Novel Insight Into Nutritional Regulation in Enhancement of Immune Status and Mediation of Inflammation Dynamics Integrated Study In Vivo and In Vitro of Teleost Grass Carp (Ctenopharyngodon idella): Administration of Threonine

Abstract

This study aims to investigate the effects of threonine (Thr) on immunoregulation in vivo and in vitro of teleost grass carp (Ctenopharyngodon idella). Juveniles (9.53 ± 0.02 g) were reared for 8 weeks with respective Thr diet (3.99, 7.70, 10.72, 14.10, 17.96, and 21.66 g/kg) and then challenged with Aeromonas hydrophila for in vivo study. Macrophages isolated from head kidney were treated in vitro for 48 h with L-Thr (0, 0.5, 1.0, 2.0, 4.0, and 8.0 mM) after 6 h of lipopolysaccharide induction. The results showed that, compared with Thr deficiency (3.99 g/kg), the optimal dietary Thr (14.10g/kg) affected the immunocyte activation in the head kidney (HK) and spleen (SP) by downregulating the mRNA expressions of MHC-II and upregulating CD4 (not CD8), and it mediated the innate immune by enhancing the activities of lysozyme (LZ), acid phosphatase content of complement 3 (C3) and C4, increasing the mRNA abundances of hepcidin, liver expressed antimicrobial peptide-2A (LEAP-2A), LEAP-2B, β-defensin1, downregulating tumor necrosis factor α (TNF-α), IL-6, IL-1β, IL-12p35, IL-12p40, IL-17AF1, and IL-17D partly by attenuating RORγ1 transcriptional factor and nuclear factor kappa B p65 (NF-κBp65) signaling cascades [IKKβ/IκBα/NF-κBp65] and upregulating transforming growth factor β1 (TGF-β1), IL-4/13A, -4/13B, IL-10, and IL-22 partly by GATA-3. Besides these, the optimal dietary Thr regulated the adaptive immune by upregulating the mRNAs of immunoglobulin M (IgM) and IgZ (not IgD). Moreover, 2 mM Thr downregulated in vitro the mRNA abundances of colony stimulating factor-1, inducible nitric oxide synthase, mannose receptor 1, matrix metalloproteinase2 (MMP-2), and MMP-9 significantly (P < 0.05), indicating that Thr could attenuate the M1-type macrophages’ activation. Moreover, L-Thr downregulated the mRNA transcripts of TNF-α, IL-6, and IL-1β associated with impairing the SOCS1/STAT1 signaling and upregulated IL-10 and TGF-β1 partly by accentuating the SOCS3/STAT3 pathway. The above-mentioned observations suggested that Thr improved the immune status in the immune organs of fish by enhancing the immune defense and mediating the inflammation process. Finally, based on the immune indices of LZ activity in HK and C3 content in SP, the optimal Thr for immune enhancement in juvenile grass carp (9.53–53.43 g) was determined to be 15.70 g/kg diet (4.85 g/100 g protein) and 14.49 g/kg diet (4.47 g/100 g protein), respectively.

Effects of Five Lipid Sources on Growth, Hematological Parameters, Immunity and Muscle Quality in Juvenile Largemouth Bass (Micropterus salmoides)

“…Moreover, higher TGF-β1 levels were found in golden pompano ( Trachinotus ovatus ) fed with adequate dietary n-3 HUFAs [ 80 ]. And TGF-β1 could act as a positive function signal marker to suppress the inflammation in fish [ 13 , 80 , 81 ]. Combined with the fatty acid profiles and the expression variations in TGF-β1 in these lipid resources in this study, this might be due to the decrease in n-3PUFAs inhibiting the expression of anti-inflammatory factors [ 81 ].…”

“…And TGF-β1 could act as a positive function signal marker to suppress the inflammation in fish [ 13 , 80 , 81 ]. Combined with the fatty acid profiles and the expression variations in TGF-β1 in these lipid resources in this study, this might be due to the decrease in n-3PUFAs inhibiting the expression of anti-inflammatory factors [ 81 ]. From the above results, it is suggested that dietary RO improves health status by activating the immune system and inhibiting inflammatory factors in largemouth bass.…”

Novel Perspective on Mechanism in Muscle Growth Inhibited by Ochratoxin A Associated with Ferroptosis: Model of Juvenile Grass Carp (Ctenopharyngodon idella) In Vivo and In Vitro Trials

“…The extraction, reverse transcription, and computation methods of muscle and cellular RNA were consistent with previous studies in our laboratory. , Primers used are given in Table S2. The specific experimental steps were carried out according to the instructions.…”

The immune enhancement effect of Nelumbo nucifera Gaertner Seed Extract (NSE) in murine macrophage RAW 264.7 cells

“…Nuclear factor-kappa B (NF-κB)는 p65와 p50의 이량체로써 거의 모든 동물세포에서 발견되며 스트레스, 중금속(heavy metal), 자외선(ultraviolet)에 자극에 반응하며, 특히, 감염에 의 한 면역조절에 중추적인 역할을 한다 [4][5][6]. 정상상태에서 NF-κB 는 I kappa B (IκB)와 결합되어 불활성화된 상태로 세포질에 존재한다.…”