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Purpose. Autophagy is a lysosomal degradation pathway that is essential for maintaining the homeostasis of the intracellular environment. Mounting evidence indicates that autophagy plays an essential role in the occurrence and development of hepatocellular cancer (HCC). This research is aimed at exploring the prognostic value of autophagy-related genes (ARGs) in HCC patients. Methods. The Wilcoxon test was used to identify differentially expressed ARGs in The Cancer Genome Atlas (TCGA) HCC cohort. Then, the TCGA cohort was randomly divided into training and testing groups. Cox and LASSO regression models were used to screen for autophagy-related genes that affect overall survival (OS) in the TCGA training group. Based on the coefficient of risk genes, we constructed an autophagy-related gene signature for predicting the prognosis of HCC patients. Finally, we validated the prognostic significance of autophagy-related gene signature using the TCGA testing group and three external datasets. Results. ATG10, BIRC5, GAPDH, and TMEM74 are risk genes for OS. According to the optimal cutoff value of risk score in each HCC dataset, HCC patients can divide into high- and low-risk groups. ARG risk score can significantly distinguish HCC patients with different survival outcomes. Meanwhile, the ARG risk score is independently correlated with OS in multiple HCC cohorts. Conclusions. The autophagy-related risk score can effectively screen high-risk HCC patients and provide guidance for clinical prevention and treatment of HCC.

Emery-Dreifuss muscular dystrophy (EDMD) is a degenerative disease primarily affecting skeletal muscles in early childhood as well as cardiac muscle at later stages. EDMD is caused by a number of mutations in genes encoding proteins associated with the nuclear envelope (e.g., Emerin, Lamin A/C, and Nesprin). Recently, a novel protein, Lim-domain only 7 ( lmo7) has been reported to play a role in the molecular pathogenesis of EDMD. Prior in vitro and in vivo studies suggested the intriguing possibility that Lmo7 plays a role in skeletal or cardiac muscle pathophysiology. To further understand the in vivo role of Lmo7 in striated muscles, we generated a novel Lmo7-null ( lmo7−/−) mouse line. Using this mouse line, we examined skeletal and cardiac muscle physiology, as well as the role of Lmo7 in a model of muscular dystrophy and regeneration using the dystrophin-deficient mdx mouse model. Our results demonstrated that lmo7−/− mice had no abnormalities in skeletal muscle morphology, physiological function, or regeneration. Cardiac function was also unaffected. Moreover, we found that ablation of lmo7 in mdx mice had no effect on the observed myopathy and muscular regeneration exhibited by mdx mice. Molecular analyses also showed no changes in dystrophin complex factors, MAPK pathway components, and Emerin levels in lmo7 knockout mice. Taken together, we conclude that Lmo7 is dispensable for skeletal muscle and cardiac physiology and pathophysiology.

RNA interference (RNAi) has been successfully applied in suppression of Hepatitis B virus (HBV) replication. To circumvent the problem that mutation in HBV genome may result in resistance when siRNA is further developed as an anti-viral drug, in this study, we established a dual small interfering RNA (siRNA) expression system, which could simultaneously express two different siRNA molecules that can specifically target two genes. To test the effectiveness of this system, we applied this new approach to express simultaneously two different 21-bp hairpin siRNA duplexes that specifically attack the HBs and HBx genes of HBV, respectively, in Bel-7402 and HepG2.2.15 cells. Results indicated that dual siRNA could simultaneously inhibit the expression of HBs and HBx gene by 83.7% and 87.5%, respectively, based on luciferase assays. In addition, dual siRNA molecules were able to significantly reduce the amount of HBV core associated DNA, which is considered as an intracellular replicative intermediate, and the viral DNA in culture supernatant. Therefore, this dual siRNA system provides a more powerful tool for the study of gene function and implicates a potential application in the treatment of viral infection.

Nemaline myopathy (NM) is a congenital myopathy with an estimated incidence of 1∶50,000 live births. It is caused by mutations in thin filament components, including nebulin, which accounts for about 50% of the cases. The identification of NM cases with nonsense mutations resulting in loss of the extreme C-terminal SH3 domain of nebulin suggests an important role of the nebulin SH3 domain, which is further supported by the recent demonstration of its role in IGF-1-induced sarcomeric actin filament formation through targeting of N-WASP to the Z-line. To provide further insights into the functional significance of the nebulin SH3 domain in the Z-disk and to understand the mechanisms by which truncations of nebulin lead to NM, we took two approaches: (1) an affinity-based proteomic screening to identify novel interaction partners of the nebulin SH3 domain; and (2) generation and characterization of a novel knockin mouse model with a premature stop codon in the nebulin gene, eliminating its C-terminal SH3 domain (NebΔSH3 mouse). Surprisingly, detailed analyses of NebΔSH3 mice revealed no structural or histological skeletal muscle abnormalities and no changes in gene expression or localization of interaction partners of the nebulin SH3 domain, including myopalladin, palladin, zyxin and N-WASP. Also, no significant effect on peak isometric stress production, passive tensile stress or Young's modulus was found. However, NebΔSH3 muscle displayed a slightly altered force–frequency relationship and was significantly more susceptible to eccentric contraction-induced injury, suggesting that the nebulin SH3 domain protects against eccentric contraction-induced injury and possibly plays a role in fine-tuning the excitation–contraction coupling mechanism.

Mechanisms controlling vascular smooth muscle cell (VSMC) plasticity and renewal still remain to be completely elucidated. A class of small RNAs called microRNAs (miRs) regulate gene expression at the post-transcriptional level. Here we demonstrate a critical role of the miR-143/145 cluster in SMC differentiation and vascular pathogenesis, also through the generation of a mouse model of miR-143 and -145 knockout. We determined that the expression of miR-143 and -145 is decreased in acute and chronic vascular stress (transverse aortic constriction and in aortas of the ApoE knockout mouse). In human aortic aneurysms, the expression of miR-143 and -145 was significantly decreased compared to control aortas. In addition, overexpression of miR-143 and -145 decreased neointimal formation in a rat model of acute vascular injury. An in-depth analysis of the miR-143/145 knockout mouse model demonstrated that this miR cluster is expressed mostly in the SMC compartment, both during development and post-natally, in vessels and SMC-containing organs. Loss of miR-143 and miR-145 expression induces structural modifications of the aorta, due to an incomplete differentiation of VSMCs. In conclusion, our results demonstrate that the miR-143/145 gene cluster plays a critical role during SMC differentiation and strongly suggest its involvement in the reversion of the VSMC differentiation phenotype that occurs during vascular disease.