Role of leukotriene D4 in promoting proliferation of cultured human airway smooth muscle cells

AIM: To investigate whether leukotriene D₄(LTD₄) would stimulates proliferation of cultured human airway smooth muscle (ASMC). METHOD: Human ASMC were isolated and subcultured, varying concentration of LTD₄ were added to the media. Cell counts were obtained, -thymidine([³H]-TdR) incorporation and inositol 1, 4, 5-trisphosphate (IP₃) accumulation were measured. RESULTS: LTD₄(0.1nmol·L^-1~10 nmol·L^-1) increased cell number and also increased incorporation of[³H]-TdR and accumulation of IP₃ in a concentration dependent manner(P＜0.01). The latter response was blocked by phospholipase C inhibition with neomycin (1 μmoL·L^-1(P＜0.01). However, neomycin had no effect on the promitogenic action of LTD₄. CONCLUSION: LTD₄ stimulates proliferation of cultured human ASMC and may play a role in airway remodeling of asthma.     

Responsiveness of the T-lymphocyte in peripheral blood from asthmatic patients to VIP

AIM: To investigate the functional state of vasoactive intestinal peptide (VIP) receptor on T-lymphocyte (T-cell)from asthmatics. METHODS: T-cells were purified from peripheral blood of asthmatics in remission and control subjects. Proliferation of T-cells was measured by [³H][³H]-TdR incorporation rate. The cAMP level in T-cells was assayed with radioimmunoassay method. We observed the influence of VIP on Con A-induced proliferation of T-cells, and cAMP level in T-cells in asthmatic and control groups. RESULTS: There was no difference in Con A-induced proliferation of T-cells between the two groups (P＞0.05). VIP, however, could inhibit the Con A-induced proliferation of T-cells from control subjects more significantly than that from asthmatics (P＜0.01). There was no difference in cAMP level in the unstimulated T-cells between the two groups (P＞0.05). The cAMP level in T-cells, however, increased more significantly in the control group than that in the asthmatic group after the treatment of VIP or NaF (P＜0.01,respectively). Adenylcyclase stimulator (forskolin)-treatment had no effect on the cAMP level in T-cells from the two groups (P＞0.05). CONCLUSION: Inhibition effect of VIP on Con A-induced proliferation of T-cells was less in asthmatics than in control subjects, which may be related to insufficiency of Gs α coupled VIP receptor on T-lymphocytes in asthmatics.     

Role of NHE-1 in the proliferation and apoptosis of pulmonary artery smooth muscle cell in rats

AIM: To evaluate the role of Na⁺/H⁺ exchanger-1(NHE-1)in the proliferation and apoptosis of pulmonary artery smooth muscle cells in rats. METHODS: Twenty Wistar rats were equally randomized into the control group and 3-week hypoxic group. Intracellular pH (pHi) of the smooth muscle was determined with fluorescence measurement of the pH-sensitive dye BCECF-AM and the expression of NHE-1 mRNA was detected with RT-PCR. The primary culture of pulmonary artery smooth muscle cell in vitro was performed. In situ cell death detection kit (TUNEL) was used to study the effect of specific NHE-1 inhibitor, dimethyl amiloride (DMA), on the apoptosis of muscle cells which had intracellular acidification. RESULTS: pHi value and expression of NHE-1 mRNA of pulmonary artery smooth muscle cell were significantly higher respectively in the hypoxic group than those in the control group (P＜0.01). DMA elevated the apoptotic ratio significantly. The effect was enhanced when DMA concentration was augmented and the time was prolonged. CONCLUSION: With the function of adjusting pHi, NHE-1 may play an important role in the proliferation and apoptosis of pulmonary artery smooth muscle cells.     

Expression of canine Kdap in normal, hyperplastic and neoplastic epidermis

Keratinocyte differentiation-associated protein, Kdap, is a recently identified small secretory protein that may act as a soluble regulator for the cornification and/or desquamation of keratinocytes. To clarify the role of Kdap in the terminal differentiation of keratinocytes, detailed in situ localisation of Kdap was studied using canine skin with normal, hyperplastic and neoplastic epidermis. In normal canine trunk skin, Kdap was expressed by granular keratinocytes, with polarity to the apical side of the cells, suggesting that canine Kdap is present in lamellar granules, as in humans. Expression of Kdap was widespread in the spinous layers in hyperplastic epidermis, but was undetectable in squamous cell carcinomas. These findings suggest that Kdap is closely related to the delay of terminal differentiation and/or release of cells in hyperplastic epidermis.     

Spontaneous Neoplastic and Hyperplastic Skin Lesions of the Woodchuck

Abstract— In a retrospective postmortem survey of laboratory woodchucks (Marmota monax), four neoplastic and one hyperplastic skin lesions were identified. These included two lipomas and single cases each of squamous cell carcinoma, apocrine gland adenoma and sebaceous gland hyperplasia. Three animals were male, the other two female. Animals ranged from 2 to 7 years of age. Four animals were negative for markers of woodchuck hepatitis virus (WHV). The other, a 7-year-old female with an axillary lipoma, was a chronic carrier. Four neoplasms were discrete masses; the digital squamous cell carcinoma was more extensive, infiltrative and interfered with prehension. The low incidence of skin tumours (0.8 per cent) parallels that described in other laboratory rodent species. Résumé— Une étude rétrospective portant sur des autopsies de marmottes de laboratoire (Marmota monax) a permis la mise en évidence de 4 lésions néoplasiques et d'une lésion hyperplasique de la peau. Il s'agissait de deux lipomes ainsi que de cas isolés d'épthélioma spinocellulaire, d'adénome apocrine et d'hyperplasie sébacée. Trois animaux étaient des mäles et deux, des femelles. L'äge variait de 2 à 7 ans. Quatre animaux étaient négatifs au marqueur de l'hépatite virale de la marmotte (WHV). Le cinquième, une femelle de 7 ans présentant un lipome axillaire, était un porteur chronique. Quatre des néoplasies étaient des masses discrètes; l'épithélioma spinocellulaire du doigt était plus extensif, infiltrant et gênait la préhension. La faible incidence des tumeurs cutanées (0,8%) est identique à celle que l'on décrit chez d'autres rongeurs de laboratoire. Zusammenfassung— In einer retrospektiven postmortalen Untersuchung von Labor-Murmeltieren (Marmota monax) wurden vier neoplastische und eine hyperplastische Hautveränderung festgestellt. Darunter waren zwei Lipome und einzelne Fälle von jeweils einem Plattenepithelkazinom, einem apokrinen Adenom und einer Talgdrüsenhyperplasie. Drei Tiere waren männlich, die beiden anderen weiblich. Das Alter der Tiere lag zwischen 2 und 7 Jahren. Vier der Tiere reagierten negativ auf Murmeltier-Hepatitis-Virus-Marker (WHV). Ein weiteres 7 Jahre altes weibliches Tier mit einem Lipom im Achselbereich war chronischer Träger. Vier der Neubildungen stellten diskrete Massen dar; das Plattenepithelkarzinom im Fußbereich war ausgedehnter, infiltrativ wachsend und beeinträchtigte die Greifbewegungen. Das geringe Vorkommen von Hauttumoren (0,8%) entspricht demjenigen, das bei anderen Nagern beschrieben wurde. Resumen En un estudio retrospectivo postmortem de marmotas de laboratio (Marmota monax) se identificaron cuatro lesiones neoplásicas cutáneas y una lesión cutánea de tipo hiperplásico. Entre estas se encontraban dos lipomas y casos individuales de carcinoma de células escamosas, adenoma de glándulas apocrinas e hiperplasia de glándulas sebáceas. Tres animales eran machos y los dos restantes eran hembras. La edad de los animales oscilaba entre los dos y los siete años. Cuatro animales fueron negativos para maracadores del virus de la hepatitis de la marmota. El otor, una hembra de 7 años de edad con un lipoma axilar, era un portador crónico. Cuatro neoplasias eran masas bien delimitadas mientras que el carcinoma de células escamosas digital era aprehensión. Esta baja incidencia de neoplasias cutánea en la marmota (0,8%) es semejante a la descrita en otros roedores de laboratorio.     

Effects of deoxynivalenol on apoptosis and proliferation of mouse thymocytes in vivo

AIM:To explore the effect of deoxynivalenol on apoptosis and proliferation of mouse thymocytes in vivo.METHODS:Effect of deoxynivalenol at different concentrations on apoptosis and proliferation of mouse thymocytes in vivo were studied with animal experiment, electron microscopic observation, DNA agarose gel electrophoresis and flow cytometric analyses. RESULTS:FCM analysis showed that the apoptosis rates of the thymocytes in DON groups (0.5 mg/kg, 1 mg/kg, 2 mg/kg, 4 mg/kg and 8 mg/kg) were significantly higher than that in control (P＜0.01). In the concentration ranging from 0.5 mg/kg to 8 mg/kg, a significant dose-dependant response correlation could be found between apoptosis rate and DON concentration. The result of DNA agarose gel electrophoresis showed that characteristic DNA ladder was found in groups treated DON at relatively higher concentrations (8 mg/kg and 4 mg/kg). Ultrastructurally, chromatin condensation and nuclear budding phenomenon could be found in the cells treated with DON. In addition to the effects on apoptosis, 4 mg/kg and 8 mg/kg DON treatment could significantly decrease the PIs of the treated thymocytes in vivo as compared with control.CONCLUSION:DON can induce and enhance murine thymocytes apoptosis in a dose-dependant manner and inhibit the proliferation activities of the treated cells.     

Origin of smooth muscle cells in vascular neointima from recipient bone marrow cells in rat aortic allograft

AIM: To study the expression of Sry gene in neointimal smooth muscle cells (NI-SMCs),and to investigate the origin of NI-SMCs in rat aortic allograft.METHODS: Sex-mismatched bone marrow transplantation was performed from male Wistar rat to female Wistar rat.Four weeks after transplantation,the aortic transplant model was constituted by means of micro-surgery in rat.The recipients were divided into four groups: female-female aortic isografts,female-female aortic allografts,male-male aortic allografts,female-chimera aortic allografts.Eight weeks after transplantation,aortic grafts were removed and processed for histological evaluation and immunohistochemistry assay.The Sry gene-specific PCR was performed on the genome of NI-SMCs to analyze its origin involved in aortic allograft.RESULTS: Excessive accumulation of α-SMA-positive SMCs resulted in significant neointima formation in rat aortic allografts.The neointimal area and NIA/MA ratio of transplanted artery were significantly increased in all aortic allograft groups compared with those in aortic isograft group (P<0.01).PCR assay indicated that a distinct DNA band with 225 bp emerged in the male-male aortic allograft group and chimera aortic allograft group respectively,but not in the female-female aortic allograft group,was observed.CONCLUSION: As the origin of NI-SMCs,recipient bone marrow cells contribute to the pathological neointimal hyperplasia of aortic allograft.     

基质细胞衍生因子1α介导小鼠内皮祖细胞修复损伤血管内膜

目的探讨损伤血管局部表达的基质细胞衍生因子1α是否能介导内皮祖细胞参与损伤血管的再内皮化,抑制新生内膜的增生。方法培养、获取小鼠骨髓源性内皮祖细胞,采用改良的Boyden小室测定基质细胞衍生因子1α诱导的内皮祖细胞迁移及AMD3100(CXCR4的拮抗剂)对其的影响。分别将内皮祖细胞培养基、内皮祖细胞及AMD3100孵育过的内皮祖细胞经心脏穿刺注射给颈动脉损伤小鼠,在14天后取损伤血管检测内皮祖细胞募集情况、再内皮化情况及新生内膜增生情况。结果基质细胞衍生因子1α能诱导内皮祖细胞迁移(与对照组比较P<0.01),AMD3100能有效阻断该作用(AMD3100组与对照组比较P>0.05)。较多注射的内皮祖细胞成功归巢到损伤血管处(14.2±3.6个/切片),AMD3100孵育过的内皮祖细胞仅少量可成功归巢(4.0±2.5个/切片);内皮祖细胞注射能加速损伤血管的再内皮化(内皮祖细胞移植组比对照组:83.45%±5.44%比66.46%±6.16%,P<0.01),AMD3100孵育过的内皮祖细胞注射则无效(68.02%±6.68%,与对照组比较P>0.05);内皮祖细胞移植组新生内膜增生厚度(19237±1875μm2)和内膜中膜比值(0.94±0.12)均小于对照组(34676±2412μm2和1.77±0.18)及AMD3100组(32451±2081μm2和1.60±0.17)(P<0.01)。结论基质细胞衍生因子1/CXCR-4在介导移植的内皮祖细胞修复损伤血管内膜中起重要作用。