Inhibition of PP2A enhances the osteogenic differentiation of human aortic valvular interstitial cells via ERK and p38 MAPK pathways

Overexpression of miRNA29a gene inhibits proliferation and promotes apoptosis of jejunal epithelial cells in yak

MicroRNAs (miRNAs) were identified to be involved in various biological functions by regulating the degradation or suppressing the translation of their downstream target genes. Recent studies have identified miR-29a play a key role in functions of mammal cell differentiation, proliferation, apoptosis, and signal transduction. However, the underlying functions for miR-29a in jejunal epithelial cells biological function still to be investigated. In order to explore the yak jejunal epithelial cells proliferation and barrier dysfunction with over expression of miR-29a gene, three 0-day-old Pamir male yaks were randomly selected and slaughtered in present study, and the jejunal epithelial cells were isolated and cultured to determine yak jejunal epithelial cells proliferation and protein composition on differential expression of miR-29a gene in Pamir plateau. Here, we demonstrated that the overexpression of miR-29a gene could inhibit the proliferation of Pamir yaks jejunum epithelial cells, and contribute to the apoptosis of Pamir yaks jejunal epithelial cells with some extent. A total of 133 differentially expressed proteins were identified in different expression of miR-29a groups by label-free Mass Spectrometry (MS), which could be concluded to two predominant themes: cell proliferation and inflammatory response. Interestingly, GPR41, as a bridge protein, was contacted two predominant themes to involved in Pamir Yaks jejunal mechanical barrier PPI network, and the target proteins displayed strong mutual interactions in the complex PPI network. Overall, our study suggested that the over-expression miR-29a inhibited the jejunal epithelial cells proliferation and the expressions of specific proteins, which damaged jejunal barrier function to slow down the intestine structure and function advanced mature development during young livestock period for influence the enhanced performance of production efficiency.

Ischemic-Preconditioning Induced Serum Exosomal miR-133a-3p Improved Post-Myocardial Infarction Repair via Targeting LTBP1 and PPP2CA

Background

Ischemic preconditioning-induced serum exosomes (IPC-exo) protected rat heart against myocardial ischemia/reperfusion injury. However, whether IPC-exo regulate replacement fibrosis after myocardial infarction (MI) and the underlying mechanisms remain unclear. MicroRNAs (miRs) are important cargos of exosomes and play an essential role in cardioprotection. We aim to investigate whether IPC-exo regulate post-MI replacement fibrosis by transferring cardioprotective miRs and its action mechanism.

Methods

Exosomes obtained from serum of adult rats in control (Con-exo) and IPC groups were identified and analyzed, subsequently intracardially injected into MI rats following ligation. Their miRs profiles were identified using high-throughput miR sequencing to identify target miRs for bioinformatics analysis. Luciferase reporter assays confirmed target genes of selected miRs. IPC-exo transfected with selected miRs antagomir or NC were intracardially administered to MI rats post-ligation. Cardiac function and degree of replacement fibrosis were detected 4 weeks post-MI.

Results

IPC-exo exerted cardioprotective effects against excessive replacement fibrosis. MiR sequencing and RT-qPCR identified miR-133a-3p as most significantly different between IPC-exo and Con-exo. MiR-133a-3p directly targeted latent transforming growth factor beta binding protein 1 (LTBP1) and protein phosphatase 2, catalytic subunit, alpha isozyme (PPP2CA). KEGG analysis showed that transforming growth factor-β (TGF-β) was one of the most enriched signaling pathways with miR-133a-3p. Comparing to injection of IPC-exo transfected with miR-133a-3p antagomir NC, injecting IPC-exo transfected with miR-133a-3p antagomir abolished protective effects of IPC-exo on declining excessive replacement fibrosis and cardiac function enhancement, while increasing the messenger RNA and protein expression of LTBP1, PPP2CA, and TGF-β1in MI rats.

Conclusion

IPC-exo inhibit excessive replacement fibrosis and improve cardiac function post-MI by transferring miR-133a-3p, the mechanism is associated with directly targeting LTBP1 and PPP2CA, and indirectly regulating TGF-β pathway in rats. Our finding provides potential therapeutic effect of IPC-induced exosomal miR-133a-3p for cardiac repair.

CircRNA ARHGAP10 promotes osteogenic differentiation through the miR-335-3p/RUNX2 pathway in aortic valve calcification

BACKGROUND

Calcific aortic valve disease (CAVD) is a common cardiovascular disease with high morbidity and mortality, and no effective prevention or treatment is available. In recent years, increasing evidence has shown that noncoding RNAs (ncRNAs) play an important role in the pathogenesis and prognosis of CAVD. Several associated circular RNAs (circRNAs) have been reported to be involved in CAVD, such as circRIC3 and TGFBR2. However, the limited number of circRNAs identified in CAVD warrants further in-depth investigation, and the comprehensive elucidation of their role in the key mechanisms of this disease is needed.

METHODS

The expression of circRNAs and microRNAs (miRNAs) were analyzed by RNA sequencing. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to analyze the expression of circRNA ARHGAP10 (circARHGAP10), miR-335-3p, and RUNX2. Luciferase reporter assay, pull-down assay, and RNA binding protein immunoprecipitation (RIP) assay were performed to evaluate the binding of miR-335-3p to circARHGAP10 or RUNX2. Alizarin red S staining showed the formation of calcified nodules in valve interstitial cells (VICs). The expression of circARHGAP10 and miR-335-3p was altered through lentivirus infection. Alkaline phosphatase (ALP) activity was used to verify the correlation between circARHGAP10 and miR-335-3p. The expression of proteins was assessed via Western blot. RNA fluorescence in situ hybridization (FISH) was used to confirm the localization of circARHGAP10 in the cytoplasm of VICs. Immunofluorescence was used to detect the expression level of RUNX2. ApoE-/- mice were used to construct a CAVD model, circARHGAP10 short hairpin RNA (shRNA) and miR-335-3p inhibitor lentivirus were intraperitoneally injected, and scramble and inhibitor normal control (NC) lentivirus were injected as controls, followed by hematoxylin and eosin (HE) staining.

RESULTS

Through RNA sequencing, we found that circARHGAP10 (hsa_circ_0008975) was highly expressed in calcific aortic valves. CircARHGAP10 knockdown effectively inhibited the extent of osteogenic differentiation of VICs. We then found that circARHGAP10 was a competing endogenous RNA (ceRNA) of miR-355-3p and that miR-355-3p targeted RUNX2. In vitro experiments confirmed that circARHGAP10 regulated the osteogenic differentiation of VICs through the miR-355-3p/RUNX2 pathway, and this was validated in vivo using an ApoE-/- mouse model.

CONCLUSIONS

These findings provide a foundation for circRNA-directed diagnostics and therapeutics for CAVD.

Prolonged exposure to environmental levels of microcystin-LR triggers ferroptosis in brain via the activation of Erk/MAPK signaling pathway

While existing research has illuminated the environmental dangers and neurotoxic effects of MC-LR exposure, the molecular underpinnings of brain damage from environmentally-relevant MC-LR exposure remain elusive. Employing a comprehensive approach involving RNA sequencing, histopathological examination, and biochemical analyses, we discovered genes differentially expressed and enriched in the ferroptosis pathway. This finding was associated with mitochondrial structural impairment and downregulation of Gpx4 and Slc7a11 in mice brains subjected to low-dose MC-LR over 180 days. Mirroring these findings, we noted reduced cell viability and GSH/GSSH ratio, along with an increased ROS level, in HT-22, BV-2, and bEnd.3 cells following MC-LR exposure. Intriguingly, MC-LR also amplified phospho-Erk levels in both in vivo and in vitro settings, and the effects were mitigated by treatment with PD98059, an Erk inhibitor. Taken together, our findings implicate the activation of the Erk/MAPK signaling pathway in MC-LR-induced ferroptosis, shedding valuable light on the neurotoxic mechanisms of MC-LR. These insights could guide future strategies to prevent MC-induced neurodegenerative diseases.

Exploring molecular profiles of calcification in aortic vascular smooth muscle cells and aortic valvular interstitial cells

Cardiovascular calcification can occur in vascular and valvular structures and is commonly associated with calcium deposition and tissue mineralization leading to stiffness and dysfunction. Patients with chronic kidney disease and associated hyperphosphatemia have an elevated risk for coronary artery calcification (CAC) and calcific aortic valve disease (CAVD). However, there is mounting evidence to suggest that the susceptibility and pathobiology of calcification in these two cardiovascular structures may be different, yet clinically they are similarly treated. To better understand diversity in molecular and cellular processes that underlie hyperphosphatemia-induced calcification in vascular and valvular structures, we exposed aortic vascular smooth muscle cells (AVSMCs) and aortic valve interstitial cells (AVICs) to high (2.5 mM) phosphate (Ph) conditions in vitro, and examined cell-specific responses. To further identify hyperphosphatemic-specific responses, parallel studies were performed using osteogenic media (OM) as an alternative calcific stimulus. Consistent with clinical observations made by others, we show that AVSMCs are more susceptible to calcification than AVICs. In addition, bulk RNA-sequencing reveals that AVSMCs and AVICs activate robust ossification-programs in response to high phosphate or OM treatments, however, the signaling pathways, cellular processes and osteogenic-associated markers involved are cell- and treatment-specific. For example, compared to VSMCs, VIC-mediated calcification involves biological processes related to osteo-chondro differentiation and down regulation of 'actin cytoskeleton'-related genes, that are not observed in VSMCs. Furthermore, hyperphosphatemic-induced calcification in AVICs and AVSMCs is independent of P13K signaling, which plays a role in OM-treated cells. Together, this study provides a wealth of information suggesting that the pathogenesis of cardiovascular calcifications is significantly more diverse than previously appreciated.

Genomic Basis of Adaptive Divergence in Leg Length between Ground- and Tree-Dwelling Species within a Bird Family

Hind limbs of tetrapods vary greatly in length and the variability can be associated with locomotor adaptation. Although the phenotypic evolution has been well documented, the underlying genetic basis remains poorly understood. We address this issue by integrating comparative genomics and functional prediction with a study system consisting of ground-dwelling, long-legged and tree-dwelling, short-legged species within the avian family Paridae. Genome-wide divergence and phenotypic correlation analyses jointly identified five highly divergent genomic regions that are significantly related with the difference in leg length between these two groups. Gene annotation for these regions detected three genes involved in skeletal development, that is, PTPA, BRINP1, and MIGA2, with the first one being under the strongest selection. Furthermore, four single nucleotide polymorphisms (SNPs) in the coding region of PTPA can well distinguish the two groups with distinct leg length. Among the four SNPs, one is non-synonymous mutation, and according to the prediction for protein structure and function, it can affect the 3D structure of the encoded protein by altering the corresponding amino acid's position. The alleles of PTPA were found in all sequenced species of the orders Palaeognathae and Psittaciformes, which typically take a ground locomotion style. A whole-genome scanning across bird species uncovered that the four SNPs are more likely to be present in resident passerines with increased leg length/wing length ratios (a proxy of leg-dependent locomotion efficiency). Our findings provide insight into the molecular evolution of locomotion performance based on leg morphology in birds.

Multiomics of Tissue Extracellular Vesicles Identifies Unique Modulators of Atherosclerosis and Calcific Aortic Valve Stenosis

BACKGROUND

Fewer than 50% of patients who develop aortic valve calcification have concomitant atherosclerosis, implying differential pathogenesis. Although circulating extracellular vesicles (EVs) act as biomarkers of cardiovascular diseases, tissue-entrapped EVs are associated with early mineralization, but their cargoes, functions, and contributions to disease remain unknown.

METHODS

Disease stage-specific proteomics was performed on human carotid endarterectomy specimens (n=16) and stenotic aortic valves (n=18). Tissue EVs were isolated from human carotid arteries (normal, n=6; diseased, n=4) and aortic valves (normal, n=6; diseased, n=4) by enzymatic digestion, (ultra)centrifugation, and a 15-fraction density gradient validated by proteomics, CD63-immunogold electron microscopy, and nanoparticle tracking analysis. Vesiculomics, comprising vesicular proteomics and small RNA-sequencing, was conducted on tissue EVs. TargetScan identified microRNA targets. Pathway network analyses prioritized genes for validation in primary human carotid artery smooth muscle cells and aortic valvular interstitial cells.

RESULTS

Disease progression drove significant convergence (P<0.0001) of carotid artery plaque and calcified aortic valve proteomes (2318 proteins). Each tissue also retained a unique subset of differentially enriched proteins (381 in plaques; 226 in valves; q<0.05). Vesicular gene ontology terms increased 2.9-fold (P<0.0001) among proteins modulated by disease in both tissues. Proteomics identified 22 EV markers in tissue digest fractions. Networks of proteins and microRNA targets changed by disease progression in both artery and valve EVs revealed shared involvement in intracellular signaling and cell cycle regulation. Vesiculomics identified 773 proteins and 80 microRNAs differentially enriched by disease exclusively in artery or valve EVs (q<0.05); multiomics integration found tissue-specific EV cargoes associated with procalcific Notch and Wnt signaling in carotid arteries and aortic valves, respectively. Knockdown of tissue-specific EV-derived molecules FGFR2, PPP2CA, and ADAM17 in human carotid artery smooth muscle cells and WNT5A, APP, and APC in human aortic valvular interstitial cells significantly modulated calcification.

CONCLUSIONS

The first comparative proteomics study of human carotid artery plaques and calcified aortic valves identifies unique drivers of atherosclerosis versus aortic valve stenosis and implicates EVs in advanced cardiovascular calcification. We delineate a vesiculomics strategy to isolate, purify, and study protein and RNA cargoes from EVs entrapped in fibrocalcific tissues. Integration of vesicular proteomics and transcriptomics by network approaches revealed novel roles for tissue EVs in modulating cardiovascular disease.

Pro-Calcifying Role of Enzymatically Modified LDL (eLDL) in Aortic Valve Sclerosis via Induction of IL-6 and IL-33

One of the contributors to atherogenesis is enzymatically modified LDL (eLDL). eLDL was detected in all stages of aortic valve sclerosis and was demonstrated to trigger the activation of p38 mitogen-activated protein kinase (p38 MAPK), which has been identified as a pro-inflammatory protein in atherosclerosis. In this study, we investigated the influence of eLDL on IL-6 and IL-33 induction, and also the impact of eLDL on calcification in aortic valve stenosis (AS). eLDL upregulated phosphate-induced calcification in valvular interstitial cells (VICs)/myofibroblasts isolated from diseased aortic valves, as demonstrated by alizarin red staining. Functional studies demonstrated activation of p38 MAPK as well as an altered gene expression of osteogenic genes known to be involved in vascular calcification. In parallel with the activation of p38 MAPK, eLDL also induced upregulation of the cytokines IL-6 and IL-33. The results suggest a pro-calcifying role of eLDL in AS via induction of IL-6 and IL-33.

Bioinformatics-Based Identification of CircRNA-MicroRNA-mRNA Network for Calcific Aortic Valve Disease

Background

Calcific aortic valve disease (CAVD) is the most common native valve disease. Valvular interstitial cell (VIC) osteogenic differentiation and valvular endothelial cell (VEC) dysfunction are key steps in CAVD progression. Circular RNA (circRNAs) is involved in regulating osteogenic differentiation with mesenchymal cells and is associated with multiple disease progression, but the function of circRNAs in CAVD remains unknown. Here, we aimed to investigate the effect and potential significance of circRNA-miRNA-mRNA networks in CAVD.

Methods

Two mRNA datasets, one miRNA dataset, and one circRNA dataset of CAVD downloaded from GEO were used to identify DE-circRNAs, DE-miRNAs, and DE-mRNAs. Based on the online website prediction function, the common mRNAs (FmRNAs) for constructing circRNA-miRNA-mRNA networks were identified. GO and KEGG enrichment analyses were performed on FmRNAs. In addition, hub genes were identified by PPI networks. Based on the expression of each data set, the circRNA-miRNA-hub gene network was constructed by Cytoscape (version 3.6.1).

Results

32 DE-circRNAs, 206 DE-miRNAs, and 2170 DE-mRNAs were identified. Fifty-nine FmRNAs were obtained by intersection. The KEGG pathway analysis of FmRNAs was enriched in pathways in cancer, JAK-STAT signaling pathway, cell cycle, and MAPK signaling pathway. Meanwhile, transcription, nucleolus, and protein homodimerization activity were significantly enriched in GO analysis. Eight hub genes were identified based on the PPI network. Three possible regulatory networks in CAVD disease were obtained based on the biological functions of circRNAs including: hsa_circ_0026817-hsa-miR-211-5p-CACNA1C, hsa_circ_0007215-hsa-miR-1252-5p-MECP2, and hsa_circ_0007215-hsa-miR-1343-3p- RBL1.

Conclusion

The present bionformatics analysis suggests the functional effect for the circRNA-miRNA-mRNA network in CAVD pathogenesis and provides new targets for therapeutics.

Protective effect of Anneslea fragrans ethanolic extract against CCl4-induced liver injury by inhibiting inflammatory response, oxidative stress and apoptosis

Anneslea Fragrans Wall. (AF) is a medicinal and edible plant distributed in China. Its leaves and bark generally used for the treatments of diarrhea, fever, and liver diseases. While its ethnopharmacological application against liver diseases has not been fully studied. This study was aimed to evaluate the hepatoprotective effect of ethanolic extract from A. fragrans (AFE) on CCl₄ induced liver injury in mice. The results showed that AFE could effectively reduce plasma activities of ALT and AST, increase antioxidant enzymes activities (SOD and CAT) and GSH level, and decrease MDA content in CCl₄ induced mice. AFE effectively decreased the expressions of inflammatory cytokines (IL-1β, IL-6, TNF-α, COX-2 and iNOS), cell apoptosis-related proteins (Bax, caspase-3 and caspase-9) and increased Bcl-2 protein expression via inhibiting MAPK/ERK pathway. Additionally, TUNEL staining, Masson and Sirius red staining, immunohistochemical analyses revealed that AFE could inhibit the CCl₄-induced hepatic fibrosis formation via reducing depositions of α-SMA, collagen I and collagen III. Conclusively, the present study demonstrated that AFE had an hepatoprotective effect by MAPK/ERK pathway to inhibit oxidative stress, inflammatory response and apoptosis in CCl₄-induced liver injury mice, suggesting that AFE might be served as a hepatoprotective ingredient in the prevention and treatment of liver injury.

Inflammatory serum factors from aortic valve stenosis patients modulate sex differences in valvular myofibroblast activation and osteoblast-like differentiation

Aortic valve stenosis (AVS) is a sexually dimorphic cardiovascular disease that is driven by fibrosis and calcification of the aortic valve leaflets. Circulating inflammatory factors present in serum from AVS patients contribute to sex differences in valve fibro-calcification by driving the activation of valvular interstitial cells (VICs) to myofibroblasts and/or osteoblast-like cells. However, the molecular mechanisms by which inflammatory factors contribute to sex-specific valve fibro-calcification remain largely unknown. In this study, we identified inflammatory factors present in serum samples from AVS patients that regulate sex-specific myofibroblast activation and osteoblast-like differentiation. After correlating serum proteomic datasets with clinical and in vitro myofibroblast datasets, we identified annexin A2 and cystatin C as candidate inflammatory factors that correlate with both AVS patient severity and myofibroblast activation measurements in vitro. Validation experiments utilizing hydrogel biomaterials as cell culture platforms that mimic the valve extracellular matrix confirmed that annexin A2 and cystatin C promote sex-specific VIC activation to myofibroblasts via p38 MAPK signaling. Additionally, annexin A2 and cystatin C increase osteoblast-like differentiation primarily in male VICs. Our results implicate serum inflammatory factors as potential AVS biomarkers that also contribute to sexually dimorphic AVS progression by driving VIC myofibroblast activation and/or osteoblast-like differentiation. Collectively, the results herein further our overall understanding as to how biological sex may impact inflammation-driven AVS and may lead to the development of sex-specific drug treatment strategies.

miRNA Expression Profiling Uncovers a Role of miR-139-5p in Regulating the Calcification of Human Aortic Valve Interstitial Cells

Calcific aortic valve disease (CAVD) is the most common structural heart disease, and the morbidity is increased with elderly population. Several microRNAs (miRNAs) have been identified to play crucial roles in CAVD, and numerous miRNAs are still waiting to be explored. In this study, the miRNA expression signature in CAVD was analyzed unbiasedly by miRNA-sequencing, and we found that, compared with the normal control valves, 152 miRNAs were upregulated and 186 miRNAs were downregulated in calcified aortic valves. The functions of these differentially expressed miRNAs were associated with cell differentiation, apoptosis, adhesion and immune response processes. Among downregulated miRNAs, the expression level of miR-139-5p was negatively correlated with the osteogenic gene RUNX2, and miR-139-5p was also downregulated during the osteogenic differentiation of primary human aortic valve interstitial cells (VICs). Subsequent functional studies revealed that miR-139-5p overexpression inhibited the osteogenic differentiation of VICs by negatively modulating the expression of pro-osteogenic gene FZD4 and CTNNB1. In conclusion, these results suggest that miR-139-5p plays an important role in osteogenic differentiation of VICs via the Wnt/β-Catenin pathway, which may further provide a new therapeutic target for CAVD.

Vascular Calcification Mechanisms: Updates and Renewed Insight into Signaling Pathways Involved in High Phosphate-Mediated Vascular Smooth Muscle Cell Calcification

Vascular calcification (VC) is associated with aging, cardiovascular and renal diseases and results in poor morbidity and increased mortality. VC occurs in patients with chronic kidney disease (CKD), a condition that is associated with high serum phosphate (Pi) and severe cardiovascular consequences. High serum Pi level is related to some pathologies which affect the behaviour of vascular cells, including platelets, endothelial cells (ECs) and smooth muscle cells (SMCs), and plays a central role in promoting VC. VC is a complex, active and cell-mediated process involving the transdifferentiation of vascular SMCs to a bone-like phenotype, systemic inflammation, decreased anti-calcific events (loss of calcification inhibitors), loss in SMC lineage markers and enhanced pro-calcific microRNAs (miRs), an increased intracellular calcium level, apoptosis, aberrant DNA damage response (DDR) and senescence of vascular SMCs. This review gives a brief overview of the current knowledge of VC mechanisms with a particular focus on Pi-induced changes in the vascular wall important in promoting calcification. In addition to reviewing the main findings, this review also sheds light on directions for future research in this area and discusses emerging pathways such as Pi-regulated intracellular calcium signaling, epigenetics, oxidative DNA damage and senescence-mediated mechanisms that may play critical, yet to be explored, regulatory and druggable roles in limiting VC.

Molecular Aspects and Prognostic Significance of Microcalcifications in Human Pathology: A Narrative Review

The presence of calcium deposits in human lesions is largely used as imaging biomarkers of human diseases such as breast cancer. Indeed, the presence of micro- or macrocalcifications is frequently associated with the development of both benign and malignant lesions. Nevertheless, the molecular mechanisms involved in the formation of these calcium deposits, as well as the prognostic significance of their presence in human tissues, have not been completely elucidated. Therefore, a better characterization of the biological process related to the formation of calcifications in different tissues and organs, as well as the understanding of the prognostic significance of the presence of these calcium deposits into human tissues could significantly improve the management of patients characterized by microcalcifications associated lesions. Starting from these considerations, this narrative review highlights the most recent histopathological and molecular data concerning the formation of calcifications in breast, thyroid, lung, and ovarian diseases. Evidence reported here could deeply change the current point of view concerning the role of ectopic calcifications in the progression of human diseases and also in the patients’ management. In fact, the presence of calcifications can suggest an unfavorable prognosis due to dysregulation of normal tissues homeostasis.