Study on Toll-Like Receptor 2-Mediated Inflammation-Induced Familial Hypertension Combined with Hyperlipemia and Its Mechanism

According to the latest clinical data, cardiovascular diseases have ranked first in prone diseases, causing 40% of the premature deaths of China’s population. This study aimed to investigate the influence of Toll-like receptor 2- (TLR2-) mediated inflammation on the occurrence and development of familial hypertension combined with hyperlipemia and its related mechanism. Blood specimens from 66 patients undergoing coronary atherosclerosis were collected and grouped, including 22 patients into the control group, 25 into the familial hypertension group, and 19 into familial hypertension combined with hyperlipemia group. In this study, ELISA was conducted for determining the levels of four inflammatory factors of TLR2 and IL-1β, IL-6, TNF-ɑ, and CCL2 in serum and the levels of relevant indicators in mice. C57Bl/6j and genetically engineered C.129(B6)-Tlr2tm1Kir/J mice were given subcutaneous injection of normal saline (wild-saline group), 8-week 40% high-fat diet (wild-high-fat group), and subcutaneous Alzet-implanted angiotensin II micropump supplemented with the research diet (wild-high fat-Ang II group, Tlr2-/--high fat-Ang II group). Blood pressure in mice was recorded consecutively with a noninvasive hemopiezometer for eight weeks. TLR2 and IL-1β, IL-6, TNF-ɑ, and CCL2 in serum of patients with familial hypertension combined with hyperlipemia and the hypertension combined with hyperlipemia mouse model were higher than those in the normal group. Under combined intervention of Ang II and the research diet, mRNA expression related to blood pressure, blood lipid, and fat metabolism in Tlr2-/- genetically engineering mice was significantly lower than that in the wild-high fat-Ang II group. The phosphorylation levels of AKT, IKK, and p65 in mice with hypertension combined with hyperlipidemia were significantly higher than those in normal group. The levels of blood pressure and blood lipid in mice after blocking the AKT or NF-κB pathway were significantly downregulated compared with those in the wild-high fat-Ang II group, with statistically significant differences (both P < 0.05 ). In conclusion, TLR2 regulates inflammation through Akt-NF-κB pathway, thus inducing the occurrence and development of familial hypertension combined with hyperlipemia.

Aeromonas hydrophila infection induces Toll-like receptor 2 (tlr2) and associated downstream signaling in Indian catfish, Clarias magur (Hamilton, 1822)

Motile Aeromonas septicaemia (MAS), caused by Aeromonas hydrophila, is one of the most significant bacterial disease responsible for mortality in Indian catfish, Clarias magur, a potential aquaculture species in the Indian subcontinent. In fish, innate immunity elicited by pathogen recognition receptors (PRRs) plays an important role in providing protection against bacterial infection. Information on PRRs including Toll-like receptors (tlrs) and their response to bacterial pathogens remains unexplored in magur. Toll-like receptor 2 (tlr2), a phylogenetically conserved germ-line encoded PRR recognizes specific microbial structure and trigger MyD88-dependent signaling pathway to induce release of various cytokines responsible for innate immune response. In the present study, tlr2 gene of magur was characterized and downstream signaling was studied following challenge with A. hydrophila. The full-length cDNA of magur tlr2 (mtlr2) comprised of 3,066 bp with a single open reading frame of 2,373 bp encoding 790 amino acids having a theoretical pI value of 6.11 and molecular weight of 90 kDa. Structurally, it comprised of signal peptide (1–42aa), one leucine-rich repeat region (LRR) at N-terminal (LRR1-NT: 50–73 aa) and C-terminal (LRR-CT: 588–608 aa), twenty LRRs in between, one trans-membrane (Tm) domain (609–631aa) followed by cytoplasmic TIR domain (670–783aa). Phylogenetically, mtlr2 is closely related to pangasius and channel catfish. Highest basal expression of mtlr2, myd88 and il-1β in spleen, nf-kb in anterior kidney was observed. Lowest basal expression of mtlr2 in skin and myd88, nf-kb and il-1β in muscle was detected. Significant up-regulation of mtlr2 and downstream expression occurred at 3, 8, 24 h post infection to A. hydrophila in important immune organs such as liver, spleen, intestine and kidney. These findings highlight the vital role of tlr2 in eliciting innate immune defence against A. hydrophila infection.