Anti-Fibrotic Effect of Synthetic Noncoding Decoy ODNs for TFEB in an Animal Model of Chronic Kidney Disease

The Effect of Platelet-Rich Plasma on Synovial Fibrosis and Cartilage Degeneration in Knee Osteoarthritis

BACKGROUND

Synovial fibrosis is a prevalent pathological feature of osteoarthritis and a primary contributor to joint pain and stiffness. Studies indicate that platelet-rich plasma (PRP) is rich in growth factors and cytokines, exhibiting anti-inflammatory, anti-apoptotic, chemotactic, and proliferative properties that can facilitate tissue repair. However, little is known about its effect on synovial fibrosis in knee osteoarthritis (KOA).

PURPOSE

To determine the effect of PRP on synovial fibrosis and cartilage degeneration in KOA.

STUDY DESIGN

Controlled laboratory study.

METHOD

Anterior cruciate ligament transection was performed to induce KOA in male Sprague-Dawley rats, and then rats were randomly assigned to 4 different groups: sham operation, KOA only, KOA treated with phosphate-buffered saline (PBS), and KOA treated with PRP. Synovial collagen fiber deposition was observed using Masson and Sirius red staining, and synovial inflammation was assessed using hematoxylin and eosin (H&E) staining. Moreover, immunohistochemistry was conducted to analyze the expression of synovial fibrosis-related factors including PLOD2, COL1A1, TIMP1, TGF-β1, and α-SMA. KOA severity and articular cartilage degradation were assessed using micro-computed tomography (micro-CT), safranin O-fast green staining, H&E staining, immunohistochemistry, and the Osteoarthritis Research Society International (OARSI) criteria. A quantitative analysis of growth factors (platelet-derived growth factor, IGF-1, epidermal growth factor, TGF-β1, fibroblast growth factor, and endothelial growth factor) in activated PRP was performed using enzyme-linked immunosorbent assay.

RESULTS

Micro-CT imaging and histological staining showed that the KOA model had been successfully established. Compared with the KOA and PBS groups, Masson staining and Sirius red staining results showed that PRP aggravated the degree of synovial fibrosis, which was consistent with the results of immunohistochemistry analysis. Immunohistochemistry analysis showed that PRP promoted the protein expression of PLOD2, COL1A1, TIMP1, TGF-β1, and α-SMA, indicating that the degree of fibrosis was aggravated. However, the PRP group showed lower OARSI and synovitis scores, as well as attenuated abnormal tibial subchondral bone remodeling, suggesting that PRP inhibited further cartilage degeneration and synovial inflammation and improved the subchondral bone microarchitecture.

CONCLUSION

PRP may aggravate KOA synovial fibrosis, but it still has an inhibitory effect on cartilage degeneration and abnormal subchondral bone remodeling.

CLINICAL RELEVANCE

Synovial fibrosis is a significant pathological feature in KOA that is closely linked to clinical symptoms like joint pain and stiffness. This study offers insights into enhancing the effectiveness of PRP therapy for patients with KOA.

Research Hotspots and Frontier Trends of Autophagy in Diabetic Cardiomyopathy From 2014 to 2024: A Bibliometric Analysis

Objective

In recent years, the investigation of autophagy mechanisms has gained prominence as a key focus for understanding the pathogenesis and therapeutic potential of diabetic cardiomyopathy. This study aims to present an overview of the current state, major research areas, and emerging trends in autophagy related to diabetic cardiomyopathy through bibliometric analysis, offering a scientific foundation for future research.

Methods

The Web of Science Core Collection served as the data source for this study, from which full-text publications were extracted. Using CiteSpace 6.3.R1, VOSviewer v1.6.18, and R-Bibliometrix, the analysis evaluated research output across dimensions such as subjects, countries, institutions, journals, authors, and co-cited references, generating a comprehensive visual map.

Results

A total of 367 publications met the inclusion criteria. Between 2014 and 2024, the volume of articles demonstrated a consistent upward trajectory. Research on autophagy in diabetic cardiomyopathy predominantly spans the disciplines of biology and medicine. China and the Fourth Military Medical University emerged as leading contributors among 41 countries and 505 institutions. Sun Dongdong was identified as the most prolific author, while Jia GH was the most frequently cited. Key journals in this field include Biochimica et Biophysica Acta - Molecular Basis of Disease and Frontiers in Cardiovascular Medicine, while Circulation Research recorded the highest number of co-citations. The most cited reference was an experimental study by Xie ZL. Current research focuses on autophagy, diabetic cardiomyopathy, oxidative stress, and their underlying mechanisms.

Conclusion

Research on the role of autophagy in diabetic cardiomyopathy has reached a stable phase of development. Future investigations should prioritize mechanistic studies and emphasize the clinical application of novel pharmacological interventions, thereby advancing therapeutic strategies and contributing to improved human health outcomes.

TXNIP deficiency attenuates renal fibrosis by modulating mTORC1/TFEB-mediated autophagy in diabetic kidney disease

Thioredoxin-interacting protein (TXNIP) is an important regulatory protein for thioredoxin (TRX) that elicits the generation of reactive oxygen species (ROS) by inhibiting the redox function of TRX. Abundant evidence suggests that TXNIP is involved in the fibrotic process of diabetic kidney disease (DKD). However, the potential mechanism of TXNIP in DKD is not yet well understood. In this study, we found that TXNIP knockout suppressed renal fibrosis and activation of mammalian target of rapamycin complex 1 (mTORC1) and restored transcription factor EB (TFEB) and autophagy activation in diabetic kidneys. Simultaneously, TXNIP interference inhibited epithelial-to-mesenchymal transformation (EMT), collagen I and fibronectin expression, and mTORC1 activation, increased TFEB nuclear translocation, and promoted autophagy restoration in HK-2 cells exposed to high glucose (HG). Rapamycin, an inhibitor of mTORC1, increased TFEB nuclear translocation and autophagy in HK-2 cells under HG conditions. Moreover, the TFEB activators, curcumin analog C1 and trehalose, effectively restored HG-induced autophagy, and abrogated HG-induced EMT and collagen I and fibronectin expression in HK-2 cells. Taken together, these findings suggest that TXNIP deficiency ameliorates renal fibrosis by regulating mTORC1/TFEB-mediated autophagy in diabetic kidney diseases.

Heyingwuzi formulation alleviates diabetic retinopathy by promoting mitophagy via the HIF-1α/BNIP3/NIX axis

BACKGROUND

Diabetic retinopathy (DR) is the primary cause of visual problems in patients with diabetes. The Heyingwuzi formulation (HYWZF) is effective against DR.

AIM

To determine the HYWZF prevention mechanisms, especially those underlying mitophagy.

METHODS

Human retinal capillary endothelial cells (HRCECs) were treated with high glucose (hg), HYWZF serum, PX-478, or Mdivi-1 in vitro. Then, cell counting kit-8, transwell, and tube formation assays were used to evaluate HRCEC proliferation, invasion, and tube formation, respectively. Transmission electron microscopy was used to assess mitochondrial morphology, and Western blotting was used to determine the protein levels. Flow cytometry was used to assess cell apoptosis, reactive oxygen species (ROS) production, and mitochondrial membrane potential. Moreover, C57BL/6 mice were established in vivo using streptozotocin and treated with HYWZF for four weeks. Blood glucose levels and body weight were monitored continuously. Changes in retinal characteristics were evaluated using hematoxylin and eosin, tar violet, and periodic acid-Schiff staining. Protein levels in retinal tissues were determined via Western blotting, immunohistochemistry, and immunostaining.

RESULTS

HYWZF inhibited excessive ROS production, apoptosis, tube formation, and invasion in hg-induced HRCECs via mitochondrial autophagy in vitro. It increased the mRNA expression levels of BCL2-interacting protein 3 (BNIP3), FUN14 domain-containing 1, BNIP3-like (BNIP3L, also known as NIX), PARKIN, PTEN-induced kinase 1, and hypoxia-inducible factor (HIF)-1α. Moreover, it downregulated the protein levels of vascular endothelial cell growth factor and increased the light chain 3-II/I ratio. However, PX-478 and Mdivi-1 reversed these effects. Additionally, PX-478 and Mdivi-1 rescued the effects of HYWZF by decreasing oxidative stress and apoptosis and increasing mitophagy. HYWZF intervention improved the symptoms of diabetes, tissue damage, number of acellular capillaries, and oxidative stress in vivo. Furthermore, in vivo experiments confirmed the results of in vitro experiments.

CONCLUSION

HYWZF alleviated DR and associated damage by promoting mitophagy via the HIF-1α/BNIP3/NIX axis.

Impaired TFEB-mediated autophagy-lysosome fusion promotes tubular cell cycle G2/M arrest and renal fibrosis by suppressing ATP6V0C expression and interacting with SNAREs

Increasing evidence suggests that autophagy plays a major role during renal fibrosis. Transcription factor EB (TFEB) is a critical regulator of autophagy- and lysosome-related gene transcription. However, the pathophysiological roles of TFEB in renal fibrosis and fine-tuned mechanisms by which TFEB regulates fibrosis remain largely unknown. Here, we found that TFEB was downregulated in unilateral ureteral obstruction (UUO)-induced human and mouse fibrotic kidneys, and kidney-specific TFEB overexpression using recombinant AAV serotype 9 (rAAV9)-TFEB in UUO mice alleviated renal fibrosis pathogenesis. Mechanically, we found that TFEB's prevention of extracellular matrix (ECM) deposition depended on autophagic flux integrity and its subsequent blockade of G2/M arrest in tubular cells, rather than the autophagosome synthesis. In addition, we together RNA-seq with CUT&Tag analysis to determine the TFEB targeted gene ATP6V0C, and revealed that TFEB was directly bound to the ATP6V0C promoter only at specific site to promote its expression through CUT&Run-qPCR and luciferase reporter assay. Interestingly, TFEB induced autophagic flux integrity, mainly dependent on scaffold protein ATP6V0C-mediated autophagosome-lysosome fusion by bridging with STX17 and VAMP8 (major SNARE complex) by co-immunoprecipitation analysis, rather than its mediated lysosomal acidification and degradation function. Moreover, we further investigated the underlying mechanism behind the low expression of TEFB in UUO-induced renal fibrosis, and clearly revealed that TFEB suppression in fibrotic kidney was due to DNMT3a-associated TFEB promoter hypermethylation by utilizing methylation specific PCR (MSP) and bisulfite-sequencing PCR (BSP), which could be effectively recovered by 5-Aza-2'-deoxycytidine (5A-za) to alleviate renal fibrosis pathogenesis. These findings reveal for the first time that impaired TFEB-mediated autophagosome-lysosome fusion disorder, tubular cell G2/M arrest and renal fibrosis appear to be sequentially linked in UUO-induced renal fibrosis and suggest that DNMT3a/TFEB/ATP6V0C may serve as potential therapeutic targets to prevent renal fibrosis.