Explore the vast range of titles available.

microRNAs (miRNAs) are small, non-coding nucleotides that regulate diverse biological processes. Altered microRNA biosynthesis or regulation contributes to pathological processes including kidney fibrosis. Kidney fibrosis is characterized by deposition of excess extracellular matrix (ECM), which is caused by infiltration of immune cells, inflammatory cells, altered chemokines, and cytokines as well as activation and accumulation of fibroblasts in the kidney. These activated fibroblasts can arise from epithelial cells epithelial-to-mesenchymal transition (EMT), from bone marrow-derived M2 phenotype macrophages macrophage-to-mesenchymal transition (MMT), from endothelial cells endothelial-to-mesenchymal transition (EndMT), from resident fibroblasts, and from bone marrow-derived monocytes and play a crucial role in fibrotic events. Disrupted microRNA biosynthesis and aberrant regulation contribute to the activation of mesenchymal programs in the kidney. miR-29 regulates the interaction between dipeptidyl peptidase-4 (DPP-4) and integrin β1 and the associated active transforming growth factor β (TGFβ) and pro-EndMT signaling; however, miR-let-7 targets transforming growth factor β receptors (TGFβRs) to inhibit TGFβ signaling. N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) is an endogenous anti-fibrotic peptide, which is associated with fibroblast growth factor receptor 1 (FGFR1) phosphorylation and subsequently responsible for the production of miR-let-7. miR-29 and miR-let-7 family clusters participate in crosstalk mechanisms, which are crucial for endothelial cell homeostasis. The physiological level of AcSDKP is vital for the activation of anti-fibrotic mechanisms including restoration of anti-fibrotic microRNA crosstalk and suppression of profibrotic signaling by mitigating DPP-4-associated mesenchymal activation in the epithelial cells, endothelial cells, and M2 phenotype macrophages. The present review highlights recent advancements in the understanding of both the role of microRNAs in the development of kidney disease and their potential as novel therapeutic targets for fibrotic disease states.

The tumor microenvironment (TME) consists of various components including cancer cells, tumor vessels, cancer‐associated fibroblasts (CAFs), and inflammatory cells. These components interact with each other via various cytokines, which often induce tumor progression. Thus, a greater understanding of TME networks is crucial for the development of novel cancer therapies. Many cancer types express high levels of TGF‐β, which induces endothelial‐to‐mesenchymal transition (EndMT), leading to formation of CAFs. Although we previously reported that CAFs derived from EndMT promoted tumor formation, the molecular mechanisms underlying these interactions remain to be elucidated. Furthermore, tumor‐infiltrating inflammatory cells secrete various cytokines, including TNF‐α. However, the role of TNF‐α in TGF‐β‐induced EndMT has not been fully elucidated. Therefore, this study examined the effect of TNF‐α on TGF‐β‐induced EndMT in human endothelial cells (ECs). Various types of human ECs underwent EndMT in response to TGF‐β and TNF‐α, which was accompanied by increased and decreased expression of mesenchymal cell and EC markers, respectively. In addition, treatment of ECs with TGF‐β and TNF‐α exhibited sustained activation of Smad2/3 signals, which was presumably induced by elevated expression of TGF‐β type I receptor, TGF‐β2, activin A, and integrin αv, suggesting that TNF‐α enhanced TGF‐β‐induced EndMT by augmenting TGF‐β family signals. Furthermore, oral squamous cell carcinoma‐derived cells underwent epithelial‐to‐mesenchymal transition (EMT) in response to humoral factors produced by TGF‐β and TNF‐α‐cultured ECs. This EndMT‐driven EMT was blocked by inhibiting the action of TGF‐βs. Collectively, our findings suggest that TNF‐α enhances TGF‐β‐dependent EndMT, which contributes to tumor progression. This study showed that TGF‐β and TNF‐α cooperate to induce the endothelial‐to‐mesenchymal transition (EndMT), in which endothelial cells (ECs) acquire mesenchymal phenotypes. The ECs that have undergone EndMT, in turn, secrete TGF‐β2 and Activin by themselves. These secreted cytokines not only stabilize the mesenchymal phenotypes of ECs, but also induce the epithelial‐to‐mesenchymal transition (EMT) of epithelial cancer cells, which contributes to formation of malignant cancer cells.

Diabetic cardiomyopathy (DCM) is one of the leading causes of heart failure in patients with diabetes mellitus, with limited effective treatments. The cardioprotective effects of sodium‐glucose cotransporter 2(SGLT2) inhibitors have been supported by amounts of clinical trials, which largely fills the gap. However, the underlying mechanism still needs to be further explored, especially in terms of its protection against cardiac fibrosis, a crucial pathophysiological process during the development of DCM. Besides, endothelial‐to‐mesenchymal transition (EndMT) has been reported to play a pivotal role in fibroblast multiplication and cardiac fibrosis. This study aimed to evaluate the effect of SGLT2 inhibitor dapagliflozin (DAPA) on DCM especially for cardiac fibrosis and explore the underlying mechanism. In vivo, the model of type 2 diabetic rats was built with high‐fat feeding and streptozotocin injection. Untreated diabetic rats showed cardiac dysfunction, increased myocardial fibrosis and EndMT, which was attenuated after treatment with DAPA and metformin. In vitro, HUVECs and primary cardiac fibroblasts were treated with DAPA and exposed to high glucose (HG). HG‐induced EndMT in HUVECs and collagen secretion of fibroblasts were markedly inhibited by DAPA. Up‐regulation of TGF‐β/Smad signalling and activity inhibition of AMPKα were also reversed by DAPA treatment. Then, AMPKα siRNA and compound C abrogated the anti‐EndMT effects of DAPA in HUVECs. From above all, our study implied that DAPA can protect against DCM and myocardial fibrosis through suppressing fibroblast activation and EndMT via AMPKα‐mediated inhibition of TGF‐β/Smad signalling.

Chronic allograft dysfunction (CAD) induced by kidney interstitial fibrosis is the main cause of allograft failure in kidney transplantation. Endothelial‐to‐mesenchymal transition (EndMT) may play an important role in kidney fibrosis. We, therefore, undertook this study to characterize the functions and potential mechanism of EndMT in transplant kidney interstitial fibrosis. Proteins and mRNAs associated with EndMT were examined in human umbilical vein endothelial cells (HUVECs) treated with transforming growth factor‐beta1 (TGF‐β1) at different doses or at different intervals with western blotting, qRT‐PCR and ELISA assays. Cell motility and migration were evaluated with motility and migration assays. The mechanism of EndMT induced by TGF‐β1 was determined by western blotting analysis of factors involved in various canonical and non‐canonical pathways. In addition, human kidney tissues from control and CAD group were also examined for these proteins by HE, Masson's trichrome, immunohistochemical, indirect immunofluorescence double staining and western blotting assays. TGF‐β1 significantly promoted the development of EndMT in a time‐dependent and dose‐dependent manner and promoted the motility and migration ability of HUVECs. The TGF‐β/Smad and Akt/mTOR/p70S6K signalling pathways were found to be associated with the pathogenesis of EndMT induced by TGF‐β1, which was also proven in vivo by the analysis of specimens from the control and CAD groups. EndMT may promote transplant kidney interstitial fibrosis by targetting the TGF‐β/Smad and Akt/mTOR/p70S6K signalling pathways, and hence, result in the development of CAD in kidney transplant recipients.

Cerebral cavernous malformation (CCM) is a major cerebrovascular disease affecting approximately 0.3–0.5% of the population and is characterized by enlarged and leaky capillaries that predispose to seizures, focal neurological deficits, and fatal intracerebral hemorrhages. Cerebral cavernous malformation is a genetic disease that may arise sporadically or be inherited as an autosomal dominant condition with incomplete penetrance and variable expressivity. Causative loss‐of‐function mutations have been identified in three genes, KRIT1 ( CCM1 ), CCM2 (MGC4607), and PDCD10 ( CCM3 ), which occur in both sporadic and familial forms. Autophagy is a bulk degradation process that maintains intracellular homeostasis and that plays essential quality control functions within the cell. Indeed, several studies have identified the association between dysregulated autophagy and different human diseases. Here, we show that the ablation of the KRIT1 gene strongly suppresses autophagy, leading to the aberrant accumulation of the autophagy adaptor p62/SQSTM1, defective quality control systems, and increased intracellular stress. KRIT1 loss‐of‐function activates the mTOR‐ULK1 pathway, which is a master regulator of autophagy, and treatment with mTOR inhibitors rescues some of the mole‐cular and cellular phenotypes associated with CCM. Insufficient autophagy is also evident in CCM2 ‐silenced human endothelial cells and in both cells and tissues from an endothelial‐specific CCM3 ‐knockout mouse model, as well as in human CCM lesions. Furthermore, defective autophagy is highly correlated to endothelial‐to‐mesenchymal transition, a crucial event that contributes to CCM progression. Taken together, our data point to a key role for defective autophagy in CCM disease pathogenesis, thus providing a novel framework for the development of new pharmacological strategies to prevent or reverse adverse clinical outcomes of CCM lesions. Synopsis This study provides new evidence on the mechanisms underlying cerebral cavernous malformation (CCM) disease pathogenesis, opening the prospect and offering valuable clues for the development of novel therapeutic approaches based on the regulation of the autophagic process. KRIT1 deletion in murine and human endothelial cell lines results in autophagy defects that cause aberrant accumulation of the autophagy adaptor p62/SQSTM1 and aggresome‐like structures. Impaired autophagy in KRIT1 deficient endothelial cells is accompanied by over‐activation of mTOR signaling pathway, suggesting novel targets for therapeutic intervention. Defective autophagy underlies major phenotypic signatures of CCM disease, including EndMt that contributes to CCM disease progression. mTOR inhibitors restore autophagy in KRIT1‐depleted cells and rescue molecular and cellular disease phenotypes, thus alleviating potential causes of CCM lesion formation and progression. Defective autophagy and consequent p62/SQSTM1 accumulation are common features of loss‐of‐function mutations of the three known CCM genes. Graphical Abstract This study provides new evidence on the mechanisms underlying cerebral cavernous malformation (CCM) disease pathogenesis, opening the prospect and offering valuable clues for the development of novel therapeutic approaches based on the regulation of the autophagic process.

Endothelial‐to‐mesenchymal transition (EndMT) induced by dysfunctional pulmonary artery endothelial cells (PAECs) is regarded as an initiating and pivotal factor in pulmonary hypertension (PH). This study focuses on identifying a novel therapeutic target for regulating EndMT in PH. A comprehensive analysis of 2 hypoxic PAECs datasets yielded 310 overlapping upregulated and 229 downregulated differentially expressed genes (DEGs). These upregulated DEGs were primarily enriched in HIF‐1 signalling pathway and glycolysis/gluconeogenesis, while downregulated only in spliceosome, as indicated by KEGG. Through PPI network analysis and the application of MCC algorithms, 5 hub genes were identified among these upregulated DEGs: GAPDH, LDHA, ALDOA, PFKL, and PFKP. Their enrichment in the 2 aforementioned pathways was confirmed by cross‐pathway DEGs analysis and ClueGo. Among the hub genes, LDHA was chosen as the key gene based upon expression and correlation analysis of the validation set from PH patients. Subsequent GSEA also revealed the enrichment of LDHA in these 2 pathways. Additionally, the increased expression of LDHA protein in tissues and cells was confirmed, and the elevated enzymatic activity of LDHA in clinical serum samples was also verified. From 2 online databases, 4 LDHA inhibitors were filtered out, and the stable binding between the inhibitors and the LDHA protein was confirmed through molecular docking and molecular dynamics simulation. Finally, the experimental results indicated that one of the inhibitors FX11 reversed EndMT by inhibiting the lactate‐SNAI1 axis, thereby alleviating hypoxia‐induced PH. The potential of LDHA as a therapeutic target for PH by modulating EndMT was proposed in this study.

Background Endothelial‐to‐mesenchymal transition (EndMT) is a common pathophysiology in valvular calcification (VC) among non‐chronic kidney disease (CKD) patients. However, few studies were investigated in CKD‐induced VC. Parathyroid hormone (PTH) was considered to be an important component of EndMT in CKD‐induced cardiovascular diseases. Therefore, determining whether PTH could induce valvular EndMT and elucidating corresponding mechanism involved further study. Methods Performing a 5/6 nephrectomy with a high phosphorus diet was done to construct VC models in rats with CKD. miRNA sequencing was used to ascertain changes in microRNA in human umbilical vein endothelial cells (HUVECs) intervened by PTH. VC was observed by Von Kossa staining and scanning electron microscope. Results PTH induced valvular EndMT in VC. Global microRNA expression profiling of HUVECs was examined in PTH versus the control in vitro, in which miR‐29a‐5p was most notably decreased and was resumed by PTHrP(7‐34) (PTH‐receptor1 inhibitor). Overexpression of miR‐29a‐5p could inhibit PTH‐induced EndMT in vitro and valvular EndMT in vivo. The dual‐luciferase assay verified that γ‐secretase‐activating protein (GASP) served as the target of miR‐29a‐5p. miR‐29a‐5p‐mimics, si‐GSAP and DAPT (γ‐secretase inhibitor) inhibited PTH‐induced γ‐secretase activation, thus blocking Notch1 pathway activation to inhibit EndMT in vitro. Moreover, Notch1 pathway activation was observed in VC. Blocking Notch1 pathway activation via AAV‐miR‐29a and DAPT inhibited valvular EndMT. In addition, blocking Notch1 pathway activation was also shown to alleviate VC. Conclusion PTH activates valvular EndMT via miR‐29a‐5p/GSAP/Notch1 pathway, which can contribute to VC in CKD rats. A model depicting how miR‐29a‐5p regulating VECs EndMT. PTH could trigger a decrease in miR‐29a through PTHR1 of VECs, leading to an increase in GSAP at the protein level. GSAP further activated γ‐secretase to increase the level of NICD in the cytoplasm, which promoted the increase of HES1 and Snail expression in the nucleus to mediate the activation of Notch1 signal and endothelial‐to‐mesenchymal transition (EndMT) which cause VECs transferring to valvular interstitial cells (VICs).

Endothelial‐to‐mesenchymal transition (EndMT) is closely associated with tumor progression. Endothelial cells (ECs) in the tumor microenvironment (TME) use EndMT programs to facilitate tumor progression; however, the underlying mechanisms in ovarian cancer are poorly understood. Here, we describe the involvement of primary cilia in EndMT of the ovarian TME. We showed that ECs from human ovarian tumors displayed robust EndMT and impaired cilia formation, as was also observed in ECs in response to ovarian cancer cell culture‐conditioned media (OV‐CM). Notably, ECs lacking primary cilia exhibited increased OV‐CM‐induced EndMT. Vascular abnormalities, such as enhanced cell migration and vessel permeability, were observed in vitro. Furthermore, in vivo experiments using endothelial‐specific kinesin family member 3A (Kif3a)‐knockout mice showed enhanced EndMT in the ovarian TME. Mechanistically, we identified ephrin type‐A receptor 2 (EphA2) as a key regulator of EndMT. Upon OV‐CM treatment, EphA2 expression increased, and depletion of EphA2 in ECs decreased OV‐CM‐induced EndMT and vascular abnormalities. These results highlight that the loss of primary cilia and the consequent EphA2 activation are key mechanisms by which EndMT programs induce the acquisition of cancer‐associated fibroblast‐like cells in the ovarian TME, thereby promoting ovarian cancer progression. Loss of primary cilia in endothelial cells promotes EndMT and vascular abnormalities in the ovarian tumor microenvironment through EphA2 activation. Using human samples, in vitro models, and endothelial‐specific Kif3a‐knockout mice, we show that primary cilia loss drives the acquisition of cancer‐associated fibroblast‐like phenotypes, thereby facilitating ovarian cancer progression.

The endothelial-mesenchymal transition (EndMT) of endothelial progenitor cells (EPCs) plays a notable role in pathological vascular remodeling. Emerging evidence indicated that long non-coding RNA-regulator of reprogramming (linc-ROR) can promote epithelial-mesenchymal transition (EMT) in a variety of cancer cells. Nevertheless, the function of linc-ROR in EPC EndMT has not been well elucidated. The present study investigated the effect and possible mechanisms of function of linc-ROR on the EndMT of EPCs. A linc-ROR overexpression lentiviral vector (LV linc-ROR) or a linc-ROR short hairpin RNA lentiviral vector (LV-shlinc-ROR) was used to up or downregulate linc-ROR expression in EPCs isolated from human umbilical cord blood. Functional experiments demonstrated that LV-linc-ROR promoted the proliferation and migration of EPCs, but inhibited EPC angiogenesis in vitro. In the meantime, reverse transcription-quantitative PCR and western blotting results showed that the expression of the endothelial cell markers vascular endothelial-cadherin and CD31 was decreased, while the expression of the mesenchymal cell markers α-smooth muscle actin and SM22α was increased at both mRNA and protein levels in LV-linc-ROR-treated EPCs, indicating that linc-ROR induced EPC EndMT. Mechanistically, the dual-luciferase reporter assay demonstrated that microRNA (miR/miRNA)-145 was a direct target of linc-ROR, and miR-145 binds to the 3’-untranslated region of Smad3. Moreover, LV-shlinc-ROR increased the expression of miR-145, but decreased the expression of Smad3. In conclusion, linc-ROR promotes EPC EndMT, which may be associated with the miR-145/Smad3 signaling pathway.

The accumulation of lactate is a rising risk factor for patients after flap transplantation. Endothelial‐to‐mesenchymal transition (EndoMT) plays a critical role in skin fibrosis. Nevertheless, whether lactate overproduction directly contributes to flap necrosis and its mechanism remain unknown. The current study reveals that skin flap mice exhibit enhanced PKM2 and fibrotic response. Endothelial‐specific deletion of PKM2 attenuates flap necrosis and ameliorates flap fibrosis in mice. Administration of lactate or overexpressing PKM2 promotes dysfunction of endothelial cells and stimulates mesenchymal‐like phenotype following hypoxia. Mechanistically, glycolytic‐lactate induces a correlation between Twist1 and p300/CBP, leading to lactylation of Twist1 lysine 150 (K150la). The increase in K150la promotes Twist1 phosphorylation and nuclear translocation and further regulates the transcription of TGFB1, hence inducing fibrosis phenotype. Genetically deletion of endothelial‐specific PKM2 in mice diminishes lactate accumulation and Twist1 lactylation, then attenuates EndoMT‐associated fibrosis following flap ischemia. The serum lactate levels of flap transplantation patients are elevated and exhibit predictive value for prognosis. This findings suggested a novel role of PKM2‐derived lactate in mediating Twist1 lactylation and exacerbates flap fibrosis and ischemia. Inhibition of glycolytic‐lactate and Twist1 lactylation reduces flap necrosis and fibrotic response might become a potential therapeutic strategy for flap ischemia. Schematic illustration exhibiting mechanism of PKM2‐driven lactate overproduction‐induced EndoMT after flap ischemia: Abnormal expression of PKM2 promotes lactate overproduction of endothelial cell; Excessive lactate facilitates EndoMT and Twist1 lactylation of endothelial cell; Fibrotic response accelerates skin flap fibrosis and necrosis.