Integrated metabolomic and lipidomic analysis revealed the protective mechanisms of Erzhi Wan on senescent NRK cells through BRL cells

ETHNOPHARMACOLOGICAL RELEVANCE

Erzhi Wan (EZW), as a prescription of traditional Chinese medicine, has been used for tonifying the liver and kidney. Although past studies have shown that EZW has potential anti-aging effect, the mechanisms associated with cellular metabolomics and lipidomics are not fully understood.

AIM OF THE STUDY

This study aimed to evaluate the anti-aging effect of EZW and investigate the mechanisms associated with cellular metabolomics and lipidomics.

MATERIALS AND METHODS

EZW solution at dosage of 3.6 g/kg in Sprague-Dawley rats was orally administered twice a day for 7 days and serum containing EZW was then collected. NRK cell senescence model induced by D-galactose was established in vitro, and non-contact co-culture cell assay was performed between senescent NRK cells and BRL cells intervened by serum containing EZW. The anti-aging effect of EZW on NRK cells was evaluated by metabolites identification, differential metabolites screening and metabolic pathways analysis through cellular metabolomics with GC-MS and lipidomics with UHPLC-Q-Exactive Orbitrap/MS.

RESULTS

Serum containing EZW indicated a protective effect through intervening BRL cells in non-contact co-culture system with D-gal-induced senescent NRK cells. For metabolic profiles, 71 endogenous metabolites were identified, among which 24 significantly differential metabolites were screened as metabolomics potential biomarkers. For lipidic profiles, 64 lipid components were identified in NRK cell samples under positive ion mode, among which 24 potential biomarkers of lipids were screened, mainly including PC and PE. 127 lipid components were identified in NRK cell samples under negative ion mode, among which 59 potential biomarkers of lipids were screened, including FA, PC, PE, PI and PS. Metabolic pathway analysis demonstrated that the identified differential metabolites found mainly involved in amino acids metabolism, energy metabolism and phospholipid biosynthesis pathways.

CONCLUSION

Serum containing EZW exhibited protective effect on D-gal-induced senescent NRK cells through intervening BRL cells by mainly regulating amino acids metabolism, energy metabolism and phospholipid biosynthesis pathways to possess its anti-aging function, providing a theoretical basis for clinical treatment of EZW.

COX-2/PGE2/VEGF signaling promotes ERK-mediated BMSCs osteogenic differentiation under hypoxia by the paracrine action of ECs

Understanding the crosstalk between endothelial cells (ECs) and bone-marrow mesenchymal stem cells (BMSCs) in response to hypoxic environments and deciphering of the underlying mechanisms are of great relevance for better application of BMSCs in tissue engineering. Here, we demonstrated that hypoxia promoted BMSCs proliferation, colony formation, osteogenic markers expression, mineralization, and extracellular signal-regulated protein kinase (ERK) phosphorylation, and that PD98059 (ERK inhibitor) blocked hypoxia-induced osteogenic differentiation. Hypoxia enhanced ECs migration, cyclooxygenase 2 (COX-2) and integrin α_vβ₃ expression, and prostaglandin E₂ (PGE₂), vascular endothelial growth factor (VEGF) secretion. NS398 (selective COX-2 inhibitor) and LM609 (integrin α_vβ₃ specific inhibitor) impaired the ECs response to hypoxia, and exogenous PGE₂ partially reversed the effects of NS398. BMSCs: ECs co-culture under hypoxia upregulated BMSCs osteogenesis and ERK phosphorylation, as well as ECs migration, integrin α_vβ₃ expression, and PGE₂ and VEGF secretion. NS398 (pretreated ECs) lessened PGE₂, VEGF concentrations of the co-culture system. NS398-treated ECs and AH6809 (combined EP1/2 antagonist)/L-798106 (selective EP3 antagonist)/L-161982 (selective EP4 antagonist)/SU5416 [VEGF receptor (VEGFR) inhibitor]-treated BMSCs impaired the co-cultured ECs-induced enhancement of BMSCs osteogenic differentiation. In conclusion, hypoxia enhances BMSCs proliferation and ERK-mediated osteogenic differentiation, and augments the COX-2-dependent PGE₂ and VEGF release, integrin α_vβ₃ expression, and migration of ECs. COX-2/PGE₂/VEGF signaling is involved in intercellular BMSCs: ECs communication under hypoxia.

Inflammatory lncRNA AK039862 regulates paraquat-inhibited proliferation and migration of microglial and neuronal cells through the Pafah1b1/Foxa1 pathway in co-culture environments

Emerging evidences having suggested that particular lncRNAs have a potential effect on PD progression through provoking damage and inflammatory responses of microglia/ dopaminergic cells. In addition, paraquat can be accumulated in human body through various approaches and have an increased risk for Parkinson's disease. However, the specific role and mechanism of lncRNA related to neurotoxic in the progression of PD is unclear. In our study, a mouse PD model was established induced by the intraperitoneal injection of paraquat (5 mg/kg and 10 mg/kg) every three days (10 times). We determined differential expression of lncRNA AK039862 and its potential targeted genes Pafah1b1/Foxa1 in PD mouse model, then we used fluorescence in situ hybridization (FISH) to visualize the cellular distribution of AK039862. Short interfering RNAs (siRNAs) and overexpression plasmids were designed for knockdown or overexpression of AK039862. To simulate the coexisting dopaminergic cells and microglia cells in vitro, we applied several non-contact co-culture models, including conditioned medium and Transwell co-culture systems. Cytotoxicity of PQ was evaluated using bv2 cells with the concentrations: 30, 60 μM, and mn9d cells with the concentrations: 50, 100 μM. As a result, we depicted multiple interesting individual and interactive features of inflammatory lncRNA AK039862 involved in PQ-induced cellular functional effects. First, we detected that AK039862 contributed to the neuronal injury process in PQ-treated mice and co-localization of AK039862 with dopaminergic cells in vivo. And interestingly, we demonstrated that PQ significantly inhibited microglia and dopaminergic cells proliferation and microglia migration in vitro. Further research indicated that the PQ-induced low expression of AK039862 rescued microglia proliferation and migration inhibition via the AK039862/Pafah1b1/Foxa1 pathway. Meanwhile, AK039862 also participated in the interaction between microglia and dopaminergic cells with PQ treatment in non-contact co-culture models. In summary, we found that PQ inhibited the proliferation and migration of microglial cells, and elucidated AK039862 played a key role in PQ-induced neuroinflammatory damage through Pafah1b1/Foxa1. Finally, inflammatory AK039862 is involved in the complex communication between microglia and dopaminergic cells in the environment of PQ damage.

Spermatozoa induce transcriptomic alterations in bovine oviductal epithelial cells prior to initial contact

The capability of spermatozoa to directly influence maternal gene expression is already established. Indeed, some of the changes induced by spermatozoa may have a direct functional importance in the pre-conceptional period. Although the mechanisms underlying these sperm-maternal interactions are not well characterized, it is possible that they could involve ligands that are released from the spermatozoa. This study therefore aimed to test whether physical contact between bovine spermatozoa and bovine oviductal epithelial cells (BOECs) is a prerequisite for spermatozoa-induced gene expression changes. We used two co-culture models: a contact co-culture model in which spermatozoa interact directly with BOECs, and a non-contact co-culture model in which an insert with the pore size of 0.4 μm was placed between spermatozoa and BOECs. Messenger RNA sequencing analysis of BOECs by RNA-seq revealed ten differentially expressed genes in contact system and 108 differentially expressed genes in the non-contact system after 10 h of co-culture. Retinol metabolism pathway and ovarian steroidogenesis pathway were significantly enriched in the non-contact co-culture system. Q-PCR analysis revealed that transcriptional responses can be rapid, with increased expression of four genes (DHRS3, CYP1B1, PTGS2, and ATF3) detectable within just 90 min of co-incubation, but with expression levels highly dependent on the type of co-culture system. The findings from our study demonstrate that direct contact with spermatozoa is not necessary to induce changes in gene expression of oviductal epithelial cells, suggesting that spermatozoa may be able to signal to maternal tissues in advance of their arrival.

Volatiles released by endophytic Pseudomonas fluorescens promoting the growth and volatile oil accumulation in Atractylodes lancea

Atractylodes lancea is a well-known, but endangered, Chinese medicinal plant whose volatile oils are its main active components. As the volatile oil content in cultivated A. lancea is much lower than that in the wild herb, the application of microbes or related elicitors to promote growth and volatile oil accumulation in the cultivated herb is an important area of research. This study demonstrates that the endophytic bacterium Pseudomonas fluorescens ALEB7B isolated from the geo-authentic A. lancea can release several nitrogenous volatiles, such as formamide and N,N-dimethyl-formamide, which significantly promote the growth of non-infected A. lancea. Moreover, the main bacterial volatile benzaldehyde significantly promotes volatile oil accumulation in non-infected A. lancea via activating plant defense responses. Notably, the bacterial nitrogenous volatiles cannot be detected in the A. lancea - Pseudomonas fluorescens symbiont while the benzaldehyde can be detected, indicating the nitrogenous volatiles or their precursors may have been consumed by the host plant. This study firstly demonstrates that the interaction between plant and endophytic bacterium is not limited to the commonly known physical contact, extending the ecological functions of endophyte in the phytosphere and deepening the understandings about the symbiotic interaction.