Genome-Wide Identification and Characterization of NAC Family in Hibiscus hamabo Sieb. et Zucc. under Various Abiotic Stresses.

NAC transcription factor is one of the largest plant gene families, participating in the regulation of plant biological and abiotic stresses. In this study, 182 NAC proteins (HhNACs) were identified based on genomic datasets of Hibiscus hamabo Sieb. et Zucc (H. hamabo). These proteins were divided into 19 subfamilies based on their phylogenetic relationship, motif pattern, and gene structure analysis. Expression analysis with RNA-seq revealed that most HhNACs were expressed in response to drought and salt stress. Research of quantitative real-time PCR analysis of nine selected HhNACs supported the transcriptome data's dependability and suggested that HhNAC54 was significantly upregulated under multiple abiotic stresses. Overexpression of HhNAC54 in Arabidopsis thaliana (A. thaliana) significantly increased its tolerance to salt. This study provides a basis for a comprehensive analysis of NAC transcription factor and insight into the abiotic stress response mechanism in H. hamabo.

Genome-wide Analysis of Basic Helix-Loop-Helix Family Genes and Expression Analysis in Response to Drought and Salt Stresses in Hibiscus hamabo Sieb. et Zucc.

The basic helix-loop-helix (bHLH) family of transcription factors is one of the most significant and biggest in plants. It is involved in the regulation of both growth and development, as well as stress response. Numerous members of the bHLH family have been found and characterized in woody plants in recent years. However, no systematic study of the bHLH gene family has been published for Hibiscus hamabo Sieb. et Zucc. In this research, we identified 162 bHLH proteins (HhbHLHs) from the genomic and transcriptomic datasets of H. hamabo, which were phylogenetically divided into 19 subfamilies. According to a gene structural study, the number of exon-introns in HhbHLHs varied between zero and seventeen. MEME research revealed that the majority of HhbHLH proteins contained three conserved motifs, 1, 4, and 5. The examination of promoter cis-elements revealed that the majority of HhbHLH genes had several cis-elements involved in plant growth and development and abiotic stress responses. In addition, the overexpression of HhbHLH2 increased salt and drought stress tolerance in Arabidopsis.

Loss of SLC27A5 Activates Hepatic Stellate Cells and Promotes Liver Fibrosis via Unconjugated Cholic Acid.

Although the dysregulation of bile acid (BA) composition has been associated with fibrosis progression, its precise roles in liver fibrosis is poorly understood. This study demonstrates that solute carrier family 27 member 5 (SLC27A5), an enzyme involved in BAs metabolism, is substantially downregulated in the liver tissues of patients with cirrhosis and fibrosis mouse models. The downregulation of SLC27A5 depends on RUNX family transcription factor 2 (RUNX2), which serves as a transcriptional repressor. The findings reveal that experimental SLC27A5 knockout (Slc27a5-/- ) mice display spontaneous liver fibrosis after 24 months. The loss of SLC27A5 aggravates liver fibrosis induced by carbon tetrachloride (CCI4 ) and thioacetamide (TAA). Mechanistically, SLC27A5 deficiency results in the accumulation of unconjugated BA, particularly cholic acid (CA), in the liver. This accumulation leads to the activation of hepatic stellate cells (HSCs) by upregulated expression of early growth response protein 3 (EGR3). The re-expression of hepatic SLC27A5 by an adeno-associated virus or the reduction of CA levels in the liver using A4250, an apical sodium-dependent bile acid transporter (ASBT) inhibitor, ameliorates liver fibrosis in Slc27a5-/- mice. In conclusion, SLC27A5 deficiency in mice drives hepatic fibrosis through CA-induced activation of HSCs, highlighting its significant implications for liver fibrosis treatment.

Genome-Wide Identification and Analysis of MYB Transcription Factor Family in Hibiscus hamabo.

MYB transcription factors constitute one of the largest gene families in plants and play essential roles in the regulation of plant growth, responses to stress, and a wide variety of physiological and biochemical processes. In this study, 204 MYB proteins (HhMYBs) were identified in the Hibiscus hamabo Sieb. et Zucc (H. hamabo) genome and systematically analyzed based on their genomic sequence and transcriptomic data. The candidate HhMYB proteins and MYBs of Arabidopsis thaliana were divided into 28 subfamilies based on the analysis of their phylogenetic relationships and their motif patterns. Expression analysis using RNA-seq and quantitative real-time PCR (qRT-PCR) indicated that most HhMYBs are differentially regulated under drought and salt stresses. qRT-PCR analysis of seven selected HhMYBs suggested that the HhMYB family may have regulatory roles in the responses to stress and hormones. This study provides a framework for a more comprehensive analysis of the role of MYBs in the response to abiotic stress in H. hamabo.

PLEKHG5 is stabilized by HDAC2-related deacetylation and confers sorafenib resistance in hepatocellular carcinoma.

Sorafenib is the first FDA-approved first-line targeted drug for advanced HCC. However, resistance to sorafenib is frequently observed in clinical practice, and the molecular mechanism remains largely unknown. Here, we found that PLEKHG5 (pleckstrin homology and RhoGEF domain containing G5), a RhoGEF, was highly upregulated in sorafenib-resistant cells. PLEKHG5 overexpression activated Rac1/AKT/NF-κB signaling and reduced sensitivity to sorafenib in HCC cells, while knockdown of PLEKHG5 increased sorafenib sensitivity. The increased PLEKHG5 was related to its acetylation level and protein stability. Histone deacetylase 2 (HDAC2) was found to directly interact with PLEKHG5 to deacetylate its lysine sites within the PH domain and consequently maintain its stability. Moreover, knockout of HDAC2 (HDAC2 KO) or selective HDAC2 inhibition reduced PLEKHG5 protein levels and thereby enhanced the sensitivity of HCC to sorafenib in vitro and in vivo, while overexpression of PLEKHG5 in HDAC2 KO cells reduced the sensitivity to sorafenib. Our work showed a novel mechanism: HDAC2-mediated PLEKHG5 posttranslational modification maintains sorafenib resistance. This is a proof-of-concept study on targeting HDAC2 and PLEKHG5 in sorafenib-treated HCC patients as a new pharmaceutical intervention for advanced HCC.

Diagnostic accuracy of red blood cell distribution width to platelet ratio for predicting staging liver fibrosis in chronic liver disease patients: A systematic review and meta-analysis.

BACKGROUND: Red cell volume distribution width to platelet ratio (RPR), as a novel noninvasive assessment, is frequently investigated. However, the utility of RPR to evaluate the diagnostic accuracy of liver fibrosis remains controversial. We performed a meta-analysis to determine the diagnostic performance of RPR for detecting staging liver fibrosis in patients with chronic liver disease. METHODS: MEDLINE, EMBASE, and Cochrane Library databases were systematically searched. Summary receiver operating characteristic curves (SROC), diagnostic odds ratios (DOR), pooled estimates of sensitivity, specificity, and likelihood ratios were used to assess the diagnostic accuracy of RPR. Meta-regression and subgroup analyses were also performed to identify factors that contributed to heterogeneity. The Quality Assessment for Studies of Diagnostic Accuracy Studies-2 tool was applied to assess the quality. RESULTS: Fifteen studies with a total of 3346 patients were included in the meta-analysis. The area under the curve for SROC to summarize diagnostic accuracy of RPR for prediction of significant fibrosis, advanced fibrosis, and cirrhosis was 0.73 (standard error [SE] = 0.02), 0.83 (SE = 0.03), and 0.85 (SE = 0.04), respectively. Pooled DOR with corresponding 95% confidence interval (CI) was 4.93 (95% CI: 3.78-6.43), 10.27 (95% CI: 6.26-16.84), and 12.16 (95% CI: 5.85-25.28), respectively, using a random effects model. Meta-regression showed that length of liver biopsy specimen potentially contributed to heterogeneity. There was no significant publication bias observed across the eligible studies. CONCLUSIONS: In chronic liver disease patients, RPR presented a good performance for prediction of significant fibrosis, advanced fibrosis, and cirrhosis. More future trials are required for prospective validation.

Pharmacological or transcriptional inhibition of both HDAC1 and 2 leads to cell cycle blockage and apoptosis via p21Waf1/Cip1 and p19INK4d upregulation in hepatocellular carcinoma.

OBJECTIVES: Histone deacetylases (HDACs) are commonly dysregulated in cancer and represent promising therapeutic targets. However, global HDAC inhibitors have shown limited efficacy in the treatment of solid tumours, including hepatocellular carcinoma (HCC). In this study, we investigated the therapeutic effect of selectively inhibiting HDAC1 and 2 in HCC. METHODS: HDAC1 inhibitor Tacedinaline (CI994), HDAC2 inhibitor Santacruzamate A (CAY10683), HDAC1/2 common inhibitor Romidepsin (FK228) and global HDAC inhibitor Vorinostat (SAHA) were used to treat HCC cells. Cell cycle, apoptosis and the protein levels of CDKs and CDKNs were performed to evaluate HCC cell growth. Inhibition of HDAC1/2 by RNAi was further investigated. RESULTS: Combined inhibition of HDAC1/2 led to HCC cell morphology changes, growth inhibition, cell cycle blockage and apoptosis in vitro and suppressed the growth of subcutaneous HCC xenograft tumours in vivo. p21Waf1/Cip1 and p19INK4d , which play roles in cell cycle blockage and apoptosis induction, were upregulated. Inhibition of HDAC1/2 by siRNA further demonstrated that HDAC1 and 2 cooperate in blocking the cell cycle and inducing apoptosis via p19INK4d and p21Waf1/Cip1 upregulation. Finally, H3K18, H3K56 and H4K12 in the p19INK4d and p21Waf1/Cip1 promoter regions were found to be targets of HDAC1/2. CONCLUSIONS: Pharmacological or transcriptional inhibition of HDAC1/2 increases p19INK4d and p21Waf1/Cip1 expression, decreases CDK expression and arrests HCC growth. These results indicated a potential pharmacological mechanism of selective HDAC1/2 inhibitors in HCC therapy.