Effect of platelet-derived growth factor-BB on pulmonary vascular remodeling in neonatal rats with hypoxic pulmonary hypertension and its mechanism / 中国当代儿科杂志

OBJECTIVES@#To study the effect of platelet-derived growth factor-BB (PDGF-BB) on pulmonary vascular remodeling in neonatal rats with hypoxic pulmonary hypertension (HPH).@*METHODS@#A total of 128 neonatal rats were randomly divided into four groups: PDGF-BB+HPH, HPH, PDGF-BB+normal oxygen, and normal oxygen (n=32 each). The rats in the PDGF-BB+HPH and PDGF-BB+normal oxygen groups were given an injection of 13 μL 6×1010 PFU/mL adenovirus with PDGF-BB genevia the caudal vein. After 24 hours of adenovirus transfection, the rats in the HPH and PDGF-BB+HPH groups were used to establish a neonatal rat model of HPH. Right ventricular systolic pressure (RVSP) was measured on days 3, 7, 14, and 21 of hypoxia. Hematoxylin-eosin staining was used to observe pulmonary vascular morphological changes under an optical microscope, and vascular remodeling parameters (MA% and MT%) were also measured. Immunohistochemistry was used to measure the expression levels of PDGF-BB and proliferating cell nuclear antigen (PCNA) in lung tissue.@*RESULTS@#The rats in the PDGF-BB+HPH and HPH groups had a significantly higher RVSP than those of the same age in the normal oxygen group at each time point (P<0.05). The rats in the PDGF-BB+HPH group showed vascular remodeling on day 3 of hypoxia, while those in the HPH showed vascular remodeling on day 7 of hypoxia. On day 3 of hypoxia, the PDGF-BB+HPH group had significantly higher MA% and MT% than the HPH, PDGF-BB+normal oxygen, and normal oxygen groups (P<0.05). On days 7, 14, and 21 of hypoxia, the PDGF-BB+HPH and HPH groups had significantly higher MA% and MT% than the PDGF-BB+normal oxygen and normal oxygen groups (P<0.05). The PDGF-BB+HPH and HPH groups had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group at all time points (P<0.05). On days 3, 7, and 14 of hypoxia, the PDGF-BB+HPH group had significantly higher expression levels of PDGF-BB and PCNA than the HPH group (P<0.05), while the PDGF-BB+normal oxygen group had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group (P<0.05).@*CONCLUSIONS@#Exogenous administration of PDGF-BB in neonatal rats with HPH may upregulate the expression of PCNA, promote pulmonary vascular remodeling, and increase pulmonary artery pressure.

Panax notoginseng saponins improve monocrotaline-induced pulmonary arterial hypertension in rats by inhibiting ADAM10/Notch3 signaling pathway / 生理学报

In this study, we investigated the effects of Panax notoginseng saponins (PNS) on pulmonary vascular remodeling and ADAM10/Notch3 pathway in pulmonary arterial hypertension (PAH). PAH rat model was established, and male Sprague Dawley (SD) rats were randomly divided into control group, monocrotaline (MCT) group and MCT+PNS group, with 10 rats in each group. Rats in the control group were intraperitoneally injected with equal volume of normal saline. Rats in the MCT group was injected intraperitoneally with 60 mg/kg MCT on the first day, and then with the same volume of normal saline every day. Rats in the MCT+PNS group was injected intraperitoneally with 60 mg/kg MCT on the first day, and then with 50 mg/kg PNS every day. The modeling time of each group lasted for 21 days. After the model was established, the mean pulmonary artery pressure (mPAP) was measured by right heart catheterization technique, the right ventricular hypertrophy index (RVHI) was calculated, the microscopic morphology and changes of pulmonary vascular wall were observed by HE and Masson staining, and the expressions of ADAM10, Notch3, Hes-1, P27, PCNA, Caspase-3 proteins and mRNA in pulmonary vascular tissue of rats were detected by Western blot and qPCR. The expression and localization of Notch3 and α-SMA were detected by immunofluorescence staining. The protein expression of ADAM10 was detected by immunohistochemical staining. The results showed that compared with the control group, mPAP, RVHI, pulmonary vessels and collagen fibers in the MCT group were significantly increased, the expressions of ADAM10, Notch3, Hes-1, and PCNA protein and mRNA were significantly increased, while the expressions of P27 and Caspase-3 protein and mRNA were decreased significantly. Compared with the MCT group, mPAP and RVHI were significantly decreased, pulmonary vessels were significantly improved and collagen fibers were significantly reduced, the expressions of protein and mRNA of ADAM10, Notch3, Hes-1, and PCNA were decreased in MCT+PNS group, but the expressions of protein and mRNA of P27 and Caspase-3 were increased slightly. The results of immunofluorescence showed that Notch3 and α-SMA staining could overlap, which proved that Notch3 was expressed in smooth muscle cells. The expression of Notch3 in the MCT group was increased significantly compared with that in the control group, while PNS intervention decreased the expression of Notch3. Immunohistochemical staining showed that compared with the control group, the amount of ADAM10 in the MCT group was increased significantly, and the expression of ADAM10 in the MCT+PNS group was decreased compared with the MCT group. These results indicate that PNS can improve the PAH induced by MCT in rats by inhibiting ADAM10/Notch3 signaling pathway.

Expressions of TOLL-like receptor 4 (TLR-4) and matrix metalloproteinase 9 (MMP-9)/Tissue inhibitor of metalloproteinase 1 (TIMP-1) in pulmonary blood vessels with chronic obstructive pulmonary diseases and their relationships with pulmonary vascular remodelling

SUMMARY OBJECTIVE: This study aims at investigating the expressions of TOLL-like receptor 4 (TLR-4) and matrix metalloproteinase 9 (MMP-9)/ tissue inhibitor of metalloproteinase 1 (TIMP-1) in pulmonary blood vessels with chronic obstructive pulmonary disease (COPD) and their relationships with pulmonary vascular remodelling (PVR). METHODS: 60 para-tumour tissues were divided into the COPD group and the control group (n=30); the inflammations, pulmonary artery wall area/total artery area (WA%), and wall thickness/vascular outer diameter (WT%) were compared. The expressions of TLR-4, MMP-9/TIMP-1, and PCNA in pulmonary vascular smooth muscle cells were detected, and their relationships with PVR were then analysed. RESULTS: The inflammations (1.6±0.8), WA% (44.0±6.4), and WT% (27.3±3.3) in the COPD group were higher than in the control group (0.3±0.5, 26.1±2.8, 15.6±1.8), and the expressions of TLR-4 (31.4±147) and MMP-9/TIMP-1 (2.2±2.6) were increased compared to the control group (4.7±4.5, 1.9±12). Correlation analysis: TLR-4 and MMP-9/TIMP-1 were positively correlated with the inflammations (r=0.18, P<0.01), WA% (r=0.68, P<0.01), and WT% (r=0.73, P<0.01), as well as positively correlated with the expression of PCNA (r=0.44, P<0.01); the upregulation of TLR-4 was positively correlated with the expressions of MMP-9 and TIMP-1. CONCLUSIONS: The upregulation of TLR-4 in the pulmonary arterial smooth muscle cells of COPD patients could promote the inflammations and the MMP-9 expression, thus causing abnormal degradation of extracellular matrix, so it played an important role in the process of PVR.

RESUMO OBJETIVO: Este estudo tem como objetivo investigar as expressões de TOLL-like receptor 4 (TLR-4) e metaloproteinase 9 da matriz (MMP-9)/inibidor de tecido da metaloproteinase 1 (TIMP-1) em vasos sanguíneos pulmonares com doença pulmonar obstrutiva crônica (DPOC) e suas relações com o remodelamento vascular pulmonar (PVR). MÉTODOS: Sessenta tecidos paratumorais foram divididos em grupo COPD e o grupo controle (n = 30). Foram comparadas as inflamações, área da parede da artéria pulmonar/área da artéria total (WA%) e espessura da parede/diâmetro externo vascular (WT%). As expressões de TLR-4, MMP-9/TIMP-1 e PCNA em células de músculo liso vascular pulmonar foram detectadas, e suas relações com PVR foram então analisadas. RESULTADOS: As inflamações (1,6 ± 0,8), WA% (44,0 ± 6,4) e WT% (27,3 ± 3,3) no grupo COPD foram maiores que no grupo controle (0,3 ± 0,5; 26,1 ± 2,8; 15,6 ± 1,8). E as expressões de TLR-4 (31,4 ± 14,7) e MMP-9/TIMP-1 (2,2 ± 2,6) foram aumentadas em relação ao grupo controle (4,7 ± 4,5, 1,9 ± 1,2). Na análise de correlação, TLR-4 e MMP-9/TIMP-1 foram positivamente correlacionadas com as inflamações (r = 0,18; P <0,01), WA% (r = 0,68; P <0,01) e WT% (r = 0,73; P <0,01), bem como correlacionadas positivamente com a expressão de PCNA (r = 0,44; P <0,01). A elevação da TLR-4 foi correlacionada positivamente com as expressões de MMP-9 e TIMP-1. CONCLUSÕES: A regulação positiva do TLR-4 nas células do músculo liso arterial pulmonar de pacientes com DPOC poderia promover as inflamações e a expressão de MMP-9, causando assim uma degradação anormal da matriz extracelular, por isso desempenhou um papel importante no processo de PVR.

Effects of 3,4-dihydroxyacetophenone on cytosolic calcium in pulmonary artery endothelial and smooth muscle cells during acute hypoxia / 华中科技大学学报（医学）（英德文版）

The effects of 3, 4-Dihydroxyacetophenone (3, 4-DHAP) on cytosolic free calcium [Ca2+]i in pulmonary artery endothelia (PAECs) and smooth muscle cells (PASMCs) during acute hypoxia were studied. Porcine pulmonary artery endothelial and smooth muscle cells (PASMCs) were cultured primarily, and they were divided into 4 groups: groups incubated under normoxia or hypoxia and those with or without treatment with 3,4-DHAP. The [Ca2+]i of both PAECs and PASMCs was measured by determining the fluorescence of fura 2 AM on spetrofluorometer. Our results showed that hypoxia caused significant elevation of [Ca2+]i, in both PAECs and PASMCs, 3,4-DHAP could attenuate the hypoxic elevation of [Ca2+]i only in PASMCs but not in PAECs. It is concluded that 3,4-DHAP decreases the hypoxic elevation of [Ca2+]i in PASMCs. This might contribute to its inhibitory effect on hypoxic pulmonary vasoconstriction.

The role of endogenous carbon monoxide in the hypoxic vascular remodeling of rat model of hypoxic pulmonary hypertension / 华中科技大学学报（医学）（英德文版）

We investigated the expression of heme oxygenase-1 (HO-1) gene and production of endogenous carbon monoxide (CO) in the rat lung tissue at different time points of chronic hypoxic pulmonary hypertension and the effect of hemin on the expression of HO-1 gene and pulmonary hypertension. A rat model of hypoxic pulmonary hypertension was recreated by exposure to intermittent normobaric hypoxic environment (10% O2). Reverse transcriptase polymerase chain reaction (RT-PCR) was performed to determine the level of HO-1 mRNA in the rat lung tissue and double wave length spectrophotometry was used to evaluate the quantity of COHb in arterial blood. Cardiac catheterization was employed to measure the right ventricular systolic pressure (RVSP) and HE staining was performed in dissected lung tissue to observe the pathological changes of the intra-acinar pulmonary arteries (IAPA). It was found that (1) There was a low level of HO-1 mRNA in normal rat lung tissue, but the level of HO-1 mRNA increased by 2-4 times in the lung tissue of hypoxic rats (P<0.01). The quantity of COHb was 2-3 times those of control group (P<0.01 or P<0.05). These were accompanied by the increased of RVSP and the thickened IAPA; (2) Hemin could keep the HO-1 mRNA and COHb in the hypoxic rat lung tissue at a high level, and partially suppressed the increase of rat RVSP, thereby ameliorating the pathological changes of IAPA. In conclusion, the upregulation of the expression of HO-1 gene and production of CO in the rat lung of hypoxic pulmonary hypertension plays a role of inhibition in the development of hypoxic pulmonary hypertension. Hemin has a therapeutic effect on hypoxic pulmonary hypertension.

Redox state of pyridine nucleotides, but not glutathione, regulate Ca2+ release by H2O2 from mitochondria of pulmonary smooth muscle.

Treatment of bovine pulmonary artery smooth muscle mitochondria with H2O2 stimulated oxidation of GSH and NAD(P)H along with an increase in Ca2+ release. Addition of oxaloacetate to mitochondrial suspension stimulated Ca2+ release and oxidation of NAD(P)H while GSH level remained unchanged. Subsequently, addition of beta-hydroxybutyrate which reduced mitochondrial pyridine nucleotides caused reuptake of the released Ca2+ without causing appreciable alteration of GSH level. Treatment of the mitochondria with 1,3-bis(2-dichloroethyl)-1-nitrosourea (BCNU), an inhibitor of glutathione reductase, significantly decreased GSH level without producing discernible change in Ca2+ release and NAD(P)H oxidation.