The cytoptrotection of small intestinal submucosa-derived gel in HL-1 cells during hypoxia/reoxygenation-induced injury.

Small intestinal submucosa (SIS)-derived gel injected into infarcted myocardium has been shown to promote repair and regeneration after myocardial infarction (MI); however, the specific impact of SIS gel on cardiomyocytes remained unknown. The aim of this study was to characterise SIS gel function in hypoxia-reoxygenation (H/R)-induced cardiomyocyte damage and its potential mechanism. HL-1 cardiomyocytes seeded on SIS matrix-coated plates, SIS gel, and uncoated plates were subjected to H/R, cell viability, apoptosis, expression of caspase-3, Bcl-2, and Bax were investigated. SIS gel and SIS matrix as coating substrates markedly improved cell viability, preventing cell apoptosis compared with uncoated plates, with SIS gel yielding the best cytoprotective effects. SIS gel down-regulated expression of pro-inflammatory cytokines (TNF-α, CCL2, and IL-6) by inhibiting the JNK-mitogen-activated protein kinase (MAPK)/NF-κB pathways. Furthermore, SIS gel protected cardiomyocytes from apoptosis by activating protein kinase B (AKT) and extracellular-signal-regulated kinase (ERK) pathways, and markedly up-regulated antiapoptotic Bcl-2 expression but inhibited that of proapoptotic Bax and c-caspase 3. Together, these findings show that SIS gel could decrease H/R-induced cell apoptosis through a mechanism potentially related to its ability to regulate expression of inflammatory cytokines and antiapoptosis signalling pathways to prevent cell apoptosis. Our findings thereby shed light on the mechanism related to SIS gel therapeutic efficacy for MI.

[Expression and clinical significance of long non-coding RNA LINC00520 in laryngeal squamous cell carcinoma].

Objective:To investigate the expression of LINC00520 in laryngeal squamous cell carcinoma(LSCC),and analyze its relevance and roles in carcinogenesis and development of LSCC.Method:The expression of LINC00520 in laryngeal squamous cell carcinoma tissue and paired adjacent normal tissue was determined by real-time PCR.The relationship between the expression of LINC00520 and the clinicopathological characteristics including clinical stage,pathological type,histological grade and lymph node metastasis of LSCC was analyzed.Result:(1)The LINC00520 expression level was significantly upregulated in LSCC tissues compared to that of paired adjacent normal tissues(P<0.000 1).(2)There were no statistical differences of the LINC00520 expression level among supraglottic,glottic and subglottic LSCCs(P>0.05).The LINC00520 expression level had no significant changes in poorly differentiated LSCC compared with that of well and moderately differentiated counterparts(P>0.05).Moreover,the expression of LINC00520 had no significant difference between T1+T2 stage and T3+T4 stage LSCC tissues(P>0.05).Interestingly,the LINC00520 level in LSCC with lymph node metastasis was significantly higher than that in patients without lymph node metastasis(P<0.01).Conclusion:Upregulation of LINC00520 in LSCC may contribute to its metastasis.

Preparation and characterization of pro-angiogenic gel derived from small intestinal submucosa.

Gels derived from decellularized small intestinal submucosa (SIS) have been used to repair ischemic myocardium and deliver protein drug. However, their material properties and effects on cell behavior are not well understood, in part because of the difficulty of gelling in vitro. In this study, soluble SIS matrix, which was easily handled and could effectively gel, was successfully prepared using a modified method. Fourier transform infrared spectroscopy confirmed that the SIS gel contained not only collagen but also sulfated glycosaminoglycans (sGAGs). Interestingly, the sustained release of vascular endothelial growth factor and basic fibroblast growth factor within the SIS gel was detected, and no initial burst release was observed. The SIS gel was more capable of evoking neovascularization than collagen type I gel, as determined by tube formation experiments in human umbilical vein endothelial cells, the mouse aortic ring assay, and animal experiments. The upregulated expression of kinase insert domain receptor (KDR), Notch1, and Ang2, the key genes in angiogenesis that were evaluated in HUVECs seeded on the SIS gel, confirmed that angiogenesis bioactive factors contained in the SIS gel are indeed active and effective. The SIS gel significantly promoted neovascularization compared to the collagen type I gel in vivo. Histology revealed adequate host tissue response in engraftment both types of gels. Together, these data demonstrate that the SIS gel is a promising and attractive candidate for tissue engineering, especially in promoting vessel formation. STATEMENT OF SIGNIFICANCE: The material properties of small intestinal submucosa (SIS) gel and the effect of these properties upon cell behavior are not well understood, in part due to the difficulty of gelling in vitro. In this study, soluble SIS matrix, which was easily handled and gelled was prepared using modified method. The material properties and biocompatibility of SIS gel were explored. The sustained release of growth factors from this gel was observed along with its degradation in vitro. The results demonstrate that the SIS gel promote angiogenesis in vitro and in vivo. The SIS gel biological properties suggest that the constituent ECM molecules released from the gel remain activity. These findings suggested that the SIS gel was a promising candidate for tissue engineering, especially in promoting vessel formation.