Effects of RhoC downregulation on the angiogenesis characteristics of myeloma vascular endothelial cells

Epigenetic signatures in cardiac fibrosis: Focusing on noncoding RNA regulators as the gatekeepers of cardiac fibroblast identity

Cardiac fibroblasts play a pivotal role in cardiac fibrosis by transformation of fibroblasts into myofibroblasts, which synthesis and secrete a large number of extracellular matrix proteins. Ultimately, this will lead to cardiac wall stiffness and impaired cardiac performance. The epigenetic regulation and fate reprogramming of cardiac fibroblasts has been advanced considerably in recent decades. Non coding RNAs (microRNAs, lncRNAs, circRNAs) regulate the functions and behaviors of cardiac fibroblasts, including proliferation, migration, phenotypic transformation, inflammation, pyroptosis, apoptosis, autophagy, which can provide the basis for novel targeted therapeutic treatments that abrogate activation and inflammation of cardiac fibroblasts, induce different death pathways in cardiac fibroblasts, or make it sensitive to established pathogenic cells targeted cytotoxic agents and biotherapy. This review summarizes our current knowledge in this field of ncRNAs function in epigenetic regulation and fate determination of cardiac fibroblasts as well as the details of signaling pathways contribute to cardiac fibrosis. Moreover, we will comment on the emerging landscape of lncRNAs and circRNAs function in regulating signal transduction pathways, gene translation processes and post-translational regulation of gene expression in cardiac fibroblast. In the end, the prospect of cardiac fibroblasts targeted therapy for cardiac fibrosis based on ncRNAs is discussed.

Transcriptomic analysis reveals the molecular mechanisms underlying osteoclast differentiation in the estrogen-deficient pullets

Several previous reports have suggested that estrogen (E2) is a vital signal responsible for the regulation of skeletal homeostasis and bone remodeling in mammals. E2 could efficiently accelerate the growth of medullary bone in pullets during sexual maturity. Furthermore, the low E2 level can strengthen the mechanical bone functions in female hens. However, mechanistic studies to describe the effects of E2 on bone in pullets during the initiation of the puberty period are remaining elusive. Therefore, the aim of this study was to explore the effect of inhibiting E2 biosynthesis on the biomechanical properties and its molecular mechanism during sexual maturity of pullets. In this study, a total of 90 Hy-line Sonia pullets with comparable body weight at 13 wk of age were selected and categorized into 2 separate groups. Daily, 0.5 mg/4 mL of letrozole (LZ) was orally administered to the treatment (TRT) group and 4 mL of saline to the control (CON) group of pullets for 6 wk. Compared with the CON group, a lower plasma E2 level was observed in the TRT group. Furthermore, plasma P, Gla protein (BGP), and 1,25-dihydroxy vitamin D3 (1,25-(OH)₂D₃) levels were markedly suppressed, whereas the plasma alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) levels were significantly elevated. Moreover, the cortical bone thickness and breaking strength of the tibia and femur, the bone mineral density of the humerus, and the bone mineral content of the humerus as well as the femur were increased significantly. The expression levels of 340 differentially expressed genes (DEGs) differed significantly between the CON and TRT group in the tibia at 19 wk of age. Among them, 32 genes were up-regulated, whereas 308 were down-regulated in the TRT group. The variations in candidate genes associated with osteoclast differentiation and cell adhesion may indicate that LZ inhibits E2 biosynthesis, consequently, reduces osteoclast differentiation by suppressing inter-cellular communication and cells attaching to extracellular matrix components. Taken together, the present study demonstrated that inhibiting E2 synthesis during sexual maturity of pullets decreased osteoclast differentiation and considerably enhanced bone quality.

Role of RhoC in cancer cell migration

Migration is one of the five major behaviors of cells. Although RhoC—a classic member of the Rho gene family—was first identified in 1985, functional RhoC data have only been widely reported in recent years. Cell migration involves highly complex signaling mechanisms, in which RhoC plays an essential role. Cell migration regulated by RhoC—of which the most well-known function is its role in cancer metastasis—has been widely reported in breast, gastric, colon, bladder, prostate, lung, pancreatic, liver, and other cancers. Our review describes the role of RhoC in various types of cell migration. The classic two-dimensional cell migration cycle constitutes cell polarization, adhesion regulation, cell contraction and tail retraction, most of which are modulated by RhoC. In the three-dimensional cell migration model, amoeboid migration is the most classic and well-studied model. Here, RhoC modulates the formation of membrane vesicles by regulating myosin II, thereby affecting the rate and persistence of amoeba-like migration. To the best of our knowledge, this review is the first to describe the role of RhoC in all cell migration processes. We believe that understanding the detail of RhoC-regulated migration processes will help us better comprehend the mechanism of cancer metastasis. This will contribute to the study of anti-metastatic treatment approaches, aiding in the identification of new intervention targets for therapeutic or genetic transformational purposes.

Rho-Proteins and Downstream Pathways as Potential Targets in Sepsis and Septic Shock: What Have We Learned from Basic Research

Sepsis and septic shock are associated with acute and sustained impairment in the function of the cardiovascular system, kidneys, lungs, liver, and brain, among others. Despite the significant advances in prevention and treatment, sepsis and septic shock sepsis remain global health problems with elevated mortality rates. Rho proteins can interact with a considerable number of targets, directly affecting cellular contractility, actin filament assembly and growing, cell motility and migration, cytoskeleton rearrangement, and actin polymerization, physiological functions that are intensively impaired during inflammatory conditions, such as the one that occurs in sepsis. In the last few decades, Rho proteins and their downstream pathways have been investigated in sepsis-associated experimental models. The most frequently used experimental design included the exposure to bacterial lipopolysaccharide (LPS), in both in vitro and in vivo approaches, but experiments using the cecal ligation and puncture (CLP) model of sepsis have also been performed. The findings described in this review indicate that Rho proteins, mainly RhoA and Rac1, are associated with the development of crucial sepsis-associated dysfunction in different systems and cells, including the endothelium, vessels, and heart. Notably, the data found in the literature suggest that either the inhibition or activation of Rho proteins and associated pathways might be desirable in sepsis and septic shock, accordingly with the cellular system evaluated. This review included the main findings, relevance, and limitations of the current knowledge connecting Rho proteins and sepsis-associated experimental models.

CircUbe3a from M2 macrophage-derived small extracellular vesicles mediates myocardial fibrosis after acute myocardial infarction

Objective: This study aimed to explore the role of circular RNAs (circRNAs) in M2 macrophage (M2M)-derived small extracellular vesicles (SEVs) in myocardial fibrosis development. Methods: The regulatory role of M2M-derived extracellular vesicles (EVs) was evaluated in a mouse model of acute myocardial infarction. Immunofluorescence, quantitative real-time PCR (RT-qPCR), nanoparticle tracking analysis, Western blot analysis and electron microscopy were used to identify macrophages, large extracellular vesicles (LEVs) and SEVs. The circRNA expression profiles of M0 macrophages (M0Ms) and M2Ms were determined by microarray analysis. Bioinformatic analysis, cell coculture and cell proliferation assays were performed to investigate the expression, function, and regulatory mechanisms of circUbe3a in vitro. qPCR, RNA immunoprecipitation (RIP), dual-luciferase reporter assays, RNA fluorescence in situ hybridization (RNA-FISH), Western blot analysis and a series of rescue experiments were used to verify the correlation among circUbe3a, miR-138-5p and RhoC. Results: CircUbe3a from M2M-derived SEVs triggered functional changes in cardiac fibroblasts (CFs). CircUbe3a was synthesized and loaded into SEVs during increased M2M infiltration after myocardial infarction. The fusion of the released SEVs with the plasma membrane likely caused the release of circUbe3a into the cytosol of CFs. Silencing or overexpressing circUbe3a altered CF proliferation, migration, and phenotypic transformation in vitro. We confirmed that circUbe3a plays a crucial role in enhancing functional changes in CFs by sponging miR-138-5p and then translationally repressing RhoC in vitro. In vivo, the addition of M2M-derived SEVs or overexpression of circUbe3a significantly exacerbated myocardial fibrosis after acute myocardial infarction, and these effects were partially abolished by circUbe3a-specific shRNA. Conclusions: Our findings suggest that M2M-derived circUbe3a-containing SEVs promote the proliferation, migration, and phenotypic transformation of CFs by directly targeting the miR-138-5p/RhoC axis, which may also exacerbate myocardial fibrosis after acute myocardial infarction.

Transcriptome Analysis Identifies Candidate Genes and Signaling Pathways Associated With Feed Efficiency in Xiayan Chicken

Feed efficiency is an important economic factor in poultry production, and the rate of feed efficiency is generally evaluated using residual feed intake (RFI). The molecular regulatory mechanisms of RFI remain unknown. Therefore, the objective of this study was to identify candidate genes and signaling pathways related to RFI using RNA-sequencing for low RFI (LRFI) and high RFI (HRFI) in the Xiayan chicken, a native chicken of the Guangxi province. Chickens were divided into four groups based on FE and sex: LRFI and HRFI for males and females, respectively. We identified a total of 1,015 and 742 differentially expressed genes associated with RFI in males and females, respectively. The 32 and 7 Gene Ontology (GO) enrichment terms, respectively, identified in males and females chiefly involved carbohydrate, amino acid, and energy metabolism. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified 11 and 5 significantly enriched signaling pathways, including those for nutrient metabolism, insulin signaling, and MAPK signaling, respectively. Protein-protein interaction (PPI) network analysis showed that the pathways involving CAT, ACSL1, ECI2, ABCD2, ACOX1, PCK1, HSPA2, and HSP90AA1 may have an effect on feed efficiency, and these genes are mainly involved in the biological processes of fat metabolism and heat stress. Gene set enrichment analysis indicated that the increased expression of genes in LRFI chickens was related to intestinal microvilli structure and function, and to the fat metabolism process in males. In females, the highly expressed set of genes in the LRFI group was primarily associated with nervous system and cell development. Our findings provide further insight into RFI regulation mechanisms in chickens.

RhoC: a fascinating journey from a cytoskeletal organizer to a Cancer stem cell therapeutic target

Tumor heterogeneity results in differential response to therapy due to the existence of plastic tumor cells, called cancer stem cells (CSCs), which exhibit the property of resistance to therapy, invasion and metastasis. These cells have a distinct, signaling network active at every stage of progression. It is difficult to envisage that the CSCs will have a unique set of signaling pathways regulating every stage of disease progression. Rather, it would be easier to believe that a single pivotal pathway having significant contribution at every stage, which can further turn on a battery of signaling mechanisms specific to that stage, would be instrumental in regulating the signaling network, enabling easy transition from one state to another. In this context, we discuss the role of RhoC which has contributed to several phenotypes during tumor progression.

RhoC (Ras homolog gene family member C) has been widely reported to regulate actin organization. It has been shown to impact the motility of cancer cells, resultantly affecting invasion and metastasis, and has contributed to carcinoma progression of the breast, pancreas, lung, ovaries and cervix, among several others. The most interesting finding has been its indispensable role in metastasis. Also, it has the ability to modulate various other phenotypes like angiogenesis, motility, invasion, metastasis, and anoikis resistance. These observations suggest that RhoC imparts the plasticity required by tumor cells to exhibit such diverse functions based on microenvironmental cues. This was further confirmed by recent reports which show that it regulates cancer stem cells in breast, ovary and head and neck cancers. Studies also suggest that the inhibition of RhoC results in abolition of advanced tumor phenotypes.

Our review throws light on how RhoC, which is capable of modulating various phenotypes may be the apt core signaling candidate regulating disease progression. Additionally, mice studies show that RhoC is not essential for embryogenesis, giving scope for its development as a possible therapeutic target. This review thus stresses on the need to understand the protein and its functioning in greater detail to enable its development as a stem cell marker and a possible therapeutic target.

Effects of RhoC downregulation on the angiogenesis characteristics of myeloma vascular endothelial cells

Background

Tumor angiogenesis plays an important role in disease progression, and RhoC has been previously found to be expressed in vascular endothelial cells (VECs); however, its role in tumor angiogenesis requires clarification. This study aimed to explore the effects of RhoC downregulation on the cytoskeleton, pseudopod formation, migration ability, and canalization capacity of myeloma vascular endothelial cells (MVECs) in vitro.

Materials and methods

The expression of RhoC in MVECs and human umbilical vein endothelial cells (HUVECs) was knocked down by shRNA, and the expression levels of RhoC mRNA were detected by quantitative reverse transcription polymerase chain reaction (qRT‐PCR). The cytoskeletal changes and pseudopods were observed by laser scanning confocal and scanning electron microscopy; VECs were incubated in two‐dimensional Matrigel and three‐dimensional microcarriers to observe tube‐like structures and budding status, respectively. The protein expression of RhoC, phosphorylation of mitogen‐activated protein kinase (p‐MAPK), and Rho‐associated coiled‐coil kinase (ROCK) was determined by Western blotting. The expression of RhoC in VECs was downregulated by RhoC shRNA, thereby decreasing the number of pseudopods, two‐dimensional tube‐like structures, and buds.

Results

When RhoC was downregulated, the expression levels of ROCK and phosphorylation of MAPK were both decreased (P < 0.05). Moreover, the expression levels of RhoC and phosphorylation of MAPK and three‐dimensional budding numbers were higher in MVECs than in HUVECs (P < 0.05). The downregulation of RhoC expression in MVECs and HUVECs inhibited pseudopod formation, migration, canalization ability, and angiogenesis (P < 0.05).

Conclusion

Our data indicated that MVECs and HUVECs were well suited for angiogenesis research, but the former cell type was shown to be more advantageous in terms of budding numbers. RhoC plays a pivotal role in MVECs angiogenesis, and the downregulation of RhoC expression could inhibit angiogenesis via the RhoC/MAPK and RhoC/ROCK signaling pathways.