ZNF148 inhibits HBV replication by downregulating RXRα transcription

BACKGROUND

Progressive hepatitis B virus (HBV) infection can result in cirrhosis, hepatocellular cancer, and chronic hepatitis. While antiviral drugs that are now on the market are efficient in controlling HBV infection, finding a functional cure is still quite difficult. Identifying host factors involved in regulating the HBV life cycle will contribute to the development of new antiviral strategies. Zinc finger proteins have a significant function in HBV replication, according to earlier studies. Zinc finger protein 148 (ZNF148), a zinc finger transcription factor, regulates the expression of various genes by specifically binding to GC-rich sequences within promoter regions. The function of ZNF148 in HBV replication was investigated in this study.

METHODS

HepG2-Na+/taurocholate cotransporting polypeptide (HepG2-NTCP) cells and Huh7 cells were used to evaluate the function of ZNF148 in vitro. Northern blotting and real-time PCR were used to quantify the amount of viral RNA. Southern blotting and real-time PCR were used to quantify the amount of viral DNA. Viral protein levels were elevated, according to the Western blot results. Dual-luciferase reporter assays were used to examine the transcriptional activity of viral promoters. ZNF148's impact on HBV in vivo was investigated using an established rcccDNA mouse model.

RESULTS

ZNF148 overexpression significantly decreased the levels of HBV RNAs and HBV core DNA in HBV-infected HepG2-NTCP cells and Huh7 cells expressing prcccDNA. Silencing ZNF148 exhibited the opposite effects in both cell lines. Furthermore, ZNF148 inhibited the activity of HBV ENII/Cp and the transcriptional activity of cccDNA. Mechanistic studies revealed that ZNF148 attenuated retinoid X receptor alpha (RXRα) expression by binding to the RXRα promoter sequence. RXRα binding site mutation or RXRα overexpression abolished the suppressive effect of ZNF148 on HBV replication. The inhibitory effect of ZNF148 was also observed in the rcccDNA mouse model.

CONCLUSIONS

ZNF148 inhibited HBV replication by downregulating RXRα transcription. Our findings reveal that ZNF148 may be a new target for anti-HBV strategies.

Identification of the MALAT1/miR-106a-5p/ZNF148 feedback loop in regulating HaCaT cell proliferation, migration and apoptosis

Aims: This study aims to investigate the function of positive feedback loops involving noncoding RNA in diabetic wound healing. Methods: We developed a mouse diabetic wound model to confirm that hyperglycemia can impair wound healing. We also used an in vitro keratinocyte model in high-glucose conditions to investigate the mechanism of delayed wound healing. Results: MALAT1 was decreased in diabetic mouse wound tissue and can promote keratinocyte biological functions. MALAT1 could bind to miR-106a-5p to modulate the expression of ZNF148, a target gene of miR-106a-5p. Surprisingly, ZNF148 bound to a region in the MALAT1 promoter to stimulate gene expression. Conclusion: ZNF148-activated MALAT1 increases ZNF148 expression by competitively binding miR-106a-3p, generating a positive feedback loop that enhances keratinocyte function.

Loss of microRNA-147 function alleviates synovial inflammation through ZNF148 in rheumatoid and experimental arthritis

MicroRNA-147 (miR-147) had been previously found induced in synoviocytes by inflammatory stimuli derived from T cells in experimental arthritis. This study was designed to verify whether loss of its function might alleviate inflammatory events in joints of experimental and rheumatoid arthritis (RA). Dark Agouti (DA) rats were injected intradermally with pristane to induce arthritis, and rno-miR-147 antagomir was locally administrated into individual ankle compared with negative control or rno-miR-155-5p antagomir (potential positive control). Arthritis onset, macroscopic severity, and pathological changes were monitored. While in vitro, gain or loss function of hsa-miR-147b-3p/hsa-miR-155-5p and ZNF148 was achieved in human synovial fibroblast cell line SW982 and RA synovial fibroblasts (RASF). The expression of miRNAs and mRNAs was detected by using RT-quantitative PCR, and protein expression was detected by using Western blotting. Anti-miR-147 therapy could alleviate the severity, especially for the synovitis and joint destruction in experimental arthritis. Gain of hsa-miR-147b-3p/hsa-miR-155-5p function in TNF-α stimulated SW982 and RASF cells could upregulate, in contrast, loss of hsa-miR-147b-3p/hsa-miR-155-5p function could downregulate the gene expression of TNF-α, IL-6, MMP3, and MMP13. Hence, such alteration could participate in synovial inflammation and joint destruction. RNAi of ZNF148, a miR-147's target, increased gene expression of TNF-α, IL-6, MMP3, and MMP13 in SW982 and RASF cells. Also, mRNA sequencing data showed that hsa-miR-147b-3p mimic and ZNF148 siRNA commonly regulated the gene expression of CCL3 and DEPTOR as well as some arthritis and inflammation-related pathways. Taken together, miR-147b-3p contributes to synovial inflammation through repressing ZNF148 in RA and experimental arthritis.

Upregulation of ZNF148 in SDHB-deficient gastrointestinal stromal tumor potentiates Forkhead box M1-mediated transcription and promotes tumor cell invasion

Succinate dehydrogenase (SDH) deficiency is associated with gastrointestinal stromal tumor (GIST) oncogenesis, but the underlying molecular mechanism remains to be further investigated. Here, we show that succinate accumulation induced by SDHB loss of function increased the expression of zinc finger protein 148 (ZNF148, also named ZBP-89) in GIST cells. Meanwhile, ZNF148 is found to be phosphorylated by ERK at Ser306, and this phosphorylation results in ZNF148 binding to Forkhead box M1 (FOXM1). Through the complex formation at the promoter, ZNF148 facilitates Histone H3 acetylation and FOXM1-mediated Snail transcription, which eventually promotes cell invasion and tumor growth. The clinical analysis indicates that SDHB deficiency is associated with elevated ZNF148 levels, and ZNF148-S306 phosphorylation level displays a positive correlation with poor prognosis in GIST patients. These findings illustrate an unidentified molecular mechanism underlying FOXM1-regulated gene transcription related to GIST cell invasion, which highlights the physiological effects of SDHB deficiency on the invasiveness of GIST.

Truncating de novo mutations in the Krüppel-type zinc-finger gene ZNF148 in patients with corpus callosum defects, developmental delay, short stature, and dysmorphisms

BACKGROUND

Krüppel-type zinc finger genes (ZNF) constitute a large yet relatively poorly characterized gene family. ZNF genes encode proteins that recognize specific DNA motifs in gene promotors. They act as transcriptional co-activators or -repressors via interaction with chromatin remodeling proteins and other transcription factors. Only few ZNF genes are currently linked to human disorders and identification of ZNF gene-associated human diseases may help understand their function. Here we provide genetic, statistical, and clinical evidence to support association of ZNF148 with a new intellectual disability (ID) syndrome disorder.

METHODS

Routine diagnostic exome sequencing data were obtained from 2172 patients with ID and/or multiple congenital anomalies.

RESULTS

In a cohort of 2172 patient-parent trios referred for routine diagnostic whole exome sequencing for ID and/or multiple congenital anomalies (MCA) in the period 2012-2016, four patients were identified who carried de novo heterozygous nonsense or frameshift mutations in the ZNF148 gene. This was the only ZNF gene with recurrent truncating de novo mutations in this cohort. All mutations resulted in premature termination codons in the last exon of ZNF148. The number of the de novo truncating mutations in the ZNF148 gene was significantly enriched (p = 5.42 × 10^-3). The newly described ZNF148-associated syndrome is characterized by underdevelopment of the corpus callosum, mild to moderate developmental delay and ID, variable microcephaly or mild macrocephaly, short stature, feeding problems, facial dysmorphisms, and cardiac and renal malformations.

CONCLUSIONS

We propose ZNF148 as a gene involved in a newly described ID syndrome with a recurrent phenotype and postulate that the ZNF148 is a hitherto unrecognized but crucial transcription factor in the development of the corpus callosum. Our study illustrates the advantage of whole exome sequencing in a large cohort using a parent-offspring trio approach for identifying novel genes involved in rare human diseases.