Network pharmacology-based analysis on geniposide, a component of gardenia jasminoides, beneficial effects to alleviate LPS-induced immune stress in piglets

Geniposide is the main medicinal component of Gardenia jasminoides, and its content is approximately 3-8% depending on its origin. Geniposide is a class of cyclic enol ether terpene glucoside compounds with strong antioxidant, free radical quenching and cancer-inhibiting activities. Many studies have reported that geniposide has hepatoprotective, cholestatic, neuroprotective, blood sugar and blood lipid regulation, soft tissue damage treatment, antithrombotic, antitumor and other effects. As a traditional Chinese medicine, gardenia, whether used as gardenia alone, as the monomer geniposide or as the effective part of cyclic either terpenoids, has been reported to have anti-inflammatory effects when used in the right amounts. Recent studies have found that geniposide has important roles in pharmacological activities such as anti-inflammation activity, inhibition of the NF-κB/IκB pathway, and cell adhesion molecule production. In this study, we predicted the anti-inflammatory and antioxidant effects of geniposide in piglets through network pharmacology based on the LPS-induced inflammatory response-regulated signaling pathway. The effects of geniposide on changes in inflammatory pathways and cytokine levels in the lymphocytes of inflammation-stressed piglets were investigated using in vivo and in vitro models of piglet lipopolysaccharide-induced oxidative stress. Network pharmacology identified 23 target genes, of which the main pathways of action were lipid and atherosclerosis, fluid shear stress and atherosclerosis, and Yersinia infection. The main relevant target genes were VEGFA, ROCK2, NOS3, and CCL2. Validation experiments showed that the interventional effects of geniposide reduced the relative expression of NF-κB pathway proteins and genes, restored the expression of COX-2 genes to normal levels, and increased the relative expression of tight junction proteins and genes in IPEC-J2 cells. This indicates that the addition of geniposide can alleviate inflammation and improve the level of cellular tight junctions.

Identification and integrated analysis of lncRNAs and miRNAs in IPEC-J2 cells provide novel insight into the regulation of the innate immune response by PDCoV infection

Background

Noncoding RNAs (ncRNAs), including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are pivotal regulators involved in the pathogenic mechanism of multiple coronaviruses. Porcine deltacoronavirus (PDCoV) has evolved multiple strategies to escape the innate immune response of host cells, but whether ncRNAs are involved in this process during PDCoV infection is still unknown.

Results

In this study, the expression profiles of miRNAs, lncRNAs and mRNAs in IPEC-J2 cells infected with PDCoV at 0, 12 and 24 hours postinfection (hpi) were identified through small RNA and RNA sequencing. The differentially expressed miRNAs (DEmiRNAs), lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) were screened from the comparison group of IPEC-J2 cells at 0 and 12 hpi as well as the comparison group of IPEC-J2 cells at 12 and 24 hpi. The target genes of these DEncRNAs were predicted. The bioinformatics analysis of the target genes revealed multiple significantly enriched functions and pathways. Among them, the genes that were associated with innate immunity were specifically screened. The expression of innate immunity-related ncRNAs and mRNAs was validated by RT–qPCR. Competing endogenous RNA (ceRNA) regulatory networks among innate immunity-related ncRNAs and their target mRNAs were established. Moreover, we found that the replication of PDCoV was significantly inhibited by two innate immunity-related miRNAs, ssc-miR-30c-3p and ssc-miR-374b-3p, in IPEC-J2 cells.

Conclusions

This study provides a data platform to conduct studies of the pathogenic mechanism of PDCoV from a new perspective and will be helpful for further elucidation of the functional role of ncRNAs involved in PDCoV escaping the innate immune response.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08722-2.

Effect of Trimethyltin chloride on proliferation and cell cycle of intestinal porcine epithelial cells

Trimethyltin chloride (TMT) is a highly toxic substance produced by organotin heat stabilizers in the synthesis of polyvinyl chloride (PVC) products. TMT is widely used in industry and agriculture. The aim of this study was to investigate the effects of TMT-induced cytotoxicity in intestinal porcine epithelial cells (IPEC-J2). Our study showed that TMT induced a decline in cell viability of IPEC-J2, caused cell shrinkage and rounded cell morphology, reduced the number of proliferating cells and the expression of proliferating cell nuclear antigen (PCNA), and increased lactate dehydrogenase (LDH) activity in cell supernatants. Simultaneously, TMT lowered the mRNA expression of Cyclin B1, and Cyclin D1, but increased P21 and P27 expression. The cell cycle progression was arrested from the G1 to the S phase. Furthermore, the mRNA expression of Bax/Bcl-2 ratio and the protein expression of cleaved Caspase-9 and cleaved Caspase-3 were significantly increased after TMT treatment, while the ratio of advanced apoptotic cells was elevated. These results indicated that TMT blocked the cell cycle, inhibited IPEC-J2 proliferation, and induced apoptosis.

Betaine attenuates LPS-induced downregulation of Occludin and Claudin-1 and restores intestinal barrier function

Background

The intestinal epithelial barrier, which works as the first line of defense between the luminal environment and the host, once destroyed, it will cause serious inflammation or other intestinal diseases. Tight junctions (TJs) play a vital role to maintain the integrity of the epithelial barrier. Lipopolysaccharide (LPS), one of the most important inflammatory factors will downregulate specific TJ proteins including Occludin and Claudin-1 and impair integrity of the epithelial barrier. Betaine has excellent anti-inflammatory activity but whether betaine has any effect on TJ proteins, particularly on LPS-induced dysfunction of epithelial barriers remains unknown. The purpose of this study is to explore the pharmacological effect of betaine on improving intestinal barrier function represented by TJ proteins. Intestinal porcine epithelial cells (IPEC-J2) were used as an in vitro model.

Results

The results demonstrated that betaine enhanced the expression of TJ proteins while LPS (1 μg/mL) downregulates the expression of these proteins. Furthermore, betaine attenuates LPS-induced decreases of TJ proteins both shown by Western blot (WB) and Reverse transcription-polymerase chain reaction (RT-PCR). The immunofluorescent images consistently revealed that LPS induced the disruption of TJ protein Claudin-1 and reduced its expression while betaine could reverse these alterations. Similar protective role of betaine on intestinal barrier function was observed by transepithelial electrical resistance (TEER) approach.

Conclusion

In conclusion, our research demonstrated that betaine attenuated LPS-induced downregulation of Occludin and Claudin-1 and restored the intestinal barrier function.

In vitro prebiotic potential of agricultural by-products on intestinal fermentation, gut barrier and inflammatory status of piglets

The inclusion of fibre-rich ingredients in diets is one possible strategy to enhance intestinal fermentation and positively impact gut ecology, barrier and immunity. Nowadays, inulin-type fructans are used as prebiotics in the feed of piglets to manipulate gut ecology for health purposes. Likewise, some by-products could be considered as sustainable and inexpensive ingredients to reduce gut disorders at weaning. In the present study, chicory root and pulp, citrus pulp, rye bran and soya hulls were tested in a three-step in vitro model of the piglet's gastro-intestinal tract combining a pepsin-pancreatin hydrolysis (digestion), a dialysis step using cellulose membranes (absorption) and a colonic batch fermentation (fermentation). The fermentation kinetics, SCFA and microbiota profiles in the fermentation broth were assessed as indicators of prebiotic activity and compared with the ones of inulin. The immunomodulatory effects of fermentation supernatant (FS) were investigated in cultured intestinal porcine epithelial cells (IPEC-J2) by high-throughput quantitative PCR. Chicory root displayed a rapid and extensive fermentation and induced the second highest butyrate ratio after inulin. Citrus pulp demonstrated high acetate ratios and induced elevated Clostridium clusters IV and XIVa levels. Chicory root and pulp FS promoted the intestinal barrier integrity with up-regulated tight and adherens junction gene expressions in comparison with inulin FS. Chicory pulp FS exerted anti-inflammatory effects in cultured IPEC-J2. The novel approach combining an in vitro fermentation model with IPEC-J2 cells highlighted that both chicory root and pulp appear to be promising ingredients and should be considered to promote intestinal health at weaning.

Hippophae rhamnoides polysaccharides protect IPEC-J2 cells from LPS-induced inflammation, apoptosis and barrier dysfunction in vitro via inhibiting TLR4/NF-κB signaling pathway

Inflammatory response caused by early weaning stress in piglets is associated with various diseases. The Hippophae rhamnoides polysaccharide (HRP) exhibits anti-inflammatory activity and immunomodulatory properties. The mechanisms for the protective effects of HRP on barrier function, inflammatory damage and apoptosis in intestinal porcine epithelial cells (IPEC-J2) induced by the lipopolysaccharide (LPS) are unknown. In this study, we first demonstrated the cytotoxicity of HRP-induced IPEC-J2 cells by reducing cell viability. IPEC-J2 cells were treated with 0-800 μg/mL doses of HRP, and 0-600 μg/mL doses were used in further experiments. Upon exposure to LPS, the viability of IPEC-J2 cells, ROS production, immunoglobulin levels (immunoglobulin M (IgM), immunoglobulin A (IgA) and immunoglobulin G (IgG)) and tight junction protein level (zonula occludens-1 (ZO-1), occluding, claudin-1) decreased. Inflammatory factors (interleukin-1beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α)) and apoptosis (Bcl-2, Bax, caspase-3, caspase-8 and caspase-9) were increased. Cell morphology and internal structure were damaged in the LPS treatment. Pre-treating cells with HRP (0-600 μg/mL) reduced inflammatory factors levels, apoptosis rate, increased immunoglobulins, tight junction protein levels and relieved cell surface morphology damage. Pre-treatment with HRP also reduced the levels of the Toll-like receptor 4 (TLR4) and Myeloid differentiation factor 88 (MyD88) and inhibited the phosphorylated NF-κB factor-kappa B (NF-κB) in cells induced by LPS. These results show that pre-treatment with HRP protected against LPS-induced IPEC-J2 cell damage through its anti-inflammatory activity.