Inhibitory effects of rosiglitazone on paraquat-induced acute lung injury in rats.

AIM: To investigate the effects of the PPAR-γ agonist rosiglitazone on acute lung injury induced by the herbicide paraquat (PQ) and the underlying mechanisms of action. METHODS: Male Sprague-Dawley rats were injected with PQ (20 mg/kg, ip). Rosiglitazone (3 or 10 mg/kg, ip) was administered 1 h before PQ exposure. Peripheral blood was collected at 4, 8, 24 and 72 h after PQ exposure for measuring the levels of MDA, TNF-α and IL-1ß, and the SOD activity. Lung tissues were collected at 72 h after PQ exposure to determine the wet-to-dry (W/D) ratios and lung injury scores, as well as the protein levels of NF-κBp65, PPAR-γ, Nrf2, IκBα and pIκBα. RESULTS: At 72 h after PQ exposure, the untreated rats showed a 100% cumulative mortality, whereas no death was observed in rosiglitazone-pretreated rats. Moreover, rosiglitazone pretreatment dose-dependently attenuated PQ-induced lung edema and lung histopathological changes. The pretreatment significantly reduced the levels of TNF-α, IL-1ß and MDA, increased SOD activity in the peripheral blood of PQ-treated rats. The pretreatment also efficiently activated PPAR-γ, induced Nrf2 expression and inhibited NF-κB activation in the lung tissues of PQ-treated rats. Furthermore, the pretreatment dose-dependently inhibited IκB-α degradation and phosphorylation, thus inhibiting NF-κB activation. CONCLUSION: Pretreatment with rosiglitazone protects rats against PQ-induced acute lung injury by activating PPAR-γ, inducing Nrf2 expression and inhibiting NF-κB activation.

Lactational zinc deficiency-induced hippocampal neuronal apoptosis by a BDNF-independent TrkB signaling pathway.

It is well-known that zinc deficiency leads to neuronal death in the brain. Here we tested the hypothesis that changes in the TrkB signaling pathway are involved in hippocampal neuronal apoptosis of suckling offspring with maternal zinc deficiency. Postpartum mice were fed a zinc-deficient (0.85 ppm) diet and their offspring were used as a lactational zinc deficiency mouse model. At P7, P14, and P21, changes in hippocampal neuronal apoptosis were assessed by Nissl and TUNEL staining. BDNF levels and TrkB neurotrophic signaling were examined using immunoblotting assay. Lactational zinc deficiency resulted in lower levels of p-TrkB and p-ERK, and higher levels of Bax/Bcl-2 and caspase-3 in the hippocampus, suggesting that zinc deficiency-induced low levels of TrkB phosphorylation would abrogate the downstream ERK signaling pathway, leading to hippocampal neuronal apoptosis. Most interestingly, our data showed that the activity of Src, a key molecule for zinc-induced TrkB activation through the BDNF-independent pathway, was inhibited significantly, and the expression levels of BDNF were significantly increased in the hippocampus of suckling mice. The present data indicate that zinc depletion-induced hippocampal neuronal apoptosis is likely through modulation of the TrkB neurotrophic signaling pathway by a BDNF-independent and Src-dependent mechanism, whereas higher expression of BDNF is considered as a protective response, which cannot fully compensate for the injury caused by maternal zinc deficiency.

Zinc Prevents Abdominal Aortic Aneurysm Formation by Induction of A20-Mediated Suppression of NF-κB Pathway.

Chronic inflammation and degradation of elastin are the main processes in the development of abdominal aortic aneurysm (AAA). Recent studies show that zinc has an anti-inflammatory effect. Based on these, zinc may render effective therapy for the treatment of the AAA. Currently, we want to investigate the effects of zinc on AAA progression and its related molecular mechanism. Rat AAA models were induced by periaortic application of CaCl2. AAA rats were treated by daily intraperitoneal injection of ZnSO4 or vehicle alone. The aorta segments were collected at 4 weeks after surgery. The primary rat aortic vascular smooth muscle cells (VSMCs) were stimulated with TNF-α alone or with ZnSO4 for 3 weeks. The results showed that zinc supplementation significantly suppressed the CaCl2-induced expansion of the abdominal aortic diameter, as well as a preservation of medial elastin fibers in the aortas. Zinc supplementation also obviously attenuated infiltration of the macrophages and lymphocytes in the aortas. In addition, zinc reduced MMP-2 and MMP-9 production in the aortas. Most importantly, zinc treatment significantly induced A20 expression, along with inhibition of the NF-κB canonical signaling pathway in vitro in VSMCs and in vivo in rat AAA. This study demonstrated, for the first time, that zinc supplementation could prevent the development of rat experimental AAA by induction of A20-mediated inhibition of the NF-κB canonical signaling pathway.

Comparison of in vivo adipogenic capabilities of two different extracellular matrix microparticle scaffolds.

BACKGROUND: The extracellular matrix is an essential microenvironment for cell survival activity. The adipose tissue extract microparticle scaffolds from human adipose tissue and small intestine submucosa microparticle scaffolds from porcine jejunum were prepared. Their effects on the adipogenic capabilities of human adipose-derived stem cells were compared in vivo. METHODS: A combination of physical and chemical methods was used to decellularize human fat and porcine jejunum. Expression of CD molecules on the adipose-derived stem cell surface was determined by flow cytometry. The stem cells were then cultured with the scaffold materials in vitro. The cell-scaffold complexes were implanted subcutaneously into nude mice, and samples were collected 4 and 8 weeks later. The adipogenic differentiation capabilities of adipose-derived stem cells were studied by histologic methods and real-time polymerase chain reaction. RESULTS: The authors observed high expression of CD90 and CD44; no expression of CD34, CD45, CD31, or CD106; and weak positive expression of CD49d on the extracted cells, which indicates that the cells were adipose-derived stem cells. The main constituent of the decellularized adipose tissue extract and small intestine submucosa microparticles was collagenous fiber, and the cells proliferated faster on the adipose tissue extract than on small intestine submucosa. Formation of adipocytes in the adipose tissue extract group was closer to that of normal human fat tissue compared with that of the small intestine submucosa group. CONCLUSIONS: Extracellular matrix microparticle scaffolds could promote proliferation, adhesion, and adipogenic differentiation of adipose-derived stem cells. The role of the adipose tissue extract microparticle scaffold in promoting adipogenesis was stronger and more suitable as a vector in fatty tissue engineering.

XAV939, a tankyrase 1 inhibitior, promotes cell apoptosis in neuroblastoma cell lines by inhibiting Wnt/ß-catenin signaling pathway.

BACKGROUND: Neuroblastoma (NB) is the most common extracranial solid tumor in childhood. The present treatment including surgery, chemotherapy and radiation, which have only 40% long-term cure rates, and usually cause tumor recurrence. Thus, looking for new effective and less toxic therapies has important significance. XAV939 is a small molecule inhibitor of tankyrase 1(TNKS1). The objective of this study is to investigate the effect of XAV939 on the proliferation and apoptosis of NB cell lines, and the related mechanism. METHODS: In the present study, we used both XAV939 treatment and RNAi method to demonstrate that TNKS1 inhibition may be a potential mechanism to cure NB. MTT method was used for determining the cell viability and the appropriate concerntration for follow-up assays. The colony formation assay, Annexin V staining and cell cycle analysis were used for detecting colony forming ability, cell apoptosis and the percentage of different cell cycle. The Western blot was used for detecting the expression of key proteins of Wnt/ beta-catenin (Wnt/ß-catenin) signaling pathway. RESULTS: The results showed that TNKS1 inhibition decreased the viability of SH-SY5Y, SK-N-SH and IMR-32 cells, induced apoptosis in SH-SY5Y as well as SK-N-SH cells, and led to the accumulation of NB cells in the S and G2/M phase of the cell cycle. Moreover, we demonstrated TNKS1 inhibition may in part blocked Wnt/ß-catenin signaling and reduced the expression of anti-apoptosis protein. Finally, we also demonstrated that TNKS1 inhibition decreased colony formation in vitro. CONCLUSIONS: These findings suggested that TNKS1 may be a potential molecule target for the treatment of NB.

Curcumin attenuates rat thoracic aortic aneurysm formation by inhibition of the c-Jun N-terminal kinase pathway and apoptosis.

OBJECTIVE: Recent studies have suggested that c-Jun N-terminal kinase (JNK) plays an important role in the formation of abdominal aortic aneurysms, and that direct blockade of JNK by specific inhibitors can effectively prevent the progression of aortic aneurysms. A study has demonstrated that curcumin can suppress the development of experimental abdominal aortic aneurysms by inhibiting inflammation. We sought to investigate whether curcumin could inhibit JNK pathways and apoptosis in thoracic aortic aneurysms. METHODS: We used a rat model of a CaCl2-induced thoracic aortic aneurysm followed by daily oral gavage with curcumin 100 mg/kg or vehicle alone. After treatment for 4 wk, tissue specimens were obtained for histologic assessments, and tissue composition was evaluated using immunohistochemistry, western blotting, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. RESULTS: Curcumin significantly suppressed the CaCl2-induced expansion of the thoracic aortic diameter and the structural preservation of medial elastin fibers. Most importantly, curcumin treatment significantly inhibited the phosphorylation of JNK and c-Jun, accompanied by less cell apoptosis in thoracic aortic aneurysm tissues. Furthermore, the expression levels of caspase-3 and the Bax/Bcl-2 ratio were significantly decreased in the aortic walls of curcumin-treated rats. CONCLUSION: The present study indicates that the beneficial effect of curcumin on degenerative aortic aneurysms is related to the inhibition of JNK and apoptosis in the walls of thoracic aortic aneurysms.

MCP-1, ICAM-1 and VCAM-1 are present in early aneurysmal dilatation in experimental rats.

Recent studies have suggested that inflammation actively participates in ascending aortic aneurysm formation. The aim of the present study was to evaluate the expression changes of adhesion molecules and MMPs in an experimental model of ascending aortic aneurysm induced by ascending aorta banding in Wistar rats. Twelve rats developed aortic dilation after ascending aorta banding treatment, while nine normal animals underwent surgery without banding were used as controls. Light microscope and scanning electron microscope showed that the wall of the ascending aorta became disorganized as well as infiltration by inflammatory cells in aneurysmal rats. By using immunohistochemical techniques, a significant increase in the immunostaining of MCP-1 was observed in the aneurysmal wall as compared to the normal aortic wall. Under similar experimental conditions, we also found that the immunostaining of ICAM-1 and VCAM-1 was markedly increased in the aneurysmal wall. In addition, gelatin zymographic analysis showed that the expression and activities of MMP-2 and MMP-9 were remarkably enhanced in the ascending aorta of ascending aortic aneurysmal rats as compared to normal rats. These results demonstrate that MCP-1, ICAM-1 and VCAM-1 are involved in the pathogenesis of ascending aortic aneurysm and an increase in the immunostaining and activity of MMP-2 and MMP-9 may promote the progression of ascending aortic aneurysm.

[Investigation of the layers and vascular density of the soft tissue in the inferior nasal portion].

OBJECTIVE: To observe the layers and vascular structures of the soft tissue (including the skin) in the inferior part of external nose (nasal inferior portion) for providing the essential morphological data used for the correction of the bulbous nose and the tip of nose with thick skin. METHODS: Under a light microscope, the density of microangium (vascular area/frame area) in each layer was measured with an image analyzer. RESULTS: The stained soft tissue in the nasal inferior portion could be definitely divided into 5 layers: epidermis, dermis, superficial fascia, fibromuscular layer and perichondrium. According to the density of microangium, the sequence of these layers was: perichondrium, reticular layer, fibromuscular layer, sub-papillary layer, superficial fascia and papillary layer. CONCLUSIONS: The soft tissue in the nasal inferior portion consists of 5 layers, which is similar to the structure of the face and neck. Both the total thickness of these 5 layers and the thickness of the dermis are much thicker than those of the Caucasus', and suit to rhinoplasty for bulbous nose According to the results of vascular density analysis, the skin thinning procedure in the rhinoplasty for bulbous nose should start from the superficial fascia firstly, then the fibromuscular layer.

[Component analysis of bone matrix via cell extraction].

OBJECTIVE: To investigate the preparation of bone acellular extra-cell matrix(AECM) and to analyze its component. METHODS: With low-osmosis theory and method of cell extraction by detergent, bone acellular extra-cell matrix was prepared. We observed morphologic changes with HE, Mallory-Heidenhain rapid one-step dyeing and Alcian blue dyeing and examined fibronectin(FN) and laminin(LN) with immunohistochemistry. RESULTS: Light microscope showed that the collagen fibers arranged regularly in AECM with blankness of bone lacunas by HE, Mallory-Heidenhain rapid one-step dyeing and that the region around bone lacunas was stained different degrees of blue-green by Alcian blue dyeing. The result of immunohistochemistry showed there are positive markers of FN and LN in ECM. CONCLUSION: This method for preparation of bone acellular extra-cell matrix is effective, and it can keep natural structure of collagen fibers and maintain components of ECM, such as proteoglycan, FN and LN.