| Title: |
LPS–TLR4 signaling attenuates CHOP-mediated apoptosis under endoplasmic reticulum stress conditions during porcine embryonic development |
| Authors: |
Gyu-Hyun Lee; Cheng-Lin Zhan; Song-Hee Lee; Qin-Yue Lu; Ying-Yan Jin; Ji-Yeon Lee; Kyung-Tae Shin; Xiang-Shun Cui |
| Source: |
Frontiers in Cell and Developmental Biology, Vol 14 (2026) |
| Publisher Information: |
Frontiers Media S.A. |
| Publication Year: |
2026 |
| Collection: |
Directory of Open Access Journals: DOAJ Articles |
| Subject Terms: |
apoptosis; CHOP; endoplasmic reticulum stress; porcine embryonic development; TLR4; Biology (General); QH301-705.5 |
| Description: |
IntroductionPersistent endoplasmic reticulum (ER) stress impairs early embryonic development by inducing apoptosis through C/EBP homologous protein (CHOP). Toll-like receptor 4 (TLR4), traditionally recognized for its role in innate immunity, has recently emerged as a modulator of intracellular stress responses. Lipopolysaccharide (LPS), a natural TLR4 agonist derived from Gram-negative bacteria, elicits both pro-inflammatory and cytoprotective effects depending on the cellular context and dosage. This study aimed to elucidate the role of TLR4 signaling in the regulation of CHOP-mediated apoptosis during porcine preimplantation development under ER stress.MethodsPorcine embryos were treated with tunicamycin (TM, 5 nM) to induce ER stress and co-treated with LPS (10 μM) to activate TLR4 signaling. Developmental competence was assessed by blastocyst formation rates, total cell number, and markers of apoptosis and autophagy.ResultsLPS treatment significantly improved blastocyst formation rates compared to TM groups (TM: 37.50 ± 4.77% vs. TM+LPS: 52.89 ± 4.86%). Consistent with this improvement, the total cell number per blastocyst was significantly restored by LPS co-treatment (Control: 55.63 ± 2.15 vs. TM: 38.61 ± 2.57; TM+LPS: 48.84 ± 0.83), confirming enhanced cell proliferation under ER stress conditions. LPS co-treatment markedly reduced CHOP protein expression and suppressed ATF4 expression, indicating alleviation of PERK-ATF4-CHOP signaling. Additionally, autophagy and apoptosis were attenuated, as evidenced by a significantly decreased LC3-II/LC3-I ratio and a reduced number of TUNEL-positive cells. Notably, TLR4 knockdown abolished these LPS-mediated protective effects, confirming the requirement of TLR4 in mitigating ER stress-induced damage.ConclusionThese findings demonstrated that LPS-mediated TLR4 signaling suppressed CHOP-induced apoptosis and autophagy under persistent ER stress, thereby improving embryonic viability. This study provides novel mechanistic insights into the non-canonical role of TLR4 ... |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
https://www.frontiersin.org/articles/10.3389/fcell.2026.1750233/full; https://doaj.org/toc/2296-634X; https://doaj.org/article/d139213de786469c9de6e881216e7e0b |
| DOI: |
10.3389/fcell.2026.1750233 |
| Availability: |
https://doi.org/10.3389/fcell.2026.1750233; https://doaj.org/article/d139213de786469c9de6e881216e7e0b |
| Accession Number: |
edsbas.F598EA92 |
| Database: |
BASE |