Smad Nuclear Interacting Protein 1 Acts as a Protective Regulator of Pressure Overload-Induced Pathological Cardiac Hypertrophy

The clinical utilization of SNIP1 and its pathophysiological mechanisms in disease

Smad intranuclear binding protein 1 (SNIP1), a highly conserved nuclear protein, functions as a transcriptional regulator and exerts a significant influence on disease progression. In addition, the N-terminal domain of SNIP1 facilitates its interaction with Smad4, a signaling protein associated with the TGF-β family, and RelA/p65, a transcription factor connected to NF-κB. This interaction further enhances the transcriptional activation of c-Myc-dependent genes. Presently, the primary emphasis in research is directed towards targeting the catalytic domain of SNIP1, as it holds promise as a potential therapeutic target for various diseases. While the significance of SNIP1 in pathological mechanisms remains uncertain, this review aims to comprehensively examine the existing literature on the association between SNIP1 and proteins implicated in the regulation of diverse clinical conditions, including cancer, inflammation, and related diseases.

SNIP1 reduces extracellular matrix degradation and inflammation via inhibiting the NF-κB signaling pathway in osteoarthritis

Osteoarthritis (OA), the most common joint disease, is characterized by inflammation and cartilage degradation. Previous studies illustrated that Smad nuclear-interacting protein 1 (SNIP1) is an inhibitor of the TGF-β signal transduction pathway and SNIP1 has been reported as an anti-inflammatory factor. This study aimed to explore the role of SNIP1 in OA progression. In this study, the SNIP1 expression was evaluated in OA human and OA mice tissue and interleukin-1 beta (IL-1β)-induced chondrocytes. The Safranin-O (SO) staining and osteoarthritis research society international (OARSI) scoring system was used to evaluate cartilage injury. The gain- and loss-of-function studies for SNIP1 were performed in chondrocytes. The SNIP1 overexpression adenovirus was injected into mice by intra-articular injection. The SNIP1 expression was decreased in OA patients, OA mice, and IL-1β-stimulated chondrocytes. The cartilage injury of medial meniscus-induced OA (DMM-OA) mice at 8 weeks showed more severe than that at 4 weeks. The expression of SNIP1 was lower at 8 weeks than that at 4 weeks. In IL-1β-stimulated chondrocytes, SNIP1 overexpression reduced the expression of TNF-α and IL-6, alleviated ECM degradation, reduced the phosphorylation levels of p65 and IκBα, and decreased the p65 level in nuclear. Moreover, overexpression of SNIP1 alleviated cartilage injury in DMM-OA mice. In brief, our study suggested that SNIP1 alleviated OA and repressed inflammation by inhibiting the activation of NF-κB. This study might provide a new insight into OA treatment.

Regulation of transforming growth factor-β signalling by SUMOylation and its role in fibrosis

Fibrosis is an abnormal healing process that only repairs the structure of an organ after injury and does not address damaged functions. The pathogenesis of fibrosis is multifactorial and highly complex; numerous signalling pathways are involved in this process, with the transforming growth factor-β (TGF-β) signalling pathway playing a central role. TGF-β regulates the generation of myofibroblasts and the epithelial-mesenchymal transition by regulating transcription and translation of downstream genes and precisely regulating fibrogenesis. The TGF-β signalling pathway can be modulated by various post-translational modifications, of which SUMOylation has been shown to play a key role. In this review, we focus on the function of SUMOylation in canonical and non-canonical TGF-β signalling and its role in fibrosis, providing promising therapeutic strategies for fibrosis.

A biallelic SNIP1 Amish founder variant causes a recognizable neurodevelopmental disorder

SNIP1 (Smad nuclear interacting protein 1) is a widely expressed transcriptional suppressor of the TGF-β signal-transduction pathway which plays a key role in human spliceosome function. Here, we describe extensive genetic studies and clinical findings of a complex inherited neurodevelopmental disorder in 35 individuals associated with a SNIP1 NM_024700.4:c.1097A>G, p.(Glu366Gly) variant, present at high frequency in the Amish community. The cardinal clinical features of the condition include hypotonia, global developmental delay, intellectual disability, seizures, and a characteristic craniofacial appearance. Our gene transcript studies in affected individuals define altered gene expression profiles of a number of molecules with well-defined neurodevelopmental and neuropathological roles, potentially explaining clinical outcomes. Together these data confirm this SNIP1 gene variant as a cause of an autosomal recessive complex neurodevelopmental disorder and provide important insight into the molecular roles of SNIP1, which likely explain the cardinal clinical outcomes in affected individuals, defining potential therapeutic avenues for future research.

MiR-223 promotes pyroptosis of enteritis cells through activating NF-κB signalling pathway by targeting SNIP1 in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a common inflammation-related intestinal disease. Studies have shown that excessive pyroptosis of intestinal cells is involved in the development of IBD. However, the regulatory mechanism of pyroptosis in IBD remains unclear. Here, our study purposed to clarify the underlying regulatory mechanism of miR-223 to promote pyroptosis in IBD.MiR-223 and Smad Nuclear Interacting Protein 1 (SNIP1) expression in colon tissues collected from IBD patients and healthy volunteers were evaluated using qRT-PCR. Cell viability and pyroptosis were evaluated by CCK8 and flow cytometry assay, respectively. Pyroptosis-related proteins and nuclear factor κB (NF-κB) signals were determined by WB. Dual-luciferase reporter gene assay was employed to investigate the binding relationship between miR-223 and SNIP1.MiR-223 was significantly upregulated in IBD colon tissues and cell models, while SNIP1 was significantly decreased. Silence of miR-223 markedly enhanced cell viability and inhibited pyroptosis in the IBD cell model. MiR-223 could bind to 3'-UTR of SNIP1 and SNIP1 could activate NF-κB signalling pathway. Further rescued experiment found that knockdown of SNIP1 dramatically abolished the bio-effects mediated by miR-223 silence on the cell viability and pyroptosis of the IBD cell model. Likewise, the inactivation of NF-κB signalling markedly weakened the regulatory roles of SNIP1 downregulation in the IBD cell model. Besides, inhibition of NF-κB signalling attenuated the pyroptosis-promoting effect of overexpressing miR-223.Our data suggested that miR-223 activated the NF-κB pathway via targeting SNIP1, thus promoting the process of cell pyroptosis, and ultimately participating in the pathogenesis of IBD.

PM2.5 exposure aggravates left heart failure induced pulmonary hypertension

Aim: Particulate matter 2.5 (PM2.5) exposure is high risk to cardiovascular diseases. We investigated the influence of PM2.5 exposure on pulmonary arterial hypertension (PAH) murine model induced by left ventricular (LV) failure. Methods: Thirty 10 weeks old C57BL/6 mice were randomised to four groups: sham group, sham + PM2.5 group, TAC group, and TAC + PM2.5 group. Eight weeks post TAC surgery, right ventricular (RV) and lung remodelling (Sirius Red staining and WGA Staining), heart and lung function (EF and RVSBP), and fibrotic genes (TGF-ti mRNA expression and collagen III protein level in lung tissue were measured. Results: Exposure to PM2.5 augments TAC induced PAH as evidenced by decreased EF value and increased RVSBP, RV cardiomyocytes size, RV and lung fibrosis, and upregulated expression of collagen III and TGF-a in comparison to TAC group in lung tissues. Even the LV EF value was deceased from 79.3 ± 3.4% to 63.4 ± 2.1% when sham group exposed to PM2.5, PM2.5 exposure had no effect on RVSBP, RV cardiomyocytes' size, RV weight/tibia length, RV and lung fibrosis, and expression of collagen III and TGF-a in sham surgery mice. Conclusions: Exposure to PM2.5 aggravates deterioration of LV failure induced PAH.

A generally conserved response to hypoxia in iPSC-derived cardiomyocytes from humans and chimpanzees

Despite anatomical similarities, there are differences in susceptibility to cardiovascular disease (CVD) between primates; humans are prone to myocardial ischemia, while chimpanzees are prone to myocardial fibrosis. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) allow for direct inter-species comparisons of the gene regulatory response to CVD-relevant perturbations such as oxygen deprivation, a consequence of ischemia. To gain insight into the evolution of disease susceptibility, we characterized gene expression levels in iPSC-CMs in humans and chimpanzees, before and after hypoxia and re-oxygenation. The transcriptional response to hypoxia is generally conserved across species, yet we were able to identify hundreds of species-specific regulatory responses including in genes previously associated with CVD. The 1,920 genes that respond to hypoxia in both species are enriched for loss-of-function intolerant genes; but are depleted for expression quantitative trait loci and cardiovascular-related genes. Our results indicate that response to hypoxic stress is highly conserved in humans and chimpanzees.

Smad nuclear interacting protein 1 (SNIP1) inhibits intestinal inflammation through regulation of epithelial barrier function

Smad nuclear interacting protein 1 (SNIP1) has been implicated in the pathogenesis of inflammatory bowel disease (IBD). However, the mechanisms involved are still largely unknown. Our results demonstrated that SNIP1 was markedly decreased in intestinal epithelial cells (IEC) from IBD patients compared with healthy controls. Impaired expression of SNIP1 caused a significant decrease of transepithelial electrical resistance but an increase of fluorescein isothiocyanate-dextran flux in Caco-2 monolayers, whereas overexpression of SNIP1 reversed such effects. Overexpression of SNIP1 also inhibited the activity of NF-κB p65 and proinflammatory cytokine production (e.g., TNF-α, IL-1β, and IL-8) by IEC. Importantly, supplementation of exogenous SNIP1 significantly ameliorated intestinal mucosal inflammation in experimental colitis, characterized by less-severe intestinal epithelial barrier damage and decreased proinflammatory cytokine production. Our data thus demonstrated a novel mechanism whereby SNIP1 regulates intestinal inflammation through modulating intestinal epithelial barrier function. Targeting SNIP1 may provide a therapeutic approach for the treatment of IBD.