Long non-coding RNA SNHG5 mediates periodontal inflammation through the NF-κB signalling pathway.

AIM: We investigated the role of long non-coding RNAs and small nucleolar RNA host gene 5 (SNHG5) in the pathogenesis of periodontitis. MATERIALS AND METHODS: A ligature-induced periodontitis mouse model was established, and gingival tissues were collected from patients with periodontitis and healthy controls. Inflammatory cytokines were detected using quantitative reverse transcription-polymerase chain reaction and western blotting analyses. Direct interactions between SNHG5 and p65 were detected by RNA pull-down and RNA immunoprecipitation assays. Micro-computed tomography, haematoxylin and eosin staining, and immunohistochemical staining were used to measure periodontal bone loss. RESULTS: SNHG5 expression was down-regulated in human and mouse periodontal tissues compared to that in the healthy controls. In vitro experiments demonstrated that SNHG5 significantly ameliorated tumour necrosis factor α-induced inflammation. Mechanistically, SNHG5 directly binds to the nuclear factor-kappa B (NF-κB) p65 subunit and inhibits its translocation, thereby suppressing the NF-κB signalling pathway activation and reducing the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing three inflammasome expression. Locally injecting si-SNHG5 aggravated the periodontal destruction. CONCLUSION: This study revealed that SNHG5 mediates periodontal inflammation through the NF-κB signalling pathway, providing a potential therapeutic target for periodontitis treatment.

Targeting SNORA38B attenuates tumorigenesis and sensitizes immune checkpoint blockade in non-small cell lung cancer by remodeling the tumor microenvironment via regulation of GAB2/AKT/mTOR signaling pathway.

BACKGROUND: Non-coding RNAs (ncRNAs), including small nucleolar RNAs (snoRNAs), are widely involved in the physiological and pathological processes of human beings. While up to date, although considerable progress has been achieved in ncRNA-related pathogenesis of non-small cell lung cancer (NSCLC), the underlying mechanisms and biological significance of snoRNAs in NSCLC still need to be further clarified. METHODS: Quantitative real-time polymerase chain reaction or RNAscope was performed to verify the expression of Small Nucleolar RNA, H/ACA Box 38B (SNORA38B) in NSCLC cell lines or clinical samples. BALB/c nude mice xenograft model or C57BL/6J mice syngeneic tumor model were estimated to detect the effects of SNORA38B in tumor growth or tumor immune microenvironment in vivo. Cytometry by time of flight, enzyme-linked immunosorbent assay and flow cytometry assay were conducted to clarify the effects and mechanisms of SNORA38B-mediated tumor immunosuppressive microenvironment. The binding activity between SNORA38B and E2F transcription factor 1(E2F1) was detected by RNA immunoprecipitation and RNA pull-down assays. Then, bioinformatics analysis and chromatin immunoprecipitation were utilized to demonstrate the regulation of GRB2-associated-binding protein 2 (GAB2) by E2F1. Moreover, the combinatorial treatment of SNORA38B locked nucleic acid (LNA) and immune checkpoint blockade (ICB) was used to treat murine Lewis lung carcinoma-derived tumor burden C57BL/6J mice to clarify the effectiveness of targeting SNORA38B in NSCLC immunotherapy. RESULTS: SNORA38B was found highly expressed in NSCLC tissues and cell lines, and associated with worse prognosis. Further results showed that SNORA38B functioned as an oncogene via facilitating cell proliferation, migration, invasion, and inhibiting cell apoptosis in vitro and promoting tumorigenesis of NSCLC cells in vivo. SNORA38B could also recruit the CD4+FOXP3+ regulatory T cells by triggering tumor cells to secrete interleukin 10, which in turn reduced the infiltration of CD3+CD8+ T cells in NSCLC tumor microenvironment (TME), favoring tumor progression and poorer immune efficacy. Mechanistically, SNORA38B mainly distributed in the nucleus, and promoted NSCLC progression by regulating GAB2 transcription to activate protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway through directly binding with E2F1. Moreover, we found that SNORA38B LNAs were able to ameliorate CD3+CD8+ T cell infiltration in TME, which sensitized NSCLC to the treatment of ICB. CONCLUSIONS: In conclusion, our data demonstrated that SNORA38B functioned as an oncogene in NSCLC both in vitro and in vivo at least in part by regulating the GAB2/AKT/mTOR pathway via directly binding to E2F1. SNORA38B could also sensitize NSCLC to immunotherapy, which may be a critical therapeutic target for NSCLC.

Splicing modulation mediated by small nuclear RNAs as therapeutic approaches for muscular dystrophies.

Splice-modulation therapy aiming at correcting genetic defects by molecular manipulation of the premessenger RNA is a promising novel therapeutic approach for genetic diseases. In recent years, these new RNA based strategies, mostly mediated by antisense oligonucleotides (AO), have demonstrated encouraging results for muscular dystrophies, a heterogeneous group of genetic disorders characterized by muscle weakness and wasting. In particular, the clinical evaluation of antisense-mediated exon-skipping for the treatment of Duchenne muscular dystrophy has shown convincing data and therefore raised hopes and expectations for neuromuscular disorders therapy. However, AO-mediated splicing modulation still faces major hurdles such as low efficacy in specific tissues, poor cellular uptake and relatively rapid clearance from circulation, which means repeated administrations are required to achieve some therapeutic efficacy. To overcome these limitations, small nuclear RNAs (snRNA) have been used to shuttle the antisense sequences, offering the advantage of a correct subcellular localization with pre-mRNAs and the potential of a permanent correction when introduced into viral vectors. Here we review the recent progress in the development of snRNA mediated splicing modulation for muscular dystrophies, focusing on the advantages offered by this technology over classical AOs but also the challenges limiting their clinical application.