The insulin-like growth factor binding protein-microfibrillar associated protein-sterol regulatory element binding protein axis regulates fibroblast-myofibroblast transition and cardiac fibrosis.

BACKGROUND AND PURPOSE: Excessive fibrogenesis is associated with adverse cardiac remodelling and heart failure. The myofibroblast, primarily derived from resident fibroblast, is the effector cell type in cardiac fibrosis. Megakaryocytic leukaemia 1 (MKL1) is considered the master regulator of fibroblast-myofibroblast transition (FMyT). The underlying transcriptional mechanism is not completely understood. Our goal was to identify novel transcriptional targets of MKL1 that might regulate FMyT and contribute to cardiac fibrosis. EXPERIMENTAL APPROACH: RNA sequencing (RNA-seq) performed in primary cardiac fibroblasts identified insulin-like growth factor binding protein 5 (IGFBP5) as one of the genes most significantly up-regulated by constitutively active (CA) MKL1 over-expression. IGFBP5 expression was detected in heart failure tissues using RT-qPCR and western blots. KEY RESULTS: Once activated, IGFBP5 translocated to the nucleus to elicit a pro-FMyT transcriptional programme. Consistently, IGFBP5 knockdown blocked FMyT in vitro and dampened cardiac fibrosis in mice. Of interest, IGFBP5 interacted with nuclear factor of activated T-cell 4 (NFAT4) to stimulate the transcription of microfibril-associated protein 5 (MFAP5). MFAP5 contributed to FMyT and cardiac fibrosis by enabling sterol response element binding protein 2 (SREBP2)-dependent cholesterol synthesis. CONCLUSIONS AND IMPLICATIONS: Our data unveil a previously unrecognized transcriptional cascade, initiated by IGFBP5, that promotes FMyT and cardiac fibrosis. Screening for small-molecule compounds that target this axis could yield potential therapeutics against adverse cardiac remodelling.

Prediction of prognosis and treatment response in ovarian cancer patients from histopathology images using graph deep learning: a multicenter retrospective study.

BACKGROUND: Ovarian cancer (OV) is a prevalent and deadly disease with high mortality rates. The development of accurate prognostic tools and personalized therapeutic strategies is crucial for improving patient outcomes. METHODS: A graph-based deep learning model, the Ovarian Cancer Digital Pathology Index (OCDPI), was introduced to predict prognosis and response to adjuvant therapy using hematoxylin and eosin (H&E)-stained whole-slide images (WSIs). The OCDPI was developed using formalin-fixed, paraffin-embedded (FFPE) WSIs from the TCGA-OV cohort, and was externally validated in two independent cohorts from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) and Harbin Medical University Cancer Hospital (HMUCH). RESULTS: The OCDPI showed prognostic ability for overall survival prediction in the PLCO (HR, 1.916; 95% CI, 1.380-2.660; log-rank test, P < 0.001) and HMUCH (HR, 2.796; 95% CI, 1.404-5.568; log-rank test, P = 0.0022) cohorts. Patients with low OCDPI experienced better survival benefits and lower recurrence rates following adjuvant therapy compared to those with high OCDPI. Multivariable analyses, adjusting for clinicopathological factors, consistently identified OCDPI as an independent prognostic factor across all cohorts (all P < 0.05). Furthermore, OCDPI performed well in patients with low-grade tumors or fresh-frozen slides, and could differentiate between HRD-deficient or HRD-intact patients with and without sensitivity to adjuvant therapy. CONCLUSION: The results from this multicenter cohort study indicate that the OCDPI may serve as a valuable and labor-saving tool to improve prognostic and predictive clinical decision-making in patients with OV.

Design and synthesis of novel quinazolin-4(1H)-one derivatives as potent and selective inhibitors targeting AKR1B1.

Inhibition of aldose reductase (AKR1B1) is a promising option for the treatment of diabetic complications. However, most of the developed small molecule inhibitors lack selectivity or suffer from low bioactivity. To address this limitation, a novel series of quinazolin-4(1H)-one derivatives as potent and selective inhibitors of AKR1B1 were designed and synthesized. Aldose reductase inhibitory activities of the novel compounds were characterized by IC50 values ranging from 0.015 to 31.497 µM. Markedly enhanced selectivity of these derivatives was also recorded, which was further supported by docking studies. Of these inhibitors, compound 5g exhibited the highest inhibition activity with selectivity indices reaching 1190.8. The structure-activity relationship highlighted the importance of N1-acetic acid and N3-benzyl groups with electron-withdrawing substituents on the quinazolin-4(1H)-one scaffold for the construction of efficient and selective AKR1B1 inhibitors.

MKL1 fuels ROS-induced proliferation of vascular smooth muscle cells by modulating FOXM1 transcription.

Reactive oxygen species (ROS) promotes vascular injury and neointima formation in part by stimulating proliferation of vascular smooth muscle cells (VSMC). The underlying transcriptional mechanism, however, is not completely understood. Here we report that VSMC-specific deletion of MKL1 in mice suppressed neointima formation in a classic model of vascular injury. Likewise, pharmaceutical inhibition of MKL1 activity by CCG-1423 similarly mollified neointima formation in mice. Over-expression of a constitutively active MKL1 in vascular smooth muscle cells enhanced proliferation in a ROS-dependent manner. On the contrary, MKL1 depletion or inhibition attenuated VSMC proliferation. PCR array based screening identified forkhead box protein M1 (FOXM1) as a direct target for MKL1. MKL1 interacted with E2F1 to activate FOXM1 expression. Concordantly, FOXM1 depletion ameliorated MKL1-dependent VSMC proliferation. Of interest, ROS-induced MKL1 phosphorylation through MK2 was essential for its interaction with E2F1 and consequently FOXM1 trans-activation. Importantly, a positive correlation between FOXM1 expression and VSMC proliferation was identified in arterial specimens from patients with restenosis. Taken together, our data suggest that a redox-sensitive phosphorylation-switch of MKL1 activates FOXM1 transcription and mediates ROS fueled vascular smooth muscle proliferation. Targeting the MK-2/MKL1/FOXM1 axis may be considered as a reasonable approach for treatment of restenosis.

A GSK3-SRF Axis Mediates Angiotensin II Induced Endothelin Transcription in Vascular Endothelial Cells.

Endothelin, encoded by ET1, is a vasoactive substance primarily synthesized in vascular endothelial cells (VECs). Elevation of endothelin levels, due to transcriptional hyperactivation, has been observed in a host of cardiovascular diseases. We have previously shown that serum response factor (SRF) is a regulator of ET1 transcription in VECs. Here we report that angiotensin II (Ang II) induced ET1 transcription paralleled activation of glycogen synthase kinase 3 (GSK3) in cultured VECs. GSK3 knockdown or pharmaceutical inhibition attenuated Ang II induced endothelin expression. Of interest, the effect of GSK3 on endothelin transcription relied on the conserved SRF motif within the ET1 promoter. Further analysis revealed that GSK3 interacted with and phosphorylated SRF at serine 224. Phosphorylation of SRF by GSK3 did not influence its recruitment to the ET1 promoter. Instead, GSK3-mediated SRF phosphorylation potentiated its interaction with MRTF-A, a key co-factor for SRF, which helped recruit the chromatin remodeling protein BRG1 to the ET1 promoter resulting in augmented histone H3 acetylation/H3K4 trimethylation. Consistently, over-expression of a constitutively active GSK enhanced Ang II-induced ET1 transcription and knockdown of either MRTF-A or BRG1 abrogated the enhancement of ET1 transcription. In conclusion, our data highlight a previously unrecognized mechanism that contributes to the transcriptional regulation of endothelin. Targeting this GSK3-SRF axis may yield novel approaches in the intervention of cardiovascular diseases.

Myeloid MKL1 Disseminates Cues to Promote Cardiac Hypertrophy in Mice.

Cardiac hypertrophy is a key pathophysiological process in the heart in response to stress cues. Although taking place in cardiomyocytes, the hypertrophic response is influenced by other cell types, both within the heart and derived from circulation. In the present study we investigated the myeloid-specific role of megakaryocytic leukemia 1 (MKL1) in cardiac hypertrophy. Following transverse aortic constriction (TAC), myeloid MKL1 conditional knockout (MFCKO) mice exhibit an attenuated phenotype of cardiac hypertrophy compared to the WT mice. In accordance, the MFCKO mice were protected from excessive cardiac inflammation and fibrosis as opposed to the WT mice. Conditioned media collected from macrophages enhanced the pro-hypertrophic response in cardiomyocytes exposed to endothelin in an MKL1-dependent manner. Of interest, expression levels of macrophage derived miR-155, known to promote cardiac hypertrophy, were down-regulated in the MFCKO mice compared to the WT mice. MKL1 depletion or inhibition repressed miR-155 expression in macrophages. Mechanistically, MKL1 interacted with NF-κB to activate miR-155 transcription in macrophages. In conclusion, our data suggest that MKL1 may contribute to pathological hypertrophy via regulating macrophage-derived miR-155 transcription.

Fecal Fungi Dysbiosis in Nonalcoholic Fatty Liver Disease.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) can systematically harm more aspects of human health than just the liver. In addition to the potential roles of the gut microbiota in NAFLD, commensal fungi can functionally replace intestinal bacteria in maintaining the host immune response in the gut by reversing disease susceptibility. Therefore, gut commensal fungi should be studied to help understand NAFLD. METHODS: The fungal compositions of 79 patients with NAFLD and 34 matched healthy subjects were studied via internal transcribed spacer sequencing. In the NAFLD group, 32 patients underwent liver biopsies to evaluate the associations between gut fungi and NAFLD development. RESULTS: The fungal microbiota distribution was skewed in the patients with NAFLD. The relative abundances of Talaromyces, Paraphaeosphaeria, Lycoperdon, Curvularia, Phialemoniopsis, Paraboeremia, Sarcinomyces, Cladophialophora, and Sordaria were higher in patients with NAFLD, whereas the abundances of Leptosphaeria, Pseudopithomyces, and Fusicolla were decreased. Patients with NAFLD exhibited more co-occurring fungal intrakingdom correlations. Several fungi were found to be associated with liver injury, lipid metabolism, and the development of NAFLD. CONCLUSIONS: This study found that gut fungi may play some roles in NAFLD development. Research on gut fungi may be of great value in diagnosing and monitoring NAFLD.

Study on the new strategy and key techniques for accurate prevention and treatment of nonalcoholic steatohepatitis based on intestinal target bacteria.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) has emerged as a major health problem worldwide; according to statistics, 10% to 25% of patients with NAFLD can progress to nonalcoholic steatohepatitis (NASH). A link between the composition and metabolites of intestinal microbiota and the development of NAFLD is becoming clearer. It is believed that microbiota factors are driving forces of hepatic steatosis and inflammation. The formulated food that contains prebiotics and dietary fiber may improve NAFLD by altering the intestinal flora and its metabolites. METHODS: The study plan to recruit adult patients (18-75 years, n = 120) with NAFLD, range of alanine aminotransferase is 1.5 to 5 times upper limit of normal (ULN) or liver biopsy is confirmed as NASH. Participants will be randomly allocated into 2 groups: formulated food (n = 80) and a placebo group (n = 40) for 24 weeks. Both groups will receive lifestyle and nutritional advice. The primary endpoint is a decrease in MRS-PDFF by more than 30% from baseline at 24 weeks. The secondary endpoints include the change of anthropometric, liver function, glycolipid metabolism, and systemic inflammation at 4, 12, and 24 weeks. In addition, we consider the changes in intestinal microbiota as an exploration to assess the abundance and diversity at 24 weeks. Weeks 24 to 36 are the follow-up period of drug withdrawal. DISCUSSION: This clinical trial will provide evidence of efficacy and safety of formulated food as a potential new therapeutic agent for NAFLD patients. TRIAL REGISTRATION: The trial is registered in the China Clinical Trial Center (ChiCTR1800016178).

BRG1 Activates PR65A Transcription to Regulate NO Bioavailability in Vascular Endothelial Cells.

Vascular endothelial cells contribute to the pathogenesis of cardiovascular diseases by producing and disseminating angiocrine factors. Nitric oxide (NO), catalyzed by endothelial NO synthase (eNOS), is one of the prototypical angiocrine factors. eNOS activity is modulated by site-specific phosphorylation. We have previously shown that endothelial-specific knockdown of BRG1 in Apoe -/- mice attenuates the development of atherosclerosis, in which eNOS-dependent NO catalysis plays an antagonizing role. Here we report that attenuation of atherogenesis in mice by BRG1 knockdown was accompanied by partial restoration of NO biosynthesis by 44% in the arteries and a simultaneous up-regulation of eNOS serine 1177 phosphorylation by 59%. Indeed, BRG1 depletion or inhibition ameliorated oxLDL-induced loss of NO bioavailability and eNOS phosphorylation in cultured endothelial cells. Further analysis revealed that BRG1 regulated eNOS phosphorylation and NO synthesis by activating the transcription of protein phosphatase 2A (PP2A) structural subunit a (encoded by PR65A). BRG1 interacted with ETS1, was recruited by ETS1 to the PR65A promoter, and cooperated with ETS1 to activate PR65A transcription. Finally, depletion of ETS1, similar to BRG1, repressed PR65A induction, normalized eNOS phosphorylation, and rescued NO biosynthesis in endothelial cells treated with oxLDL. In conclusion, our data characterize a novel transcriptional cascade that regulates NO bioavailability in vascular endothelial cells.

The Role of Intestinal Fungi and Its Metabolites in Chronic Liver Diseases.

Current studies have confirmed that liver diseases are closely related to intestinal microorganisms; however, those studies have mainly concentrated on bacteria. Although the proportion of intestinal microorganisms accounted for by colonizing fungi is very small, these fungi do have a significant effect on the homeostasis of the intestinal microecosystem. In this paper, the characteristics of intestinal fungi in patients with chronic liver diseases such as alcoholic liver disease, nonalcoholic fatty liver disease and cirrhosis are summarized, and the effects of intestinal fungi and their metabolites are analyzed and discussed. It is important to realize that not only bacteria but also intestinal fungi play important roles in liver diseases.

Forkhead transcription factor FOXO3a mediates interferon-γ-induced MHC II transcription in macrophages.

Macrophages are professional antigen-presenting cells relying on the expression of class II major histocompatibility complex (MHC II) genes. Interferon-γ (IFN-γ) activates MHC II transcription via the assembly of an enhanceosome centred on class II trans-activator (CIITA). In the present study, we investigated the role of the forkhead transcription factor FOXO3a in IFN- γ-induced MHC II transcription in macrophages. Knockdown of FOXO3a, but not FOXO1 or FOXO4, diminished IFN-γ-induced MHC II expression in RAW cells. On the contrary, over-expression of FOXO3a, but neither FOXO1 nor FOXO4, enhanced CIITA-mediated trans-activation of the MHC II promoter. IFN-γ treatment promoted the recruitment of FOXO3a to the MHC II promoter. Co-immunoprecipitation and RE-ChIP assays showed that FOXO3a was a component of the MHC II enhanceosome forming interactions with CIITA, RFX5, RFXB and RFXAP. FOXO3a contributed to MHC II transcription by altering histone modifications surrounding the MHC II promoter. Of interest, FOXO3a was recruited to the type IV CIITA promoter and directly activated CIITA transcription by interacting with signal transducer of activation and transcription 1 in response to IFN-γ stimulation. In conclusion, our data unveil a novel role for FOXO3a in the regulation of MHC II transcription in macrophages.

Berberine prevents non-alcoholic steatohepatitis-derived hepatocellular carcinoma by inhibiting inflammation and angiogenesis in mice.

Hepatocellular carcinoma (HCC) is one of the most malignant and poor prognosis tumors, which was increasingly caused by nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NAFLD/NASH) in western countries. In this study, we aimed to investigate the mechanism and therapeutic prospect of berberine in the treatment of NASH-HCC mice. Combination of STZ injection and high fat and high-cholesterol diet (HFHC) was used to establish NASH-HCC model. The effect of berberine intervention is studied from histology, biochemistry and molecular level. Our results showed that administration of berberine to NASH-HCC mice reduced the incidence of tumors and mitigated NASH. Berberine significantly reduced the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose (GLU), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and total cholesterol (TC). Transcriptome sequencing and bioinformatics analysis identified numberous genes and various pathways may participate in the favorite effect of berberine. Specifically, berberine suppressed the expressions of genes related to lipogenesis, inflammation, fibrosis and angiogenesis. Moreover, our results showed that berberine suppressed phosphorylation of p38MAPK and ERK as well as COX2 expression significantly. This suggested berberine achieved its biological functions mainly by regulating inflammation and angiogenesis genes involving p38MAPK/ERK-COX2 pathways. This study demonstrated the anti-tumor effects of berberine and its possible mechanism, providing a potential drug for treating NASH-HCC.

Angiotensin II induced CSF1 transcription is mediated by a crosstalk between different epigenetic factors in vascular endothelial cells.

Endothelium-derived colony stimulating factor (CSF1) plays a key role in a range of human pathologies. Angiotensin II (Ang II) has been documented to stimulate CSF1 transcription although the underlying epigenetic mechanism remains unclear. Here we report that induction of CSF1 transcription by Ang II in vascular endothelial cells paralleled alterations of signature histone modifications surrounding the CSF1 promoter. Specifically, ChIP assays indicated that there was a simultaneous up-regulation of both acetylated H3 and trimethylated H3K4, indicative of transcriptional activation, and down-regulation of dimethyl H3K9, implicated in transcriptional repression, surrounding the proximal CSF1 promoter. Further analysis revealed that silencing of brahma related gene 1 (BRG1), a chromatin remodeling protein, abrogated CSF1 induction by Ang II. In the meantime, BRG1 silencing erased H3 acetylation and H3K4 trimethylation and restored H3K9 dimethylation. Mechanistically, BRG1 interacted with and recruited SET1A, a histone H3K4 methyltransferase, and JMJD1A, a histone H3K9 demethylase, to the CSF1 promoter to alter chromatin structure thereby promoting CSF1 trans-activation in response to Ang II stimulation. Knockdown of either SET1A or JMJD1A blocked CSF1 induction by Ang II. Finally, we demonstrate that the crosstalk between BRG1 and histone modifying enzymes was mediated by the transcription factor AP-1. In conclusion, our data unveil a novel epigenetic mechanism whereby a BRG1-centered complex mediates transcriptional activation of CSF1 by Ang II in vascular endothelial cells.

Beta-nerve growth factor promotes neurogenesis and angiogenesis during the repair of bone defects.

We previously showed that the repair of bone defects is regulated by neural and vascular signals. In the present study, we examined the effect of topically applied ß-nerve growth factor (ß-NGF) on neurogenesis and angiogenesis in critical-sized bone defects filled with collagen bone substitute. We created two symmetrical defects, 2.5 mm in diameter, on either side of the parietal bone of the skull, and filled them with bone substitute. Subcutaneously implanted osmotic pumps were used to infuse 10 µg ß-NGF in PBS (ß-NGF + PBS) into the right-hand side defect, and PBS into the left (control) defect, over the 7 days following surgery. Immunohistochemical staining and hematoxylin-eosin staining were carried out at 3, 7, 14, 21 and 28 days postoperatively. On day 7, expression of ß III-tubulin was lower on the ß-NGF + PBS side than on the control side, and that of neurofilament 160 was greater. On day 14, ß III-tubulin and protein gene product 9.5 were greater on the ß-NGF + PBS side than on the control side. Vascular endothelial growth factor expression was greater on the experimental side than the control side at 7 days, and vascular endothelial growth factor receptor 2 expression was elevated on days 14 and 21, but lower than control levels on day 28. However, no difference in the number of blood vessels was observed between sides. Our results indicate that topical application of ß-NGF promoted neurogenesis, and may modulate angiogenesis by promoting nerve regeneration in collagen bone substitute-filled defects.

Inhibition of proliferation and differentiation and promotion of apoptosis by cyclin L2 in mouse embryonic carcinoma P19 cells.

Cyclin L2 (CCNL2) is a novel member of the cyclin gene family. In a previous study, we demonstrated that CCNL2 expression was upregulated in ventricular septum tissues from patients with ventricular septal defect compared to healthy controls. In the present study, we established a stable CCNL2-overexpressing P19 cell line that can differentiate to myocardial cells when treated with 1% dimethyl sulfoxide (DMSO). Our data showed that stable CCNL2-overexpressing P19 cells were less differentiated after treatment with 1% DMSO and that expression of myocardial cell differentiation-related genes (such as cardiac actin, GATA4, Mef2C, Nkx2.5, and BNP) were reduced compared to vector-only transfected P19. Moreover, P19 cells overexpressing the CCNL2 gene had a reduced growth rate and a remarkably decreased S phase. We also found that these cells underwent apoptosis, as detected by two different apoptosis assays. The anti-apoptotic Bcl-2 protein was also downregulated in these cells. In addition, real-time PCR analysis revealed that expression of Wnt and beta-catenin was suppressed and GSK3beta was induced in the CCNL2-overexpressing P19 cells. These data suggest that overexpression of CCNL2 inhibited proliferation and differentiation of mouse embryonic carcinoma P19 cells and induced them to undergo apoptosis, possibly through the Wnt signal transduction pathway.