Objective To investigate the effect and mechanism of baicalin on blood lipid metabolism and immune function in rats with gestational diabetes mellitus (GDM). Methods Female rats fed with high-fat and high-sugar diet and male rats fed with ordinary diet were caged together to prepare pregnant rats, and the GDM rat model was established by intraperitoneal injection of streptozotocin (35 mg/kg). GDM rats were randomly divided into a model group, a fasudil (FA) (RhoA/RocK inhibitor) group (10 mg/kg), low-dose (100 mg/kg) and high-dose (200 mg/kg) baicalin groups, and a high-dose baicalin combined with LPA (RhoA/RocK activator) group (200 mg/kg baicalin+1 mg/kg LPA ), with 12 rats in each group. Another 12 pregnant rats fed with high-fat and high-sugar diet were selected as the control group. After 2 weeks of corresponding drug intervention in each group, the level of fasting blood glucose (FBG) was detected by blood glucose meter. The level of fasting insulin (FINS) in serum was detected by ELISA, and the insulin resistance index (HOMA-IR) was calculated. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) in serum, and the levels of immunomodulator tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and IL-10 in peripheral blood were detected by the kit. The histopathological changes of liver were observed by HE staining. The proportion of T lymphocyte subsets in peripheral blood was detected by flow cytometry. The mRNA and protein expressions of Ras homolog gene family member A (RhoA), Rho associated coiled-coil forming protein kinase 1 (ROCK1), and ROCK2 in liver tissue were detected by real-time quantitative PCR and Western blot. Results Compared with the control group, the levels of FBG, FINS, HOMA-IR, ALT, AST, TG, TC, and LDL-C in serum, the levels of TNF-α, IL-6, the percentage of CD8⁺T cell in peripheral blood, and the mRNA and protein expression of RhoA, ROCK1, and ROCK2 in liver tissue in the model group were higher; the level of HDL-C in serum, the percentage of IL-10 levels, CD3⁺T cells, CD4⁺T cell, and CD4⁺T/CD8⁺T ratio in peripheral blood were lower. Compared with the model group, the levels of FBG, FINS, HOMA-IR, ALT, AST, TG, TC, and LDL-C in serum, the levels of TNF-α, IL-6, the percentage of CD8⁺T cell in peripheral blood, and the mRNA and protein expression of RhoA, ROCK1, and ROCK2 in liver tissue in the the FA group and low-dose and high-dose baicalin groups were lower; the level of HDL-C in serum, IL-10 level, the percentage of CD3⁺T cells, CD4⁺T cell, and CD4⁺T/CD8⁺T ratio in peripheral blood were higher. LPA could obviously weaken the improvement effects of baicalin on blood lipid metabolism and immune function in GDM rats. Conclusion Baicalin may improve blood lipid metabolism and immune function in GDM rats by inhibiting the RhoA/ROCK pathway.
Animals ; Female ; Diabetes, Gestational/metabolism* ; Pregnancy ; rho-Associated Kinases/genetics* ; Flavonoids/pharmacology* ; Rats ; rhoA GTP-Binding Protein/genetics* ; Lipid Metabolism/drug effects* ; Male ; Signal Transduction/drug effects* ; Rats, Sprague-Dawley ; Blood Glucose/metabolism* ; Lipids/blood* ; Tumor Necrosis Factor-alpha/blood* ; rho GTP-Binding Proteins

Objective: The underlying mechanism of Ezrin in ovarian cancer (OVCA) is far from being understood. Therefore, this study aimed to assess the role of Ezrin in OVCA cells (SKOV3 and CaOV3) and investigate the associated molecular mechanisms. Methods: We performed Western blotting, reverse transcription-quantitative polymerase chain reaction, MTT, cell colony, cell wound healing, transwell migration and invasion, RhoA and Rac active pull down assays, and confocal immunofluorescence experiments to evaluate the functions and molecular mechanisms of Ezrin overexpression or knockdown in the proliferation and metastasis of OVCA cells. Results: The ectopic expression of Ezrin significantly increased cell proliferation, invasiveness, and epithelial-mesenchymal transition (EMT) in OVCA cells. By contrast, the knockdown of endogenous Ezrin prevented OVCA cell proliferation, invasiveness, and EMT. Lastly, we observed that Ezrin can positively regulate the active forms of RhoA rather than Rac-1 in OVCA cells, thereby promoting robust stress fiber formation. Conclusion Our results indicated that Ezrin regulates OVCA cell proliferation and invasiveness by modulating EMT and induces actin stress fiber formation by regulating Rho-GTPase activity, which provides novel insights into the treatment of the OVCA.
Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Cytoskeletal Proteins/metabolism* ; Epithelial-Mesenchymal Transition ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Neoplasm Invasiveness ; Ovarian Neoplasms/pathology* ; Stress Fibers/metabolism* ; rhoA GTP-Binding Protein/metabolism*

BACKGROUND: Microribose nucleic acids (miRNAs) are implicated in the progression of lung adenocarcinoma. MicroRNA-345-5p (miR-345-5p) is a recently identified anti-oncogene in some human cancers, but its functional role and possible molecular mechanism in lung adenocarcinoma remain unknown. This study aimed to identify the biological function and underlying mechanism of miR-345-5p in lung adenocarcinoma cells. METHODS: In this study, lung adenocarcinoma tissues and adjacent tissues were collected in the First Affiliated Hospital of Anhui Medical University between April 2016 and February 2017. The expression of miR-345-5p and ras homolog family member A (RhoA) in lung adenocarcinoma tissues and human lung adenocarcinoma cell lines (A549, H1650, PC-9, and H441) was detected by reverse transcription quantitative polymerase chain reaction analysis. Functional assays including colony formation, flow cytometry analysis, wound healing, and transwell assays were performed to assess the proliferation, apoptosis, migration, and invasion of lung adenocarcinoma cells. In addition, RNA pulldown and luciferase reporter assays were conducted to evaluate the relationship between miR-345-5p and RhoA. Difference between the two groups was analyzed with Student's t test, while that among multiple groups was analyzed with one-way analysis of variance. RESULTS: MiR-345-5p expression displayed lower level in lung adenocarcinoma tissues (0.241 ± 0.095 vs.1.000 ± 0.233, t = 19.247, P < 0.001) and cell lines (F = 56.992, P < 0.001) than control tissues and cells. Functional experiments demonstrated that upregulation of miR-345-5p inhibited the malignant phenotypes of lung adenocarcinoma cells via suppressing cell proliferation, migration, invasion, and facilitating cell apoptosis. Additionally, RhoA was verified to be the downstream target of miR-345-5p. Expression of RhoA was downregulated by overexpression of miR-345-5p in PC-9 (0.321 ± 0.047 vs. 1.000 ± 0.127, t = 8.536, P < 0.001) and H1650 (0.398 ± 0.054 vs. 1.000 ± 0.156, t = 4.429, P = 0.011) cells. Rescue assays revealed that overexpression of RhoA rescued the suppressive effects of miR-345-5p upregulation on proliferation, migration, and invasion of lung adenocarcinoma cells. Further, miR-345-5p was found to regulate the Rho/Rho-associated protein kinase (ROCK) signaling pathway by downregulation of RhoA in lung adenocarcinoma cells. CONCLUSIONS MiR-345-5p plays a tumor suppressor role in lung adenocarcinoma cells by downregulating RhoA to inactivate the Rho/ROCK pathway.
Adenocarcinoma of Lung/genetics* ; Cell Line, Tumor ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Gene Expression Regulation, Neoplastic ; Humans ; Lung Neoplasms/genetics* ; MicroRNAs/genetics* ; Up-Regulation/genetics* ; rho-Associated Kinases/genetics* ; rhoA GTP-Binding Protein/genetics*

OBJECTIVE: To elucidate the underlying mechanism of Panax notoginseng saponin (PNS) on gastric epithelial cell injury and barrier dysfunction induced by dual antiplatelet (DA). METHODS: Human gastric mucosal epithelial cell (GES-1) was cultured and divided into 4 groups: a control, a DA, a PNS+DA and a LY294002+PNS+DA group. GES-1 apoptosis was detected by flow cytometry, cell permeability were detected using Transwell, level of prostaglandins E2 (PGE2), 6-keto-prostaglandin F1α (6-keto-PGF1α) and vascular endothelial growth factor (VEGF) in supernatant were measured by enzyme linked immunosorbent assay (ELISA), expression of phosphatidylinositide 3-kinase (PI3K), phosphorylated-PI3K (p-PI3K), Akt, phosphorylated-Akt (p-Akt), cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), glycogen synthase kinase-3β (GSK-3β) and Ras homolog gene family member A (RhoA) were measured by Western-blot. RESULTS: DA induced apoptosis and hyper-permeability in GES-1, reduced supernatant level of PGE2, 6-keto-PGF1α and VEGF (P<0.05). Addition of PNS reduced the apoptosis of GES-1 caused by DA, restored the concentration of PGE2, 6-keto-PGF1α and VEGF (P<0.05). In addition, PNS attenuated the alteration of COX-1 and COX-2 expression induced by DA, up-regulated p-PI3K/p-Akt, down-regulated RhoA and GSK-3β. LY294002 mitigated the effects of PNS on cell apoptosis, cell permeability, VEGF concentration, and expression of RhoA and GSK-3β significantly. CONCLUSIONS PNS attenuates the suppression on COX/PG pathway from DA, alleviates DA-induced GES-1 apoptosis and barrier dysfunction through PI3K/Akt/ VEGF-GSK-3β-RhoA network pathway.
Cyclooxygenase 1 ; Epithelial Cells/metabolism* ; Glycogen Synthase Kinase 3 beta ; Humans ; Panax notoginseng ; Phosphatidylinositol 3-Kinases/metabolism* ; Platelet Aggregation Inhibitors ; Proto-Oncogene Proteins c-akt/metabolism* ; Saponins/pharmacology* ; Vascular Endothelial Growth Factor A ; rhoA GTP-Binding Protein

OBJECTIVE: To observe the effects of electroacupuncture (EA) at "Jiaji" (EX-B 2) points combined with nerve mobilization on protein and mRNA expression of RhoA in rabbits with sciatic nerve injury, and to provide theoretical basis for the treatment of peripheral nerve injury by EA at "Jiaji" (EX-B 2) points combined with nerve mobilization. METHODS: A total of 180 New Zealand rabbits were randomly divided into a normal control group, a model control group, a nerve mobilization group, an EA group, an EA plus nerve mobilization group, 36 rabbits in each group. Each group was further divided into a 1-week subgroup, 2-week subgroup and 4-week subgroup, 12 rabbits in each subgroup. The sciatic nerve injury model was made by clamping method. The rabbits in the normal control group did not receive any intervention. The rabbits in the model control group was normally fed after operation. The rabbits in the nerve mobilization group were treated with nerve mobilization; the manipulation lasted for 1 s and relaxed for 5 s, 10 times per day, 6 days per week. The rabbits in the EA group were treated with EA at "Jiaji" (EX-B 2) points (L-L), once a day, 30 min each time, 6 times per week. The rabbits in the EA plus nerve mobilization group were treated with EA at "Jiaji" (EX-B 2) points, followed by nerve mobilization. The function of sciatic nerve on the injured side was evaluated by toe tension reflex and modified Tarlov score; the tissues of corresponding segments of spinal cord L-L and sciatic nerve were taken; the expression of RhoA gene was detected by real-time PCR and the expression of RhoA protein was detected by Western Blot. RESULTS: ① Toe tension reflex and modified Tarlov score: at 1, 2 and 4 weeks, the scores in the model control group were lower than those in the normal control group (all <0.01). The scores in the subgroup of nerve mobilization group, EA group and EA plus nerve mobilization group were higher than those in the model control group (all <0.01), and the scores in the subgroup of EA plus nerve mobilization group were higher than those in the nerve mobilization group and the EA group (all <0.01); the recovery was the best at 4 weeks. ② The mRNA and protein expression of RhoA: in segment of spinal cord, at 1, 2 and 4 weeks, the expression in the model control group was higher than that in the normal control group (all <0.01). The expression in the subgroup of nerve mobilization group, EA group and EA plus nerve mobilization group was lower than that in the model control group (all <0.01), and the expression in the subgroup of EA plus nerve mobilization group was lower than that in the nerve mobilization group and the EA group (all <0.01); at 1 week and 4 weeks, the expression in the nerve mobilization group was lower than that in the EA group (all <0.01); at 2 weeks, the expression in the nerve mobilization group was higher than that in the EA group (all <0.01). In the sciatic nerve, at 1, 2 and 4 weeks, the expression in the model control group was higher than that in the normal control group (all <0.01). The expression in the subgroup of nerve mobilization group, EA group and EA plus nerve mobilization group was lower than that in the model control group (all <0.01); at 2 weeks and 4 weeks, the expression in the EA plus nerve mobilization group was lower than that in the nerve mobilization group and EA group (all <0.01); at 1 week, the expression in the nerve mobilization group was lower than that in the EA group and EA plus nerve mobilization group (all <0.01), but the differences between the EA group and the EA plus nerve mobilization group were not significant (>0.05); at 2 weeks, the expression in the nerve mobilization group was higher than that in the EA group (all <0.01); at 4 weeks, the expression in the nerve mobilization group was lower than that in the EA group (all <0.01). CONCLUSION The nerve mobilization and EA at "Jiaji" (EX-B 2) points could both promote the repair of injured sciatic nerve, which may be related to the down-regulation of RhoA expression, and the combination of the two methods has better effects.
Acupuncture Points ; Animals ; Chlorophenols ; Electroacupuncture ; Peripheral Nerve Injuries ; RNA, Messenger ; metabolism ; Rabbits ; Sciatic Nerve ; injuries ; rhoA GTP-Binding Protein

OBJECTIVE: To investigate the regulation mechanism of RhoA signaling pathway during the enamel formation by using the EGFP-RhoA^{Dominant Negative} (EGFP-RhoA^DN) transgenic mice model, from the aspect of adherens junctions, and to provide a theory basis for mechanism of enamel development defects. METHODS: The enamel thickness of mandibular first molars of EGFP-RhoA^DN transgenic mice and wild type (WT) mice were observed by scanning electronic microscopy at 20 kV, and the enamel thickness of the distal face of the central cusp was measured at 10 locations via analysis by ImageJ (Rasband, 1997-2009). The enamel organs from mandibular first molars from postnatal-4-day (P4) EGFP-RhoA^DN mice and wild type mice were isolated, and the total RNA and protein were extracted from the epithelium of the enamel organs. The expression level of the adherens junctions components in ameloblasts layer of the postnatal-4-day EGFP-RhoA^DN transgenic mice and wild type mice mandibular first molars were detected by real-time PCR and Western blot assay. RESULTS: The EGFP-RhoA^DN transgenic mice had decreased enamel thickness in their bilateral mandibular first molars versus those of control group (n=20), and enamel thickness was (84.60±0.20) μm vs. (106.24±0.24) μm, P<0.05. The protein expressions of E-cadherin, α-E-catenin and pan-cadherin in ameloblasts layer of postnatal-4-day EGFP-RhoA^DN transgenic mice molars were down-regulated, and the protein level of β-catenin in ameloblasts layer of P4 EGFP-RhoA^DN transgenic mice molars was up-regulated. The mRNA level of E-cadherin in ameloblasts layer of P4 EGFP-RhoA^DN transgenic mice molars was down-regulated versus that of WT mice, and the gene expression of E-cadherin was 0.93±0.01 vs. 1.00±0.02, P<0.05. The mRNA level of β-catenin in ameloblasts layer of P4 EGFP-RhoA^DN transgenic mice molars was up-regulated versus that of WT mice, and the gene expression of β-catenin was 1.23±0.03 vs. 1.00±0.05, P<0.05. CONCLUSION In the mandibular first molars of EGFP-RhoA^DN transgenic mice, the enamel formation was disrupted and the adherens junctions of EGFP-RhoA^DN transgenic mice ameloblasts were implicated during amelogenesis. RhoA signaling pathway may play a critical role in enamel development by altering the adherens junctions in ameloblasts.
Adherens Junctions ; Ameloblasts ; Amelogenesis ; Animals ; Antigens, CD ; Cadherins/metabolism* ; Dental Enamel/metabolism* ; Enamel Organ ; Humans ; Mice ; Mice, Transgenic ; Molar ; Signal Transduction ; alpha Catenin ; beta Catenin ; rhoA GTP-Binding Protein/physiology*

Astragalus membranaceus (Radix Astragali, RA) and Atractylodes macrocephala (Rhizoma Atractylodis Macrocephalae, RAM) are often used to treat gastrointestinal diseases. In the present study, we determined the effects of polysaccharides extracts from these two herbs on IEC-6 cell migration and explored the potential underlying mechanisms. A migration model with IEC-6 cells was induced using a single-edged razor blade along the diameter of cell layers in six-well polystyrene plates. The cells were grown in control media or media containing spermidine (5 μmol·L, SPD), alpha-difluoromethylornithine (2.5 mmol·L, DFMO), 4-Aminopyridine (40 μmol·L, 4-AP), the polysaccharide extracts of RA or RAM (50, 100, or 200 mg·L), DFMO plus SPD, or DFMO plus polysaccharide extracts of RA or RAM for 12 or 24 h. Next, cytosolic free Ca ([Ca]) was measured using laser confocal microscopy, and cellular polyamine content was quantified with HPLC. Kv1.1 mRNA expression was assessed using RT-qPCR and Kv1.1 and RhoA protein expressions were measured with Western blotting analysis. A cell migration assay was carried out using Image-Pro Plus software. In addition, GC-MS was introduced to analyze the monosaccharide composition of both polysaccharide extracts. The resutls showed that treatment with polysaccharide extracts of RA or RAM significantly increased cellular polyamine content, elevated [Ca] and accelerated migration of IEC-6 cells, compared with the controls (P < 0.01). Polysaccharide extracts not only reversed the inhibitory effects of DFMO on cellular polyamine content and [Ca], but also restored IEC-6 cell migration to control level (P < 0.01 or < 0.05). Kv1.1 mRNA and protein expressions were increased (P < 0.05) after polysaccharide extract treatment in polyamine-deficient IEC-6 cells and RhoA protein expression was increased. Molar ratios of D-ribose, D-arabinose, L-rhamnose, D-mannose, D-glucose, and D-galactose was 1.0 : 14.1 : 0.3 : 19.9 : 181.3 : 6.3 in RA and 1.0 : 4.3 : 0.1 : 5.7 : 2.8 : 2.2 in RAM. In conclusion, treatment with RA and RAM polysaccharide extracts stimulated migration of intestinal epithelial cells via a polyamine-Kv1.1 channel activated signaling pathway, which facilitated intestinal injury healing.
Animals ; Astragalus propinquus ; chemistry ; Atractylodes ; chemistry ; Cell Line ; Cell Movement ; drug effects ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; pharmacology ; Epithelial Cells ; cytology ; drug effects ; metabolism ; Intestines ; cytology ; drug effects ; Kv1.1 Potassium Channel ; genetics ; metabolism ; Polyamines ; metabolism ; Polysaccharides ; chemistry ; isolation & purification ; pharmacology ; Rats ; Rhizome ; chemistry ; Signal Transduction ; drug effects ; rhoA GTP-Binding Protein ; metabolism

OBJECTIVEThis study investigated the effect of RhoA silencing through RNA interference on proliferation and growth of tongue cancer cells, as well as explored the possible mechanisms of this effect.

METHODSSSC-4 tongue cancer cells were cultured in vitro and then transfected with small interfering RNA to knock down RhoA expression. The tested cells were divided into three groups: experimental group (experimental group 1: transfected with RhoA-siRNA-1; experi-mental group 2: transfected with RhoA-siRNA-2), negative control group (transfected by random sequence NC-siRNA), and blank control group (transfected with Lipofectamine). The expression levels of RhoA mRNA were respectively measured by quantitative real-time polymerase chain reaction and western blot assay. Moreover, the expression levels of cyclin D1, p21, and p27 and RhoA protein were evaluated by Western blot assay. Proliferation and growth potentiality were analyzed through evaluation of doubling times and methyl thiazolyl tetrazolium assessment.

RESULTSThe expression levels of RhoA gene and protein of experimental groups significantly decreased following siRNA transfection compared with those in the negative and blank control groups. The expression of cyclin D1 decreased significantly and that of p21 and p27 increased significantly. The doubling time was extended and the growth potentiality decreased.

CONCLUSIONSThe results indicated that RhoA silencing can inhibit proliferation of tongue cancer cells, whereas RhoA affects cell proliferation by regulating the cell cycle pathway. Thus, RhoA is a potential target in gene therapy for tongue cancer.

Cell Line, Tumor ; Cell Proliferation ; Cyclin D1 ; Gene Silencing ; Humans ; Neoplasms, Squamous Cell ; RNA, Messenger ; RNA, Small Interfering ; Real-Time Polymerase Chain Reaction ; Tongue Neoplasms ; Transfection ; rhoA GTP-Binding Protein

OBJECTIVETo study the possible effect of antepartum taurine supplementation in regulating the activity of Rho family factors and promoting the proliferation of neural stem cells in neonatal rats with fetal growth restriction (FGR), and to provide a basis for antepartum taurine supplementation to promote brain development in children with FGR.

METHODSA total of 24 pregnant Sprague-Dawley rats were randomly divided into three groups: control, FGR, and taurine (n=8 each ). A rat model of FGR was established by food restriction throughout pregnancy. RT-PCR, immunohistochemistry, and Western blot were used to measure the expression of the specific intracellular markers for neural stem cells fatty acid binding protein 7 (FABP7), Rho-associated coiled-coil containing protein kinase 2 (ROCK2), ras homolog gene family, member A (RhoA), and Ras-related C3 botulinum toxin substrate (Rac).

RESULTSThe FGR group had significantly lower OD value of FABP7-positive cells and mRNA and protein expression of FABP7 than the control group, and the taurine group had significantly higher OD value of FABP7-positive cells and mRNA and protein expression of FABP7 than the FGR group (P<0.05). The FGR group had significantly higher mRNA expression of RhoA and ROCK2 than the control group. The taurine group had significantly higher mRNA expression of RhoA and ROCK2 than the control group and significantly lower expression than the FGR group (P<0.05). The FGR group had significantly lower mRNA expression of Rac than the control group. The taurine group had significantly higher mRNA expression of Rac than the FGR and control groups (P<0.05). The FGR group had significantly higher protein expression of RhoA and ROCK2 than the control group. The taurine group had significantly lower protein expression of RhoA and ROCK2 than the FGR group (P<0.05).

CONCLUSIONSAntepartum taurine supplementation can promote the proliferation of neural stem cells in rats with FGR, and its mechanism may be related to the regulation of the activity of Rho family factors.

Animals ; Animals, Newborn ; Body Weight ; drug effects ; Brain ; drug effects ; Cell Proliferation ; drug effects ; Fatty Acid-Binding Protein 7 ; analysis ; Female ; Fetal Growth Retardation ; drug therapy ; Male ; Neural Stem Cells ; drug effects ; physiology ; Rats ; Rats, Sprague-Dawley ; Taurine ; pharmacology ; rho-Associated Kinases ; analysis ; genetics ; rhoA GTP-Binding Protein ; analysis ; genetics

As a neuropeptide, neurotensin (NTS) is widely expressed in central and peripheral nervous system, which is mainly mediated byneurotensin receptor1 (NTSR1) to activate the related downstream signaling pathways. After summarized the function and mechanism of NTS/NTSR1 in various malignant tumors, we found that NTS/NTSR1 played essential roles during tumor initiation and development. NTS/NTSR1 regulates tumor initiation, proliferation, apoptosis, metastasis and differentiation mainly through three pathways, including IP3/Ca2+ /PKC/MAPKs pathway, MMPs/EGFR/MAPKs (PI3K/Akt) pathway, or Rho-GTPsaes and non-receptor tyrosine kinase pathway. Besides, NTS/NTSR1 is also regulated by some upstream pathways and some traditional Chinese medicine preparations and traditional Chinese medicine therapies. In this article, we summarized the function of NTS/NTSR1 and its mechanisms, and discussed the prospective in its application to clinical diagnosis and drugs targeting.
Animals ; Humans ; Medicine, Chinese Traditional ; Neoplasms ; etiology ; Neurotensin ; chemistry ; physiology ; Receptor, Epidermal Growth Factor ; physiology ; Receptors, Neurotensin ; chemistry ; physiology ; Signal Transduction ; physiology ; rhoA GTP-Binding Protein ; physiology