Lysophosphatidic acid regulates adhesion molecules and enhances migration of human oral keratinocytes

Lysophospholipase D activity on oral mucosa cells in whole mixed human saliva involves in production of bioactive lysophosphatidic acid from lysophosphatidylcholine

We reported that lysophosphatidic acid (LPA) is present at 0.8 μM in mixed human saliva (MS). In this study, we examined the distribution, origin, and enzymatic generation pathways of LPA in MS. LPA was distributed in the medium and cell pellet fraction; a true level of soluble LPA in MS was about 150 nM. The soluble LPA was assumed to be generated by ecto-type lysophospholipase D on exfoliated cells in MS from LPC that originated mainly from the major salivary gland saliva. Our results with the albumin-back extraction procedures suggest that a significant pool of LPA is kept in the outer layer of the plasma membranes of detached oral mucosal cells. Such pool of LPA may contribute to wound healing in upper digestive organs including oral cavity. We obtained evidence that the choline-producing activity in MS was mainly due to Ca2+-activated lysophospholipase D activity of glycerophosphodiesterase 7.

Deregulated expression of the 14q32 miRNA cluster in clear cell renal cancer cells

Clear cell renal cell carcinomas (ccRCC) are characterized by arm-wide chromosomal alterations. Loss at 14q is associated with disease aggressiveness in ccRCC, which responds poorly to chemotherapeutics. The 14q locus contains one of the largest miRNA clusters in the human genome; however, little is known about the contribution of these miRNAs to ccRCC pathogenesis. In this regard, we investigated the expression pattern of selected miRNAs at the 14q32 locus in TCGA kidney tumors and in ccRCC cell lines. We demonstrated that the miRNA cluster is downregulated in ccRCC (and cell lines) as well as in papillary kidney tumors relative to normal kidney tissues (and primary renal proximal tubule epithelial (RPTEC) cells). We demonstrated that agents modulating expression of DNMT1 (e.g., 5-Aza-deoxycytidine) could modulate 14q32 miRNA expression in ccRCC cell lines. Lysophosphatidic acid (LPA, a lysophospholipid mediator elevated in ccRCC) not only increased labile iron content but also modulated expression of a 14q32 miRNA. Through an overexpression approach targeting a subset of 14q32 miRNAs (specifically at subcluster A: miR-431-5p, miR-432-5p, miR-127-3p, and miR-433-3p) in 769-P cells, we uncovered changes in cellular viability and claudin-1, a tight junction marker. A global proteomic approach was implemented using these miRNA overexpressing cell lines which uncovered ATXN2 as a highly downregulated target. Collectively, these findings support a contribution of miRNAs at 14q32 in ccRCC pathogenesis.

Norway Spruce Balm: Phytochemical Composition and Ability to Enhance Re-epithelialization In Vitro

The balm of the Norway spruce (Picea abies) is a well-known traditional herbal medicine used to cure wounds. Even though clinical trials have confirmed its empirical use, the active constituents, their mode of action, and the exact composition of this natural product are still unknown. In this study, the balm was subjected to fractionated extraction and further purified employing flash chromatography, HPLC-PDA-ELSD, preparative and analytical TLC. Hydroxycinnamic acids ( 1: - 3: ), the lignan pinoresinol ( 4: ), four hydroxylated derivatives of dehydroabietic acid (DHAA) ( 5:  -  8: ), and dehydroabietic acid ( 9: ) were isolated. Their structures were elucidated by LC-MS, 1D- and 2D-NMR. Four extracts, two commercially available resin acids-pimaric acid ( 10: ) and isopimaric acid ( 11: )-and the isolated compounds were tested for increased re-epithelialization of cell-free areas in a human adult low calcium high temperature keratinocytes monolayer. Lysophosphatidic acid (10 µM) served as positive control and ranged between 100% and 150% rise in cell-covered area related to the vehicle control. Two extracts containing carboxylic acids and non-acidic apolar constituents, respectively, boosted wound closure by 47% and 36% at 10 and 3 µg/mL, respectively. Pinoresinol, DHAA, three of its hydroxylated derivatives, and pimaric and isopimaric acid as well as defined combinations of the hydroxylated DHAA derivatives led to a significantly enhanced wound closure by up to 90% at concentrations between 1 and 10 µM. Overall, lignans and diterpene resin acids, main constituents of Norway spruce balm, are able to increase migration or proliferation of keratinocytes in vitro. The presented data link the phytochemistry of this natural wound healing agent with boosted re-epithelialization.

A low level of lysophosphatidic acid in human gingival crevicular fluid from patients with periodontitis due to high soluble lysophospholipase activity: Its potential protective role on alveolar bone loss by periodontitis

We previously detected a submicromolar concentration of lysophosphatidic acid (LPA) in human saliva. Here, we compare LPA concentrations in human gingival crevicular fluid (GCF) from patients with periodontitis and healthy controls, and examine how the local LPA levels are regulated enzymatically. The concentrations of LPA and its precursor lysophospholipids in GCF was measured by liquid chromatography-tandem mass spectrometry. The LPA-producing and LPA-degrading enzymatic activities were measured by quantifying the liberated choline and free fatty acid, respectively. The concentration of LPA in GCF of periodontitis patients was lower than that of healthy controls, due to higher soluble lysophospholipase activity toward LPA. LPA was found to prevent survival of Sa3, a human gingival epithelium-derived tumor cell line, activate Sa3 through Ca²⁺ mobilization, and release interleukin 6 from Sa3 in vitro. Furthermore, local injection of LPA into the gingiva attenuated ligature-induced experimental alveolar bone loss induced by oral bacteria inoculation in a rat model of periodontitis in vivo. A high concentration of LPA in human GCF is necessary to maintain normal gingival epithelial integrity and function, protecting the progression of periodontitis.