Lithocholic Acid Alleviates Deoxynivalenol-Induced Inflammation and Oxidative Stress via PPARγ-Mediated Epigenetically Transcriptional Reprogramming in Porcine Intestinal Epithelial Cells

Magnesium-based implants accelerate femoral fracture healing through promoting histone lactylation-mediated osteoclastogenesis inhibition

AIMS

To investigate the molecular mechanisms by which magnesium (Mg)-based implants, specifically Mg-containing intramedullary nails (Mg-IMNs), promote femoral fracture healing.

MATERIALS AND METHODS

Rats with femoral fractures were treated with Mg-IMNs. In vitro experiments were conducted to assess the impact of Mg2+ on osteoclastogenesis and histone lactylation. Histological analysis, Western blotting, and qRT-PCR were employed to evaluate osteoclast maturation and the molecular pathways involved. In vivo, lactate was administered to replicate Mg-IMN effects, and lactate production was inhibited to observe potential reversal effects.

KEY FINDINGS

Mg-IMNs significantly enhanced fracture healing by inhibiting osteoclastogenesis. Mg2+ promoted intracellular lactate production, leading to histone lactylation, which suppressed osteoclast maturation by downregulating NFATc1. The P300/H3K18LA/HDAC1 pathway was identified as a key mediator in this process. Additionally, lactate administration mimicked the effects of Mg-IMNs, while blocking lactate reversed these effects.

SIGNIFICANCE

This study uncovers a novel mechanism by which Mg2+ promotes fracture healing through histone lactylation-mediated inhibition of osteoclastogenesis. These findings offer new therapeutic strategies for enhancing fracture repair via epigenetic regulation.

The regulatory role of protein lactylation in various diseases: Special focus on the regulatory role of non-histone lactylation

Lactylation, an emerging form of post-translational modification derived from lactate, plays a pivotal role in numerous cellular processes such as tumor proliferation, metabolism, inflammation, and embryonic development. However, the precise molecular mechanisms by which lactylation controls these biological functions in both physiological and pathological contexts remain elusive. This review summarizes the latest reported regulatory mechanisms of protein lactylation in various diseases since 2024, introducing the latest research progress regarding the regulatory functions of protein lactylation in pathological processes, with particular attention to the regulatory mechanisms of non-histone lactylation modification in diseases. Finally, it outlines the potential of targeted lactylation therapy, proposes the main directions for future research, and emphasizes its scientific significance for future studies.

Lithocholic acid attenuates DON-induced inflammatory responses via epigenetic regulation of DUSP5 and TRAF5 in porcine intestinal epithelial cells

Deoxynivalenol (DON) is the most common mycotoxin that frequently contaminates human food and animal feed, resulting in intestinal diseases and systemic immunosuppression. Lithocholic acid (LCA) exhibits various pharmacological activities. RNA-seq and ChIP-qPCR analysis were used in the current study to investigate the protective mechanism of LCA for DON-induced inflammatory Responses via Epigenetic Regulation of DUSP5 and TRAF5 in porcine ileal epithelial cell lines (IPI-2I) cells. The IPI-2I cells were treated with the vehicle group, 250 ng/mL DON, 20 μmol/L LCA, 250 ng/mL DON+ 20 μmol/L LCA for 24 h could induce inflammatory Responses via Epigenetic Regulation of DUSP5 and TRAF5 in IPI-2I cells. By analyzing the transcriptional profiles of DON and LCA-treated IPI-2I, we observed significant transcriptional changes in IPI-2I cells. Further analysis of up-and down-regulated differential genes revealed the enrichment of pathways closely related to inflammation and apoptosis, such as the MAPK signaling pathway, IL17 signaling pathway, and Wnt signaling pathway. An upregulated (p < 0.05) relative mRNA expression level of RAP1B, GDNF, FGF2, IL1R1, RAPGEF2, DUSP5, TGFB3, CACNA1G, TEK and RPS6KA2 were noted in IPI-2I exposed to DON. DON-exposed IPI-2I cells dramatically enhanced (p < 0.05) histone marks associated with transcriptional activation, H3K9ac, H3K18ac, H3K27ac, H3K4me1, H3K9bhb, H3K18bhb Pol-II and Ser5 Pol-II at the enhancers of DUSP5 and TRAF5. Overall, our findings provide a theoretical basis for understanding the mechanism of action of LCA in attenuating DON-induced intestinal injury and for better understanding the potential of LCA as a treatment or prevention of mycotoxin-associated intestinal diseases in swine production.

Early Weaning Inhibits Intestinal Stem Cell Expansion to Disrupt the Intestinal Integrity of Duroc Piglets via Regulating the Keap1/Nrf2 Signaling

There are different stress resistance among different breeds of pigs. Changes in intestinal stem cells (ISCs) are still unclear among various breeds of piglets after early weaning. In the current study, Taoyuan Black and Duroc piglets were slaughtered at 21 days of age (early weaning day) and 24 days of age (3 days after early weaning) for 10 piglets in each group. The results showed that the rate of ISC-driven epithelial renewal in local Taoyuan Black pigs hardly changed after weaning for 3 days. However, weaning stress significantly reduced the weight of the duodenum and jejunum in Duroc piglets. Meanwhile, the jejunal villus height, tight junction-related proteins (ZO-1, Occludin, and Claudin1), as well as the trans-epithelial electrical resistance (TEER) values, were down-regulated after weaning for 3 days in Duroc piglets. Moreover, compared with Unweaned Duroc piglets, the numbers of Olfm4+ ISC cells, PCNA+ mitotic cells, SOX9+ secretory progenitor cells, and Villin+ absorptive cells in the jejunum were reduced significantly 3 days after weaning. And ex vivo jejunal crypt-derived organoids exhibited growth disadvantages in weaned Duroc piglets. Notably, the Keap1/Nrf2 signaling activities and the expression of HO-1 were significantly depressed in weaned Duroc piglets compared to Unweaned Duroc piglets. Thus, we can conclude that ISCs of Duroc piglets were more sensitive to weaning stress injury than Taoyuan Black piglets, and Keap1/Nrf2 signaling is involved in this process.

PXR Activation Relieves Deoxynivalenol-Induced Liver Oxidative Stress Via Malat1 LncRNA m6A Demethylation

Deoxynivalenol (DON) is a prevalent toxin causing severe liver damage through hepatocellular oxidative stress. However, the underlying mechanisms and effective therapeutic approaches remain unknown. Here, the unique role of the xenobiotic metabolism factor pregnane X receptor (PXR) in mediating DON-induced hepatocellular oxidative stress is investigated. Treatment with the PXR agonist 3-indole-propionic acid (IPA) alleviates DON-induced oxidative stress and liver injury both in vitro and in vivo. Mechanistically, it is discovered for the first time that PXR agonist IPA directly transactivates the m6A demethylase FTO expression, leading to site-specific demethylation and decreased abundance of YTHDC1-bound Malat1 lncRNA at single-nucleotide resolution. The diminished m6A modification of Malat1 lncRNA reduces its stability and augments antioxidant pathways governed by NRF2, consequently mitigating DON-induced liver injury. Furthermore, Malat1 knockout mice exhibit decreased DON-induced liver injury, emphasizing the role of Malat1 lncRNA in oxidative stress. Collectively, the findings establish that PXR-mediated m6A-dependent Malat1 lncRNA expression determines hepatocyte oxidative stress via m6A demethylase FTO, providing valuable insights into the potential mechanisms underlying DON-induced liver injury and offers potential therapeutic strategies for its treatment.