1.Effect of RhoE expression on the migration and invasion of tongue squamous cell carcinoma.
Kai ZHAO ; Wen-Hong YUAN ; Wen-Jian LI ; Zeng-Peng CHI ; Shao-Ru WANG ; Zheng-Gang CHEN
West China Journal of Stomatology 2021;39(5):510-517
OBJECTIVES:
This study aims to investigate the effect of RhoE expression on the migration and invasion of tongue squamous cell carcinoma (TSCC).
METHODS:
Forty-eight TSCC cases were selected from the Maxillofacial Surgery Center of Qingdao Municipal Hospital from 2017 to 2019. The expression of RhoE in the specimens (TSCC and adjacent tissues) was detected by immunohistochemistry, and RhoE mRNA and protein were extracted to further detect the expression of RhoE. SCC-4 and CAL-27 cells were selected for
RESULTS:
The expression level of RhoE in TSCC was significantly lower than that in adjacent tissues (
CONCLUSIONS
RhoE expression is low in TSCC. Over expression RhoE in TSCC can significantly decrease its migration and invasion abilities. Hence, RhoE may play an important role in regulating the metastasis and invasion of TSCC and provide a new target for gene therapy.
Carcinoma, Squamous Cell
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Cell Line, Tumor
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Humans
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Matrix Metalloproteinase 2
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Neoplasm Invasiveness
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Tongue
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Tongue Neoplasms
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rho GTP-Binding Proteins/genetics*
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rho-Associated Kinases
2.MicroRNA-23a reduces lipopolysaccharide-induced cellular apoptosis and inflammatory cytokine production through Rho-associated kinase 1/sirtuin-1/nuclear factor-kappa B crosstalk.
Xiao-Jun SHI ; Ye JIN ; Wei-Ming XU ; Qing SHEN ; Jun LI ; Kang CHEN
Chinese Medical Journal 2021;134(7):829-839
BACKGROUND:
MicroRNAs are closely associated with the progression and outcomes of multiple human diseases, including sepsis. In this study, we examined the role of miR-23a in septic injury.
METHODS:
Lipopolysaccharide (LPS) was used to induce sepsis in a rat model and H9C2 and HK-2 cells. miR-23a expression was evaluated in rat myocardial and kidney tissues, as well as H9C2 and HK-2 cells. A miR-23a mimic was introduced into cells to identify the role of miR-23a in cell viability, apoptosis, and the secretion of inflammatory cytokines. Furthermore, the effect of Rho-associated kinase 1 (ROCK1), a miR-23a target, on cell damage was evaluated, and molecules involved in the underlying mechanism were identified.
RESULTS:
In the rat model, miR-23a was poorly expressed in myocardial (sham vs. sepsis 1.00 ± 0.06 vs. 0.27 ± 0.03, P < 0.01) and kidney tissues (sham vs. sepsis 0.27 ± 0.03 vs. 1.00 ± 0.06, P < 0.01). Artificial overexpression of miR-23a resulted in increased proliferative activity (DNA replication rate: Control vs. LPS vs. LPS + Mock vs. LPS + miR-23a: H9C2 cells: 34.13 ± 3.12 vs. 12.94 ± 1.21 vs. 13.31 ± 1.43 vs. 22.94 ± 2.26, P < 0.05; HK-2 cells: 15.17 ± 1.43 vs. 34.52 ± 3.46 vs. 35.19 ± 3.12 vs. 19.87 ± 1.52, P < 0.05), decreased cell apoptosis (Control vs. LPS vs. LPS + Mock vs. LPS + miR-23a: H9C2 cells: 11.39 ± 1.04 vs. 32.57 ± 2.29 vs. 33.08 ± 3.12 vs. 21.63 ± 2.35, P < 0.05; HK-2 cells: 15.17 ± 1.43 vs. 34.52 ± 3.46 vs. 35.19 ± 3.12 vs. 19.87 ± 1.52, P < 0.05), and decreased production of inflammatory cytokines, including interleukin-6 (Control vs. LPS vs. LPS + Mock vs. LPS + miR-23a: H9C2 cells: 59.61 ± 5.14 vs. 113.54 ± 12.30 vs. 116.51 ± 10.69 vs. 87.69 ± 2.97 ng/mL; P < 0.05, F = 12.67, HK-2 cells: 68.12 ± 6.44 vs. 139.65 ± 16.62 vs. 143.51 ± 13.64 vs. 100.82 ± 9.74 ng/mL, P < 0.05, F = 9.83) and tumor necrosis factor-α (Control vs. LPS vs. LPS + Mock vs. LPS + miR-23a: H9C2 cells: 103.20 ± 10.31 vs. 169.67 ± 18.84 vs. 173.61 ± 15.91 vs. 133.36 ± 12.32 ng/mL, P < 0.05, F = 12.67, HK-2 cells: 132.51 ± 13.37 vs. 187.47 ± 16.74 vs. 143.51 ± 13.64 vs. 155.79 ± 15.31 ng/mL, P < 0.05, F = 9.83) in cells. However, ROCK1 was identified as a miR-23a target, and further up-regulation of ROCK1 mitigated the protective function of miR-23a in LPS-treated H9C2 and HK-2 cells. Moreover, ROCK1 suppressed sirtuin-1 (SIRT1) expression to promote the phosphorylation of nuclear factor-kappa B (NF-κB) p65, indicating the possible involvement of this signaling pathway in miR-23a-mediated events.
CONCLUSION
Our results indicate that miR-23a could suppress LPS-induced cell damage and inflammatory cytokine secretion by binding to ROCK1, mediated through the potential participation of the SIRT1/NF-κB signaling pathway.
Animals
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Apoptosis/genetics*
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Cell Line
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Cytokines
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Inflammation/genetics*
;
Lipopolysaccharides
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MicroRNAs/genetics*
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NF-kappa B
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Rats
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Sirtuin 1
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rho-Associated Kinases/genetics*
3.Upregulation of miR-345-5p suppresses cell growth of lung adenocarcinoma by regulating ras homolog family member A (RhoA) and Rho/Rho associated protein kinase (Rho/ROCK) pathway.
Qiao-Yun ZHOU ; Shu-Yu GUI ; Peng ZHANG ; Mei WANG
Chinese Medical Journal 2021;134(21):2619-2628
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*
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Cell Line, Tumor
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Cell Movement/genetics*
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Cell Proliferation/genetics*
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Gene Expression Regulation, Neoplastic
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Humans
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Lung Neoplasms/genetics*
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MicroRNAs/genetics*
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Up-Regulation/genetics*
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rho-Associated Kinases/genetics*
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rhoA GTP-Binding Protein/genetics*
4.Serum response factor participates in RhoA-induced endothelial cell F-actin rearrangements.
Ya-Ling HAN ; Hai-Bo YU ; Cheng-Hui YAN ; Zi-Min MENG ; Xiao-Lin ZHANG ; Jian KANG ; Shao-Hua LI ; Shi-Wen WANG
Acta Physiologica Sinica 2005;57(3):295-302
RhoA is one of the main members of RhoGTPase family involved in cell morphology, smooth muscle contraction, cytoskeletal microfilaments and stress fiber formation. It has been demonstrated that RhoA modulates endothelial cell permeability by its effect on F-actin rearrangement, but the molecular mechanism of rearrangement of actin cytoskeleton remains unclear. Recent studies prove that RhoA/Rho kinase regulates smooth muscle specific actin dynamics by activating serum response factor (SRF)-dependent transcription. To further investigate the molecular mechanism of the rearrangement of vascular endothelial cell actin cytoskeleton, we explored the relationship between the activation of SRF and F-actin rearrangement induced by RhoA in human umbilical vein endothelial cells (HUVECs). HUVECs were infected with the constitutively active forms of RhoA (Q63LRhoA) or the dominant negative forms of RhoA(T19NRhoA) using retrovirus vector pLNCX-Q63LRhoA or pLNCX-T19NRhoA, the positive clone was obtained by G418 selection. The expression and distribution of SRF in normal and infected cells were evaluated by immunohistochemistry and Western blot in complete medium and in serum-free medium. The effect of F-actin polymerization was detected by Rhodamine-Phalloidine staining. Infection of PLNCX-Q63LRhoA induced F-actin rearrangement and stress fiber formation in HUVECs, as well as enhanced the expression of SRF in the nuclei. In contrast, the cells infected with T19NRhoA showed no distinct changes. With serum deprivation, the expression of SRF increased obviously in both normal and infected HUVECs, but the subcellular localization of SRF was evidently different. In HUVECs, the localization of SRF was in the nuclei after 3 d with serum deprivation, but it was redistributed outside the nuclei after 5 d with serum deprivation. In cells infected with Q63LRhoA, the immunolocalization of SRF was always in the nuclei compared with HUVECs infected with T19NRhoA, which was almost always localized in the cytoplasm. In HUVECs, the rearrangement of F-actin and formation of stress fiber increased after 3 d with serum deprivation, but appeared decreased and unpolymerized after 5 d with serum deprivation. The polymerization of F-actin and the formation of stress fiber in HUVECs infected with Q63LRhoA kept during the period of serum-free culture, whereas the rearrangement of F-actin in cells infected with T19NRhoA was not found. These results suggest that RhoA influences endothelial F-actin rearrangement in part by regulating the expression and subcellular localization of SRF.
Actins
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biosynthesis
;
genetics
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Cytoskeleton
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metabolism
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Endothelium, Vascular
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cytology
;
metabolism
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Humans
;
Intracellular Signaling Peptides and Proteins
;
Protein-Serine-Threonine Kinases
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metabolism
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Serum Response Factor
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biosynthesis
;
genetics
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Umbilical Veins
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cytology
;
rho-Associated Kinases
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rhoA GTP-Binding Protein
;
physiology
5.Correlation of expression of RhoA (RhoC and their effector ROCK-1 with malignant phenotype of ovarian cancer cells in vitro.
Zhi-qiang HAN ; A-li ZHANG ; Ming-fu WU ; Yu-lan LIU ; Gang CHEN ; Fu-jun LI ; Qing-lei GAO ; Guo-ning LIAO ; Yun-ping LU ; Shi-xuan WANG ; Ding MA
Chinese Journal of Oncology 2004;26(7):385-388
OBJECTIVETo investigate the expression of RhoA, RhoC and their effector ROCK-1 in four ovarian cancer cell lines in vitro and their correlation with invasiveness.
METHODSExpression of RhoA, RhoC and ROCK-1 mRNA and protein in four ovarian cancer cell lines SW626, Skov-3, A2780 and Caov-3 was detected by RT-PCR and Western blot assay. Invasion assay was done in Boyden chamber.
RESULTSThe expression levels of RhoA, RhoC and ROCK-1 mRNA and protein varied in the four different cell lines examined. The expression level of RhoC, but not RhoA and ROCK-1, was significantly correlated with the invasive capability of these cells in vitro (r = 0.95, P < 0.01). Expression of RhoA at the level of transcription was not correlated with that at the translation level. The expression of RhoA and RhoC did not correlate with that of ROCK-1.
CONCLUSIONExpression level of RhoC may serve as an independent parameter in evaluating metastasis and become a new target in inhibiting ovarian cancer metastasis.
Cell Line, Tumor ; Cell Movement ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Intracellular Signaling Peptides and Proteins ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Ovarian Neoplasms ; genetics ; metabolism ; pathology ; Phenotype ; Protein Biosynthesis ; Protein-Serine-Threonine Kinases ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Transcription, Genetic ; rho GTP-Binding Proteins ; biosynthesis ; genetics ; rho-Associated Kinases ; rhoA GTP-Binding Protein ; biosynthesis ; genetics ; rhoC GTP-Binding Protein
6.Inhibitory effect and acting mechanism of Tongxinluo on IL-1beta-mediated coronary intimal hyperplasia and 5-hydroxytryptamine-induced coronary vasospasm in small swine.
Qi-Gang GUAN ; Ding-Yin ZENG ; Xi-Zhuo SUN
Chinese Journal of Integrated Traditional and Western Medicine 2008;28(7):627-631
OBJECTIVETo observe the inhibitory effect of Tongxinluo (TXL) on coronary vaso spasm in small swine in vivo, and to investigate its possible acting mechanism.
METHODSThe model of coronary atherosclerosis in 16 male small swines was established by left thoracotomy after anesthesia, isolated the sections of left anterio-descending branch and proximal end of rotator branch with similar outer diameter, and encapsulated them with paper-towel holding 2.5 microg interleukin-1beta. Two weeks later, the condition of coronary vasospasm induced by catheter intra-coronary injection of 5-hydroxytryptamine (5-HT, 10 microg/kg) was observed through coronary artery contrast examination. The 12 swines with successfully formed coronary vaso spasm were randomly divided into 2 groups, the TXL group and the control group. They were fed with special diet, but TXL 1 g/(kg d) was administered additionally to the TXL group for 4 weeks. The observation on coronary vasospasm was repeated 1 week after discontinuation of TXL treatment, then the animals were sacrificed, their vascular sections enclosed with IL-1beta was taken to conduct the pathologic examination and to detect the expressions of Rho kinase mRNA and its substrate myosin- binding subunit phosphorylation (MBS-P) by RT-PCR and Western blot method.
RESULTSCoronary artery contrast showed that local coronary stenosis occurred in the 12 model swines to different extents (20% - 30%, and vascular spasm on them could be induced by 5-HT. At the time of repeating examination, 11 vascular sections in the control group still maintain their positive spasm reaction to 5-HT, but only 2 in the TXL group did so, the reaction turned to negative in 1 and 10 in the two groups respectively. Pathological examination showed that different degrees of macrophage aggregation could be found in both groups. The degree of lumen stricture and endometrial hyperplasia in the TXL group was obviously attenuated than those in the control group. The expressions of Rho kinase mRNA and MBS-P in the control group were up-regulated obviously. As compared with those in the control group, they were inhibited significantly in the TXL group, as (71.5 +/- 2.4) vs (98.2 +/- 7.7)% and 16,633 +/- 1,390 vs 25,818 +/- 4,745, respectively (all P < 0.05).
CONCLUSIONTXL could obviously inhibit the coronary intimal hyperplasia mediated by IL-1beta and coronary vasospasm induced by 5-HT, one of its mechanisms is possibly the inhibition on the intracellular Rho kinase mRNA expression in the IL-1beta enclosed vascular section to decrease the level of MBS-P.
Animals ; Coronary Vasospasm ; chemically induced ; drug therapy ; genetics ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; therapeutic use ; Gene Expression ; drug effects ; Humans ; Interleukin-1beta ; genetics ; metabolism ; Male ; Random Allocation ; Serotonin ; adverse effects ; Swine ; rho-Associated Kinases ; genetics ; metabolism
7.Expression of RhoC and ROCK-1 and their effects on MAPK and Akt proteins in prostate carcinoma.
Qiang BU ; Hua-ming TANG ; Jian TAN ; Xiao HU ; Dong-wen WANG
Chinese Journal of Oncology 2011;33(3):202-206
OBJECTIVETo detect the expression of RhoC and Rho kinase 1 (ROCK-1) in prostate carcinoma, and explore the possible mechanism of RhoC/ROCK-1 in the pathogenesis of prostate carcinoma.
METHODSTissue specimens from 73 patients with prostate carcinoma and corresponding paracancerous tissues were obtained by prostate cancer biopsy or radical prostatectomy. The expression of RhoC/ROCK-1 mRNA was detected by RT-PCR. Western blot and immunohistochemistry were performed to dertect the expression of RhoC/ROCK-1 protein. Eukaryotic expression plasmids of RhoC were constructed and transfected into PC-3M-2B4 cells. p-MAPK and p-Akt were detected by Western bolt.
RESULTSThe expression levels of RhoC and ROCK-1 mRNA in the prostate carcinomas were significantly higher than those in corresponding paracancerous tissues [72.6% (53/73) vs. 34.2% (25/73); 68.5% (50/73) vs. 38.4% (28/73), P < 0.01], respectively. The results indicated that RhoC/ROCK-1 mRNA expression had no significant correlation with Gleason grade. However, the expression of RhoC/ROCK-1 mRNA showed a significant positive correlation with distant metastasis. The RhoC/ROCK-1 protein expression in prostate cancer was also higher than corresponding paracancerous tissues, and showed a significant positive correlation with p-MAPK and p-Akt expression levels. In addition, p-MAPK and p-Akt expression levels were up-regulated in the transcripts.
CONCLUSIONExpression levels of RhoC and ROCK-1 in prostate carcinoma are higher than those in corresponding paracancerous tissues, showing a significant positive correlation with distant metastasis. RhoC/ROCK-1 may be involved in the development, invasion and metastasis of prostate carcinoma.
Bone Neoplasms ; metabolism ; secondary ; Cell Line, Tumor ; Humans ; Male ; Mitogen-Activated Protein Kinases ; metabolism ; Neoplasm Grading ; Neoplasm Staging ; Phosphorylation ; Prostatectomy ; Prostatic Neoplasms ; metabolism ; pathology ; surgery ; Proto-Oncogene Proteins c-akt ; metabolism ; RNA, Messenger ; metabolism ; Transfection ; Up-Regulation ; rho GTP-Binding Proteins ; genetics ; metabolism ; rho-Associated Kinases ; genetics ; metabolism ; rhoC GTP-Binding Protein
8.Effect of blocking of ROCK-1, an effector of small G protein Rho, on the malignant behavior of ovarian tumor cells in vitro.
Zhi-Qiang HAN ; Zhen-Ya HONG ; Chun-Xia HU ; Yi HU ; Cai-Hong CHEN ; Yun-Ping LU ; Shi-Xuan WANG ; Jian-Feng ZHOU ; Ding MA
Chinese Journal of Oncology 2007;29(10):723-727
OBJECTIVETo investigate the possible role of ROCK-1 in ovarian cancer invasion and metastasis.
METHODSROCK-1 ASODN was transfected into SW626 and Caov-3 cell lines mediated by Lipofectamine 2000. The expressions of ROCK-1 mRNA and protein were detected by RT-PCR and Western-blot assay. Boyden chamber was used to assess the effect of ROCK-1 ASODN on the invasion and migration of the cell lines. The changes in the adhesion and proliferation of the transfected cells were detected by MTT assay.
RESULTSThe expressions level of ROCK-1 mRNA and protein in the cell lines were decreased significantly after transfection at doses of 10 micromol/L and 20 micromol/L ROCK-1 ASODN. When compared with the control group, the invasion capability of transfected cells was inhibited to an extent of 75.6% +/- 3.8% and 54.7% +/- 2.9%, respectively, for SW626 cell line, and 68.8% +/- 4.7% and 50.0% +/- 4.5% for Caov-3 cell line, respectively. The random migratory activity of these two cell lines was inhibited by 80.0% +/- 1.3%, 63.7% +/- 1.9%, 72.5% +/- 3.4% and 55.9% +/- 2.5%, respectively, and the inhibition of chemotaxis activity of the two cell lines was 83.9% +/- 1.4%, 64.1% +/- 1.3%, 72.5% +/- 3.4% and 54.5% +/- 1.9%, respectively. No significant difference was found in the adhesion and proliferation of the cells transfected with ROCK-1 ASODN and control cells.
CONCLUSIONThe expression of ROCK-1 was closely related to the invasion capability and migratory activity of ovarian cancer cells. ROCK-1 may play a crucial role in invasion and metastasis of ovarian cancer.
Cell Adhesion ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Down-Regulation ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Oligonucleotides, Antisense ; genetics ; Ovarian Neoplasms ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Transfection ; rho-Associated Kinases ; genetics ; metabolism
9.Screening lentiviral vectors carrying effective siRNA of the ROCK2 gene.
Qiang PENG ; Fu-Nian MA ; Rui JIANG ; Feng CHEN
National Journal of Andrology 2014;20(5):392-399
OBJECTIVETo screen the lentiviral vector carrying siRNA and capable of significantly suppressing the ROCK2 gene expression in the corpus cavernosum smooth muscle cells of spontaneously hypertensive rats (SHR).
METHODSWe designed and synthesized 4 siRNA fragments targeting the ROCK2 gene and packaged them into lentiviral vectors. We collected corpus cavernosum smooth muscle cell samples from 5 male SHRs and randomly divided them into groups A (non-transfection control), B (GFP lentiviral transfection), C, D, E, and F (lentiviral transfection with siRNA fragments 1 -4 targeting the ROCK2 gene). Each group consisted of 5 samples and each sample 3 x 10(4) cells. At 48 hours after transfecting MOI = 80 into the SHR corpus cavernosum smooth muscle cells, we detected the expression of GFP under the fluorescent microscope and the mRNA expression of the ROCK2 gene by RT-PCR.
RESULTSThe transfection efficiency of the SHR corpus cavernosum smooth muscle cells was > 50%. Compared with group A, the expression of ROCK2 mRNA in the corpus cavernosum smooth muscle cells showed no remarkable change in group B (P > 0.05) but was inhibited very significantly in C ([43.91 +/- 8.19]%), D ([47.15 +/- 6.64]%), and F ([25.7 +/- 6.03]%) (P < 0.01), and significantly in E ([16.81 +/- 5.94]%, P < 0.05).
CONCLUSIONWe successfully constructed 4 lentiviral vectors carrying siRNA targeting the ROCK2 gene, all of which can significantly suppress the ROCK2 expression in the SHR corpus cavernosum smooth muscle cells, and one has a highly strong inhibitory effect.
Animals ; Gene Silencing ; Genetic Vectors ; Lentivirus ; genetics ; Male ; Myocytes, Smooth Muscle ; Penis ; cytology ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; Random Allocation ; Rats ; Rats, Inbred SHR ; Transfection ; methods ; rho-Associated Kinases ; genetics
10.Downregulation of Rho associated coiled-coil forming protein kinase 1 in the process of delayed myocardialization of cardiac proximal outflow tract septum in connexin 43 knockout mice embryo.
Chun-hua QI ; Xiao-qing ZHAO ; Duan MA ; Xiao-jing MA ; Guo-min ZHOU ; Guo-ying HUANG
Chinese Medical Journal 2011;124(13):2021-2027
BACKGROUNDThe connexin43 knockout (Cx43 KO) mouse dies at birth with an enlarged conotruncal region, which leads to the obstruction of the right outflow tract (OFT). Since myocardialization of the proximal OFT septum is one of the key events during heart development, we investigated the process in the Cx43 KO embryo hearts. Rho associated coiled-coil forming protein kinase 1 (ROCK1), is a recently found key molecule to regulate the myocardialization of OFT, but its spatiotemporal expression pattern during myocardialization remains unknown. The objective of this study was to investigate the differentially expressed pattern of ROCK1 between Cx43 KO and wild type embryo hearts, and its relationship with the delayed myocardialization in Cx43 KO embryo hearts.
METHODSUsing immunohistochemistry, the processes of myocardiolization were investigated both in Cx43 KO and wild type embryo hearts. The differentially expressed pattern of ROCK1 between Cx43 KO and wildtype embryo hearts was evaluated both at the mRNA and protein level by real-time RT-PCR and immunohistochemistry.
RESULTSThe expression of α-sarcomeric actin (α-SCA) in the proximal OFT septum of Cx43 KO embryos was delayed. Meanwhile, it was shown that the downregulation of ROCK1 coincided with delayed myocardialization. The expression of ROCK1 protein was mainly limited to the proximal outflow tract septum from embryo day (E) E11.5 to E15.5. Its expression pattern was similar with that of α-SCA. Real-time RT-PCR found that the expression level of Rock-1 mRNA began at a low level on E11.5 and reached peak at E13.5 and E14.5.
CONCLUSIONSROCK1 may have an important role in the process of myocardialization of the proximal OFT septum. Downregulation of ROCK1 is likely to contribute to the aberrant myocardialization in Cx43 KO embryo hearts.
Actins ; metabolism ; Animals ; Connexin 43 ; genetics ; metabolism ; Heart ; embryology ; physiopathology ; Heart Septum ; Immunohistochemistry ; Mice ; Mice, Knockout ; Myocardium ; metabolism ; pathology ; Real-Time Polymerase Chain Reaction ; rho-Associated Kinases ; genetics ; metabolism