Expression of a novel versican variant in dorsal root ganglia from spared nerve injury rats

The Contribution of Vascular Proteoglycans to Atherothrombosis: Clinical Implications

The vascular extracellular matrix (ECM) produced by endothelial and smooth muscle cells is composed of collagens and glycoproteins and plays an integral role in regulating the structure and function of the vascular wall. Alteration in the expression of these proteins is associated with endothelial dysfunction and has been implicated in the development and progression of atherosclerosis. The ECM composition of atherosclerotic plaques varies depending on plaque phenotype and vulnerability, with distinct differences observed between ruptured and erodes plaques. Moreover, the thrombi on the exposed ECM are diverse in structure and composition, suggesting that the best antithrombotic approach may differ depending on plaque phenotype. This review provides a comprehensive overview of the role of proteoglycans in atherogenesis and thrombosis. It discusses the differential expression of the proteoglycans in different plaque phenotypes and the potential impact on platelet function and thrombosis. Finally, the review highlights the importance of this concept in developing a targeted approach to antithrombotic treatments to improve clinical outcomes in cardiovascular disease.

Inhibition of Nonsense-Mediated Decay Induces Nociceptive Sensitization through Activation of the Integrated Stress Response

RNA stability is meticulously controlled. Here, we sought to determine whether an essential post-transcriptional regulatory mechanism plays a role in pain. Nonsense-mediated decay (NMD) safeguards against translation of mRNAs that harbor premature termination codons and controls the stability of ∼10% of typical protein-coding mRNAs. It hinges on the activity of the conserved kinase SMG1. Both SMG1 and its target, UPF1, are expressed in murine DRG sensory neurons. SMG1 protein is present in both the DRG and sciatic nerve. Using high-throughput sequencing, we examined changes in mRNA abundance following inhibition of SMG1. We confirmed multiple NMD stability targets in sensory neurons, including ATF4. ATF4 is preferentially translated during the integrated stress response (ISR). This led us to ask whether suspension of NMD induces the ISR. Inhibition of NMD increased eIF2-α phosphorylation and reduced the abundance of the eIF2-α phosphatase constitutive repressor of eIF2-α phosphorylation. Finally, we examined the effects of SMG1 inhibition on pain-associated behaviors. Peripheral inhibition of SMG1 results in mechanical hypersensitivity in males and females that persists for several days and priming to a subthreshold dose of PGE2. Priming was fully rescued by a small-molecule inhibitor of the ISR. Collectively, our results indicate that suspension of NMD promotes pain through stimulation of the ISR.SIGNIFICANCE STATEMENT Nociceptors undergo long-lived changes in their plasticity which may contribute to chronic pain. Translational regulation has emerged as a dominant mechanism in pain. Here, we investigate the role of a major pathway of RNA surveillance called nonsense-mediated decay (NMD). Modulation of NMD is potentially beneficial for a broad array of diseases caused by frameshift or nonsense mutations. Our results suggest that inhibition of the rate-limiting step of NMD drives behaviors associated with pain through activation of the ISR. This work reveals complex interconnectivity between RNA stability and translational regulation and suggests an important consideration in harnessing the salubrious benefits of NMD disruption.

Joint effect of THBS2 and VCAN accelerating the poor prognosis of gastric cancer

OBJECTIVE

Gastric cancer is the most common malignant tumor of the digestive system. The progression from gastritis to gastric cancer may be related to genetic factors, but the specific molecular mechanism remains unclear. Therefore, an in-depth study of the molecular mechanism of gastritis and gastric cancer is significant.

METHODS

We downloaded two gene profiles, GSE2669 and GSE116312, from the Gene Expression Omnibus (GEO) database. This study aims to apply bioinformatics technology to mine differentially expressed genes (DEGs), DEGs annotation, protein-protein interaction (PPI) network creation, and hub gene identification and expression between gastric cancer patients and gastritis patients. Overall survival analysis of hub genes, analysis by comparative toxicogenomics database for hub genes in gastric cancer, THBS2 and VCAN protein expression by immunohistochemistry for gastric cancer and gastritis as well as design of the biological process (BP) neural network was implemented.

RESULTS

The MSLN, SPP1, THBS2, SPARC, FN1, IGFBP7, VCAN were up-regulated in gastric carcinoma samples, while FGA was down-regulated. The protein expression of THBS2 and VCAN in gastric cancer was significantly higher than that in gastritis. VCAN protein expression was positively associated with tumor invasion (P = 0.011) and HER2 overexpression (P = 0.031). Strong correlation among THBS2, VCAN, and gastric cancer based on the BP neural network.

CONCLUSION

THBS2 and VCAN may be potential targets for improving gastric cancer patients' diagnosis and clinical efficacy.

Versican-A Critical Extracellular Matrix Regulator of Immunity and Inflammation

The extracellular matrix (ECM) proteoglycan, versican increases along with other ECM versican binding molecules such as hyaluronan, tumor necrosis factor stimulated gene-6 (TSG-6), and inter alpha trypsin inhibitor (IαI) during inflammation in a number of different diseases such as cardiovascular and lung disease, autoimmune diseases, and several different cancers. These interactions form stable scaffolds which can act as "landing strips" for inflammatory cells as they invade tissue from the circulation. The increase in versican is often coincident with the invasion of leukocytes early in the inflammatory process. Versican interacts with inflammatory cells either indirectly via hyaluronan or directly via receptors such as CD44, P-selectin glycoprotein ligand-1 (PSGL-1), and toll-like receptors (TLRs) present on the surface of immune and non-immune cells. These interactions activate signaling pathways that promote the synthesis and secretion of inflammatory cytokines such as TNFα, IL-6, and NFκB. Versican also influences inflammation by interacting with a variety of growth factors and cytokines involved in regulating inflammation thereby influencing their bioavailability and bioactivity. Versican is produced by multiple cell types involved in the inflammatory process. Conditional total knockout of versican in a mouse model of lung inflammation demonstrated significant reduction in leukocyte invasion into the lung and reduced inflammatory cytokine expression. While versican produced by stromal cells tends to be pro-inflammatory, versican expressed by myeloid cells can create anti-inflammatory and immunosuppressive microenvironments. Inflammation in the tumor microenvironment often contains elevated levels of versican. Perturbing the accumulation of versican in tumors can inhibit inflammation and tumor progression in some cancers. Thus versican, as a component of the ECM impacts immunity and inflammation through regulating immune cell trafficking and activation. Versican is emerging as a potential target in the control of inflammation in a number of different diseases.