The angiogenic response is essential for the repair of ischemic brain tissue. Integrin α6 (Itga6) expression has been shown to increase under hypoxic conditions and is expressed exclusively in vascular structures; however, its role in post-ischemic angiogenesis remains poorly understood. In this study, we demonstrate that mice with endothelial cell-specific knockout of Itga6 exhibit reduced neovascularization, reduced pericyte coverage on microvessels, and accelerated breakdown of microvascular integrity in the peri-infarct area. In vitro, endothelial cells with ITGA6 knockdown display reduced proliferation, migration, and tube-formation. Mechanistically, we demonstrated that ITGA6 regulates post-stroke angiogenesis through the PI3K/Akt-eNOS-VEGFA axis. Importantly, the specific overexpression of Itga6 in endothelial cells significantly enhanced neovascularization and enhanced the integrity of microvessels, leading to improved functional recovery. Our results suggest that endothelial cell Itga6 plays a crucial role in key steps of post-stroke angiogenesis, and may represent a promising therapeutic target for promoting recovery after stroke.
Animals ; Nitric Oxide Synthase Type III/metabolism* ; Mice ; Proto-Oncogene Proteins c-akt/metabolism* ; Integrin alpha6/genetics* ; Endothelial Cells/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Stroke/pathology* ; Vascular Remodeling/physiology* ; Vascular Endothelial Growth Factor A/metabolism* ; Mice, Knockout ; Signal Transduction/physiology* ; Mice, Inbred C57BL ; Male ; Neovascularization, Physiologic/physiology*

OBJECTIVETo explore the clinicopathological significance and relationship of Tspan 1 and Integrin α6 expression in pancreatic ductal adenocarcinoma (PDAC) tissue and pancreatic cancer cell lines.

METHODSImmunohistochemistry was used to detect the expression of Tspan 1 and Integrin α6 in 95 paraffin-embedded PDAC specimens and 55 adjacent non-cancerous pancreatic tissues which were collected from May 2004 to January 2013.Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detected the protein and mRNA expression in 16 paired fresh PDAC specimens of the pancreas and adjacent non-cancerous pancreatic tissues and 6 different pancreatic cancer cell lines.χ(2) test, Spearman-rank correlation analysis, Kaplan-Meier method and multivariate Cox regression analysis were used to analyze the data.

RESULTSTspan 1 and Integrin α6 were significantly over-expressed in PDAC than in adjacent non-cancerous pancreatic tissues (χ(2) = 7.429, P < 0.05; χ(2) = 15.1, P < 0.01). Lymph node metastasis, TNM stage and post-operation recurrence were positively correlated with the expression of Tspan 1 (χ(2) = 6.688, P < 0.01; χ(2) = 13.055, P < 0.01; χ(2) = 6.116, P < 0.05) . TNM stage was positively correlated with the expression of Integrin α6 (χ(2) = 8.896, P < 0.05) . Tspan 1 was correlated with Integrin α6 (r = 0.223, P < 0.05) . The expressions of Tspan 1 and Integrin α6 were negatively correlated with survival time (χ(2) = 5.263, P < 0.05;χ(2) = 10.124, P < 0.01) . Multivariate analysis revealed that Tspan 1 and Integrin α6 expressions were independent prognostic factors in PDAC patients (χ(2) = 6.152, P < 0.05; χ(2) = 9.479, P < 0.01). Western blot (t = 2.278, P < 0.05; t = 3.153, P < 0.05) and qRT-PCR (t = 2.439, P < 0.05; t = 3.258, P < 0.05) showed that Tspan 1 and Integrin α6 expressions were higher in PDAC tissues than in adjacent non-cancerous pancreatic. Tspan 1 and Integrin α6 were expressed in all six pancreatic cancer cell lines.In SW1990 which derived from metastasis PDAC, Tspan 1 and Integrin α6 expressions were higher than the cell lines from primary tumor.

CONCLUSIONTspan 1 and Integrin α6 expression can up-regulate the invasion and metastasis of PDAC and may be used to predict the prognosis of PDAC.

Adenocarcinoma ; pathology ; Carcinoma, Pancreatic Ductal ; pathology ; Cell Line, Tumor ; Humans ; Immunohistochemistry ; Integrin alpha6 ; metabolism ; Kaplan-Meier Estimate ; Lymphatic Metastasis ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Pancreas ; Pancreatic Neoplasms ; pathology ; Prognosis ; Real-Time Polymerase Chain Reaction ; Tetraspanins ; metabolism

Over-expression of CD151 was found to be associated with metastasis and poor prognosis of prostatic carcinoma. This study was designed to examine the mechanism by which CD151 promotes the proliferation and migration of prostatic cancer cells. The pAAV-CD151, pAAV-GFP and pAAV-CD151-AAA mutant plasmids were constructed and used to transiently transfect PC3 cells (a prostatic carcinoma 3 cell line) by the mediation of Fugene HD. Then, the cells were assigned to control group, pAAV-GFP group, pAAV-CD151 group, and pAAV-CD151-AAA group respectively. Cell proliferation was evaluated by using the 3-[4,5-dimet-hylthiazol-2-yl]-2,5, diphenyltetrazolium bromide (MTT) method. Cell migration assay was performed by using Boyden chambers. The formation of CD151-integrin α3/α6 complex was determined by the method of co-immunoprecipitation. The protein expression levels of CD151 and extracellular signal-regulated kinase (ERK) were measured by Western blotting. The results showed that transfection of pAAV-CD151 or pAAV-CD151-AAA mutant increased the expression of CD151 protein in PC3 cells. Co-immunoprecipitation showed that more CD151-integrin α3/α6 complex was formed in the pAAV-CD151 group than in the control group, the pAAV-GFP group and the pAAV-CD151-AAA mutant group. Furthermore, the proliferative and migrating capacity of PC3 cells was substantially increased in the pAAV-CD151 group but inhibited in the pAAV-CD151-AAA mutant group. CD151 transfection increased the expression of phospho-ERK. Taken together, it was concluded that CD151 promotes the proliferation and migration of PC3 cells through the formation of CD151-integrin complex and the activation of phosphorylated ERK.
Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Humans ; Integrin alpha3 ; metabolism ; Integrin alpha6 ; metabolism ; Male ; Prostatic Neoplasms ; metabolism ; pathology ; Tetraspanin 24 ; metabolism

Breast cancer stem cells are a group of undifferentiated cells with self-renewal and multidifferentiation potential. Chemotherapeutic and radiotherapeutic resistance, hypoxic resistance, high tumorigenicity, high cell invasion, and metastatic abilities are characteristics of these cells, which are responsible for breast cancer recurrence. Therefore, the correct sorting and identification of breast cancer stem cells is a primary step for research in this field. This article briefly describes the recent progress on sorting and identification technologies for breast cancer stem cells. Sorting technologies include the side population technique, technologies that depend on cell surface markers, ALDEFLUOR assays, and in situ detection. Identification technologies include mammosphere cultures, limited dilution in vitro, and in-vivo animal models. This review provides an important reference for breast cancer stem cell research, which will explore new methods for the treatment of patients with breast cancer.
AC133 Antigen ; ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; metabolism ; Aldehyde Dehydrogenase ; metabolism ; Animals ; Antigens, CD ; metabolism ; Breast Neoplasms ; pathology ; Female ; Flow Cytometry ; methods ; Glycoproteins ; metabolism ; Humans ; Hyaluronan Receptors ; metabolism ; Integrin alpha6 ; metabolism ; Integrin beta1 ; metabolism ; Integrin beta3 ; metabolism ; Isoenzymes ; metabolism ; Membrane Proteins ; metabolism ; Neoplasm Proteins ; metabolism ; Neoplastic Stem Cells ; metabolism ; pathology ; Peptides ; metabolism ; Retinal Dehydrogenase ; metabolism ; Side-Population Cells ; cytology ; metabolism

The adaptor protein, LAD/TSAd, plays essential roles in T cell activation. To further understand the functions of this protein, we performed yeast two-hybrid screening using TSAd as bait and identified 67 kDa laminin binding protein (LBP) as the interacting partner. Subsequently, TSAd-LBP interaction was confirmed in D1.1 T cell line. Upon costimulation by T cell receptor (TCR) plus laminin crosslinking or TCR plus integrin alpha6 crosslinking, LBP was coimmunoprecipitated with TSAd. Moreover, TCR plus laminin costimulation-dependent T cell migration was enhanced in D1.1 T cells overexpressing TSAd but was disrupted in D1.1 cells overexpressing dominant negative form of TSAd or TSAd shRNA. These data show that, upon TCR plus integrin costimulation, TSAd associates with LBP and mediates T lymphocyte migration.
Adaptor Proteins, Signal Transducing/genetics/*metabolism ; Amino Acids, Diamino/metabolism ; Carrier Proteins/*metabolism ; *Cell Movement ; Humans ; Integrin alpha6/metabolism ; Jurkat Cells ; Mutation ; Protein Binding ; RNA, Small Interfering/genetics ; *Receptor Cross-Talk ; Receptors, Antigen, T-Cell/metabolism ; T-Lymphocytes/*metabolism ; Transgenes ; Two-Hybrid System Techniques

In postmenopausal osteoporosis, estrogen deficiency leads to unbalance of bone metabolism, decreased bone formation and increased bone resorption, and the result is reduced bone mineral density (BMD) and bone stiffness. The processes of bone formation and resorption involves the expression of integrins in anchoragedependent cells, such as osteoblast and osteoclast. The osteoporosis-induced rats frequently demonstrated the loss of trabecular bone volume in the tibia, vertebra and mandible due to estrogen depletion. However, in maxilla, study has been rare because of its anatomical limits. So the objective of this study was to investigate bony change and property of integrin expression in maxilla of osteoporosis-induced rats. 12-week-old female Sprague-Dawley rats were bilaterally ovariectomized (OVX). At 1, 2, 3, 4, 8 and 12 weeks, control and OVX group rats were sacrificed respectively. BMD of maxilla of the rats was measured using dual-energy X-ray absorptiometry (DEXA). And then the histopathologic observation, histomorphometric analysis and immunohistochemistry with CD44, alpha2 integrin, alpha5 integrin, alpha6 integrin, alphav integrin and beta3 integrin were done. BMD of alveolar bone in maxilla was decreased with significance statistically after OVX 4 weeks and was decreased 18.15% at OVX 12 weeks group compared to control group. From OVX 4 to 12 weeks, the thickness of periodontal ligament space was decreased, the number of osteoclast and the size of marrow stroma were increased than control group. By histomorphometric analysis, the size of marrow stroma of alveolar bone in maxilla was increased 86.42% at OVX 12 weeks group compared to control group. CD44 was widely expressed throughout the odontoblast, cementoblast, dental pulp, preiodontal ligament, osteocyte, osteoclast and perivascular tissue at control group, and CD44 immunoreactivity was increased the odontoblast, osteoblast and osteoclast at OVX groups. alpha2 integrin was expressed the odontoblast and osteoblast at control group, but alpha2 integrin immunoreactivity was decreased the osteoblast at OVX 12 weeks group. alpha5 integrin was expressed the cementoblast, osteoblast and osteoclast at control group, and alpha5 integrin immunoreactivity was decreased the osteoblast and was increased the osteoclast from OVX 4 weeks group. alpha6 integrin was weakly expressed the odontoblast, cementoblast, osteoblast and osteoclast at control group, and alpha6 integrin immunoreactivity was weakly increased the osteoclast from OVX 4 weeks. alphav integrin was expressed the odontoblast and osteoclast at control group, and alphav integrin immunoreactivity was strongly increased the osteoclast from OVX 4 weeks. beta3 integrin was expressed the osteocyte and osteoclast at control group, and beta3 integrin immunoreactivity was strongly increased the osteoclast from OVX 4 weeks. From these results, alveolar bone in maxilla of OVX rats was decreased BMD gradually. Moreover, alpha2 and alpha5 integrin expression of osteoblast was decreased, and alpha5, alphav and beta3 integrin expression of osteoclast was increased in OVX rats. Thus, this study indicates that consideration of reduced BMD is necessary in dental procedure of postmenopausal women.
Absorptiometry, Photon ; Animals ; Bone Density* ; Bone Marrow ; Bone Resorption ; Dental Cementum ; Dental Pulp ; Estrogens ; Female ; Humans ; Immunohistochemistry ; Integrin alpha2 ; Integrin alpha5 ; Integrin alpha6 ; Integrin alphaV ; Integrin beta3 ; Integrins ; Ligaments ; Mandible ; Maxilla* ; Metabolism ; Odontoblasts ; Osteoblasts ; Osteoclasts ; Osteocytes ; Osteogenesis ; Osteoporosis, Postmenopausal ; Ovariectomy* ; Periodontal Ligament ; Rats* ; Rats, Sprague-Dawley ; Spine ; Tibia

OBJECTIVETo explore the expression of integrin alpha 6 in hepatic sinusoidal capillaration.

METHODSThe rat hepatic fibrosis model was established by injection of carbon tetrachloride subcutaneously. Then the expression of laminin and integrin alpha 6 subunit was observed by immunohistochemistry and dot immuno-blotting.

RESULTSWe observed sinusoidal capillaration formed by deposition of laminin along sinusoids in Disse interspace by immunohistochemistry staining. In normal rat the expression of integrin alpha 6 was restricted to portal vascular endothelial cells and bile duct epithelial cell membranes. No expression was observed in sinusoidal endothelial cell membranes. When capillaration integrin alpha 6 was detected in a continuous pattern along the sinusoids, the content of integrin alpha 6 was significantly higher in fibrotic liver tissues than in normal liver tissues as measured by dot immuno-blotting (P<0.05).

CONCLUSIONSDuring fibrogenesis, laminin continuously accumulate in liver tissues and form basement membrane resulting in sinusoidal capillaration, and then induce the expression of integrin alpha 6 on SEC membranes.

Animals ; Antigens, CD ; biosynthesis ; Carbon Tetrachloride ; Immunoblotting ; Immunohistochemistry ; Integrin alpha6 ; Laminin ; metabolism ; Liver ; metabolism ; pathology ; Liver Cirrhosis, Experimental ; chemically induced ; metabolism ; pathology ; Male ; Rats ; Rats, Wistar ; Time Factors