Over-expression of miR-146b and its regulatory role in intestinal epithelial cell viability, proliferation, and apoptosis in piglets

Probiotics in miRNA-Mediated Regulation of Intestinal Immune Homeostasis in Pigs: A Physiological Narrative

The microbiota plays a crucial role in maintaining the host's intestinal homeostasis, influencing numerous physiological functions. Various factors, including diet, stress, and antibiotic use, can lead to such imbalances. Probiotics have been shown to restore the microbiota, contributing to maintaining this balance. For instance, the weaning stage in piglets is crucial; this transition can cause unfavorable changes that may contribute to the onset of diarrhea. Probiotic supplementation has increased due to its benefits. However, its mechanism of action is still controversial; one involves the regulation of intestinal immunity. When recognized by immune system cells through membrane receptors, probiotics activate intracellular signaling pathways that lead to changes in gene expression, resulting in an anti-inflammatory response. This complex regulatory system involves transcriptional and post-transcriptional mechanisms, including the modulation of various molecules, emphasizing microRNAs. They have emerged as important regulators of innate and adaptive immune responses. Analyzing these mechanisms can enhance our understanding of probiotic-host microbiota interactions, providing insights into their molecular functions. This knowledge can be applied not only in the swine industry, but also in studying microbiota-related disorders. Moreover, these studies serve as animal models, helping to understand better conditions such as inflammatory bowel disease and other related disorders.

Colchicine ameliorates short-term abdominal aortic aneurysms by inhibiting the expression of NLRP3 inflammasome components in mice

BACKGROUND

Abdominal aortic aneurysms (AAA) are often associated with chronic inflammation and pose a significant risk to affected individuals. Colchicine, known for its anti-inflammatory properties, has shown promise in managing cardiovascular diseases. However, its specific role in the development of AAA remains poorly understood.

METHODS AND RESULTS

In this study, we employed a short-term AAA model induced by angiotensin II (Ang II, 1000 ng/kg/min) and calcium chloride (CaCl2, 0.5 mol/l) in male ApoE-/- and C57BL/6 mice (8-12 weeks old) to investigate the effects of colchicine on AAA progression. Colchicine (0.4 mg/kg) was administered orally once daily, starting on the same day as AAA induction. After a 4-week duration, we observed a significant reduction in AAA diameter, degradation of elastic fibers, and expression of components related to the Nucleotide-binding oligomerization domain-like receptor family protein 3 (NLRP3) inflammasome in the vessel wall of colchicine-treated mice compared to the saline group. Mechanistically, colchicine (5 μm/l, for 24h) inhibited the expression of NLRP3 inflammasome components through the P38-ERK/MicroRNA145-toll-like receptor 4 (TLR4) pathway in RAW264.7 cells.

CONCLUSIONS

Our study demonstrates the effectiveness of colchicine in suppressing NLRP3 inflammasome components, thereby delaying AAA progression in the Ang II and CaCl2-induced short-term model. These findings suggest the potential of colchicine as a pharmacological treatment option for AAA.

Pectin supplementation ameliorates intestinal epithelial barrier function damage by modulating intestinal microbiota in lipopolysaccharide-challenged piglets

During weaning, infants and young animals are susceptible to severe enteric infections, thus inducing intestinal microbiota dysbiosis, intestinal inflammation, and impaired intestinal barrier function. Pectin (PEC), a prebiotic polysaccharide, enhances intestinal health with the potential for therapeutic effect on intestinal diseases. One 21-days study was conducted to investigate the protective effect of pectin against intestinal injury induced by intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS) in a piglet model. A total of 24 piglets (6.77±0.92 kg BW; Duroc × Landrace × Large White; barrows; 21 d of age) were randomly assigned into three groups: control group, LPS-challenged group, and PEC + LPS group. Piglets were administrated with LPS or saline on d14 and d21 of the experiment. All piglets were slaughtered and intestinal samples were collected after 3 h administration on d21. Pectin supplementation ameliorated the LPS-induced inflammation response and damage to the ileal morphology. Meanwhile, pectin also improved intestinal mucin barrier function, increased the mRNA expression of MUC2, and improved intestinal mucus glycosylation. LPS challenge reduced the diversity of intestinal microbiota and enriched the relative abundance of Helicobacter. Pectin restored alpha diversity improved the structure of the gut microbiota by enriching anti-inflammatory bacteria and short-chain fatty acid (SCFA)-producing bacteria, and increased the concentrations of acetate. In addition, Spearman rank correlation analysis also revealed the potential relationship between intestinal microbiota and intestinal morphology, intestinal inflammation, and intestinal glycosylation in piglets. Taken together, these results indicate that pectin enhances intestinal integrity and barrier function by altering intestinal microbiota composition and their metabolites, which subsequently alleviates intestinal injury and finally improves the growth performance of piglets.

Transcriptome and iTRAQ-Based Proteome Reveal the Molecular Mechanism of Intestinal Injury Induced by Weaning Ewe's Milk in Lambs

Early feeding regime has a substantial lifelong effect on lambs and weaning ewe's milk can lead to the intestinal injury of lambs. To explore the molecular regulatory mechanism of intestinal injury of lambs under weaning stress, the jejunum was conducted transcriptome and then integrated analyzed with our previous proteome data. A total of 255 upregulated genes and 285 downregulated genes were significantly identified. These genes showed low overlapping with differentially expressed proteins identified by isobaric tags for relative and absolute quantification (iTRAQ). However, according to their functions, the differentially expressed genes (DEGs) and proteins with the same expression trend were enriched for the similar Gene Ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as intestinal lipid absorption, urea cycle, peroxisome proliferator-activated receptor (PPAR) signaling pathway, and ferroptosis. Furthermore, the DEGs, including FABP2, ACSL3, APOA2, APOC3, and PCK1, might play essential roles in intestinal lipid absorption and immune response through the PPAR signaling pathway and ferroptosis. This study could provide new insights into early lamb breeding at the molecular level.

Identification of differentially expressed miRNAs after Lactobacillus reuteri treatment in the ileum mucosa of piglets

BACKGROUND

Lactobacillus reuteri I5007 possesses many excellent probiotic characteristics in piglets. miRNA plays important role in host-microbiota interactions, but the mechanism by which L. reuteri I5007 regulates intestinal function through its influence on miRNA expression is unknown.

OBJECTIVE

This study analyzed the miRNA expression patterns in the ileum mucosa tissue of piglets by L. reuteri I5007 treatment, aim to clarify its molecular mechanism for regulating intestinal function through miRNA.

METHODS

Neonatal piglets were orally administered L. reuteri I5007 or a placebo daily starting on day 1, and differential expression of ileal miRNAs was analyzed at 10 and 20 days of age by small RNA sequencing.

RESULTS

361 known porcine miRNAs were identified, and ten miRNAs were highly expressed in the ileum mucosa in both treatments. Nineteen differentially expressed (DE) miRNAs were identified in response to L. reuteri treatment, and four DE miRNAs (ssc-miR-196a, -196b-5p, -1285 and -10386) were differentially expressed at both time points. The KEGG pathway analyses showed the targets of 19 DE miRNAs were involved in 63 significantly enriched pathways, including the PI3K-Akt and MAPK pathways, which were confirmed to play important roles in probiotic-host communication. L. reuteri I5007 exerted anti-inflammatory effects by influencing the levels of inflammatory cytokines. Suppressor of cytokine signalling 4 gene was the target gene of ssc-miR-196a/-196b-5p, overexpression of ssc-miR-196a/-196b-5p downregulated the mRNA expression of IL-1β and TNFα in IPEC-J2 cells.

CONCLUSION

Our study provides new insight into the role of miRNAs in the intestinal function of piglets after L. reuteri I5007 treatment.

Altered expression of miRNAs and mRNAs reveals the potential regulatory role of miRNAs in the developmental process of early weaned goats

MicroRNAs (miRNAs) play pivotal roles in growth, development, and stress responses. However, the regulatory function of miRNAs in early weaned goats remains unclear. Deep sequencing comparison of mRNA and miRNA expression profiles showed that 18 miRNAs and 373 genes were differentially expressed in pre- and post-weaning Chongming white goats. Bioinformatics analysis indicated that these differentially expressed genes are involved in cellular processes, developmental processes, and growth in terms of biological process analysis. KEGG analysis showed that downregulated genes were enriched in salivary secretion, bile secretion, vascular smooth muscle contraction, and calcium signaling pathways. Additionally, a miRNA-mRNA co-expression network of the 18 dysregulated miRNAs and their 107 target mRNAs was constructed using a combination of Pearson’s correlation analysis and prediction by miRanda software. Among the downregulated miRNAs, two (chi-miR-206 and chi-miR-133a/b) were muscle development-related and the others were cell proliferation associated. Further RT-qPCR analysis confirmed that downregulated miRNAs (chi-miR-99b-3p, chi-miR-224, and chi-miR-10b-5p) were highly expressed in muscle tissues (heart, spleen, or kidney) of the rapid growth period (7-month old) in Chongming white goats. The results of the present study suggested that weaning induced cell proliferation repression in post-weaning goats, providing new insight into the mechanism of muscle development of goats, although additional details remain to be elucidated in the future.

DPP-4 inhibition by linagliptin prevents cardiac dysfunction and inflammation by targeting the Nlrp3/ASC inflammasome

We compared the effects of linagliptin (Lina, a DPP4 inhibitor) and GLP-1 receptor activation by exenatide followed by exendin-4 in an infusion pump (EX) on infarct size (IS), post-infarction activation of the inflammasome and remodeling in wild-type (WT) and db/db diabetic mice. Mice underwent 30 min ischemia followed by 24 h reperfusion. IS was assessed by TTC. Additional mice underwent permanent coronary artery occlusion. Echocardiography was performed 2w after infarction. Activation of the inflammasome in the border zone of the infarction was assessed by rt-PCR and ELISA 2w after reperfusion. Further in vitro experiments were done using primary human cardiofibroblasts and cardiomyocytes exposed to simulated ischemia-reoxygenation. Lina and EX limited IS in both the WT and the db/db mice. Lina and EX equally improved ejection fraction in both the WT and the db/db mice. mRNA levels of ASC, NALP3, IL-1β, IL-6, Collagen-1, and Collagen-3 were higher in the db/db mice than in the WT mice. Infarction increased these levels in the WT and db/db mice. Lina more than EX attenuated the increase in ASC, NALP3, IL-1β, IL-6, Collagen-1 and Collagen-3, TNFα and IL-1β, and decreased apoptosis, especially in the db/db mice. In vitro experiments showed that Lina, but not EX, attenuated the increase in TLR4 expression, an effect that was dependent on p38 activation with downstream upregulation of Let-7i and miR-146b levels. Lina and EX had similar effects on IS and post-infarction function, but Lina attenuated the activation of the inflammasome and the upregulation of collagen-1 and collagen-3 more than direct GLP-1 receptor activation. This effect depends on p38 activation with downstream upregulation of miR-146b levels that suppresses TLR4 expression.