Sphingosine 1-phosphate (S1P) is a signaling lipid molecule involved in various cellular processes. It is important to develop a quantitative method for S1P to determine endogenous levels and to investigate its functions. Especially since S1P is a tiny lipid component of most biological samples, highly sensitive analysis by LC-MS/MS is required. The main challenge in S1P analysis by chromatography is peak broadening due to the presence of a polar phosphate and zwitterion formation in S1P. In this study, we used hydrogen fluoride (HF) to efficiently remove a phosphate and then analyzed the surrogate, sphingosine, as a sharp peak by LC-ESI-MS/MS. We optimized the dephosphorylation reaction in terms of reaction time, temperature, and HF concentration. Multiple reaction monitoring (MRM) for dephosphorylated form of S1P and C17-S1P as internal standard at m/z transition 300.4>282.4 (quantification ion), 300.4>262.4 (qualification ion), 286.3>268.2 (internal standard). This method was validated by essential parameters such as specificity, linearity, range, LOQ, LOD, accuracy, precision, and repeatability. To confirm this new method, we quantified S1P levels in various serum products (100.02 ~ 284.38 nM). To apply the method in vivo, we analyzed S1P in plasma and kidney tissues obtained from a chronic kidney disease (CKD) mouse model. S1P levels were increased only in CKD kidney tissue but not in plasma. In conclusion, by applying the dephosphorylation step with HF, we established a new sensitive LC-MS/MS quantitative method for S1P that can be applied to biological samples.

Breath volatile organic compound analysis is a non-invasive tool for assessing health status; the compositional profile of these compounds in the breath of patients with chronic kidney disease is believed to change with decreasing renal function. We aimed to identify breath volatile organic compounds for recognizing patients with chronic kidney disease. Using thermal desorption-gas chromatography-mass spectrometry, untargeted analysis of breath markers was performed using breath samples of healthy controls (n=18) versus non-dialysis (n=21) and hemodialysis (n=12) patients with chronic kidney disease in this cross-sectional study. A total of 303 volatile organic compounds alongside 12 clinical variables were used to determine the breath volatile organic compound profile. Metabolomic analysis revealed that age, systolic blood pressure, and fifty-eight breath volatile organic compounds differed significantly between the chronic kidney disease group (non-dialysis + hemodialysis) and healthy controls. Thirty-six volatile organic compounds and two clinical variables that showed significant associations with chronic kidney disease in the univariate analysis were further analyzed. Different spectras of breath volatile organic compounds between the control and chronic kidney disease groups were obtained. Multivariate model incorporating age, 2-methyl-pentane, and cyclohexanone showed high performance (accuracy, 86%) in identifying patients with chronic kidney disease, with odds ratios (95% confidence interval) P-values of 0.18 (0.07-2.49) 0.013; 2.10 (0.94-2.24) 0.025; and 2.31 (0.88–2.64) 0.008, respectively. Hence, renal dysfunction-associated characteristic profiles of breath volatile organic substances can be used as non-invasive markers to screen for chronic kidney disease.

Sphingosine-1-phosphate (S1P) synthesized by sphingosine kinase (SPHK) is a signaling molecule, involved in cell proliferation, growth, differentiation, and survival. Indeed, a sharp increase of S1P was linked to the pathological outcome with inflammation, cancer metastasis or angiogenesis etc. In this regard, the SPHK/S1P axis regulation has been a specific issue in anticancer strategy to turn accumulated sphingosine (SPN) into cytotoxic ceramides (Cers). For these purposes, there have been numerous chemicals synthesized for SPHK inhibition. In this study, we investigated the comparative efficiency of dansylated PF-543 (DPF-543) on the Cers synthesis along with PF-543. DPF-543 deserved attention in strong cytotoxicity, due to the cytotoxic Cers accumulation by ceramide synthase (CerSs). DPF-543 exhibited dual actions on Cers synthesis by enhance the serine palmitoyltransferase (SPT) activity, and by inhibiting SPHKs which eventually induced an unusual environment of the high amount of 3-ketosphinganine and sphinganine (SPA). SPA in turn was consumed to synthesize Cers via de novo pathway. Interestingly, PF-543 increased only the SPN level, but not for SPA. In addition, DPF-543 mildly activates acid sphingomyelinase (aSMase) that contributes a partial increase on Cers. Collectively, a dansyl-modified DPF-543 relatively en-hanced Cers accumulation via de novo pathway which was not observed in PF-543. Our results demonstrated that the structural modification on SPHK inhibitors is still an attractive anticancer strategy by regulating sphingolipid metabolism.

Hair loss attributed to excessive stress from work and lifestyle changes has become a growing concern, particularly among young individuals. However, currently used drugs such as minoxidil and finasteride impose a plethora of side effects. Therefore, natural substances as alternatives have garnered research interest. A recent study showed the efficacy of Malva verticillata seed extracts in alleviating hair loss via upregulation of the Wnt/β-catenin signaling pathway. In this study, the efficacy of M. verticillata seed extracts on alleviation of hair loss was further investigated. Further fractionation and purification of the seed extracts using silica gel column chromatography and preparative high-performance liquid chromatography helped identify linoleic acid (LA) and oleic acid as the major bioactive components. LA insufficiency is reported to cause hair loss. However, its mechanism of action is not clearly known. Here, we explored the efficacy of LA treatment on preventing hair loss and its underlying mechanism of action. We found that LA treatment activated Wnt/β-catenin signaling and induced dermal papilla cell (DPC) proliferation in cell proliferation assays. Moreover, it increased the expression of cell cycle proteins such as cyclin D1 and cyclin-dependent kinase 2. LA treatment also increased the expression of vascular endothelial growth factor, insulin-like growth factor-1, hepatocyte growth factor, and keratinocyte growth factor in a concentration-dependent manner and significantly inhibited that of DKK-1, induced by dihydrotestosterone. These findings suggest that LA treatment induces hair growth by increasing DPC proliferation and alleviates androgenic alopecia by activating Wnt/β-catenin signaling in DPCs.

Hair loss attributed to excessive stress from work and lifestyle changes has become a growing concern, particularly among young individuals. However, currently used drugs such as minoxidil and finasteride impose a plethora of side effects. Therefore, natural substances as alternatives have garnered research interest. A recent study showed the efficacy of Malva verticillata seed extracts in alleviating hair loss via upregulation of the Wnt/β-catenin signaling pathway. In this study, the efficacy of M. verticillata seed extracts on alleviation of hair loss was further investigated. Further fractionation and purification of the seed extracts using silica gel column chromatography and preparative high-performance liquid chromatography helped identify linoleic acid (LA) and oleic acid as the major bioactive components. LA insufficiency is reported to cause hair loss. However, its mechanism of action is not clearly known. Here, we explored the efficacy of LA treatment on preventing hair loss and its underlying mechanism of action. We found that LA treatment activated Wnt/β-catenin signaling and induced dermal papilla cell (DPC) proliferation in cell proliferation assays. Moreover, it increased the expression of cell cycle proteins such as cyclin D1 and cyclin-dependent kinase 2. LA treatment also increased the expression of vascular endothelial growth factor, insulin-like growth factor-1, hepatocyte growth factor, and keratinocyte growth factor in a concentration-dependent manner and significantly inhibited that of DKK-1, induced by dihydrotestosterone. These findings suggest that LA treatment induces hair growth by increasing DPC proliferation and alleviates androgenic alopecia by activating Wnt/β-catenin signaling in DPCs.