As prediction of rapidly aging society, bone health is considered increasingly important and received more attention than ever. Bone health is regulated by balancing between bone resorptive osteoclasts and bone formative osteoblasts. Disruption of balance between bone-resorbing osteoclasts and bone-forming osteoblasts results in bone disease. Natural products have recently received much attention as an alternative tool for the development of novel therapeutic strategy. Baicalein is reported it has anti-cancer, anti-inflammatory and antioxidant effects. Baicalein also has been known that it has both promotive effect on MC3T3-E1 cell line and inhibitory effect on RAW 264.7 cell line. However, the inhibitory mechanism of baicalein using bone marrow derived macrophages (BMMs) on osteoclast differentiation remains not clear. In this study, the suppressive mechanism by baicalein on osteoblast differentiation was evaluated. Bicalein inhibited receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclast differentiation in BMMs in a dose dependent manner without any toxicity. Baicalein suppressed phosphorylation of protein kinaseB (Akt), c-Jun N-terminal kinases (JNK) and phosphoinositide-specific phospholipaseCgamma2 (PLCgamma2). Furthermore, Baicalein suppressed the induction of RANKL-induced c-Fos and Nuclear factor of activated T cell c1 (NFATc1), essential genes on osteoclastogenesis. In BMMs, Bicalein inhibited the mRNA expression of tartrate-resistant acid phosphatase (TRAP), osteoclast-associated receptor (OSCAR), cathepsinK, dendritic cell-specific transmembrane protein (DC-STAMP). Moreover, baicalein promoted differentiation of osteoblast on bone marrow stromal cells (BMSCs). Taken together, these results suggest that baicalein has a potential for treating bone lytic diseases, such as osteoporosis, periodontitis, and rheumatoid arthritis.
Acid Phosphatase ; Aging ; Antioxidants ; Arthritis, Rheumatoid ; Biological Products ; Bone Diseases ; Bone Marrow* ; Cell Line ; Genes, Essential ; Macrophages* ; Mesenchymal Stromal Cells ; Osteoblasts ; Osteoclasts* ; Osteoporosis ; Periodontitis ; Phospholipase C gamma ; Phosphorylation ; Phosphotransferases ; RANK Ligand ; RNA, Messenger

OBJECTIVETo investigate the changes in the expression of phospholipase C-gamma1tyr783 (PLC-γ1tyr783) in the condylar cartilage of a young rat during functional mandibular protraction. This work also explores the function of PLC-γ1tyr783 in the rat mandibular condylar cartilage bone remodeling, which could provide experimental evidence for clinical bone ortho- pedic work.

METHODSA total of 60 four-week-old male Sprague-Dawley (SD) rats were used in this study. The rats were divided equally and randomly into experimental group and control group. The functional appliances that were fitted to the upper incisors of the animals in the experimental group were worn 24 h a day after the rats were fed for 7 d with homemade pellet feed. The animals in the experimental group, along with their matched controls, were sacrificed after 1, 3, 7, 14, 21, and 28 d. The bilateral condylar was fixed, decalcified, dehyded, and then conventional paraffin embedded. Immunohisto- chemistry of PLC-γ1tyr783 was applied to observe its express distribution and variation.

RESULTSThe expression of PLC-&gamma;1tyr783 decreased gradually in the control group, which showed age-related changes (P > 0.05). On the 14th day, PLC-&gamma;1tyr783 expres- sion in the experimental group was significantly higher than that in the control group. PLC-&gamma;1tyr783 expression began to appear statistically and significantly different between the two groups (P < 0.01).

CONCLUSIONPLC-&gamma;1tyr783 is involved in the bone remodeling process of the rat condylar cartilage after functional mandibular-protraction.

Animals ; Bone Remodeling ; Cartilage ; Male ; Mandibular Condyle ; Phospholipase C gamma ; Phosphoric Diester Hydrolases ; Rats ; Rats, Sprague-Dawley

In women with preeclampsia (PE), endothelial cell (EC) dysfunction can lead to altered secretion of paracrine factors that induce peripheral vasoconstriction and proteinuria. This study examined the hypothesis that PE sera may directly or indirectly, through human umbilical vein ECs (HUVECs), stimulate phospholipase C-gamma1-1,4,5-trisphosphate (PLC-gamma1-IP3) signaling, thereby increasing protein kinase C-alpha (PKC-alpha) activity, collagen I expression and intracellular Ca2+ concentrations ([Ca2+]i) in human umbilical artery smooth muscle cells (HUASMCs). HUASMCs and HUVECs were cocultured with normal or PE sera before PLC-gamma1 silencing. Increased PLC-gamma1 and IP3 receptor (IP3R) phosphorylation was observed in cocultured HUASMCs stimulated with PE sera (P<0.05). In addition, PE serum significantly increased HUASMC viability and reduced their apoptosis (P<0.05); these effects were abrogated with PLC-gamma1 silencing. Compared with normal sera, PE sera increased [Ca2+]i in cocultured HUASMCs (P<0.05), which was inhibited by PLC-gamma1 and IP3R silencing. Finally, PE sera-induced PKC-alpha activity and collagen I expression was inhibited by PLC-gamma1 small interfering RNA (siRNA) (P<0.05). These results suggest that vasoactive substances in the PE serum may induce deposition in the extracellular matrix through the activation of PLC-gamma1, which may in turn result in thickening and hardening of the placental vascular wall, placental blood supply shortage, fetal hypoxia-ischemia and intrauterine growth retardation or intrauterine fetal death. PE sera increased [Ca2+]i and induced PKC-alpha activation and collagen I expression in cocultured HUASMCs via the PLC-gamma1 pathway.
Adult ; Apoptosis ; Calcium/*metabolism ; Cell Line ; Cell Survival ; Cells, Cultured ; Coculture Techniques ; Collagen Type I/analysis/*metabolism ; Female ; Human Umbilical Vein Endothelial Cells ; Humans ; Muscle, Smooth, Vascular/*cytology/metabolism ; Phospholipase C gamma/genetics/*metabolism ; Pre-Eclampsia/*blood/*metabolism/pathology ; Pregnancy ; Protein Kinase C-alpha/metabolism ; RNA Interference ; *Signal Transduction ; Young Adult

OBJECTIVE: To explore the expression of phospholipase Cgamma-2 (PLCgamma-2), lipoxygenase-12 (12-LOX) and arachidonic acid (AA) in laryngeal squamous cell carcinoma and to study the the relationship between lipid metabolism and laryngeal squamous cell carcinoma. METHOD: In 30 cases of carcinoma tissue and peritumoral laryngeal mucosa tissues (confirmed to be normal laryngeal tissues by pathology), immunohistochemical method (Streptavidin-peroxidase method, SP method) was used for the detection of expression of PLCgamma-2 and 12-LOX, and gas chromatography/mass spectrometry (GC/MS) for the content of the arachidonic acid in carcinoma tissue and peritumoral normal laryngeal mucosa tissues. RESULT: The positive rates of PLCgamma-2 and 12-LOX in carcinoma tissue were higher than in peritumoral normal laryngeal mucosa tissues with statistically significance differences (P < 0.05). The content of arachidonic acid was lower in carcinoma tissue than in peritumoral normal laryngeal mucosa tissues with statistically significance difference (P < 0.05). The positive expressions of PLCgamma-2 and 12-LOX were closely correlated to tnm stage, histological differentiation and lymph node metastasis (P < 0.05). The content of arachidonic acid had no significant correlations with tnm stage, histological differentiation and lymph node metastasis (P > 0.05). Both the expression of PLCgamma-2 and 12-LOX and the content of arachidonic acid had no statistically significant correlation with age (P > 0.05). CONCLUSION PLCgamma-2, AA and 12-LOX play important roles in laryngeal squamous cell carcinoma. It may be meaningful to the treatment of laryngeal carcinoma by suppressing this passway.
Aged ; Arachidonate 12-Lipoxygenase ; metabolism ; Arachidonic Acid ; metabolism ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Head and Neck Neoplasms ; metabolism ; pathology ; Humans ; Laryngeal Neoplasms ; metabolism ; pathology ; Male ; Middle Aged ; Neoplasm Staging ; Phospholipase C gamma ; metabolism ; Squamous Cell Carcinoma of Head and Neck

OBJECTIVETo study the effects of theanine on dopamine (DA), 5-hydroxy tryptamine (5-TH) and glutamate receptor 2 (GluR2) mRNA, phospholipase-&gamma;1 (PLC-&gamma;1) mRNA in cerebral ischemia-reperfusion injury rats and explore the mechanism of protective effects of theanine on the induced brain injury by ischemia-reperfusion in rats.

METHODSAccording to random number table, a total of 56 sprague-dawley rats in SPF grade about six-week old and 100 - 120 grams weighting were divided into five groups according to the body weight levels: model group (n = 12), sham-operation group (n = 8), low theanine group (10 mg/kg), middle theanine group (30 mg/kg) and high theanine group (90 mg/kg). There were 12 rats in each of the theanine group. The rats in model group and sham-operation groups were given distilled water, and the rats in theanine groups were given corresponding theanine solution intragastrically for fifteen days. Then the cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion (MCAO). The score of neurological behavior was evaluated at the 3rd and 24th hours after reperfusion. Rats were sacrificed at 24 hours after reperfusion, the concentrations of DA, 5-HT and theanine in rats brain following ischemia-reperfusion were determined. At the same time, we determined the levels of reactive oxygen species (ROS) and activities of catalase (CAT) in mitochondria of brain. The expressions of GluR2 mRNA and PLC-&gamma;1 mRNA in rat brain were examined by reverse transcription polymerase chain reaction (RT-PCR) technique.

RESULTSThe score of neurological behavior of rats in model group, theanine-low, middle, high dose groups at the 3rd hour was 6.000 ± 0.926, 4.100 ± 0.738, 3.444 ± 0.726 and 2.250 ± 0.886 respectively (F = 29.70, P < 0.01), and the score at the 24th hour in these groups was 6.625 ± 0.916, 5.000 ± 0.817, 3.667 ± 0.707 and 2.625 ± 0.916 respectively(F = 34.68, P < 0.01). The concentration of DA in model group, theanine-low, middle, high dose groups and sham-operation group was (10.26 ± 1.12), (12.48 ± 1.09), (14.55 ± 0.94), (15.97 ± 0.92) and (11.98 ± 0.63) µg/g respectively (F = 43.76, P < 0.01). The concentration of 5-HT in these groups was (1.091 ± 0.160), (0.818 ± 0.101), (0.571 ± 0.050), (0.453 ± 0.111) and (0.863 ± 0.063) µg/g respectively (F = 48.68, P < 0.01). The level of ROS was (3.072 ± 0.503), (1.331 ± 0.268), (1.295 ± 0.061), (0.804 ± 0.200) and (2.158 ± 0.218) U×min⁻¹×mg⁻¹ (F = 80.82, P < 0.01) respectively and the activities of CAT in these groups were (4.880 ± 1.121), (8.405 ± 1.356), (9.535 ± 2.511), (15.090 ± 4.054) and (21.260 ± 6.054) U/g respectively (F = 28.58, P < 0.01). The expressions of GluR2 mRNA were 0.842 ± 0.020, 1.063 ± 0.100, 1.170 ± 0.152, 1.254 ± 0.131 and 1.012 ± 0.056 respectively (F = 9.23, P < 0.01). The expressions of PLC-&gamma;1 mRNA in these groups were 0.737 ± 0.090, 0.887 ± 0.045, 0.963 ± 0.025, 0.991 ± 0.049 and 0.867 ± 0.079 respectively(F = 10.24, P < 0.01).

CONCLUSIONTheanine has a protective effect on the induced brain injury by ischemia-reperfusion in rats, which might be associated with its interaction with monoamine neurotransmitters and up-regulating the expressions of GluR2 mRNA and PLC-&gamma;1 mRNA.

Animals ; Biogenic Monoamines ; metabolism ; Brain ; drug effects ; metabolism ; Brain Ischemia ; genetics ; metabolism ; Glutamates ; pharmacology ; Male ; Neurotransmitter Agents ; pharmacology ; Phospholipase C gamma ; genetics ; metabolism ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptors, AMPA ; genetics ; metabolism ; Reperfusion Injury ; genetics ; metabolism

Phosphatidylinositol phosphates (PtdInsPs) are ubiquitous membrane phospholipids that play diverse roles in cell growth and differentiation. To clarify the regulation mechanism acting on neurofilament light chain (NF-L) self assembly, we examined the effects of various PtdInsPs on this process. We found that PtdInsPs, including PI(4,5)P2, directly bind to the positively charged Arg54 of murine NF-L, and this binding promotes NF-L self assembly in vitro. Mutant NF-L (R53A/R54A) proteins lacking binding affinity to PtdInsPs did not have the same effect, but the mutant NF-L proteins showed greater self assembly than the wild-type in the absence of any PtdInsP. These results collectively suggest that Arg54 plays a pivotal role in NF-L self assembly by binding with PtdInsPs.
Animals ; Fluorescent Antibody Technique ; Mice ; Mutation/genetics ; Neurofilament Proteins/genetics/*metabolism ; Phosphatidylinositol Phosphates/*metabolism ; Phospholipase C gamma/metabolism ; *Protein Multimerization

Regulation of B cell receptor (BCR)-induced Ca2+ signaling by CD40 co-stimulation was compared in long-term BCR-stimulated immature (WEHI-231) and mature (Bal-17) B cells. In response to long-term pre-stimulation of immature WEHI-231 cells to alpha-IgM antibody (0.5~48 hr), the initial transient decrease in BCR-induced [Ca2+]i was followed by spontaneous recovery to control level within 24 hr. The recovery of Ca2+ signaling in WEHI-231 cells was not due to restoration of internalized receptor but instead to an increase in the levels of PLCgamma2 and IP3R-3. CD40 co-stimulation of WEHI-231 cells prevented BCR-induced cell cycle arrest and apoptosis, and it strongly inhibited the recovery of BCR-induced Ca2+ signaling. CD40 co-stimulation also enhanced BCR internalization and reduced expression of PLCgamma2 and IP3R-3. Pre-treatment of WEHI-231 cells with the antioxidant N-acetyl-L-cysteine (NAC) strongly inhibited CD40-mediated prevention of the recovery of Ca2+ signaling. In contrast to immature WEHI-231 cells, identical long-term alpha-IgM pre-stimulation of mature Bal-17 cells abolished the increase in BCR-induced [Ca2+]i, regardless of CD40 co-stimulation. These results suggest that CD40-mediated signaling prevents antigen-induced cell cycle arrest and apoptosis of immature B cells through inhibition of sustained BCR-induced Ca2+ signaling.
Acetylcysteine ; Apoptosis ; B-Lymphocytes ; Cell Cycle Checkpoints ; Phospholipase C gamma ; Precursor Cells, B-Lymphoid ; Reactive Oxygen Species

Growth factor stimulation induces Y783 phosphorylation of phosphoinositide-specific PLC-gamma1, and the subsequent activation of this enzyme in a cellular signaling cascade. Previously, we showed that a double point mutation, Y509A/F510A, of PLC-gamma1, abolished interactions with translational elongation factor 1-alpha. Here, we report that the Y509A/F510A mutant PLC-gamma1 displayed extremely high levels of Y783 phosphorylation and enhanced catalytic activity, compared to wild-type PLC-gamma1, upon treatment of COS7 cells with EGF. In quiescent COS7 cells, the Y509A/F510A mutant PLC-gamma1 exhibited a constitutive hydrolytic activity, whereas the wild-type counterpart displayed a basal level of activity. Upon treatment of COS7 cells with EGF, the Y783F mutation in Y509A/F510A PLC-gamma1 (Y509A/F510A/Y783F triple mutant) cells also led to an enhanced catalytic activity, whereas Y783F mutation alone displayed a basal level of activity. Our results collectively suggest that the Y509A/F510A mutant is more susceptible to receptor tyrosine kinase-induced Y783 phosphorylation than is wild-type PLC-gamma1, but no longer requires Y783 phosphorylation step for the Y509A/F510A mutant PLC-gamma1 activation in vivo.
Amino Acid Substitution/drug effects/*genetics ; Animals ; COS Cells ; Cercopithecus aethiops ; Enzyme Activation/drug effects ; Epidermal Growth Factor/*pharmacology ; Hydrolysis/drug effects ; Mutant Proteins/metabolism ; Phosphatidylinositols/*metabolism ; Phospholipase C gamma/*genetics/metabolism ; Phosphorylation/drug effects ; Phosphotyrosine/*metabolism ; Point Mutation/*genetics ; Rats

AIMThe mechanism of vascular endothelial growth factor165 (VEGF165) on intracellular free magnesium ([Mg2+]i) in human umbilical vein endothelial cells (HUVECs) was investigated.

METHODS[Mg2+]i in HUVECs loaded with fluorescent magnesium indicator mag-fura-2 were quantitatively detected the use of intracellular cation measurement system.

RESULTSVEGF165 significantly increased [Mg2+]i in the extracellular Mg2+ and this effect could be blocked by pretreatment with tyrosine kinase inhibitors (tyrphostin A23 and genistein), phosphatidylinositol 3-kinase (PI3K) inhibitors (wortmannin and LY294002) and phospholipase Cgamma (PLCgamma) inhibitor (U73122). In contrast, phospholipase Cgamma (PLCgamma) inhibitor analog (U73343), mitogen-activated protein kinase inhibitors (SB202190 and PD98059) had no effect on the VEGF165-induced [Mg2+]i increase.

CONCLUSIONThe increase of [Mg2+]i by VEGF165 originates from intracellular Mg2+ pool through tyrosine kinase/ PI3K/PLCgamma-dependent signaling pathways.

Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; cytology ; metabolism ; physiology ; Humans ; Magnesium ; metabolism ; Neovascularization, Physiologic ; drug effects ; Phosphatidylinositol 3-Kinases ; metabolism ; Phospholipase C gamma ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Signal Transduction ; Vascular Endothelial Growth Factor A ; physiology

RAS guanyl-releasing protein 3 (RasGRP3), a member of the Ras subfamily of GTPases, functions as a guanosine triphosphate (GTP)/guanosine diphosphate (GDP)-regulated switch that cycles between inactive GDP- and active GTP-bound states during signal transduction. Various growth factors enhance hepatocellular carcinoma (HCC) proliferation via activation of the Ras/Raf-1/ extracellular signal-regulated kinase (ERK) pathway, which depends on RasGRP3 activation. We investigated the relationship between polymorphisms in RasGRP3 and progression of hepatitis B virus (HBV)-infected HCC in a Korean population. Nineteen RasGRP3 SNPs were genotyped in 206 patients with chronic liver disease (CLD) and 86 patients with HCC. Our results revealed that the T allele of the rs7597095 SNP and the C allele of the rs7592762 SNP increased susceptibility to HCC (OR=1.55, p=0.04 and OR=1.81~2.61, p=0.01~0.03, respectively). Moreover, patients who possessed the haplotype (ht) 1 ( A-T-C-G) or diplotype (dt) 1 ( ht1/ht1) variations had increased susceptibility to HCC (OR=1.79 ~2.78, p=0.01~0.03). In addition, we identified an association between haplotype1 (ht1) and the age of HCC onset; the age of HCC onset are earlier in ht1 +/+ than ht1 +/- or ht1 -/- (HR=0.42~0.66, p=0.006~0.015). Thus, our data suggest that RasGRP3 SNPs are significantly associated with an increased risk of developing HCC.
Alleles ; Carcinoma, Hepatocellular ; GTP Phosphohydrolases ; Guanosine Triphosphate ; Haplotypes ; Hepatitis B virus ; Humans ; Intercellular Signaling Peptides and Proteins ; Liver ; Liver Diseases ; Phospholipase C gamma ; Phosphotransferases ; Polymorphism, Single Nucleotide ; Polyphosphates ; Signal Transduction