The crystallin alpha B (HSPB5)-tripartite motif containing 33 (TRIM33) axis mediates myocardial fibrosis induced by angiotensinogen II through transforming growth factor-β (TGF-β1)-Smad3/4 signaling

Epigenetic targets and their inhibitors in the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a deadly lung disease characterized by fibroblast proliferation, excessive extracellular matrix buildup, inflammation, and tissue damage, resulting in respiratory failure and death. Recent studies suggest that impaired interactions among epithelial, mesenchymal, immune, and endothelial cells play a key role in IPF development. Advances in bioinformatics have also linked epigenetics, which bridges gene expression and environmental factors, to IPF. Despite the incomplete understanding of the pathogenic mechanisms underlying IPF, recent preclinical studies have identified several novel epigenetic therapeutic targets, including DNMT, EZH2, G9a/GLP, PRMT1/7, KDM6B, HDAC, CBP/p300, BRD4, METTL3, FTO, and ALKBH5, along with potential small-molecule inhibitors relevant for its treatment. This review explores the pathogenesis of IPF, emphasizing epigenetic therapeutic targets and potential small molecule drugs. It also analyzes the structure-activity relationships of these epigenetic drugs and summarizes their biological activities. The objective is to advance the development of innovative epigenetic therapies for IPF.

Small Extracellular Vesicles from Young Healthy Human Plasma Inhibit Cardiac Fibrosis After Myocardial Infarction via miR-664a-3p Targeting SMAD4

Purpose

Cardiac fibrosis, a key contributor to ventricular pathologic remodeling and heart failure, currently lacks effective therapeutic approaches.

Patients and Methods

Small extracellular vesicles from young healthy human plasma (Young-sEVs) were characterized via protein marker, transmission electron microscopy, and nanoparticle tracking analysis, then applied in cellular models and mouse models of cardiac fibrosis. Western blotting and qRT-PCR were used to identify protective signaling pathways in cardiac fibroblasts (CFs).

Results

Young-sEVs significantly inhibited cardiac fibrosis and subsequent cardiac dysfunction post-myocardial infarction (MI) in mice. The main findings included that echocardiographic assessments four weeks post-MI indicated that Young-sEVs improved left ventricular ejection fraction (LVEF) and fractional shortening (LVFS), and reduced left ventricular internal diameter in diastole (LVIDd) and systole (LVIDs). Treatment with Young-sEVs also decreased Masson-positive fibroblast areas and collagen synthesis in cardiac tissue. However, sEVs from the old control group did not achieve the above effect. Consistent with in vivo results, Young-sEVs could also inhibit the proliferation, migration, and collagen synthesis of CFs in the TGF-β1-induced cellular fibrosis model. High-throughput microRNA (miRNA) sequencing and qRT-PCR analysis revealed that miR-664a-3p was abundant in Young-sEVs. The high expression of miR-664a-3p significantly inhibited the proliferation, migration, and collagen synthesis of TGF-β1-induced CFs. However, suppressing the expression of miR-664a-3p in Young-sEVs eliminated their therapeutic effect on cardiac fibrosis in mice. Further studies confirmed SMAD4 as a direct downstream target of miR-664a-3p, whose overexpression could reverse the anti-fibrotic effects of miR-664a-3p.

Conclusion

In summary, these findings firstly revealed that Young-sEVs could directly bind to the 3'-untranslated region of SMAD4 mRNA through miR-664a-3p, thereby inhibiting the TGF-β/SMAD4 signaling pathway to protect heart from fibrosis and improve cardiac function. Considering the ease of obtaining plasma-derived sEVs, our study offers a promising therapeutic strategy for heart failure, with the potential for rapid clinical translation in the near future.

Enhanced fibrotic potential of COL1A1hiNR4A1low fibroblasts in ischemic heart revealed by transcriptional dynamics heterogeneity analysis at both bulk and single-cell levels

Background

Fibroblasts in the fibrotic heart exhibit a heterogeneous biological behavior. The specific subsets of fibroblasts that contribute to progressive cardiac fibrosis remain unrevealed. Our aim is to identify the heart fibroblast (FB) subsets that most significantly promote fibrosis and the related critical genes as biomarkers for ischemic heart disease.

Methods

The single nuclei RNA sequencing (snRNA-seq) and bulk RNA sequencing datasets used in this study were obtained from the Gene Expression Omnibus (GEO). The activity of gene sets related to progressive fibrosis was quantified for each FB cluster using the AddmoleculeScore function. Differentially expressed genes (DEGs) for the specific cell cluster with the highest fibrotic transcription dynamics were identified and integrated with bulk RNA sequencing data for analysis. Multiple machine learning models were employed to identify the optimal gene panel for diagnosing ischemic heart disease (IHD) based on the intersected DEGs. The effectiveness and robustness of the gene-derived diagnostic tool were validated using two independent IHD cohorts.Subsequently, we validated the signature genes using a rat post-myocardial infarction heart failure model.

Results

We conducted an analysis on high-quality snRNA-seq data obtained from 3 IHD and 4 cardiac sarcoidosis heart samples, resulting in the identification of 16 FB clusters. Cluster2 exhibited the highest gene activity in terms of fibrosis-related transcriptome dynamics. The characteristic gene expression profile of this FB subset indicated a specific upregulation of COL1A1 and several pro-fibrotic factors, including CCDC102B, GUCY1A3, TEX41, NREP, TCAP, and WISP, while showing a downregulation of NR4A1, an endogenous inhibitor of the TGF-β pathway. Consequently, we designated this subgroup as COL1A1hiNR4A1low FB. Gene set enrichment analysis (GSEA) shows that the gene expression pattern of COL1A1hiNR4A1low FB was closer to pathways associated with cardiac fibrosis. Through machine learning, ten feature genes from COL1A1hiNR4A1low FB were selected to construct a diagnostic tool for IHD. The robustness of this new tool was validated using an independent cohort and heart failure rats.

Conclusion

COL1A1hiNR4A1low FB possess heightened capability in promoting cardiac fibrosis. Additionally, it offers molecular insights into the mechanisms underlying the regulation of the TGF-β pathway. Furthermore, the characteristic genes of COL1A1hiNR4A1 FB could serve as valuable tools for diagnosing of IHD.

Cardiac-targeted delivery of a novel Drp1 inhibitor for acute cardioprotection

Dynamin-related protein 1 (Drp1) is a mitochondrial fission protein and a viable target for cardioprotection against myocardial ischaemia-reperfusion injury. Here, we reported a novel Drp1 inhibitor (DRP1i1), delivered using a cardiac-targeted nanoparticle drug delivery system, as a more effective approach for achieving acute cardioprotection. DRP1i1 was encapsulated in cubosome nanoparticles with conjugated cardiac-homing peptides (NanoDRP1i1) and the encapsulation efficiency was 99.3 ± 0.1 %. In vivo, following acute myocardial ischaemia-reperfusion injury in mice, NanoDRP1i1 significantly reduced infarct size and serine-616 phosphorylation of Drp1, and restored cardiomyocyte mitochondrial size to that of sham group. Imaging by mass spectrometry revealed higher accumulation of DRP1i1 in the heart tissue when delivered as NanoDRP1i1. In human cardiac organoids subjected to simulated ischaemia-reperfusion injury, treatment with NanoDRP1i1 at reperfusion significantly reduced cardiac cell death, contractile dysfunction, and mitochondrial superoxide levels. Following NanoDRP1i1 treatment, cardiac organoid proteomics further confirmed reprogramming of contractile dysfunction markers and enrichment of the mitochondrial protein network, cytoskeletal and metabolic regulation networks when compared to the simulated injury group. These proteins included known cardioprotective regulators identified in human organoids and in vivo murine studies following ischaemia-reperfusion injury. DRP1i1 is a promising tool compound to study Drp1-mediated mitochondrial fission and exhibits promising therapeutic potential for acute cardioprotection, especially when delivered using the cardiac-targeted cubosome nanoparticles.

Biological effects and mechanism of β-amyloid aggregation inhibition by penetrable recombinant human HspB5-ACD structural domain protein

Alzheimer's disease (AD) is a global medical challenge. Studies have shown that neurotoxicity caused by pathological aggregation of β-amyloid (Aβ) is an important factor leading to AD. Therefore, inhibiting the pathological aggregation of Aβ is the key to treating AD. The recombinant human HspB5-ACD structural domain protein (AHspB5) prepared by our group in the previous period has been shown to have anti-amyloid aggregation effects, but its inability to penetrate biological membranes has limited its development. In this study, we prepared a recombinant fusion protein (T-AHspB5) of TAT and AHspB5. In vitro experiments showed that T-AHspB5 inhibited the formation of Aβ1-42 protofibrils and had the ability to penetrate the blood-brain barrier; in cellular experiments, T-AHspB5 prevented Aβ1-42-induced oxidative stress damage, apoptosis, and inflammatory responses in neuronal cells, and its mechanism of action was related to microglia activation and mitochondria-dependent apoptotic pathway. In animal experiments, T-AHspB5 improved memory and cognitive dysfunction and inhibited pathological changes of AD in APP/PS1 mice. In conclusion, this paper is expected to reveal the intervention mechanism and biological effect of T-AHspB5 on pathological aggregation of Aβ1-42, provide a new pathway for the treatment of AD, and lay the foundation for the future development and application of T-AHspB5.

CircBCL2L13 attenuates cardiomyocyte oxidative stress and apoptosis in cardiac ischemia‒reperfusion injury via miR-1246/PEG3 signaling

Ischemia‒reperfusion (I/R) is a common complication in the clinical treatment of acute myocardial infarction (MI), in which cardiomyocytes play a pivotal role in the recovery of cardiac function after reperfusion injury. The expression of numerous circular ribonucleic acids (circRNAs) is disrupted in I/R-induced cardiac damage, but the potential role of circRNAs in I/R damage has not been fully elucidated. The purpose of the present study was to clarify the biological action and molecular mechanism of circRNA 002166 (also termed circCL2L13) in postmyocardial I/R. Oxygen-glucose deprivation/reoxygenation (OGD/R) in an in vivo model was performed to simulate I/R damage. real-time polymerase chain reaction analysis was also conducted to evaluate the relationships of the SOD1, SOD2, NRF2, HO1 and GPX4 indicators with oxidative stress injury. TUNEL immunofluorescence was used to evaluate the degree of cardiomyocyte apoptosis in the different treatment groups. The circBCL2L13 level was markedly upregulated in myocardial tissues from a mouse I/R model. Overexpression of circBCL2L13 markedly attenuated the expression of oxidative stress-related genes and apoptosis in OGD/R-induced cardiomyocytes. A mechanistic study revealed that circBCL2L13 functions as a ceRNA for miR-1246 and modulates paternally expressed gene 3 (PEG3). Eventually, circBCL2L13 was proven to regulate PEG3 by targeting miR-1246, thereby protecting against OGD/R-induced cardiomyocyte oxidative damage and apoptosis. In conclusion, our study confirmed that the circBCL2L13/miR-1246/PEG3 axis suppressed the progression of OGD/R injury in cardiomyocytes, which might lead to new therapeutic strategies for cardiac I/R injury.

Genomic and transcriptome insight into the structure and immunity role of TRIM proteins in Chinese soft-shelled turtles (Pelodiscus sinensis) after Aeromonas hydrophila infection

BACKGROUND

TRIM proteins, recognized as a class of E3 ubiquitin ligases, are increasingly acknowledged for their antipathogen immune functions in mammals and fish. In the Chinese soft-shelled turtle (Pelodiscus sinensis), a secondary aquatic reptile that occupies a unique evolutionary position, the TRIM gene has rarely been reported.

METHODS AND RESULTS

In the present study, 48 PsTRIM proteins were identified from the genome of Pelodiscus sinensis via Hidden Markov Model (HMM) searches and Signal Transduction ATPases with Numerous Domains (SMART) analysis. These PsTRIMs were found across 43 distinct scaffolds, and phylogenetic analyses classified them into three principal clades. The PsTRIMs feature a conserved assembly of either RING-B-box-coiled-coil (RBCC) or B-box-coiled-coil (BBC) domains at the N-terminus, in addition to eight unique domains at the C-terminus, including the B30.2 domain, 19 of which were identified. Expression profiling revealed ubiquitous expression of the 48 PsTRIMs across various P. sinensis tissues. Notably, seven PsTRIMs exhibited significant differential expression in liver transcriptomes following infection with Aeromonas hydrophila. Weighted gene coexpression network analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis implicated PsTRIM14 and PsTRIM28 as key players in host defense against bacterial invasion. Real-time quantitative PCR results indicated that PsTRIM1, PsTRIM2, PsTRIM14, and PsTRIM28 experienced marked upregulation in P. sinensis livers at 12 h post-infection with A. hydrophila.

CONCLUSIONS

Our study is the first to comprehensively identify and analyze the functions of TRIM genes in P. sinensis, unveiling their considerable diversity and potential roles in modulating immune responses.

Tripartite motif containing 33 demonstrated anticancer effect by degrading c‑Myc: Limitation of glutamine metabolism and proliferation in endometrial carcinoma cells

Tripartite motif containing 33 (TRIM33) has been reported to be involved in various tumor progression. However, its role in endometrial carcinoma (EC) remains to be elucidated. By mining the publicly available databases UALCAN and TIMER, low expression of TRIM33 was found in tumor tissues of EC patients. Clinically, downregulation of TRIM33 in EC tissues was positively correlated with the extensive muscle invasion and poor differentiation grade. In vitro, experiments performed on human HEC‑1‑A and AN3CA cells showed that overexpression of TRIM33 inhibited the proliferation, migration and invasion of EC cells, whereas TRIM33 knockdown resulted in the opposite results. Furthermore, upregulation of TRIM33 significantly inhibited the glutamine uptake and decreased the intracellular glutamate in EC cells, which is evidenced by the reduction of solute carrier family 1 member 5 and glutaminase. In vivo, TRIM33 also dramatically inhibited tumor growth and glutamine metabolism. Additionally, co‑immunoprecipitation assay confirmed the interaction between TRIM33 and c‑Myc. Overexpression of TRIM33 could reduce the protein stability of c‑Myc by promoting its degradation. In addition, upregulation of c‑Myc could reverse the effects of TRIM33 on EC cells. Together, the present study demonstrated that TRIM33 acted as a tumor suppressor in EC, which is manifested in its inhibition of glutamine metabolism and cell growth via promoting c‑Myc protein degradation.

Tubular cell transcriptional intermediary factor 1γ deficiency exacerbates kidney injury-induced tubular cell polyploidy and fibrosis

Tubulointerstitial fibrosis is considered the final convergent pathway of progressive chronic kidney diseases (CKD) regardless of etiology. However, mechanisms underlying kidney injury-induced fibrosis largely remain unknown. Recent studies have indicated that transcriptional intermediary factor 1γ (TIF1γ) inhibits the progression of fibrosis in other organs. Here, we found that TIF1γ was highly expressed in the cytoplasm and nucleus of the kidney proximal tubule. Interestingly, we found tubular TIF1γ expression was decreased in patients with CKD, including those with diabetes, hypertension, and IgA nephropathy, and in mouse models with experimental kidney fibrosis (unilateral ureteral obstruction [UUO], folic acid nephropathy [FAN], and aristolochic acid-induced nephrotoxicity). Tubule-specific knock out of TIF1γ in mice exacerbated UUO- and FAN-induced tubular cell polyploidy and subsequent fibrosis, whereas overexpression of kidney TIF1γ protected mice against kidney fibrosis. Mechanistically, in tubular epithelial cells, TIF1γ exerted an antifibrotic role via transforming growth factor-β (TGF-β)-dependent and -independent signaling. TIF1γ hindered TGF-β signaling directly by inhibiting the formation and activity of the transcription factor Smad complex in tubular cells, and we discovered that TIF1γ suppressed epidermal growth factor receptor (EGFR) signaling upstream of TGF-β signaling in tubular cells by ubiquitylating EGFR at its lysine 851/905 sites thereby promoting EGFR internalization and lysosomal degradation. Pharmacological inhibition of EGFR signaling attenuated exacerbated polyploidization and the fibrotic phenotype in mice with tubule deletion of TIF1γ. Thus, tubular TIF1γ plays an important role in kidney fibrosis by suppressing profibrotic EGFR and TGF-β signaling. Hence, our findings suggest that maintaining homeostasis of tubular TIF1γ may be a new therapeutic option for treating tubulointerstitial fibrosis and subsequent CKD.

KLF9 positively regulates TRIM33 to inhibit abnormal synovial fibroblast proliferation, migration as well as inflammation in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) can cause irreversible joint injury and serious disability. This study aimed to investigate how TRIM33 regulated by KLF9 affects the aggressive behaviors of synovial fibroblasts induced by tumor necrosis factor-α (TNF-α).

MATERIALS AND METHODS

TNF-α-induced MH7A cells were used to simulate the in vitro model of RA. TRIM33 and KLF9 expression in TNF-α-challenged MH7A cells and transfection efficiency were analyzed via real-time reverse transcription polymerase chain reaction together with western blot. The viability, proliferation, invasion, and migration of TNF-α-induced MH7A cells after transfection was respectively detected by CCK-8, EdU staining, transwell, and wound-healing assays. The expression of invasion and migration-related proteins and inflammation-related proteins was determined by western blot and the levels of inflammatory factors were detected by enzyme-linked immunosorbent assay. The combination between TRIM33 and KLF9 was substantiated through dual-luciferase reporter assay and chromatin immunoprecipitation.

RESULTS

TRIM33 and KLF9 expression in TNF-α-challenged MH7A cells was downregulated. TRIM33 elevation inhibited TNF-α-elicited proliferation, metastasis as well as inflammation of MH7A cells. Moreover, KLF9 was combined with TRIM33 and KLF9 promoted transcription of TRIM33. The inhibitory effect of TRIM33 overexpression on proliferation, invasion and migration and inflammation of MH7A cells induced by TNF-α was alleviated by the downregulation of KLF9.

CONCLUSION

KLF9 positively regulates TRIM33 to suppress the abnormal MH7A cell proliferation, migration, and reduce inflammation upon exposure to TNF-α, which was reversed by inhibiting KLF9.