D-mannose reduces adipogenesis by inhibiting the PI3K/AKT signaling pathway

PURPOSE

To explore the effects and potential mechanisms of D-mannose on adipogenic differentiation of two kinds of representative mesenchymal stem cells (MSCs).

METHODS

We cultured two kinds of representative MSCs, human adipose tissue-derived stromal cells (hADSCs) as well as human bone marrow mesenchymal stem cells (hBMSCs), with adipogenic-induced medium containing D-mannose or D-fructose as the control. Oil red O staining, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot (WB) were used to detect whether D-mannose had effects on adipogenic differentiation of MSCs. RNA sequencing (RNA-seq) transcriptomic analysis was further used to explore the potential mechanisms of D-mannose on adipogenic differentiation of MSCs. After that, qRT-PCR and WB were used to verify the results of RNA-seq. Last, we removed bilateral ovaries of female rats to establish an estrogen deficiency obesity model, and gave D-mannose intragastric administration. One month later, the femurs of rats were sliced for oil red O staining, and the inhibitory effect of D-mannose on lipid formation in vivo was studied.

RESULTS

Oil red O staining, qRT-PCR and WB in vitro demonstrated that D-mannose inhibited the adipogenic differentiation of both hADSCs and hBMSCs. Oil red O staining of femur sections proved that D-mannose was able to reduce in vivo adipogenesis. The results of RNA-seq transcriptomic analysis revealed that the adipogenesis-inhibition effects of D-mannose were performed by antagonizing the PI3K/AKT signaling pathway. Besides, qRT-PCR and WB further verified the results of RNA-seq.

CONCLUSION

Our study indicated that D-mannose was able to reduce adipogenic differentiation of both hADSCs and hBMSCs by antagonizing the PI3K/AKT signaling pathway. D-mannose is expected to be a safe and effective treatment strategy for obesity.

Effects of Ilicis Chinensis folium extract supplementation on growth performance, serum parameters, intestinal morphology, and antioxidant capacity of broiler chickens

BACKGROUND

Ilicis chinensis folium extract (ICFE) is a powder extracted and processed with Ilex chinensis Sims (ICS) which has numerous bioactivities and is conventionally used in traditional Chinese medicine. Nonetheless, there has been no definitive study evaluating ICFE's application as a feed supplement for broilers. This research sought to determine the chemical composition and evaluate how dietary ICFE supplementation affects the growth performance, serum metrics, intestinal structure, and antioxidant capacity of broilers.

METHODS

A total of 360 one-day-old broiler chicks were assigned to four treatments (with 9 replicates of 10 chicks, each) of dietary supplementation with ICFE at 0, 250, 500, and 1,000 mg /kg for 42 days.

RESULTS

Ten polyphenolic compounds and two triterpenoid glycosides were detected by HPLC. In the grower stage and overall, broilers supplemented with 500 and 1,000 mg/kg ICFE exhibited a higher ADFI (P < 0.05) than the controls. Additionally, compared to the controls, broilers receiving low, medium, or high dosages of ICFE exhibited higher average daily gains (P < 0.05) throughout the starter stage and overall. Organ indices showed no significant variation, suggesting that ICFE was non-toxic. ICFE supplementation increased the height of villi in the duodenum and jejunum, reduced crypt depth, and increased the villus/crypt ratio in the duodenum (P < 0.05). Serum concentrations of IL-4 and IgA were increased in ICFE-supplemented broilers. The serum malondialdehyde concentration was reduced, whereas superoxide dismutase activity and total antioxidant capacity increased through supplementation with ICFE.

CONCLUSION

ICFE supplementation can improve intestinal morphology, antioxidant capacity, and growth performance of broilers. Hence, ICFE is a promising and safe alternative to antibiotics in broilers, and 500 mg/kg appears to be the optimal dose.

Dexmedetomidine Alleviates Neuropathic Pain via the TRPC6-p38 MAPK Pathway in the Dorsal Root Ganglia of Rats

Purpose

Neuropathic pain is a chronic intractable disease characterized by allodynia and hyperalgesia. Effective treatments are unavailable because of the complicated mechanisms of neuropathic pain. Transient receptor potential canonical 6 (TRPC6) is a nonselective calcium (Ca2+)-channel protein related to hyperalgesia. Dexmedetomidine (Dex) is an alpha-2 (α2) adrenoreceptor agonist that mediates intracellular Ca2+ levels to alleviate pain. However, the relationship between TRPC6 and Dex is currently unclear. We speculated that the α2 receptor agonist would be closely linked to the TRPC6 channel. We aimed to investigate whether Dex relieves neuropathic pain by the TRPC6 pathway in the dorsal root ganglia (DRG).

Methods

The chronic constriction injury (CCI) model was established in male rats, and we evaluated the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL). The expression of TRPC6 and Iba-1 in the DRG were analyzed using quantitative real-time polymerase chain reaction, Western blot, and immunofluorescence assay. The levels of inflammatory cytokines were measured using an enzyme-linked immunosorbent assay.

Results

Compared with the CCI normal saline group, both the MWT and TWL were significantly improved after 7 days of Dex administration. Results demonstrated that TRPC6 expression was increased in the DRG following CCI but was suppressed by Dex. In addition, multiple administrations of Dex inhibited the phosphorylation level of p38 mitogen-activated protein kinase and the upregulation of neuroinflammatory factors.

Conclusion

The results of this study demonstrated that Dex exhibits anti-nociceptive and anti-inflammatory properties in a neuropathic pain model. Moreover, our findings of the CCI model suggested that Dex has an inhibitory effect on TRPC6 expression in the DRG by decreasing the phosphorylation level of p38 in the DRG.