Effect of LYRM1 knockdown on proliferation, apoptosis, differentiation and mitochondrial function in the P19 cell model of cardiac differentiation in vitro

LncRNA CRNDE modulates cardiac progenitor cells' proliferation and migration via the miR-181a/LYRM1 axis in hypoxia

Background

The cardiac progenitor cells provide a valuable method for myocardial infarction related heart failure therapies. But cardiac progenitor cell quickly loses the proliferation abilities during the myocardial infarction. In this paper, we aim to explore the role of lncRNA CRNDE in the modulation of cardiac progenitor cell reproduction and migration.

Methods

Cardiac progenitor cells were isolated from neonatal adult Sprague-Dawley rats by removing the heart and homogenizing the tissue. Various siRNAs and RNA mimics were co-transfected to the cells. A list of characterization methods, including qRT-PCR, Western blotting, luciferase assay, CCK-8 assay, and EdU incorporation assay, were utilized to verify the roles and interactions of CRNDE, miR-181a, and LYRM1 in cardiac progenitor cells’ proliferation and migration potentials.

Results

LncRNA CRNDE expressions were substantially promoted in the CoCl2-related hypoxia cardiac progenitor cell model. CRNDE suppression inhibited cardiac progenitor cell reproduction and migration under hypoxic conditions. The miR-181a-inhibitor restored the reproduction and migration potentials of cardiac progenitor cells after CRNDE knockdown in hypoxia. LYR motif containing 1 (LYRM1) was a target of miR-181a, and miR-181a negatively modulated its expressions. LYRM1 knockdowns inhibited miR-181a-inhibitor's protective effects for cardiac progenitor cell functions in hypoxia.

Conclusions

Our experiments and analysis demonstrated that CRNDE could modulate cardiac progenitor cell proliferation and migration potentials via the miR-181a/LYRM1 axis in hypoxia.

The Mitochondrial Acyl-carrier Protein Interaction Network Highlights Important Roles for LYRM Family Members in Complex I and Mitoribosome Assembly

NDUFAB1 is the mitochondrial acyl carrier protein (ACP) essential for cell viability. Through its pantetheine-4'-phosphate post-translational modification, NDUFAB1 interacts with members of the leucine-tyrosine-arginine motif (LYRM) protein family. Although several LYRM proteins have been described to participate in a variety of defined processes, the functions of others remain either partially or entirely unknown. We profiled the interaction network of NDUFAB1 to reveal associations with 9 known LYRM proteins as well as more than 20 other proteins involved in mitochondrial respiratory chain complex and mitochondrial ribosome assembly. Subsequent knockout and interaction network studies in human cells revealed the LYRM member AltMiD51 to be important for optimal assembly of the large mitoribosome subunit, consistent with recent structural studies. In addition, we used proteomics coupled with topographical heat-mapping to reveal that knockout of LYRM2 impairs assembly of the NADH-dehydrogenase module of complex I, leading to defects in cellular respiration. Together, this work adds to the catalogue of functions executed by LYRM family of proteins in building mitochondrial complexes and emphasizes the common and essential role of NDUFAB1 as a protagonist in mitochondrial metabolism.

Agonism of GPR39 displays protective effects against advanced glycation end-product (AGE)-induced degradation of extracellular matrix in human SW1353 cells

Excessive degradation of the cartilage articular extracellular matrix (ECM) in chondrocytes has been considered as an important pathological characteristics of OA. In the present study, we demonstrate that the G protein-coupled receptor GPR39 is expressed on SW1353 chondrocytes and is significantly downregulated in response to advanced glycation end products (AGEs). Our findings show that agonism of GPR39 exerts significant protective effects against AGE-induced degradation of articular extracellular matrix. Agonism of GPR39 rescued degradation of type II collagen by decreasing expression of the collagen-degrading enzymes matrix metalloproteinase (MMP)-3 and MMP-13. Additionally, agonism of GPR39 rescued AGE-induced suppression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. Agonism of GPR39 prevented degradation of aggrecan by downregulating AGE-induced expression of a disintegrin and metalloproteinase with type I thrombospondin motif (ADAMTS)-4 and ADAMTS-5. Finally, we demonstrate that the effects of GPR39 are mediated through the p38 mitogen activated protein kinase (MAPK)/nuclear factor-κB (NF-κB) cellular signaling pathway. Taken together, our findings show for the first time that targeted therapies involving GPR39 may provide a novel approach for the prevention and treatment of osteoarthritis.

Dehydrocostus lactone suppresses ox-LDL-induced attachment of monocytes to endothelial cells

Atherosclerosis is a cardiovascular disease that affects most people to at least some extent by old age. Many factors contribute to atherogenesis, and although it is extremely common, the mechanisms behind the pathogenesis of the disease remain poorly understood. Endothelial dysfunction is thought to be one of the main causes of atherosclerosis along with numerous other factors, such as oxidative stress and proinflammatory cytokine upregulation. The culmination of the complications that lead to atherogenesis is the formation of a fatty plaque on the intima of the arterial endothelium. In this study, we explore these aspects and others in regard to the treatment potential of dehydrocostus lactone (DHL), which is naturally occurring in certain flora such as the Saussurea lappa costus plant. Having long been used in traditional Chinese medicine, the effects of this plant are only just beginning to be studied by modern science. Among our most noteworthy findings are that DHL exerts an inhibitory effect against the increased expression of VCAM-1 and E-selectin induced by exposure to oxidized low-density lipoprotein (ox-LDL), which has been linked to the development and progression of atherosclerosis. The introduction of DHL also significantly diminished the downstream effects of VCAM-1 and E-selectin, such as the attachment of monocytes to the endothelium and the release of proinflammatory cytokines and chemokines, including TNF-α, MCP-1, and HMGB1. Furthermore, DHL is capable of rescuing the expression of KLF2, an important regulator of VCAM-1 and E-selectin expression. Together, our findings demonstrate the potential of DHL as a prophylactic or therapeutic treatment against ox-LDL-induced atherosclerosis via inhibition of the attachment of monocytes to endothelial cells.