SIG1459: A novel phytyl‐cysteine derived TLR2 modulator with in vitro and clinical anti‐acne activity

Cutibacterium (formerly Propionibacterium acnes) is a major contributor to the pathogenesis of acne. C. acnes initiates an innate immune response in keratinocytes via recognition and activation of toll‐like receptor‐2 (TLR2), a key step in comedogenesis. Tetramethyl‐hexadecenyl‐cysteine‐formylprolinate (SIG1459), a novel anti‐acne isoprenylcysteine (IPC) small molecule, is shown in this study to have direct antibacterial activity and inhibit TLR2 inflammatory signalling. In vitro antibacterial activity of SIG1459 against C. acnes was established demonstrating minimal inhibitory concentration (MIC = 8.5 μmol\L), minimal bactericidal concentration (MBC = 16.1 μmol\L) and minimal biofilm eradication concentration (MBEC = 12.5 μmol\L). To assess SIG1459's anti‐inflammatory activity, human keratinocytes were exposed to C. acnes and different TLR2 ligands (peptidoglycan, FSL‐1, Pam3CSK4) that induce pro‐inflammatory cytokine IL‐8 and IL‐1α production. Results demonstrate SIG1459 inhibits TLR2‐induced IL‐8 release from TLR2/TLR2 (IC₅₀ = 0.086 μmol\L), TLR2/6 (IC₅₀ = 0.209 μmol\L) and IL‐1α from TLR2/TLR2 (IC₅₀ = 0.050 μmol\L). To assess the safety and in vivo anti‐acne activity of SIG1459, a vehicle controlled clinical study was conducted applying 1% SIG1459 topically (n = 35 subjects) in a head‐to‐head comparison against 3% BPO (n = 15 subjects). Utilizing the Investigator Global Assessment scale for acne as primary endpoint, results demonstrate 1% SIG1459 significantly outperformed 3% BPO over 8 weeks, resulting in 79% improvement as compared to 56% for BPO. Additionally, 1% SIG1459 was well tolerated. Thus, SIG1459 and phytyl IPC compounds represent a novel anti‐acne technology that provides a safe dual modulating benefit by killing C. acnes and reducing the inflammation it triggers via TLR2 signalling.     

体外沉默异戊二烯基半胱氨酸羧基甲基转移酶基因对舌鳞状细胞癌迁移和侵袭的影响

目的 通过构建异戊二烯基半胱氨酸羧基甲基转移酶(ICMT)小分子干扰RNA(siRNA)沉默ICMT,研究沉默ICMT基因对舌鳞状细胞癌(TSCC)迁移和侵袭的影响.方法 通过脂质体转染的方法将siRNA转染至人TSCC CAL-27和SCC-4细胞(ICMT-siRNA组),并设阴性对照组(转染NC-siRNA)和空...     

N-acetyl-S-farnesyl-l-cysteine suppresses chemokine production by human dermal microvascular endothelial cells

Isoprenylcysteine (IPC) molecules modulate G-protein-coupled receptor signalling. The archetype of this class is N-acetyl-S-farnesyl-l-cysteine (AFC). Topical application of AFC locally inhibits skin inflammation and elicitation of contact hypersensitivity in vivo. However, the mechanism of these anti-inflammatory effects is not well understood. Dermal microvascular endothelial cells (ECs) are involved in inflammation, in part, by secreting cytokines that recruit inflammatory cells. We have previously shown that the sympathetic nerve cotransmitter adenosine-5'-triphosphate (ATP) and adenosine-5'-O-(3-thio) triphosphate (ATPγS), an ATP analogue that is resistant to hydrolysis, increase secretion of the chemokines CXCL8 (interleukin-8), CCL2 (monocyte chemotactic protein-1) and CXCL1 (growth-regulated oncogene α) by dermal microvascular ECs. Production of these chemokines can also be induced by the exposure to the proinflammatory cytokine TNFα. We have now demonstrated that AFC dose-dependently inhibits ATP-, ATPγS- and TNFα-induced production of CXCL1, CXCL8 and CCL2 by a human dermal microvascular EC line (HMEC-1) in vitro under conditions that do not affect cell viability. Inhibition of ATPγS- or TNFα-stimulated release of these chemokines was associated with reduced mRNA levels. N-acetyl-S-geranyl-l-cysteine, an IPC analogue that is inactive in inhibiting G-protein-coupled signalling, had greatly reduced ability to suppress stimulated chemokine production. AFC may exert its anti-inflammatory effects through the inhibition of chemokine production by stimulated ECs.     

体外沉默异戊二烯基半胱氨酸羧基甲基转移酶对人舌鳞状细胞癌细胞增殖和凋亡的影响

目的 通过小干扰RNA(siRNA)干扰技术体外沉默异戊二烯基半胱氨酸羧基甲基转移酶(Icmt)基因,探讨体外沉默Icmt对舌鳞状细胞癌(TSCC)细胞增殖和凋亡能力的影响.方法 针对人Icmt基因序列设计并构建3条siRNA,经脂质体瞬时转染技术转染抑制TSCC细胞系CAL-27和SCC-4细胞Icmt表达,同时设置...     

Akt/mammalian target of rapamycin signaling pathway regulates neurite outgrowth in cerebellar granule neurons stimulated by methylcobalamin

Methylcobalamin (MeCbl), a vitamin B12 analog, promotes neurite outgrowth by activating Akt in neurons. However, Akt is involved in many cellular functions, and the downstream signal of Akt that promotes neurite outgrowth in neurons in the presence of MeCbl remains obscure. Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase that regulates multiple cellular functions including neurite outgrowth. mTOR is regarded as important for the regeneration of injured nerves. In this study, we examined the relationship between MeCbl and mTOR activity and found that MeCbl increases mTOR activity via the activation of Akt and promotes neurite outgrowth in cerebellar granule neurons via the activation of mTOR.