Ginseng gintonin is an exogenous ligand of lysophosphatidic acid (LPA) receptors. Accumulating evidence shows LPA helps in rapid recovery of corneal damage. The aim of this study was to evaluate the therapeutic efficacy of gintonin in a rabbit model of corneal damage. We investigated the signal transduction pathway of gintonin in human corneal epithelium (HCE) cells to elucidate the underlying molecular mechanism. We next evaluated the therapeutic effects of gintonin, using a rabbit model of corneal damage, by undertaking histochemical analysis. Treatment of gintonin to HCE cells induced transient increases of [Ca²⁺](i) in concentration-dependent and reversible manners. Gintonin-mediated mobilization of [Ca²⁺](i) was attenuated by LPA1/3 receptor antagonist Ki16425, phospholipase C inhibitor U73122, inositol 1,4,5-triphosphate receptor antagonist 2-APB, and intracellular Ca²⁺ chelator BAPTA-AM. Gintonin facilitated in vitro wound healing in a concentration-dependent manner. When applied as an eye-drop to rabbits with corneal damage, gintonin rapidly promoted recovery. Histochemical analysis showed gintonin decreased corneal apoptosis and increased corneal cell proliferation. We demonstrated that LPA receptor activation by gintonin is linked to in vitro and in vivo therapeutic effects against corneal damage. Gintonin can be applied as a clinical agent for the rapid healing of corneal damage.
Apoptosis ; Cell Proliferation ; Corneal Injuries ; Epithelium, Corneal ; Humans ; In Vitro Techniques ; Inositol 1,4,5-Trisphosphate ; Mortuary Practice ; Panax ; Rabbits ; Receptors, Lysophosphatidic Acid ; Signal Transduction ; Therapeutic Uses ; Type C Phospholipases ; Wound Healing* ; Wounds and Injuries*

Transcriptional co-activator with a PDZ-binding motif (TAZ) is an important factor in lysophosphatidic acid (LPA)-induced promotion of migration and proliferation of human mesenchymal stem cells (MSCs). The expression of TAZ significantly increased at 6 h after LPA treatment, and TAZ knockdown inhibited the LPA-induced migration and proliferation of MSCs. In addition, embryonic fibroblasts from TAZ knockout mice exhibited the reduction in LPA-induced migration and proliferation. The LPA1 receptor inhibitor Ki16425 blocked LPA responses in MSCs. Although TAZ knockdown or knockout did not reduce LPA-induced phosphorylation of ERK and AKT, the MEK inhibitor U0126 or the ROCK inhibitor Y27632 blocked LPA-induced TAZ expression along with the reduction in the proliferation and migration of MSCs. Our data suggest that TAZ is an important mediator of LPA signaling in MSCs in the downstream of MEK and ROCK signaling.
Animals ; Fibroblasts ; Humans* ; Mesenchymal Stromal Cells* ; Mice ; Mice, Knockout ; Phosphorylation ; Receptors, Lysophosphatidic Acid

Transcriptional co-activator with a PDZ-binding motif (TAZ) is an important factor in lysophosphatidic acid (LPA)-induced promotion of migration and proliferation of human mesenchymal stem cells (MSCs). The expression of TAZ significantly increased at 6 h after LPA treatment, and TAZ knockdown inhibited the LPA-induced migration and proliferation of MSCs. In addition, embryonic fibroblasts from TAZ knockout mice exhibited the reduction in LPA-induced migration and proliferation. The LPA1 receptor inhibitor Ki16425 blocked LPA responses in MSCs. Although TAZ knockdown or knockout did not reduce LPA-induced phosphorylation of ERK and AKT, the MEK inhibitor U0126 or the ROCK inhibitor Y27632 blocked LPA-induced TAZ expression along with the reduction in the proliferation and migration of MSCs. Our data suggest that TAZ is an important mediator of LPA signaling in MSCs in the downstream of MEK and ROCK signaling.
Animals ; Fibroblasts ; Humans* ; Mesenchymal Stromal Cells* ; Mice ; Mice, Knockout ; Phosphorylation ; Receptors, Lysophosphatidic Acid

Initial discovery on sphingosine 1-phosphate (S1P) as an intracellular second messenger was faced unexpectedly with roles of S1P as a first messenger, which subsequently resulted in cloning of its G protein-coupled receptors, S1P₁₋₅. The molecular identification of S1P receptors opened up a new avenue for pathophysiological research on this lipid mediator. Cellular and molecular in vitro studies and in vivo studies on gene deficient mice have elucidated cellular signaling pathways and the pathophysiological meanings of S1P receptors. Another unexpected finding that fingolimod (FTY720) modulates S1P receptors accelerated drug discovery in this field. Fingolimod was approved as a first-in-class, orally active drug for relapsing multiple sclerosis in 2010, and its applications in other disease conditions are currently under clinical trials. In addition, more selective S1P receptor modulators with better pharmacokinetic profiles and fewer side effects are under development. Some of them are being clinically tested in the contexts of multiple sclerosis and other autoimmune and inflammatory disorders, such as, psoriasis, Crohn’s disease, ulcerative colitis, polymyositis, dermatomyositis, liver failure, renal failure, acute stroke, and transplant rejection. In this review, the authors discuss the state of the art regarding the status of drug discovery efforts targeting S1P receptors and place emphasis on potential clinical applications.
Acute Kidney Injury ; Animals ; Clone Cells ; Cloning, Organism ; Colitis, Ulcerative ; Dermatomyositis ; Drug Discovery* ; Fingolimod Hydrochloride ; Graft Rejection ; In Vitro Techniques ; Liver Failure ; Mice ; Multiple Sclerosis ; Polymyositis ; Psoriasis ; Receptors, Lysosphingolipid* ; Second Messenger Systems ; Sphingosine* ; Stroke

BACKGROUNDThe sphingosine 1-phosphate (S1P) receptors (S1PRs) are a group of G protein-coupled receptors expressed on the surface of lymphocytes. The interaction between S1P and S1PRs plays a significant role in the migration and distribution of lymphocytes.

OBJECTIVETo investigate the influence of S1PR5 defect on the lymphocytes distribution in mice.

METHODSThe distribution of different subsets of lymphocyte in the mice with S1PR5 defect was examined by flow cytometry.

RESULTSCompared with wild type mice, the number of NK cells in the peripheral blood (PB) and spleen (SP) from the mice with S1PR5 defect decreased very significantly 〔PB: 6.4±0.45% vs 2.2±0.47(P<0.01,n=3)；SP: 3.0±0.91% vs 0.68±0.14%(P<0.05,n=3)〕. However, the NK cell number in the bone marrow (BM) and lymphonodes (LN) of the mice with S1PR5 defect increased very significantly 〔BM: 0.97±0.20 % vs 2.6±0.35% (P<0.01, n=3); LN: 0.35±0.16% vs 1.7±0.15% (P<0.01, n=3)〕. The percentages of CD3(+) lymphocyte in peripheral blood, spleen and lymph node were not statistically significantly different between these 2 types of mice 〔PB: 17.3±7.9% vs 17.0±4.6% (P>0.05, n=3); SP: 33.0±6.0% vs 27.4±1.8% (P>0.05, n=3); LN: 42.3±10.7% vs 51.2±2.7% (P>0.05, n=3)〕.

CONCLUSIONS1PR5 defect can significantly influence the NK cell distribution.

Animals ; Bone Marrow ; Cell Count ; Flow Cytometry ; Lymphocytes ; Lysophospholipids ; Mice ; Receptors, Lysosphingolipid ; Sphingosine ; analogs & derivatives

OBJECTIVETo establish the S1PR5 gene knockout mouse model by using CRISPR/Cas9 gene editing technique so as to provide the tool for studying the regulating role of sphingosine-1-phosphate receptor 5 (S1PR5) in allogeneic hematopoietic stem cell transplantation.

METHODSSingle guide RNA (sgRNA) plasmids against the exon 3 of S1PR5 were designed and constructed. Then the sgRNA and hCas9 were transcribed by T7 RNA polymerase in vitro. Cas9 mRNA and sgRNA were mixed and microinjected into fertilized eggs of C57BL/6 mice. T7E1 digestion and gene sequencing were used to detect the mutations of S1PR5. Quantitative PCR (qPCR) and Western blot were used to detect the expression of S1PR5.

RESULTSFinally 2 kinds of F2 generation of homozygous S1PR5 deficent mice (S1PR5-170/-170 mice and S1PR5-215/-215 mice) were gained, and in these 2 model mice the S1PR5 did not express at mRNA and protein levels.

CONCLUSIONA mouse model with S1PR5 dificiency has been successfully established, which shall lay a foundation for future investigation of S1PR5.

Animals ; CRISPR-Cas Systems ; Gene Editing ; Gene Knockout Techniques ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Microinjections ; Mutation ; Plasmids ; RNA, Guide ; Receptors, Lysosphingolipid ; Zygote

OBJECTIVETo explore the effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) mobilization on S1P5 expression in T lymphocyte subsets of allo-HSCT donors.

METHODSThe peripheral blood was collected from 10 allo-hematopoietic stem cell transplantation (allo-HSCT) donors before and after mobilization with rhG-CSF for 4 days. The flow cytometry was used to detect S1P5 expression in T lymphocyte subsets.

RESULTSThere was no S1P5 expression on the surface of T-lymphocytes both before and after rhG-CSF mobilization. After fixation with permeabilization agent, S1P5 expression could be detected in lymphocytes after rhG-CSF mobilization, which indicates S1P5 may be located in cells. Compared with level before rhG-CSF mobilization, S1P5 expression was significantly increased in T lymphocyte subsets after rhG-CSF mobilization, CD3(+)T cells (57.92±2.32)% vs (7.94±1.47)%(P<0.05）, CD4(+)T cells (72.58±1.73)% vs （5.48±0.82）%(P<0.05）, CD8(+)T cells（51.79±3.57）% vs （6.46±1.01）%（P<0.05）,CD3-/CD56(+)NK cells（40.00±1.47）% vs（4.97±0.74）%（P<0.05）. The up-regulated level of S1P5 expression in CD4(+)T cells was most high(P<0.05).

CONCLUSIONS1P5 expression significantly increases in T lymphocyte subsets after rhG-CSF mobilization, and the up-regulated level of S1P5 expression in CD4(+)T cells is the most high.

Flow Cytometry ; Granulocyte Colony-Stimulating Factor ; Hematopoietic Stem Cell Transplantation ; Humans ; Receptors, Lysosphingolipid ; Recombinant Proteins ; T-Lymphocyte Subsets ; Transplantation, Homologous

OBJECTIVETo investigate the expressions of sphingosine-1-phosphate receptors 1-3 (S1P1- 3) in the corpus cavernosum of castrated male rats and its relationship with the NOS/NO/cGMP and RhoA/Rho kinase signaling pathways.

METHODSWe equally randomized 18 eight-week-old healthy male SD rats into a sham-operation control, a castration, and a testosterone replacement (TR) group and harvested the bilateral testes and epididymides from the rats in the latter two groups, followed by 4 weeks of subcutaneous injection of testosterone propionate at 3 mg per kilogram of the body weight per day for those in the TR group and that of plant oil for those in the control and castration groups. At the age of 12 weeks, we measured the serum testosterone (T) level and maximum intracavernous pressure/mean arterial pressure (ICPmax/MAP) of the animals and determined the expressions of SlP1-3, eNOS, P-eNOS, ROCK1, and ROCK2 in the corpus cavernosum by Western blot and immunohistochemistry.

RESULTSThe serum T level was significantly decreased in the rats of the castration group as compared with those of the control and TR groups ([0.41 ± 0.04] vs [16.01 ± 1.02] and [15.84 ± 1.32] nmol/L, P < 0.01), with no statistically significant difference between the latter two groups. The ICPmax/MAP at 0 V, 3 V, and 5 V electric stimulation was remarkably lower in the rats of the castration group (0.088 ± 0.014, 0.323 ± 0.014, and 0.432 ± 0.012) than in those of the control group (0.155 ± 0.011, 0.711 ± 0. 010, and 0.819 ± 0.024) and TR group (0.153 ± 0.012, 0.696 ± 0.017, and 0.763 ± 0.027) (P < 0.01), with no significant difference between the latter two groups. With GAPDH as internal control, the animals of the castration group showed markedly reduced expressions of S1P1 ([49.99 ± 3.39]%), eNOS ([46.82 ± 3.81]%) , and P-eNOS ([45.42 ± 4.35]%) in comparison with those in the control group ([72.57 ± 3.06], [89.76 ± 3.98], and [82.53 ± 8.92] and TR group ([71.77 ± 4.43], [87.19 ± 4.23], and [79.82 ± 7.38]%) (P < 0.01) , while the expressions of S1P2, S1P3, ROCK1, and ROCK2 were significantly upregulated in the castration group ([82.35 ± 4.13], [61.03 ± 5.14], [74.50 ± 4.02], and [69.83 ± 5.75]%) as compared with those in the control group ([41.67 ± 1.68], [31.66 ± 2.67], [35.69 ± 5.56], and [39.85 ± 7.17]%) and TR group ([42.80 ± 3.87], [32.25 ± 4.22], 38.06 ± 5.21], and [42.36 ± 4.44]%) (P < 0.01).

CONCLUSIONAndrogen deficiency induces significant reduction of ICPmax/ MAP in male rats, which is possibly associated with the decline of S1P1 in the corpus cavernosum, inhibition of the eNOS/NO/cGMP signaling pathway, increased expressions of S1P2 and S1P3, and activation of the RhoA/Rho kinase signaling pathway.

Animals ; Male ; Nitric Oxide Synthase Type III ; metabolism ; Orchiectomy ; Penis ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Lysosphingolipid ; metabolism ; Testosterone ; blood ; pharmacology ; rho-Associated Kinases ; metabolism

Lysophosphatidic acid (LPA) is a signaling lipid that binds to six known lysophosphatidic acid receptors (LPARs), named LPA1-LPA6. These receptors initiate signaling cascades relevant to development, maintenance, and healing processes throughout the body. The diversity and specificity of LPA signaling, especially in relation to cancer and autoimmune disorders, makes LPA receptor modulation an attractive target for drug development. Several LPAR-specific analogues and small molecules have been synthesized and are efficacious in attenuating pathology in disease models. To date, at least three compounds have passed phase I and phase II clinical trials for idiopathic pulmonary fibrosis and systemic sclerosis. This review focuses on the promising therapeutic directions emerging in LPA signaling toward ameliorating several diseases, including cancer, fibrosis, arthritis, hydrocephalus, and traumatic injury.
Arthritis ; Autoimmune Diseases ; Fibrosis ; Hydrocephalus ; Idiopathic Pulmonary Fibrosis ; Pathology ; Pharmacology ; Receptors, Lysophosphatidic Acid ; Scleroderma, Systemic ; Sensitivity and Specificity

BACKGROUNDOverexpression of G-protein coupled receptor 34 (GPR34) affects the progression and prognosis of human gastric adenocarcinoma, however, the role of GPR34 in gastric cancer development and progression has not been well-determined. The current study aimed to investigate the effect of GPR34 knockdown on the proliferation, migration, and apoptosis of HGC-27 gastric cancer cells and the underlying mechanisms.

METHODSThe expression of GPR34 in gastric cancer cell line HGC-27 was detected by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. HGC-27 cells were employed to construct the stable GPR34 knockdown cell model in this study. Real-time RT-PCR and Western blotting were applied to validate the effect of short hairpin RNA (ShRNA) on the expression of GPR34 in HGC-27 gastric cells. The proliferation, migration of these cells were examined by Cell Counting Kit-8 and transwell. We also measured expression profile of PI3K/PDK1/AKT and ERK using Western blotting.

RESULTSThe ShRNA directed against GPR34 effectively inhibited both endogenous mRNA and protein expression levels of GPR34, and significantly down-regulated the expression of PIK3CB (P < 0.01), PIK3CD (P < 0.01), PDK1 (P < 0.01), phosphorylation of PDK1 (P < 0.01), Akt (P < 0.01), and ERK (P < 0.01). Furthermore, GPR34 knockdown resulted in an obvious reduction in HGC-27 cancer cell proliferation and migration activity (P < 0.01).

CONCLUSIONSGPR34 knockdown impairs the proliferation and migration of HGC-27 gastric cancer cells in vitro and provides a potential implication for therapy of gastric cancer.

Apoptosis ; genetics ; physiology ; Blotting, Western ; Cell Line, Tumor ; Cell Proliferation ; genetics ; physiology ; Humans ; RNA, Small Interfering ; genetics ; Real-Time Polymerase Chain Reaction ; Receptors, Lysophospholipid ; genetics ; metabolism ; Stomach Neoplasms ; genetics ; metabolism