Neurokinin A TFA is an endogenous tachykinin neuropeptide and a potent selective agonist of the neurokinin 2 receptor (NK2R)[1-2]. Neurokinin A TFA can be used in research related to gastrointestinal disorders, chronic visceral pain, asthma, and overactive bladder syndrome[3-4].
In vitro, K562 hematopoietic progenitor cells were stimulated with Neurokinin A TFA (10nM) for 16 hours. Neurokinin A TFA inhibited the expression of cell cycle activators Cdk2 and Cyclin A, upregulated p53 and p21 expression, activated Smad4 via a non-classical pathway, and induced TGF-β1 production at the translational level, primarily through NK2 receptor activation[5]. Human keratinocytes and mouse PAM 212 keratinocytes were treated with Neurokinin A TFA (0.1–100nM) for 3–48 hours. Neurokinin A TFA directly induced nerve growth factor mRNA expression and bioactive protein secretion via NK1 and NK2 receptors, promoted neurite outgrowth in PC-12 cells, and upregulated epidermal keratinocyte nerve growth factor protein expression in mouse skin through capsaicin-induced neuropeptide release[6].
In vivo, Neurokinin A TFA (1μg/site) was injected into the gingival tissue of C57BL/6 mice with ligation-induced periodontitis (twice daily for 5 days). Neurokinin A TFA did not significantly induce osteoclast activation or immune cell infiltration[7]. Sprague Dawley rats were administered Neurokinin A TFA (1.0–100μg) via intrathecal injection (5 minutes after a single injection). Neurokinin A TFA induced NK-1 receptor internalization in spinal cord dorsal horn superficial layer (lamina I) neurons by activating the neurokinin-1 receptor (NK-1R), with an EC₅₀ value of 210μM[8].
References:
[1] Gerard NP, Eddy RL Jr, Shows TB, et al. The human neurokinin A (substance K) receptor. Molecular cloning of the gene, chromosome localization, and isolation of cDNA from tracheal and gastric tissues. J Biol Chem. 1990 Nov 25;265(33):20455-62.
[2] Munekata E. Neurokinin A and B. Comp Biochem Physiol C Comp Pharmacol Toxicol. 1991;98(1):171-9.
[3] Regoli D, Rhaleb NE, Dion S, et al. Neurokinin A. A pharmacological study. Pharmacol Res. 1990 Jan-Feb;22(1):1-14.
[4] Wiesenfeld-Hallin Z, Xu XJ. The differential roles of substance P and neurokinin A in spinal cord hyperexcitability and neurogenic inflammation. Regul Pept. 1993 Jul 2;46(1-2):165-73.
[5] Ricardo M, Trzaska KA, Rameshwar P. Neurokinin-A inhibits cell cycle activators in K562 cells and activates Smad 4 through a non-canonical pathway: a novel method in neural-hematopoietic axis. J Neuroimmunol. 2008 Nov 15;204(1-2):85-91.
[6] Burbach GJ, Kim KH, Zivony AS, et al. The neurosensory tachykinins substance P and neurokinin A directly induce keratinocyte nerve growth factor. J Invest Dermatol. 2001 Nov;117(5):1075-82.
[7] Siddiqui YD, Nie X, Wang S, et al. Substance P aggravates ligature-induced periodontitis in mice. Front Immunol. 2023 Apr 14;14:1099017.
[8] Trafton JA, Abbadie C, Basbaum AI. Differential contribution of substance P and neurokinin A to spinal cord neurokinin-1 receptor signaling in the rat. J Neurosci. 2001 May 15;21(10):3656-64.
Neurokinin A TFA是一种内源性的速激肽家族神经肽，是神经激肽2受体（NK2R）的强效选择性激动剂[1-2]。Neurokinin A TFA可用于胃肠道功能紊乱、慢性内脏痛、哮喘和膀胱过度活动症等相关研究[3-4]。
在体外，Neurokinin A TFA(10nM)刺激K562造血祖细胞16小时，Neurokinin A TFA通过激活NK2受体抑制细胞周期激活因子Cdk2和Cyclin A的表达，上调p53和p21的表达，同时通过非经典途径激活Smad 4，诱导TGF-β1的翻译产生[5]。Neurokinin A TFA(0.1-100nM)处理人类角质形成PC-12细胞和鼠源PAM 212角质形成细胞3-48小时，Neurokinin A TFA通过NK1和NK2受体直接诱导神经生长因子mRNA表达和生物活性蛋白分泌，促进PC-12细胞神经突生长，并在小鼠皮肤中通过辣椒素诱导的神经肽释放上调表皮角质形成细胞的神经生长因子蛋白表达[6]。
在体内，Neurokinin A TFA（1μg/位点）注射到结扎诱导的牙周炎C57BL/6小模型的牙龈组织（每日两次，持续5天），Neurokinin A TFA未显著诱导破骨细胞活化或免疫细胞浸润[7]。Neurokinin A TFA（1.0-100μg）鞘内注射处理Sprague Dawley大鼠（单次注射后5分钟）。Neurokinin A TFA通过激活神经激肽-1受体（NK-1R）诱导脊髓背角浅层（I层）神经元中NK-1R内化，EC50值为210μM[8]。