influenced the molecular functions of sialyltransferase and IP3R, as well as the biosynthesis of glycosphingolipids and lactate metabolism. The complex interaction between the ER and mitochondria, driven by the GRP75 and its associated IP3R1-GRP75-VDAC1 complex, is crucial for calcium homeostasis and cardiomyocyte's adaptive response to ER stress. Modulating GRP75 could offer a strategy to regulate calcium dynamics, diminish glycolysis, and thereby mitigate cardiomyocyte apoptosis.

Unveiling the emerging role of curcumin to alleviate ochratoxin A-induced muscle toxicity in grass carp (Ctenopharyngodon idella): in vitro and in vivo studies

BACKGROUND

Ochratoxin A (OTA), a globally abundant and extremely hazardous pollutant, is a significant source of contamination in aquafeeds and is responsible for severe food pollution. The developmental toxicity of OTA and the potential relieving strategy of natural products remain unclear. This study screened the substance curcumin (Cur), which had the best effect in alleviating OTA inhibition of myoblast proliferation, from 96 natural products and investigated its effect and mechanism in reducing OTA myotoxicity in vivo and in vitro.

METHODS

A total of 720 healthy juvenile grass carp, with an initial average body weight of 11.06 ± 0.05 g, were randomly assigned into 4 groups: the control group (without OTA and Cur), 1.2 mg/kg OTA group, 400 mg/kg Cur group, and 1.2 mg/kg OTA + 400 mg/kg Cur group. Each treatment consisted of 3 replicates (180 fish) for 60 d.

RESULTS

Firstly, we cultured, purified, and identified myoblasts using the tissue block culture method. Through preliminary screening and re-screening of 96 substances, we examined cell proliferation-related indicators such as cell viability and ultimately found that Cur had the best effect. Secondly, Cur could alleviate OTA-inhibited myoblast differentiation and myofibrillar development-related proteins (MyoG and MYHC) in vivo and in vitro and improve the growth performance of grass carp. Then, Cur could also promote the expression of OTA-inhibited protein synthesis-related proteins (S6K1 and TOR), which was related to the activation of the AKT/TOR signaling pathway. Finally, Cur could downregulate the expression of OTA-enhanced protein degradation-related genes (murf1, foxo3a, and ub), which was related to the inhibition of the FoxO3a signaling pathway.

CONCLUSIONS

In summary, our data demonstrated the effectiveness of Cur in alleviating OTA myotoxicity in vivo and in vitro. This study confirms the rapidity, feasibility, and effectiveness of establishing a natural product screening method targeting myoblasts to alleviate fungal toxin toxicity.

Juan-tong-yin potentially impacts endometriosis pathophysiology by enhancing autophagy of endometrial stromal cells via unfolded protein reaction-triggered endoplasmic reticulum stress

ETHNOPHARMACOLOGICAL RELEVANCE

Endometriosis (EMs) is characterized by inflammatory lesions, dysmenorrhea, infertility, and chronic pelvic pain. Single-target medications often fail to provide systemic therapeutic results owing to the complex mechanism underlying endometriosis. Although traditional Chinese medicines-such as Juan-Tong-Yin (JTY)-have shown promising results, their mechanisms of action remain largely unknown.

AIM OF THE STUDY

To elucidate the therapeutic mechanism of JTY in EMs, focusing on endoplasmic reticulum (ER) stress-induced autophagy.

MATERIALS AND METHODS

The major components of JTY were detected using high-performance liquid chromatography-mass spectrometry (HPLC-MS). The potential mechanism of JTY in EMs treatment was predicted using network pharmacological analysis. Finally, the pathogenesis of EMs was validated in a clinical case-control study and the molecular mechanism of JTY was validated in vitro using endometrial stromal cells (ESCs).

RESULTS

In total, 241 compounds were analyzed and identified from JTY using UPLC-MS. Network pharmacology revealed 288 targets between the JTY components and EMs. Results of the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses indicated that regulating autophagy, migration, apoptosis, and inflammation were the key mechanisms of JTY in treating EMs. Meanwhile, we found that protein kinase R-like endoplasmic reticulum kinase (PERK), Beclin-1, and microtubule-associated protein light chain 3 B (LC3B) expressions were lower in endometria of patients with EMs than in those with normal eutopic endometria (p < 0.05). Additionally, during in vitro experiments, treatment with 20% JTY-containing serum significantly suppressed ESC proliferation, achieving optimal effects after 48 h. Electron microscopy revealed significantly increased autophagy flux in the JTY group compared with the control group. Moreover, JTY treatment significantly reduced the migratory and invasive abilities of ESCs and upregulated protein expression of PERK, eukaryotic initiation factor 2α (eIF2α)/phospho-eukaryotic initiation factor 2α (p-eIF2α), activating Transcription Factor-4 (ATF4), Beclin-1, and LC3BII/I, while subsequently downregulating NOD-like receptor thermal protein domain associated protein 3 (NLRP3) and interleukin 18 (IL-18) expression. However, administration of GSK2656157-a highly selective PERK inhibitor-reversed these changes.

CONCLUSION

JTY ameliorates EMs by activating PERK associated with unfolded protein reaction, enhancing cell ER stress and autophagy, improving the inflammatory microenvironment, and decreasing the migration and invasion of ESCs.

Esculin suppresses the PERK-eIF2α-CHOP pathway by enhancing SIRT1 expression in oxidative stress-induced rat chondrocytes, mitigating osteoarthritis progression in a rat model

OBJECTIVE

Osteoarthritis (OA) is a degenerative disease characterized by the gradual degeneration of chondrocytes, involving endoplasmic reticulum (ER) stress. Esculin is a natural compound with antioxidant, anti-inflammatory and anti-tumor properties. However, its impact on ER stress in OA therapy has not been thoroughly investigated. We aim to determine the efficiency of Esculin in OA treatment and its underlying mechanism.

METHODS

We utilized the tert-butyl hydroperoxide (TBHP) to establish OA model in chondrocytes. The expression of SIRT1, PERK/eIF2α pathway-related proteins, apoptosis-associated proteins and ER stress-related proteins were detected by Western blot and Real-time PCR. The apoptosis was evaluated by flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. X-ray imaging, Hematoxylin & Eosin staining, Safranin O staining and immunohistochemistry were used to assess the pharmacological effects of Esculin in the anterior cruciate ligament transection (ACLT) rat OA model.

RESULTS

Esculin downregulated the expression of PERK/eIF2α pathway-related proteins, apoptosis-associated proteins and ER stress-related proteins, while upregulated the expression of SIRT1 and Bcl2 in the TBHP-induced OA model in vitro. It was coincident with the results of TUNEL staining and flow cytometry. We further confirmed the protective effect of Esculin in the rat ACLT-related model.

CONCLUSION

Our results suggest the potential therapeutic value of Esculin on osteoarthritis. It probably inhibits the PERK-eIF2α-ATF4-CHOP pathway by upregulating SIRT1, thereby mitigating endoplasmic reticulum stress and protecting chondrocytes from apoptosis.

The molecular mechanism of thrombospondin family members in cardiovascular diseases

Cardiovascular diseases have been identified as vital factors in global morbidity and mortality in recent years. The available evidence suggests that various cytokines and pathological proteins participate in these complicated and changeable diseases. The thrombospondin (TSP) family is a series of conserved, multidomain calcium-binding glycoproteins that cause cell-matrix and cell-cell effects via interactions with other extracellular matrix components and cell surface receptors. The TSP family has five members that can be divided into two groups (Group A and Group B) based on their different structures. TSP-1, TSP-2, and TSP-4 are the most studied proteins. Among recent studies and findings, we investigated the functions of several family members, especially TSP-5. We review the basic concepts of TSPs and summarize the relevant molecular mechanisms and cell interactions in the cardiovascular system. Targeting TSPs in CVD and other diseases has a remarkable therapeutic benefit.

Deciphering the omicron variant: integrated omics analysis reveals critical biomarkers and pathophysiological pathways

BACKGROUND

The rapid emergence and global dissemination of the Omicron variant of SARS-CoV-2 have posed formidable challenges in public health. This scenario underscores the urgent need for an enhanced understanding of Omicron's pathophysiological mechanisms to guide clinical management and shape public health strategies. Our study is aimed at deciphering the intricate molecular mechanisms underlying Omicron infections, particularly focusing on the identification of specific biomarkers.

METHODS

This investigation employed a robust and systematic approach, initially encompassing 15 Omicron-infected patients and an equal number of healthy controls, followed by a validation cohort of 20 individuals per group. The study's methodological framework included a comprehensive multi-omics analysis that integrated proteomics and metabolomics, augmented by extensive bioinformatics. Proteomic exploration was conducted via an advanced Ultra-High-Performance Liquid Chromatography (UHPLC) system linked with mass spectrometry. Concurrently, metabolomic profiling was executed using an Ultra-Performance Liquid Chromatography (UPLC) system. The bioinformatics component, fundamental to this research, entailed an exhaustive analysis of protein-protein interactions, pathway enrichment, and metabolic network dynamics, utilizing state-of-the-art tools such as the STRING database and Cytoscape software, ensuring a holistic interpretation of the data.

RESULTS

Our proteomic inquiry identified eight notably dysregulated proteins (THBS1, ACTN1, ACTC1, POTEF, ACTB, TPM4, VCL, ICAM1) in individuals infected with the Omicron variant. These proteins play critical roles in essential physiological processes, especially within the coagulation cascade and hemostatic mechanisms, suggesting their significant involvement in the pathogenesis of Omicron infection. Complementing these proteomic insights, metabolomic analysis discerned 146 differentially expressed metabolites, intricately associated with pivotal metabolic pathways such as tryptophan metabolism, retinol metabolism, and steroid hormone biosynthesis. This comprehensive metabolic profiling sheds light on the systemic implications of Omicron infection, underscoring profound alterations in metabolic equilibrium.

CONCLUSIONS

This study substantially enriches our comprehension of the physiological ramifications induced by the Omicron variant, with a particular emphasis on the pivotal roles of coagulation and platelet pathways in disease pathogenesis. The discovery of these specific biomarkers illuminates their potential as critical targets for diagnostic and therapeutic strategies, providing invaluable insights for the development of tailored treatments and enhancing patient care in the dynamic context of the ongoing pandemic.

TSP-1 increases autophagy level in cartilage by upregulating HSP27 which delays progression of osteoarthritis

This study aimed to determine whether Thrombospondin-1 (TSP-1) can be used as a biomarker to diagnose early osteoarthritis (OA) and whether it has a chondroprotective effect against OA. We examined TSP-1 expression in cartilage, synovial fluid, and serum at different time points after anterior cruciate ligament transection (ACLT) surgery in rats. Subsequently, TSP-1 was overexpressed or silenced to detect its effects on extracellular matrix (ECM) homeostasis, autophagy level, proliferation and apoptosis in chondrocytes. Adenovirus encoding TSP-1 was injected into the knee joints of ACLT rats to test its effect against OA. Combined with proteomic analysis, the molecular mechanism of TSP-1 in cartilage degeneration was explored. Intra-articular injection of an adenovirus carrying the TSP-1 sequence showed chondroprotective effects against OA. Moreover, TSP-1 expression decreases with OA progression and can effectively promote cartilage proliferation, inhibit apoptosis, and helps to sustain the balance between ECM anabolism and catabolism. Overexpression of TSP-1 also can increase autophagy by upregulating Heat Shock Protein 27 (HSP27, hspb1), thereby enhancing its effect as a stimulator of autophagy. TSP-1 is a hopeful strategy for OA treatment.

Integrating single-cell and spatial transcriptomics reveals endoplasmic reticulum stress-related CAF subpopulations associated with chordoma progression

BACKGROUND

With cancer-associated fibroblasts (CAFs) as the main cell type, the rich myxoid stromal components in chordoma tissues may likely contribute to its development and progression.

METHODS

Single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, bulk RNA-seq, and multiplexed quantitative immunofluorescence (QIF) were used to dissect the heterogeneity, spatial distribution, and clinical implication of CAFs in chordoma.

RESULTS

We sequenced here 72 097 single cells from 3 primary and 3 recurrent tumor samples, as well as 3 nucleus pulposus samples as controls using scRNA-seq. We identified a unique cluster of CAF in recurrent tumors that highly expressed hypoxic genes and was functionally enriched in endoplasmic reticulum stress (ERS). Pseudotime trajectory and cell communication analyses showed that this ERS-CAF subpopulation originated from normal fibroblasts and widely interacted with tumoral and immune cells. Analyzing the bulk RNA-seq data from 126 patients, we found that the ERS-CAF signature score was associated with the invasion and poor prognosis of chordoma. By integrating the results of scRNA-seq with spatial transcriptomics, we demonstrated the existence of ERS-CAF in chordoma tissues and revealed that this CAF subtype displayed the most proximity to its surrounding tumor cells. In subsequent QIF validation involving 105 additional patients, we confirmed that ERS-CAF was abundant in the chordoma microenvironment and located close to tumor cells. Furthermore, both ERS-CAF density and its distance to tumor cells were correlated with tumor malignant phenotype and adverse patient outcomes.

CONCLUSIONS

These findings depict the CAF landscape for chordoma and may provide insights into the development of novel treatment approaches.

Melatonin attenuates diabetic cardiomyopathy by increasing autophagy of cardiomyocytes via regulation of VEGF-B/GRP78/PERK signaling pathway

AIMS

Diabetic cardiomyopathy (DCM) is a major cause of mortality in patients with diabetes, and the potential strategies for treating DCM are insufficient. Melatonin (Mel) has been shown to attenuate DCM, however, the underlying mechanism remains unclear. The role of vascular endothelial growth factor-B (VEGF-B) in DCM is little known. In present study, we aimed to investigate whether Mel alleviated DCM via regulation of VEGF-B and explored its underlying mechanisms.

METHODS AND RESULTS

We found that Mel significantly alleviated cardiac dysfunction and improved autophagy of cardiomyocytes in type 1 diabetes mellitus (T1DM) induced cardiomyopathy mice. VEGF-B was highly expressed in DCM mice in comparison with normal mice, and its expression was markedly reduced after Mel treatment. Mel treatment diminished the interaction of VEGF-B and Glucose-regulated protein 78 (GRP78) and reduced the interaction of GRP78 and protein kinase RNA -like ER kinase (PERK). Furthermore, Mel increased phosphorylation of PERK and eIF2α, then up-regulated the expression of ATF4. VEGF-B-/- mice imitated the effect of Mel on wild type diabetic mice. Interestingly, injection with Recombinant adeno-associated virus serotype 9 (AAV9)-VEGF-B or administration of GSK2656157 (GSK), an inhibitor of phosphorylated PERK abolished the protective effect of Mel on DCM. Furthermore, rapamycin, an autophagy agonist displayed similar effect with Mel treatment; while 3-Methyladenine (3-MA), an autophagy inhibitor neutralized the effect of Mel on high glucose-treated neonatal rat ventricular myocytes.

CONCLUSIONS

These results demonstrated that Mel attenuated DCM via increasing autophagy of cardiomyocytes, and this cardio-protective effect of Mel was dependent on VEGF-B/GRP78/PERK signaling pathway.

Dibromoacetonitrile induced autophagy by mediating the PERK signalling pathway and ROS interaction in HT22 cell

Dibromoacetonitrile (DBAN) is a high-risk haloacetonitrile (HAN) generated as a byproduct of chloramine disinfection in drinking water. DBAN-induced neurotoxicity in mouse hippocampal neuronal cells (HT22) and mammals was observed to be related to reactive oxygen species (ROS). ROS, endoplasmic reticulum stress (ERS) and autophagy play crucial roles in regulating a variety of cellular processes. However, whether ERS and autophagy are associated with HAN-responsive apoptosis remains unclear. This study indicated that DBAN (10 μM, 24 h) activated the ERS protein kinase like endoplasmic reticulum kinase (PERK) signaling pathway. The ERS inhibitor 4-phenylbutyric acid (4-PBA) reversed DBAN-inhibited cell viability and alleviated DBAN-induced apoptosis in HT22 cell, indicating that activation of the ERS PERK pathway mediates DBAN induced cytotoxicity. Moreover, DBAN activated autophagy. The autophagy inhibitor 3-methyladenine(3-MA) reversed DBAN-inhibited cell viability and alleviated DBAN-induced apoptosis in HT22 cell, suggesting that autophagy activation mediates DBAN-induced cell toxicity. Notably, the results showed that 4-PBA inhibited DBAN-activated autophagy, demonstrating that ERS-PERK promotes DBAN-induced cellular autophagy. Pretreatment with antioxidant N-acetylcysteine (NAC) inhibited the increase in ROS production and the activation of ERS, and protected cells from toxicity. Furthermore, 4-PBA pretreatment reduced the increase in ROS production, indicating that the ROS and PERK promote each other and form a positive feedback loop. ROS also promoted DBAN-induced autophagy. In summary, our findings indicate that DBAN induced autophagy by mediating the PERK signalling pathway and ROS interaction, leading to HT22 cell damage. Accordingly, targeting these pathogenic mechanisms may provide a potential target and theoretical basis for preventing and improving HAN-induced neurotoxicity.

Single-cell Transcriptomics Reveals Activation of Macrophages in All-trans Retinoic Acid (atRA)-induced Cleft Palate

Cleft palate is among the most common birth defects with an impact on swallowing and speaking and is difficult to diagnose with ultrasound during pregnancy. In this study, we systematically capture the cellular composition of all-trans retinoic acid (atRA)-exposed and normal embryonic gestation 16.5 days mouse palate by the single-cell RNA sequencing technique. The authors identified 14 major cell types with the largest proportion of fibroblasts. The proportion of myeloid cells in atRA-exposed palate was markedly higher than those in the normal palate tissue, especially M1-like macrophages and monocytes. The upregulated genes of the different expression genes between atRA-exposed palate and normal palate tissue were linked to the biological processes of leukocyte chemotaxis and migration. Protein TLR2, CXCR4, THBS1, MRC1, transcription factor encoding genes Cebpb, Fos, Jun, Rela, and signaling pathway IL-17 and phagosome were found to be significantly involved in these processes. Subsequently, cellular communication network analysis suggested that myeloid-centered cell interactions SELL, SELPLG, MIF, CXCL, ANNEXIN, THBS, and NECTIN were significantly more activated in atRA-exposed palate. Overall, we delineate the single-cell landscape of atRA-induced cleft palate, revealing the effects of overexposure to atRA during palate tissue development and providing insights for the diagnosis of cleft palate.

LncRNA MIR217HG aggravates pressure-overload induced cardiac remodeling by activating miR-138/THBS1 pathway

AIM

Cardiac hypertrophy and fibrosis are associated with cardiac remodeling and heart failure. We have previously shown that miRNA-217, embedded within the third intron of MIR217HG, aggravates pressure overload-induced cardiac hypertrophy by targeting phosphatase and tensin homolog. However, whether the MIR217HG transcript itself plays a role in cardiac remodeling remains unknown.

METHODS

Real-time PCR assays and RNA in situ hybridization were performed to detect MIR217HG expression. Lentiviruses and adeno-associated viruses with a cardiac-specific promoter (cTnT) were used to control MIR217HG expression in vitro and in vivo. Transverse aortic constriction (TAC) surgery was performed to develop cardiac remodeling models. Cardiac structure and function were analyzed using echocardiography and invasive pressure-volume analysis.

KEY FINDINGS

MIR217HG expression was increased in patients with heart failure. MIR217HG overexpression aggravated pressure-overload-induced myocyte hypertrophy and fibrosis both in vivo and in vitro, whereas MIR217HG knockdown reversed these phenotypes. Mechanistically, MIR217HG increased THBS1 expression by sponging miR-138. MiR-138 recognized the 3'UTR of THBS1 and repressed THBS1 expression in the absence of MIR217HG. Silencing THBS1 expression reversed MIR217HG-induced cardiac hypertrophy and remodeling.

CONCLUSION

MIR217HG acts as a potent inducer of cardiac remodeling that may contribute to heart failure by activating the miR-138/THBS1 pathway.

Mechanism Exploration on the Immunoregulation of Allogeneic Heart Transplantation Rejection in Rats With Exosome miRNA and Proteins From Overexpressed IDO1 BMSCs

Immunoregulation and indoleamine 2,3-dioxygenase 1 (IDO1) play pivotal roles in the rejection of allogeneic organ transplantation. This study aims to elucidate the immune-related functional mechanisms of exosomes (Exos) derived from bone marrow-derived mesenchymal stem cells (BMSCs) overexpressing IDO1 in the context of allogeneic heart transplantation (HTx) rejection. A rat model of allogeneic HTx was established. Exos were extracted after transfection with oe-IDO1 and oe-NC from rat BMSCs. Exos were administered via the caudal vein for treatment. The survival of rats was analyzed, and reverse transcription qualitative PCR (RT-qPCR) and immunohistochemistry (IHC) were employed to detect the expression of related genes. Histopathological examination was conducted using hematoxylin and eosin (HE) staining, and flow cytometry was utilized to analyze T-cell apoptosis. Proteomics and RNA-seq analyses were performed on Exos. The data were subjected to functional enrichment analysis using the R language. A protein interaction network was constructed using the STRING database, and miRWalk, TargetScan, and miRDB databases predicted the target genes, differentially expressed miRNAs, and transcription factors (TFs). Exos from BMSCs overexpressing IDO1 prolonged the survival time of rats undergoing allogeneic HTx. These Exos reduced inflammatory cell infiltration, mitigated myocardial damage, induced CD4 T-cell apoptosis, and alleviated transplantation rejection. The correlation between Exos from BMSCs overexpressing IDO1 and immune regulation was profound. Notably, 13 immune-related differential proteins (Anxa1, Anxa2, C3, Ctsb, Hp, Il1rap, Ntn1, Ptx3, Thbs1, Hspa1b, Vegfc, Dcn, and Ptpn11) and 10 significantly different miRNAs were identified. Finally, six key immune proteins related to IDO1 were identified through common enrichment pathways, including Thbs1, Dcn, Ptpn11, Hspa1b, Il1rap, and Vegfc. Thirteen TFs of IDO1-related key miRNAs were obtained, and a TF-miRNA-mRNA-proteins regulatory network was constructed. Exosome miRNA derived from BMSCs overexpressing IDO1 may influence T-cell activation and regulate HTx rejection by interacting with mRNA.

DDIT4 is essential for DINP-induced autophagy of ovarian granulosa cells

As one of the most important phthalates, di-isononyl phthalate (DINP) has been widely used as a common plasticizer in the food and personal care products sectors. In our previous study, we found that DINP can induce autophagy of ovarian granulosa cells; while the underlying mechanism is unclear. In the study, we showed that DINP exposure could induce autophagy of ovarian granulosa cells and KGN cells, accompanied with the increase in the mRNA and protein level of DDIT4. Furthermore, overexpression of DDIT4 were shown to induce autophagy of KGN cells; while knockdown of DDIT4 inhibited DINP-induced autophagy, implying that DDIT4 played an important role in DINP-induced autophagy of ovarian granulosa cells. There were three putative binding sites of transcription factor ATF4 in the promoter region of DDIT4 gene, suggesting that DDIT4 might be regulated by ATF4. Herein, we found that overexpression of ATF4 could upregulate the expression of DDIT4 in KGN cells, while knockdown of ATF4 inhibited its expression. Subsequently, ATF4 was identified to bind to the promoter region of DDIT4 gene and promote its transcription. The expression of ATF4 was also increased in the DINP-exposed granulosa cells, and ATF4 overexpression promoted autophagy of KGN cells; whereas knockdown of ATF4 alleviated DINP-induced upregulation of DDIT4 and autophagy of the cells. Taken together, DINP triggered autophagy of ovarian granulosa cells through activating ATF4/DDIT4 signals.

Investigation of a UPR-Related Gene Signature Identifies the Pro-Fibrotic Effects of Thrombospondin-1 by Activating CD47/ROS/Endoplasmic Reticulum Stress Pathway in Lung Fibroblasts

Unfolded protein response (UPR) signaling and endoplasmic reticulum (ER) stress have been linked to pulmonary fibrosis. However, the relationship between UPR status and pulmonary function and prognosis in idiopathic pulmonary fibrosis (IPF) patients remains largely unknown. Through a series of bioinformatics analyses, we established a correlation between UPR status and pulmonary function in IPF patients. Furthermore, thrombospondin-1 (TSP-1) was identified as a potential biomarker for prognostic evaluation in IPF patients. By utilizing both bulk RNA profiling and single-cell RNA sequencing data, we demonstrated the upregulation of TSP-1 in lung fibroblasts during pulmonary fibrosis. Gene set enrichment analysis (GSEA) results indicated a positive association between TSP-1 expression and gene sets related to the reactive oxygen species (ROS) pathway in lung fibroblasts. TSP-1 overexpression alone induced mild ER stress and pulmonary fibrosis, and it even exacerbated bleomycin-induced ER stress and pulmonary fibrosis. Mechanistically, TSP-1 promoted ER stress and fibroblast activation through CD47-dependent ROS production. Treatment with either TSP-1 inhibitor or CD47 inhibitor significantly attenuated BLM-induced ER stress and pulmonary fibrosis. Collectively, these findings suggest that the elevation of TSP-1 during pulmonary fibrosis is not merely a biomarker but likely plays a pathogenic role in the fibrotic changes in the lung.

Deciphering the molecular and cellular atlas of immune cells in septic patients with different bacterial infections

BACKGROUND

Sepsis is a life-threatening organ dysfunction caused by abnormal immune responses to various, predominantly bacterial, infections. Different bacterial infections lead to substantial variation in disease manifestation and therapeutic strategies. However, the underlying cellular heterogeneity and mechanisms involved remain poorly understood.

METHODS

Multiple bulk transcriptome datasets from septic patients with 12 types of bacterial infections were integrated to identify signature genes for each infection. Signature genes were mapped onto an integrated large single-cell RNA (scRNA) dataset from septic patients, to identify subsets of cells associated with different sepsis types, and multiple omics datasets were combined to reveal the underlying molecular mechanisms. In addition, an scRNA dataset and spatial transcriptome data were used to identify signaling pathways in sepsis-related cells. Finally, molecular screening, optimization, and de novo design were conducted to identify potential targeted drugs and compounds.

RESULTS

We elucidated the cellular heterogeneity among septic patients with different bacterial infections. In Escherichia coli (E. coli) sepsis, 19 signature genes involved in epigenetic regulation and metabolism were identified, of which DRAM1 was demonstrated to promote autophagy and glycolysis in response to E. coli infection. DRAM1 upregulation was confirmed in an independent sepsis cohort. Further, we showed that DRAM1 could maintain survival of a pro-inflammatory monocyte subset, C10_ULK1, which induces systemic inflammation by interacting with other cell subsets via resistin and integrin signaling pathways in blood and kidney tissue, respectively. Finally, retapamulin was identified and optimized as a potential drug for treatment of E. coli sepsis targeting the signature gene, DRAM1, and inhibiting E. coli protein synthesis. Several other targeted drugs were also identified in other types of sepsis, including nystatin targeting C1QA in Neisseria sepsis and dalfopristin targeting CTSD in Streptococcus viridans sepsis.

CONCLUSION

Our study provides a comprehensive overview of the cellular heterogeneity and underlying mechanisms in septic patients with various bacterial infections, providing insights to inform development of stratified targeted therapies for sepsis.

Exogenous Ang-(1-7) inhibits autophagy via HIF-1α/THBS1/BECN1 axis to alleviate chronic intermittent hypoxia-enhanced airway remodelling of asthma

Obstructive sleep apnoea (OSA)-induced chronic intermittent hypoxia (CIH) has been considered a risk factor for severe asthma. Airway remodelling, which could be modulated by autophagy, plays a key role in severe asthma. However, the extent of autophagy's involvement in CIH-potentiated airway remodelling remains largely unexplored. Furthermore, we had found that angiotensin-(1-7) [Ang-(1-7)] has therapeutic effects on airway remodelling in asthma, but the underlying mechanism is either unclear. This study aimed to explore how CIH aggravates asthma and mechanism of protective effects of Ang-(1-7) on airway remodelling, with a focus on autophagy. We observed that CIH promoted epithelial-to-mesenchymal transition (EMT), indicated by elevated EMT and fibrotic markers such as Snail and Collagen IV, both in vitro and in vivo. CIH intensified cell autophagy, evident from increased LC3B expression and reduced p62 levels. Ang-(1-7) reversed the CIH-enhanced expression of Snail, Collagen IV, and LC3B. To explore how CIH enhanced autophagy in cellular and animal model of asthma, overexpression of hypoxia-inducible factor 1-alpha (HIF-1α) and Thrombospondin 1 (THBS1) were identified in CIH-exposure mice lung compared with normal mice lung tissues from the GEO database. Finally, through chromatin immunoprecipitation and immunoprecipitation assays, we verified that Ang-(1-7) inhibits CIH-induced binding of HIF-1α to the promoter of THBS1, and also disrupts the protein-protein interaction between THBS1 and the autophagy-associated protein Beclin 1 (BECN1), ultimately leading to autophagy inhibition. Our findings suggest that exogenous Ang-(1-7) can inhibit autophagy via HIF-1α/THBS1/BECN1 axis, thereby alleviating CIH-enhanced airway remodelling in asthma. These findings imply the potential therapeutic effect of Ang-(1-7) in asthma with OSA.

New perspective on mechanism in muscle toxicity of ochratoxin A: Model of juvenile grass carp (Ctenopharyngodon idella)

Ochratoxin A (OTA) is a common fungal toxin that pollutes raw materials of aquatic feeds (such as corn, soybean meal, and wheat). This study explored the effects of OTA through diet on muscle toxicity in juvenile grass carp (Ctenopharyngodon idella). The following results were obtained for the muscle. (1) With an increase in dietary OTA, the residue of OTA in muscle increased, muscle fiber diameter and density decreased, and even muscle fiber breakage. (2) OTA caused oxidative stress by downregulating GPx1 (a, b) and Trx via inhibited the PGC1-α/Nrf2 signaling pathway. (3) OTA exacerbated endoplasmic reticulum stress in the muscle by causing endoplasmic reticulum expansion (results of transmission electron microscopy) and upregulating the expression of GRP78, eIF2α, ATF6, PERK, and CHOP. (4) OTA reduced muscle fiber diameter by inhibiting protein synthesis (AKT, TOR, and S6K1) and promoting the mRNA expression of protein degradation-related genes (MURF1, MAFBX, and FoxO3a), as well as by reducing AKT and promoting the immunofluorescence expression of FoxO3. (5) OTA inhibits collagen deposition by downregulating TGF-β1, TGF-βR1, Smad2, Smad3, Smad4, CTGF, TIMP, PHD, and LOX mRNA expressions as well as the CTGF immunofluorescence expression. Moreover, based on the GSH and collagen content contents, the upper safe dose for OTA-induced toxicity was 963.6 and 1129.6 μg/kg diet, respectively. Using the example of OTA, our research has provided new insights that raise concerns about the quality of aquatic products by exploring muscle toxicity caused by mycotoxins.

PHB2 ameliorates Doxorubicin-induced cardiomyopathy through interaction with NDUFV2 and restoration of mitochondrial complex I function

BACKGROUND

Doxorubicin (DOX) is among the most widely employed antitumor agents, although its clinical applications have been largely hindered by severe cardiotoxicity. Earlier studies described an essential role of mitochondrial injury in the pathogenesis of DOX cardiomyopathy. PHB2 (Prohibitin 2) is perceived as an essential regulator for mitochondrial dynamics and oxidative phosphorylation (OXPHOS) although its involvement in DOX cardiomyopathy remains elusive.

METHODS

To decipher the possible role of PHB2 in DOX cardiomyopathy, tamoxifen-induced cardiac-specific PHB2 conditional knockout mice were generated and subjected to DOX challenge. Cardiac function and mitochondrial profiles were examined. Screening of downstream mediators of PHB2 was performed using proteomic profiling and bioinformatic analysis, and was further verified using co-immunoprecipitation and pulldown assays.

RESULTS

Our data revealed significantly downregulated PHB2 expression in DOX-challenged mouse hearts. PHB2CKO mice were more susceptible to DOX cardiotoxicity compared with PHB2flox/flox mice, as evidenced by more pronounced cardiac atrophy, interstitial fibrosis and decrease in left ventricular ejection fraction and fractional shortening. Mechanistically, PHB2 deficiency resulted in the impairment of mitochondrial bioenergetics and oxidative phosphorylation in DOX cardiotoxicity. Proteomic profiling and interactome analyses revealed that PHB2 interacted with NDUFV2 (NADH-ubiquinone oxidoreductase core subunit V2), a key subunit of mitochondrial respiratory Complex I to mediate regulatory property of PHB2 on mitochondrial metabolism. PHB2 governed the expression of NDUFV2 by promoting its stabilization, while PHB2 deficiency significantly downregulated NDUFV2 in DOX-challenged hearts. Cardiac overexpression of PHB2 alleviated mitochondrial defects in DOX cardiomyopathy both in vivo and in vitro.

CONCLUSIONS

Our study defined a novel role for PHB2 in mitochondrial dynamics and energetic metabolism through interacting with NDUFV2 in DOX-challenged hearts. Forced overexpression of PHB2 may be considered a promising therapeutic approach for patients with DOX cardiomyopathy.

Ryanodine receptor 2 (RYR2) dysfunction activates the unfolded protein response and perturbs cardiomyocyte maturation

AIMS

Calcium-handling capacity is a major gauge of cardiomyocyte maturity. Ryanodine receptor 2 (RYR2) is the pre-dominant calcium channel that releases calcium from the sarcoplasmic reticulum/endoplasmic reticulum (SR/ER) to activate cardiomyocyte contraction. Although RYR2 was previously implied as a key regulator of cardiomyocyte maturation, the mechanisms remain unclear. The aim of this study is to solve this problem.

METHODS AND RESULTS

We performed Cas9/AAV9-mediated somatic mutagenesis to knockout RYR2 specifically in cardiomyocytes in mice. We conducted a genetic mosaic analysis to dissect the cell-autonomous function of RYR2 during cardiomyocyte maturation. We found that RYR2 depletion triggered ultrastructural and transcriptomic defects relevant to cardiomyocyte maturation. These phenotypes were associated with the drastic activation of ER stress pathways. The ER stress alleviator tauroursodeoxycholic acid partially rescued the defects in RYR2-depleted cardiomyocytes. Overexpression of ATF4, a key ER stress transcription factor, recapitulated defects in RYR2-depleted cells. Integrative analysis of RNA-Seq and bioChIP-Seq data revealed that protein biosynthesis-related genes are the major direct downstream targets of ATF4.

CONCLUSION

RYR2-regulated ER homeostasis is essential for cardiomyocyte maturation. Severe ER stress perturbs cardiomyocyte maturation primarily through ATF4 activation. The major downstream effector genes of ATF4 are related to protein biosynthesis.

Clinical phenotyping of plasma thrombospondin-2 reveals relationship to right ventricular structure and function in pulmonary hypertension

Background

Converging evidence from proteogenomic analyses prioritises thrombospondin-2 (TSP2) as a potential biomarker for idiopathic or heritable pulmonary arterial hypertension (PAH). We aimed to assess TSP2 levels in different forms of pulmonary hypertension (PH) and to define its clinical phenotype.

Methods

Absolute concentrations of TSP2 were quantified in plasma samples from a prospective single-centre cohort study including 196 patients with different forms of PH and 16 disease controls (suspected PH, but normal resting pulmonary haemodynamics). In an unbiased approach, TSP2 levels were related to 152 clinical variables.

Results

Concentrations of TSP2 were increased in patients with PH versus disease controls (p<0.001 for group comparison). The discriminatory ability of TSP2 levels to distinguish between patients and controls was superior to that of N-terminal pro-brain natriuretic peptide (p=0.0023 for comparison of areas under the curve). Elevation of TSP2 levels was consistently found in subcategories of PAH, in PH due to lung disease and due to left heart disease. Phenotypically, TSP2 levels were robustly related to echocardiographic markers that indicate the right ventricular (RV) response to chronically increased afterload with increased levels in patients with impaired systolic function and ventriculoarterial uncoupling. Focusing on PAH, increased TSP2 levels were able to distinguish between adaptive and maladaptive RV phenotypes (area under the curve 0.87, 95% CI 0.76-0.98).

Interpretation

The study indicates that plasma TSP2 levels inform on the presence of PH and associate with clinically relevant RV phenotypes in the setting of increased afterload, which may provide insight into processes of RV adaptability.

Jianpi-Qingchang decoction alleviates ulcerative colitis by modulating endoplasmic reticulum stress-related autophagy in intestinal epithelial cells

Endoplasmic reticulum stress (ERS)-related autophagy is involved in the occurrence and development of ulcerative colitis (UC). Therefore, regulating ERS-related autophagy is a potential therapeutic target for the treatment of UC. Jianpi-Qingchang (JPQC) decoction, consisting of nine Chinese herbal medicines, is used to treat patients with UC. However, its mechanism of action has not been completely elucidated. Here, we aimed to reveal the therapeutic effects and mechanisms of JPQC in UC. We established a colitis model using dextran sulfate sodium (DSS) and an ERS model using thapsigargin (Tg) and administered JPQC. We systematically examined ERS-related autophagy associated protein expression, inflammatory cytokines, apoptotic cells, and autophagic flux. Moreover, the cellular ultrastructure was observed via transmission electron microscopy (TEM). We found that JPQC reduced disease activity index (DAI) scores, counteracted colonic tissue damage, decreased the number of autophagosomes, inhibited proinflammatory cytokines, enhanced anti-inflammatory cytokines, and dampened ERS-related autophagy associated protein gene expression.

Influence of extracellular matrix composition on tumour cell behaviour in a biomimetic in vitro model for hepatocellular carcinoma

The tumor micro-environment (TME) of hepatocellular carcinoma (HCC) consists out of cirrhotic liver tissue and is characterized by an extensive deposition of extracellular matrix proteins (ECM). The evolution from a reversible fibrotic state to end-stage of liver disease, namely cirrhosis, is characterized by an increased deposition of ECM, as well as changes in the exact ECM composition, which both contribute to an increased liver stiffness and can alter tumor phenotype. The goal of this study was to assess how changes in matrix composition and stiffness influence tumor behavior. HCC-cell lines were grown in a biomimetic hydrogel model resembling the stiffness and composition of a fibrotic or cirrhotic liver. When HCC-cells were grown in a matrix resembling a cirrhotic liver, they increased proliferation and protein content, compared to those grown in a fibrotic environment. Tumour nodules spontaneously formed outside the gels, which appeared earlier in cirrhotic conditions and were significantly larger compared to those found outside fibrotic gels. These tumor nodules had an increased expression of markers related to epithelial-to-mesenchymal transition (EMT), when comparing cirrhotic to fibrotic gels. HCC-cells grown in cirrhotic gels were also more resistant to doxorubicin compared with those grown in fibrotic gels or in 2D. Therefore, altering ECM composition affects tumor behavior, for instance by increasing pro-metastatic potential, inducing EMT and reducing response to chemotherapy.

Transcriptomics reveals the effects of NTRK1 on endoplasmic reticulum stress response-associated genes in human neuronal cell lines

Background

NTRK1 gene, encoding TrkA, is essential for the nervous system and drives a variety of biological processes, including pain. Given the unsatisfied analgesic effects of some new drugs targeting NTRK1 in clinic, a deeper understanding for the mechanism of NTRK1 in neurons is crucial.

Methods

We assessed the transcriptional responses in SH-SY5Y cells with NTRK1 overexpression using bioinformatics analysis. GO and KEGG analyses were performed, PPI networks were constructed, and the functional modules and top 10 genes were screened. Subsequently, hub genes were validated using RT-qPCR.

Results

A total of 419 DEGs were identified, including 193 upregulated and 226 downregulated genes. GO showed that upregulated genes were mainly enriched in response to endoplasmic reticulum (ER) stress, protein folding in ER, etc., and downregulated genes were highly enriched in a series of cellular parts and cellular processes. KEGG showed DEGs were enriched in protein processing in ER and pathways associated with cell proliferation and migration. The finest module was dramatically enriched in the ER stress response-related biological process. The verified seven hub genes consisted of five upregulated genes (COL1A1, P4HB, HSPA5, THBS1, and XBP1) and two downregulated genes (CCND1 and COL3A1), and almost all were correlated with response to ER stress.

Conclusion

Our data demonstrated that NTRK1 significantly influenced the gene transcription of ER stress response in SH-SY5Y cells. It indicated that ER stress response could contribute to various functions of NTRK1-dependent neurons, and therefore, ER stress response-associated genes need further study for neurological dysfunction implicated in NTRK1.