Cell Cycle Arrest-Driven Fibrosis

Authentication and validation of key genes in the treatment of atopic dermatitis with Runfuzhiyang powder: combined RNA-seq, bioinformatics analysis, and experimental research

Background

Atopic dermatitis (AD) is inflammatory disease. So far, therapeutic mechanism of Runfuzhiyang powder on AD remains to be studied. This study aimed to mine key biomarkers to explore potential molecular mechanism for AD incidence and Runfuzhiyang powder treatment.

Methods

The control group, AD group, treat group (AD mice treated with Runfuzhiyang powder were utilized for studying. Differentially expressed AD-related genes were acquired by intersecting of key module genes related to control group, AD group and treatment group which were screened by WGCNA and AD-related differentially expressed genes (DEGs). KEGG and GO analyses were further carried out. Next, LASSO regression analysis was utilized to screen feature genes. The ROC curves were applied to validate the diagnostic ability of feature genes to obtain AD-related biomarkers. Then protein-protein interaction (PPI) network, immune infiltration analysis and single-gene gene set enrichment analysis (GSEA) were presented. Finally, TF-mRNA-lncRNA and drug-gene networks of biomarkers were constructed.

Results

4 AD-related biomarkers (Ddit4, Sbf2, Senp8 and Zfp777) were identified in AD groups compared with control group and treat group by LASSO regression analysis. The ROC curves revealed that four biomarkers had good distinguishing ability between AD group and control group, as well as AD group and treatment group. Next, GSEA revealed that pathways of E2F targets, KRAS signaling up and inflammatory response were associated with 4 biomarkers. Then, we found that Ddit4, Sbf2 and Zfp777 were significantly positively correlated with M0 Macrophage, and were significantly negatively relevant to Resting NK. Senp8 was the opposite. Finally, a TF-mRNA-lncRNA network including 200 nodes and 592 edges was generated, and 20 drugs targeting SENP8 were predicted.

Conclusion

4 AD-related and Runfuzhiyang powder treatment-related biomarkers (Ddit4, Sbf2, Senp8 and Zfp777) were identified, which could provide a new idea for targeted treatment and diagnosis of AD.

Znhit1 Regulates p21Cip1 to Control Mouse Lens Differentiation

Purpose

The transparency of the ocular lens is essential for refracting and focusing light onto the retina, and transparency is controlled by many factors and signaling pathways. Here we showed a critical role of chromatin remodeler zinc finger HIT-type containing 1 (Znhit1) in maintaining lens transparency.

Methods

To explore the roles of Znhit1 in lens development, the cre-loxp system was used to generate lens-specific Znhit1 knockout mice (Znhit1Mlr10-Cre; Znhit1 cKO). Morphological changes in mice lenses were examined using hematoxylin and eosin staining. RNA sequencing (RNA-seq) and assay for transposase accessible chromatin using sequencing (ATAC-seq) were applied to screen transcriptome changes. Immunofluorescence staining were performed to assess proteins distribution and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining were used for determining apoptosis. The mRNAs expression was examined by quantitative RT-PCR and proteins expression by Western blot.

Results

Lens-specific conditional knockout mice had a severe cataract, microphthalmia phenotype, and seriously abnormal lens fiber cells differentiation. Deletion of Znhit1 in the lens resulted in decreased cell proliferation and increased cell apoptosis of the lens epithelia. ATAC-seq showed that Znhit1 deficiency increased chromatin accessibility of cyclin-dependent kinase inhibitors, including p57Kip2 and p21Cip1, and upregulated the expression of these genes in mRNA and protein levels. And we also showed that loss of Znhit1 lead to lens fibrosis by upregulating the expression of p21Cip1.

Conclusions

Our findings suggested that Znhit1 is required for the survival of lens epithelial cells. The loss of Znhit1 leads to the overexpression of p21Cip1, further resulting in lens fibrosis, and impacted the establishment of lens transparency.

Z-Guggulsterone alleviates renal fibrosis by mitigating G2/M cycle arrest through Klotho/p53 signaling

Chronic kidney disease (CKD) has become a major public health problem worldwide. Renal fibrosis is considered to be the final outcome and potential therapeutic target of CKD. Z-Guggulsterone (Z-GS), an active compound derived from Commiphora mukul, has been proved to be effective in various diseases. The present study was aimed to evaluate the effect and mechanism of Z-GS on renal fibrosis. Unilateral ureteral obstruction (UUO) mice and hypoxia-induced HK-2 cells were used to simulate renal fibrosis, respectively. The mice and cells were treated with different doses of Z-GS to observe the pharmacological action. Results demonstrated that Z-GS lightened renal function and histopathological injury induced by UUO. Z-GS also alleviated renal fibrosis in mice by inhibiting the expressions of α-SMA, TGF-β, and Collagen Ⅳ. Besides, Z-GS delayed G2/M cycle arrest by promoting the expressions of CDK1 and CyclinB1. Experiments in vitro indicated that Z-GS increased cell viability while decreased LDH release in hypoxia-induced HK-2 cells. In addition, fibrosis and G2/M cycle arrest induced by hypoxia in HK-2 cells were retarded by Z-GS. The study of its possible mechanism exhibited that Z-GS increased the level of Klotho and inhibited p53 level. Nevertheless, the effect of Z-GS on Klotho/p53 signaling was reversed by siRNA-Klotho. Moreover, siRNA-Klotho eliminated the effects of Z-GS on G2/M cycle arrest and fibrosis. Taken together, this study clarified that Z-GS alleviated renal fibrosis and G2/M cycle arrest through Klotho/p53 signaling. People who have suffered CKD may potentially benefit from treatment with Z-GS.