Expressions of TLR4, MyD88, IRAK4 and NF-κΒ in the oviduct of Chinese brown frog (Rana dybowskii)

Abstract

One special physiological phenomenon of the Chinese brown frog (Rana dybowskii) is that its oviduct goes through expansion prior to pre-hibernation instead of expanding during the breeding period. Our previous study discovered that some cytokines such as interleukin-1 beta (IL-1β) and its receptor type I (IL1R1) proteins were expressed in the oviduct of Rana dybowskii. In this study, we continued to investigate the localizations and expression levels of cytokines including toll-like receptor 4 (TLR4) and its related factors, myeloid differentiation factor 88 (MyD88), interleukin-1 receptor-associated kinase (IRAK) and nuclear factor kappa B (NF-κΒ) in the oviduct of Rana dybowskii during the breeding period and pre-hibernation. Morphological results showed that there were significant differences in oviductal weight and pipe diameter with significantly higher values in pre-hibernation than those of the breeding period. Strong immunostaining of TLR4, MyD88, IRAK4 and NF-κΒ were observed in the pre-hibernation. These proteins levels had no significant difference between these two periods except MyD88 which was significantly higher in the pre-hibernation. The mRNA expression levels of MyD88 and NF-κΒ were obviously higher in pre-hibernation than those of the breeding period. These findings suggested that TLR4/MyD88 signal pathway might participate in the oviductal functions of Rana dybowskii during the breeding period and pre-hibernation.

Immune-Enhancing Effects of a Novel Glucan from Purple Sweet Potato Ipomoea batatas (L.) Lam on RAW264.7 Macrophage Cells via TLR2- and TLR4-Mediated Pathways

“…When the IKK complex is activated, the phosphorylation of IKK causes the phosphorylation and degradation of IκB-α; then, NF-κB is released and translocated to the nucleus, is phosphorylated by nuclear kinases, and leads to the transcriptions of the immune-related gene. 40 To investigate whether the NF-κB signaling pathway also participated in macrophage activation by PSPP-1, we further studied the expressions of key proteins or their phosphorylated proteins by western blot. The results showed that PSPP-1 nearly unchanged the expressions of IKKα/β but activated the degradation of IκB-α and increased the phosphorylation of IKKα/β and IκB-α in RAW264.7 cells, which were significantly different in comparison to the control group (P < 0.05).…”

“…Generally, NF-κB is inactive and retained in the cytoplasm by specific inhibitor IκB-α, and the IKK complex (IKK α and IKK β) is a critical regulatory protein for the phosphorylation of IκBs. When the IKK complex is activated, the phosphorylation of IKK causes the phosphorylation and degradation of IκB-α; then, NF-κB is released and translocated to the nucleus, is phosphorylated by nuclear kinases, and leads to the transcriptions of the immune-related gene …”

Theabrownin Isolated from Pu-Erh Tea Enhances the Innate Immune and Anti-Inflammatory Effects of RAW264.7 Macrophages via the TLR2/4-Mediated Signaling Pathway

“…The activation of NF-κB (p65) requires IκBα phosphorylation. When activated p65 enters the nucleus and is phosphorylated (p-p65) by nuclear kinase, it induces the transcription of immune-related genes, promotes cytokine production, and enhances the innate and adaptive immunity [ 43 ]. PI3K is a lipid kinase that regulates key physiological and pathological cellular activities.…”

Investigation of seasonal changes in lipid synthesis and metabolism-related genes in the oviduct of Chinese brown frog (<em>Rana dybowskii</em>)

“…These findings are consistent with our previous studies. 2 , 31 , 33 , 34 However, in studies on the Argentine shortfin squid, it has been found that the reproductive organs (ovary and oviduct) account for an increasing proportion of energy during sexual maturation, building up energy for reproduction. 38 Different from non-breeding, the weight and length of the oviduct in guinea hens ( Numida meleagris ) displayed increased values during the breeding season.…”

“… 31 , 32 The dried product of the dilated oviduct, known as Oviductus Ranae , is widely used in traditional Chinese medicine due to its nourishing properties for Yin, lung moisture, and kidney essence replenishment. 33 , 34 Oviductus Ranae contains a variety of nutrients, with proteins and lipids being the most significant components, with lipid content of up to 50%. 34 …”