Receptor interacting protein-2 plays a critical role in human lung epithelial cells survival in response to Fas-induced cell-death

Transcriptome alterations in chicken HD11 cells with steady knockdown and overexpression of RIPK2 gene

Receptor interacting protein kinase 2 (RIPK2) is involved in a variety of signaling pathway to produce a series of inflammatory cytokines in response to a diverse of bacterial, viral and protozoal pathogens. However, the underlying regulating of RIPK2 remain unknown. Transcriptome alterations in chicken HD11 cells following RIPK2 overexpression or silencing by shRNA were analyzed by next-generation sequencing. Both overexpression and knockdown of the RIPK2 gene caused wide-spread changes in gene expression in chicken HD11 cells. Differentially expressed genes (DEGs) caused by altered RIPK2 gene expression were associated with multiple biological processes linked with biological regulation, response to stimulus, cell communication, and signal transduction etc. KEGG analysis revealed that many of the DEGs were enriched in VEGF signaling pathway, ECM-receptor interaction, Focal adhesion, TGF-beta signaling pathway etc. Moreover, we show that initiation genes, TGFB1 and TGFB3, in the TGF-beta signaling pathway are biological targets regulated by RIPK2 in chicken HD11 cells. This is the first transcriptome-wide study in which RIPK2-regulated genes in chicken cells have been screened. Our findings elucidate the molecular events associated with RIPK2 in chicken HD11 cells.

Expression and Prognostic Value of PIK3CA, VEGF, IL-8, IL-10, and RIP2 in Diffuse Large B-Cell Lymphoma

BACKGROUND

To explore clinical features and prognostic value of vascular endothelial growth factor (VEGF), interleukin (IL) 8, IL-10, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and receptor-interacting protein-2 (RIP2) in diffuse large B-cell lymphoma (DLBCL).

METHODS

A total of 68 DLBCL patients admitted to the Affiliated Hospital of Hebei Engineering University from January 2017 to June 2021 were included in this retrospective analysis. Serum VEGF was detected by enzyme-linked immunosorbent assay, serum IL-8 and IL-10 were detected by chemiluminescent enzyme immunoassay, and expression of PIK3CA and RIP2 in tumors was detected by immunohistochemistry. The correlation between clinical features of DLBCL and tumor-related index were analyzed. Cox regression was conducted to explore risk factors and hazard ratio.

RESULTS

The serum level or expressions of VEGF, IL-8, IL-10, and RIP2 were significantly elevated with the increase of Ann Arbor Stage, International Prognostic Index (IPI) scores, Eastern Cooperative Oncology Group (ECOG) scores, serum lactate dehydrogenase (LDH) level, and the number of extranodal sites (all P < 0.05). Beside, these serum indexes were significantly higher in patients with the presence of extranodal involvement and germinal center B-cell (GCB), but significantly lower in patients with the presence of bone marrow involvement (all P < 0.05). Cox regression analysis for overall survival revealed that high expression of VEGF, high level of serum IL-8, serum IL-10, and RIP2, Ann Arbor Stage (III-IV), number of extranodal sites (>1), serum LDH level (≥245 U/L), IPI scores (3-5), ECOG scores (≥2), and bone marrow involvement were independent risk factors for the prognosis of DLBCL patients (all P < 0.05).

CONCLUSION

The serum levels of VEGF, IL-8, and IL-10, as well as the expression of RIP2 and PIK3CA in tumor tissues, were highly correlated to clinical features of DLBCL, and high expression level of these indexes may have adverse effects for the prognosis of DLBCL patients.

A regulatory region on RIPK2 is required for XIAP binding and NOD signaling activity

Signaling via the intracellular pathogen receptors nucleotide-binding oligomerization domain-containing proteins NOD1 and NOD2 requires receptor interacting kinase 2 (RIPK2), an adaptor kinase that can be targeted for the treatment of various inflammatory diseases. However, the molecular mechanisms of how RIPK2 contributes to NOD signaling are not completely understood. We generated FLAG-tagged RIPK2 knock-in mice using CRISPR/Cas9 technology to study NOD signaling mechanisms at the endogenous level. Using cells from these mice, we were able to generate a detailed map of post-translational modifications on RIPK2. Similar to other reports, we did not detect ubiquitination of RIPK2 lysine 209 during NOD2 signaling. However, using site-directed mutagenesis we identified a new regulatory region on RIPK2, which dictates the crucial interaction with the E3 ligase XIAP and downstream signaling outcomes.

CARD3 Promotes Cerebral Ischemia-Reperfusion Injury Via Activation of TAK1

Background Although multiple signaling cascades and molecules contributing to the pathophysiological process have been studied, the treatments for stroke against present targets have not acquired significant clinical progress. Although CARD3 (caspase activation and recruitment domain 3) protein is an important factor involved in regulating immunity, inflammation, lipid metabolism, and apoptosis, its role in cerebral stroke is currently unknown. Methods and Results Using a mouse model of ischemia-reperfusion (I-R) injury based on transient blockage of the middle cerebral artery, we have found that CARD3 expression is upregulated in a time-dependent manner during I-R injury. Further animal study revealed that, relative to control mice, CARD3-knockout mice exhibited decreased inflammatory response and neuronal apoptosis, with reduced infarct volume and lower neuropathological scores. In contrast, neuron-specific CARD3-overexpressing transgenic (CARD3-TG) mice exhibited increased I-R induced injury compared with controls. Mechanistically, we also found that the activation of TAK1 (transforming growth factor-β-activated kinase 1) was enhanced in CARD3-TG mice. Furthermore, the increased inflammation and apoptosis seen in injured CARD3-TG brains were reversed by intravenous administration of the TAK1 inhibitor 5Z-7-oxozeaenol. Conclusions These results indicate that CARD3 promotes I-R injury via activation of TAK1, which not only reveals a novel regulatory axis of I-R induced brain injury but also provides a new potential therapeutic approach for I-R injury.

Involvement of receptor-interacting protein 140 in estrogen-mediated osteoclasts differentiation, apoptosis, and bone resorption

Estrogen withdrawal following menopause results in an increase of osteoclasts formation and bone resorption, which is one of the most important mechanisms of postmenopausal osteoporosis. Recently, growing evidence has suggested that receptor-interacting protein 140 was implicated in estrogen-regulated metabolic disease, including fat metabolism and lipid metabolism. However, little is known regarding the role of receptor-interacting protein 140 in the regulation of bone metabolic by estrogen. In the present study, Western blotting disclosed that estrogen brings a significant increasing expression of receptor-interacting protein 140 in osteoclasts, but not in osteoblasts and bone marrow mesenchymal stem cells. Furthermore, analysis of TRAP staining and bone resorption assay showed that depletion of receptor-interacting protein 140 could significantly alleviate the inhibitory effects of estrogen on osteoclasts formation and bone resorption activity. Moreover, estrogen could induce osteoclasts apoptosis by increasing receptor-interacting protein 140 expression through the Fas/FasL pathway. Taken together, receptor-interacting protein 140 might be a critical player in estrogen-mediated osteoclastogenesis and bone resorption.

A Pathophysiologic Approach to Biomarkers in Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is an acute-onset hypoxic condition with radiographic bilateral lung infiltration. It is characterized by an acute exudative phase combining diffuse alveolar damage and lung edema followed by a later fibroproliferative phase. Despite an improved understanding of ARDS pathobiology, our ability to predict the development of ARDS and risk-stratify patients with the disease remains limited. Biomarkers may help to identify patients at the highest risk of developing ARDS, assess response to therapy, predict outcome, and optimize enrollment in clinical trials. After a short description of ARDS pathobiology, here, we review the scientific evidence that supports the value of various ARDS biomarkers with regard to their major biological roles in ARDS-associated lung injury and/or repair. Ongoing research aims at identifying and characterizing novel biomarkers, in order to highlight relevant mechanistic explorations of lung injury and repair, and to ultimately develop innovative therapeutic approaches for ARDS patients. This review will focus on the pathophysiologic, diagnostic, and therapeutic implications of biomarkers in ARDS and on their utility to ultimately improve patient care.

HMGB1 release triggered by the interaction of live retinal cells and uveitogenic T cells is Fas/FasL activation-dependent

Background

It is not clear how invading autoreactive T cells initiate the pathogenic process inside the diseased organ in T cell-mediated organ-specific autoimmune disease. In experimental autoimmune uveitis (EAU) induced by adoptive transfer of interphotoreceptor retinoid-binding protein (IRBP)-specific T cells in mice, we have previously reported that intraocular inflammation was initiated by infiltrating IRBP-specific T cells that directly interacted with retinal cells and resulted in the active release of high mobility group box 1 (HMGB1), an important member of damage associate molecular patterns (DAMPs). Furthermore, blockade of HMGB1 in our murine model reduced intraocular inflammation via suppression of IRBP-specific T cell functions. These results have demonstrated that HMGB1 is an early and critical mediator of induction of intraocular inflammation. The present study identified the cell surface molecule that triggers HMGB1 secretion.

Methods

Retinal explants from Fas-deficient (Fas^lpr) and wild-type (Wt) C57BL/6 (B6) mice were cultured with activated IRBP 1–20 peptide-specific T cells or with a Fas-activating antibody (Jo2), and then the level of HMGB1 in culture supernatants were detected by ELISA. In addition, released HMGB1 was examined in the eye of Fas^lpr and Wt mice after IRBP-specific T cell transfer. Uveitis was evaluated in the IRBP-specific T cell transferred Fas^lpr mice after recombinant HMGB1 was restored within the eye and in the IRBP-specific T cell transferred Wt mice after they were treated with a Fas antagonist (Met12).

Results

In contrast to retinal explants from Wt mice, those from Fas^lpr mice did not release HMGB1 after exposure to IRBP-specific T cells or to Jo2. The release of HMGB1 by Wt retinal explants was suppressed by Met 12. Moreover, after IRBP-specific T cell injection, Fas^lpr mice did not release HMGB1 in the eye or develop EAU, but intravitreous injection of HMGB1 resulted in intraocular inflammation. Finally, tEAU in Wt mice was attenuated by local treatment with Met 12. Unlike HMGB1, Fas-induced IL-1 and IL-18 were not essential for tEAU induction.

Conclusion

Our results show that interaction of retinal cells with infiltrating uveitogenic T cells leads to rapid release of HMGB1 via the Fas/FasL inflammatory signaling pathway.

p53 mediated apoptosis in osteosarcoma MG-63 cells by inhibition of FANCD2 gene expression

PURPOSE

The aim of this study was to investigate the association between osteosarcoma (OS) and Fanconi anemia (FA) related pathways and the molecular mechanisms.

METHODS

siRNA for Fanconi anemia complementation group D2 (FANCD2) was constructed and transfected into the osteosarcoma cell line MG-63 cells. Expression of TP53INP1, p53, p21, caspase-9, and caspase-3 mRNA in MG-63 cells were examined by real-time fluorescence quantitative PCR, and the protein levels were also determined by western blot.

RESULTS

After silence of the FANCD2 gene in MG-63 cells, cell proliferation was inhibited, cell cycle was arrested and cell apoptosis was induced. The apoptosis was mediated by the p53 signaling pathway. After FANCD2 expression was inhibited, TP53INP1 gene expression was up-regulated, phosphorylation of p53 was promoted and the p21 protein was activated, leading to cell cycle arrested in G1, finally resulted in caspase-dependent cell apoptosis.

CONCLUSIONS

Inhibition of FANCD2 gene expression can induce apoptosis of osteosarcoma cells, which indicated that FANCD2 played an important role in the development of osteosarcoma and it might be a potential target for treatment of osteosarcoma.