-
Xi Zhang,
Jin-Ping Guo,
Ya-Li Chi, Yan-Chun Liu,
Chuan-Sen Zhang,
Xiang-Qun Yang,
Hai-Yan Lin,
Er-Peng Jiang,
Shao-Hu Xiong,
Zhi-Ying Zhang,
Bao-Hai Liu
[show abstract]
[hide abstract]
ABSTRACT: The mechanisms governing the development of cardiac pacemaking and conduction system are not well understood. In order to provide evidence for the derivation of pacemaking cells and the signal that induce and maintain the cells in the developing heart, Nkx2.5(+) cardiac progenitor cells (CPCs) were isolated from embryonic heart tubes of rats. Endothelin-1 was subsequently added to the CPCs to induce differentiation of them towards cardiac pacemaking cells. After the treatment, Nkx2.5(+) CPCs displayed spontaneous beating and spontaneously electrical activity as what we have previously described. Furthermore, RT-PCR and immunofluorescence staining demonstrated that Tbx3 expression was increased and Nkx2.5 expression was decreased in the induced cells 4 days after ET-1 treatment. And the significantly increased expression of Hcn4 and connexin-45 were detected in the induced cells 10 days after the treatment. In addition, Nkx2.5(+) CPCs were transfected with pGCsi-Tbx3 4 days after ET-1 treatment in an attempt to determine the transcription regulatory factor governing the differentiation of the cells into cardiac pacemaking cells. The results showed that silencing of Tbx3 decreased the pacemaking activity and led to down-regulation of pacemaker genes in the induced cells. These results confirmed that Nkx2.5(+) CPCs differentiated into cardiac pacemaking cells after being treated with ET-1 and suggested that an ET-1-Tbx3 molecular pathway govern/mediate this process. In conclusion, our study support the notion that pacemaking cells originate from Nkx2.5(+) CPCs present in embryonic heart tubes and endothelin-1 might be involved in diversification of cardiomyogenic progenitors toward the cells.
Molecular and Cellular Biochemistry 04/2012; 366(1-2):309-18. · 2.06 Impact Factor
-
Xi Zhang,
Chuan-Sen Zhang, Yan-Chun Liu,
Xiang-Qun Yang,
Shao-Hu Xiong,
Yu Wen,
Er-Peng Jiang,
Rui Li,
Zhi-Ying Zhang,
Fang Liu,
Yong Ye
[show abstract]
[hide abstract]
ABSTRACT: A variety of studies have reported on the isolation and expansion of cardiac stem cells from adult hearts. However, there is little information concerning cardiac stem/progenitor cells derived from embryonic hearts/heart tubes. To provide more evidence for embryonic heart-derived stem/progenitor cells, Nkx2.5+ human cardiac progenitorcells (hCPCs) were isolated and cloned from human heart tubes. The cells stained positive for Nkx2.5 and Oct-4, and negative for alpha-smooth muscle actin (alpha-SMA), cytokeratin, factor-VIII, alpha-sarcomeric actin and c-Kit. GATA-4 expression of Nkx2.5+ hCPCs was higher than that of embryonic limb bud mesenchymal cells of the control group (p < 0.05). These cells were passaged continuously for >3 months (23 passages) and proliferated actively in vitro. After being treated with 5-azacytidine, Nkx2.5+ hCPCs underwent cardiomyogenic differentiation. Ultrastructural observation confirmed that the longitudinal section of these cardiomyogenic differentiation cells clearly revealed typical sarcomeres and intercalated discs. alpha-MHC, alpha-sarcomeric actin and GATA-4 levels were increased in Nkx2.5+ hCPCs treated with 5-azacytidine compared to untreated cells. Nkx2.5+ hCPCs exhibited positive staining and had a higher expression for alpha-SMA when cocultured with canine vascular endothelial cells. After Nkx2.5+ hCPCs were treated with endothelin-1, all cells displayed spontaneous electrical activity and spontaneous beating. Connexin-40 and -45 were stained positive in the treated cells. In conclusion, Nkx2.5+ hCPCs derived from heart tubes have been isolated and cloned in vitro. These cells are capable of long-term self-renewal and possess a potential to differentiate into cardiac muscle-like cells, cardiac pacemaking cells and smooth muscle-like cells. They could have a significant impact on cardiac regeneration medicine and developmental biology.
Cells Tissues Organs 02/2009; 190(4):194-208. · 2.20 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To provide morphological basis for chyle leakage due to operation on upper abdomen or retroperitoneum region.
The original part of thoracic duct, cisterna chyle, intestinal trunk, left and right lumbar trunks were examined in 32 adult cadavers.
(1) The occurrence rate of cisterna chili was 22% (7 cases), among which 4 cases were oval, 3 cases were triangle. The cisterna chyle was (24 +/- 6) mm in length; the width of middle part was (4.1 +/- 0.9) mm. It was located to the right of midline at the level between the twelfth thoracic vertebral body and the second lumbar vertebral body anteriorly. (2) The original part of thoracic duct was (2.8 +/- 0.7) mm in diameter. The confluence form of thoracic duct included: left lumbar trunk and intestinal trunk united to form the common trunk first, right lumbar trunk then joined the common trunk (9 cases, 36%); right lumbar trunk and intestinal trunk united to form the common trunk first, left lumbar trunk then joined the common trunk (8 cases, 32%); left and right lumbar trunk united to form the common trunk first, intestinal trunk then joined the common trunk (4 cases, 16%); left, right lumbar trunk and intestinal trunk joined together (3 cases, 12%). (3) The intestinal trunk was (36 +/- 15) mm in length. It ascended on the left of descending aorta, superior to the left renal artery, crossed the second lumbar vertebra anteriorly, and joined left or right lumbar trunk to form common trunk, which extended to the cisterna chili or thoracic duct to the right of lumbar vertebra. (4) The lengths of left and right lumbar trunks were (107 +/- 24) mm and (111 +/- 18) mm, the external diameters of origins were (1.7 +/- 0.4) mm and (1.9 +/- 0.4) mm, and the external diameters of terminations were (2.2 +/- 0.6) mm and (2.2 +/- 0.5) mm, respectively.
The larger lymph tubes should be protected emphatically in the relevant region when dissecting the root of celiac and superior mesenteric artery and the termination of inferior mesenteric vein during abdominal operation.
Zhonghua wai ke za zhi [Chinese journal of surgery] 08/2004; 42(14):857-60.
-
[show abstract]
[hide abstract]
ABSTRACT: To investigate whether man-made porous chitosan-gelatin complex scaffold was a appropriate scaffold for tissue engineering cartilage.
Chondrocytes isolated from Changfeng crossbred swines' auricular cartilage were seeded onto chitosan- gelatin scaffolds to be cultured in a three dimensional environment. The chondrocyte- polymer constructs were implanted into the subcutaneous tissue of the swines' abdomenal wall. Specimens were harvested and analyzed by gross observation, histology, type II collagen immunohistochemistry and biochemistry after 10 and 16 weeks in vivo respectively.
H.E staining showed cartilage was formed, and chondrocytes were enclosed in lacuna with histological characteristics similar to natural cartilage. Some clusters of neocartilage surrounded by fibrous tissues were observed. Elastic fibres were observed in the mesenchyma of cartilage 16 weeks after by Vehoeff's staining. Immunohistochemical staining of the neocartilage with anti- type II collagen showed the presence of type II collagen in the ECM of tissue engineered cartilage. The proteoglycans content in tissue engineered cartilage was close to that of natural swine's auricular cartilage.
The experiments demonstrated that using chitosan-gelatin complex scaffold we can generate autologous cartilage on animals with normal immune system. Porous chitosan- gelatin complex scaffolds may be a suitable scaffolds for tissue engineered cartilage.
Zhonghua yi xue za zhi 05/2003; 83(7):577-9.
