PTPRO activates TLR4/NF-κB signaling to intensify lipopolysaccharide-induced pneumonia cell injury

Abstract

Background: Protein tyrosine phosphatase receptor type O (PTPRO) belongs to the PTP (protein tyrosine phosphatase) family and is widely expressed in parenchymal cells, such as breast and lung epithelial cells. PTPRO has been shown to enhance inflammatory responses and has been implicated in the pathogenesis of inflammation-associated diseases. The role of PTPRO in pneumonia was investigated. Methods: Human embryonic lung fibroblasts (HFL1) were treated with increasing concentrations of lipopolysaccharide at 5, 10, or 20 μg/mL to induce inflammatory and apoptotic injuries. Expression of PTPRO was detected by western blot. Inflammation and apoptosis were assessed by ELISA and flow cytometry assays, respectively. Results: Lipopolysaccharide induced decreased cell viability, and increased inflammation and apoptosis in HFL1. PTPRO was upregulated in HFL1 post lipopolysaccharide treatment, and silencing of PTPRO enhanced lipopolysaccharide-induced cell viability of HFL1, and suppressed the inflammation and apoptosis. However, overexpression of PTPRO aggravated lipopolysaccharide-induced cytotoxicity in HFL1. Overexpression of PTPRO upregulated protein expression of TLR4 and p-p65 in lipopolysaccharide-induced HFL1, while knockdown of PTPRO reduced the level of p-IκBα to downregulate levels of TLR4 and p-p65. Conclusion: PTPRO contributed to pro-inflammatory and pro-apoptotic effects on lipopolysaccharide-induced HFL1 through activation of TLR4/NF-κB signaling.

The Impact of Processing and Extraction Methods on the Allergenicity of Targeted Protein Quantification as Well as Bioactive Peptides Derived from Egg

“…The EW protein OVM is the allergen that causes the most severe reactions. The disulfide bonds within its three structurally distinct domains (I, II, and III) aid in its resistance to heat denaturation and proteolytic digestion [ 229 , 230 ]. OVM is a serine protease inhibitor that protects against trypsin and elastase, among other proteolytic enzymes [ 231 , 232 ].…”

“…OVM is a serine protease inhibitor that protects against trypsin and elastase, among other proteolytic enzymes [ 231 , 232 ]. Regarding allergenicity, domain III is the most important since it contains both IgE- and IgG-binding epitopes, making it a primary determinant of egg allergy [ 229 , 230 ]. OVM retains its allergenic reactivity even after being subjected to methods that permanently disrupt protein structure, such as heat treatment (e.g., 100 °C for 30 min) or chemical treatment with denaturing detergents (e.g., urea) [ 233 , 234 ].…”

Protein tyrosine phosphatase PTPRO represses lung adenocarcinoma progression by inducing mitochondria-dependent apoptosis and restraining tumor metastasis

“…Protein tyrosine phosphatase receptor type O (PTPRO), one of the receptor-type PTPs (RPTPs), was first found in renal glomerular epithelial cells [5]. As a transmembrane protein and expressed in several parenchymal and inflammatory cells (including lung, liver, breast, macrophages, and lymphocytes) [6], PTPRO has been linked to both elemental biological processes and development of inflammatory diseases, such as embryogenesis [7], osteoclast function [8], immune response [9], neuron differentiation [10,11], atherosclerosis [6], lung injury [12,13] and hepatitis [14]. Increasing studies demonstrated the critical functions of PTPRO in tumor suppression of certain cancer types.…”

Comprehensively Analyze the Prognosis Significance and Immune Implication of PTPRO in Lung Adenocarcinoma

“…Based on previous studies, PTPRO has been shown to act as a tumor suppressor in the development of various tumors. The initial study found that overexpression of PTPRO inhibited the progression of lung cancer [ 13 ]. Another study revealed that PTPRO suppress tumor cell proliferation and promotes apoptosis by dephosphorylating signal transducer and activator of transcription 3 (STAT3) in liver cancer [ 14 ].…”