Cytomembrane Trafficking Pathways of Connexin 26, 30, and 43.

The connexin gene family is the most prevalent gene that contributes to hearing loss. Connexins 26 and 30, encoded by GJB2 and GJB6, respectively, are the most abundantly expressed connexins in the inner ear. Connexin 43, which is encoded by GJA1, appears to be widely expressed in various organs, including the heart, skin, the brain, and the inner ear. The mutations that arise in GJB2, GJB6, and GJA1 can all result in comprehensive or non-comprehensive genetic deafness in newborns. As it is predicted that connexins include at least 20 isoforms in humans, the biosynthesis, structural composition, and degradation of connexins must be precisely regulated so that the gap junctions can properly operate. Certain mutations result in connexins possessing a faulty subcellular localization, failing to transport to the cell membrane and preventing gap junction formation, ultimately leading to connexin dysfunction and hearing loss. In this review, we provide a discussion of the transport models for connexin 43, connexins 30 and 26, mutations affecting trafficking pathways of these connexins, the existing controversies in the trafficking pathways of connexins, and the molecules involved in connexin trafficking and their functions. This review can contribute to a new way of understanding the etiological principles of connexin mutations and finding therapeutic strategies for hereditary deafness.

Differential mRNA Expressions in HCMV infected HUVECs.

Objective: The aim was to identify the gene expressions of human cytomegalovirus (HCMV)-infected human umbilical vein endothelial cells (HUVECs) and to study its possible pathogenic mechanism on atherosclerosis using microarray technology. Methods: The gene expression differences in HCMV AD169 strain-infected HUVECs were studied by the microarray technology to explore the potential molecular mechanism of HCMV infection. The qPCRs were performed to verify the transcriptome results. Results: A total of 2,583 differentially expressed genes, including 407 down-regulated genes and 2,176 up-regulated genes, were detected by the systematic bioinformatics analysis. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the significantly differentially expressed genes were mainly involved in regulating protein kinase activity, inflammatory response, ubiquitination, protein phosphorylation, cell metabolism, and exosomes, among which 12 genes had significant changes and were screened by protein-protein interaction (PPI) analysis and verified by qPCR. The experimental qPCR results were consistent with the microarray results. Conclusion: The GO and KEGG analyses revealed that the regulation of protein kinase activity, inflammatory response, ubiquitination, protein phosphorylation, and cell metabolism played important roles in the process of endothelial cell infection. Furthermore, 12 genes were involved in the process of HCMV infection of endothelial cells and contributed to the current understanding of the infection and pathogenic mechanisms of atherosclerosis.