Endometrial integrin expression in women undergoing IVF and ICSI: a comparison of the two groups and fertile controls

BACKGROUND: Integrins are thought to play a vital role in implantation. Three integrins in particular (alpha(4)beta(1), alpha(v)beta(3) and alpha(1)beta(1)) are all present during the implantation window. Defects in their expression have been linked to tubal disease, unexplained infertility and endometriosis. Hence, a reduced endometrial integrin expression would be expected in women attending for IVF due to these causes of infertility when compared with those with male factor infertility attending for ICSI. METHODS: Women attending for IVF (n = 25) and ICSI (n = 25) treatment were recruited, and timed endometrial biopsies were taken during the 'implantation window' (cycle day 20-24). A group of fertile women (n = 15) attending for sterilization was used as controls. RESULTS: There was no significant difference in integrin expression between patients undergoing IVF or ICSI. Neither did these groups differ from the control group. CONCLUSIONS: The endometrium in patients undergoing ICSI treatment is sometimes thought to be more receptive, as the infertility might be due to a male factor. This study shows that there is no significant difference in integrin expression between patients attending for IVF or ICSI and the control group. These data add to the increasing uncertainty about the clinical value of assessing the endometrium with only one marker, in this case integrins.     

Establishment of an in vitro assay to measure the invasion of ovarian carcinoma cells through mesothelial cell monolayers

Ovarian carcinoma is the leading cause of gynecological cancer deaths in the United States. Secondary tumor growths form by tumor cell invasion through the mesothelial lining of the peritoneal cavity and peritoneal organs. To study this interaction, we developed a dye-based in vitro model system in which mesothelial cells were grown as confluent monolayers, permeabilized, and then co-cultured with ovarian carcinoma cells for up to seven days. The mesothelial cells were then stained with trypan blue dye, which enabled the visualization of ovarian carcinoma cell invasion through the monolayers of mesothelial cells. Ovarian carcinoma cell invasion was inhibited for up to 7 days by the addition of GRGDSP peptides, a blocking monoclonal antibody against the β1 integrin subunit, or blocking monoclonal antibodies against matrix metalloproteinases 2 and 9. Cell invasion was also inhibited by hyaluronan and GM6001, a chemical inhibitor of matrix metalloproteinases. Differential gene expression of matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases, and disintegrins were observed in primary ovarian carcinoma tumors and secondary metastases, compared to normal ovaries. Taken together, these results suggest that complex interactions between integrins, disintegrins, matrix metalloproteinases, and tissue inhibitors of matrix metalloproteinases may mediate ovarian carcinoma cell invasion, and that the dye-based assay described herein is a suitable model system for its study. This revised version was published online in July 2006 with corrections to the Cover Date.     

Structure–activity relationship of human bone sialoprotein peptides

In the current study, the relationship between the structure of the RGD‐containing human bone sialoprotein (hBSP) peptide 278–293 and its attachment activity toward osteoblast‐like (MC3T3) cells was investigated. This goal was accomplished by examining the comparative cell‐attachment activities of several truncated forms of peptide 278–293. Computer modeling of the various peptides was also performed to assess the role of secondary structure in peptide bioactivity. Elimination of tyrosine‐278 at the N‐terminus resulted in a more dramatic loss of cell‐attachment activity compared with the removal of either tyrosine‐293 or the arg‐ala‐tyr (291–293) tripeptide. Although replacement of the RGD (arg‐gly‐asp) peptide moiety with peptide KAE (lys‐ala‐glu) resulted in a dramatic loss of cell‐attachment activity, a peptide containing RGE (arg‐gly‐glu) in place of RGD retained 70–85% of the parental peptide's attachment activity. These results suggest that the N‐terminal RGD‐flanking region of hBSP peptide 278–293, in particular the tyrosine‐278 residue, represents a second cell‐attachment site that stabilizes the RGD–integrin receptor complex. Computer modeling also suggested that a β‐turn encompassing RGD or RGE in some of the hBSP peptides may facilitate its binding to integrins by increasing the exposure of the tripeptide. This knowledge may be useful in the future design of biomimetic peptides which are more effective in promoting the attachment of osteogenic cells to implant surfaces in vivo.     

Expression of adhesion molecules in Langerhans' cell histiocytosis

Expression of adhesion molecules was investigated in six biopsy specimens of Langerhans' cell histiocytosis using immunocytochemistry. Cells with Langerhans' cell histiocytosis morphology were stained for ICAM-1, for the beta-1 integrins alpha-4 (VLA-4) and alpha-5 (VLA-5), and for the beta-2 integrins LFA-1, MAC-1 and p150,95. This pattern of reactivity was different from that of epidermal Langerhans' cells of the normal skin which were not immunostained. A variable number of CD68+ multinucleated giant cells was present in five biopsies. They were less reactive than the cells of Langerhans' cell histiocytosis for alpha-4 (VLA-4) and LFA-1, were positive for MAC-1 and p150,95 and were characterized by prominent expression of the beta-1 integrins alpha-2 (VLA-2), alpha-3 (VLA-3) and of VnR (alpha-v/ beta-3). The repertoire of adhesion molecules expressed by giant cells is indicative of profound cell-matrix interactions, whereas that of Langerhans' histiocytosis cells suggests particularly active cell–cell interactions. Blood vessels of the lesions were stained for beta-1 integrins, for vitronectin receptor and for molecules involved in adhesion and trans-endothelial migration of circulating leukocytes, such as ICAM-1, VCAM-1 and E-selectin. Additional findings were the observation of CD1a+ multinucleated giant cells in a single case, suggesting a possible lineage relationship with the histiocytosis cells, and the demonstration of some Ki-67+ Langerhans' cell histiocytosis cells and CD1a+ mitotic figures in four of six cases, indicating local proliferation of Langerhans' histiocytosis cells.     

Role of Integrin CD103 in Promoting Destruction of Renal Allografts by CD8+ T Cells

Infiltration of CD8(+)TCRalphabeta(+) T-effector populations (CD8 effectors) into graft epithelial compartments has long been recognized as a key lesion in progression of clinical renal allograft rejection. While the afferent phase of allograft immunity is increasingly well-defined, the efferent pathways by which donor-reactive CD8-effector populations access and ultimately destroy the graft renal tubules (rejection per se) have received remarkably little attention. This is an important gap in our knowledge of transplantation immunology, because epithelial compartments comprise the functional elements of most commonly transplanted organs including not only kidney, but also liver, lung, pancreas, and intestine. Furthermore, there is increasing evidence that attack of graft epithelial elements by CD8-effector populations not only causes short-term graft dysfunction but is also a major contributor to development of chronic allograft nephropathy and late graft loss, which now represent the salient clinical problems. Recent studies of the T-cell integrin, alpha(E)beta(7) (CD103), have provided insight into the mechanisms that promote interaction of CD8 effectors with graft epithelial compartments. The purpose of this communication is to review the known properties of the CD103 molecule and its postulated role in the efferent phase of renal allograft rejection.     

荷瘤裸鼠整合素αv β3受体显像的实验研究

目的探讨99Tcm标记精氨酸-甘氨酸-天冬氨酸（RGD）小分子多肽（GY11）作为肿瘤显像剂的可能性.方法利用SnCl2直接还原法进行GY11的^99Tcm标记.建立荷人黑色素瘤A375、肺癌H460和宫颈癌HeLa BALB/c裸鼠肿瘤模型,分别进行体内分布和肿瘤显像研究.结果GY11的^99Tcm标记率为80%.黑色素瘤A375荷瘤裸鼠体内分布显示,^99Tcm-GY11主要经肾脏快速从血液中清除,注射后2 h肿瘤摄取量为3.13%ID/g,肿瘤/血和肿瘤/骨骼肌比值随时间的推移而增加,注射后1和6 h比值分别为3.0、4.3和8.1、15.1.对于黑色素瘤A375和肺癌H460荷瘤裸鼠,^99Tcm-GY11静脉注射后2 h肿瘤均能清楚显示,24 h后显像更清晰;2 h后宫颈癌HeLa肿瘤能显影,但6 h后肿瘤放射性基本清除.结论^99Tcm-GY11有望成为肿瘤αvβ3受体显像剂.     

Treatment with 3‐aminobenzamide during ex vivo lung perfusion of damaged rat lungs reduces graft injury and dysfunction after transplantation

Ex vivo lung perfusion (EVLP) with pharmacological reconditioning may increase donor lung utilization for transplantation (LTx). 3‐Aminobenzamide (3‐AB), an inhibitor of poly(ADP‐ribose) polymerase (PARP), reduces ex vivo lung injury in rat lungs damaged by warm ischemia (WI). Here we determined the effects of 3‐AB reconditioning on graft outcome after LTx. Three groups of donor lungs were studied: Control (Ctrl): 1 hour WI + 3 hours cold ischemia (CI) + LTx; EVLP: 1 hour WI + 3 hours EVLP + LTx; EVLP + 3‐AB: 1 hour WI + 3 hours EVLP + 3‐AB (1 mg^.mL^?1) + LTx. Two hours after LTx, we determined lung graft compliance, edema, histology, neutrophil counts in bronchoalveolar lavage (BAL), mRNA levels of adhesion molecules within the graft, as well as concentrations of interleukin‐6 and 10 (IL‐6, IL‐10) in BAL and plasma. 3‐AB reconditioning during EVLP improved compliance and reduced lung edema, neutrophil infiltration, and the expression of adhesion molecules within the transplanted lungs. 3‐AB also attenuated the IL‐6/IL‐10 ratio in BAL and plasma, supporting an improved balance between pro‐ and anti‐inflammatory mediators. Thus, 3‐AB reconditioning during EVLP of rat lung grafts damaged by WI markedly reduces inflammation, edema, and physiological deterioration after LTx, supporting the use of PARP inhibitors for the rehabilitation of damaged lungs during EVLP.     

Recombinant human ADAMTS13 treatment and anti‐NET strategies enhance skin allograft survival in mice

Enhancing skin allograft longevity lessens the need for new allografts before optimal intervention is available. Reduced activity of ADAMTS13 (an enzyme that cleaves the pro‐thrombotic and proinflammatory von Willebrand factor) and presence of neutrophil extracellular traps (NETs) have been implicated in liver and lung allograft failures. The effect of ADAMTS13 treatment and the impact of NETs on skin allografts, however, remain unexplored. Here, we adopted a murine model of complete mismatch full‐thickness skin transplant by grafting dorsal skin from BALB/c mice to C57BL/6J background mice. Recombinant human ADAMTS13 (rhADAMTS13) treatment of graft recipients increased allograft survival. Western blot and immunofluorescence microscopy revealed the presence of NETs in allografts of vehicle, but surprisingly, not in rhADAMTS13‐treated mice, 3 days after surgery. Recapitulating the observations in mice, NETs were also observed in all the examined allografts from burn patients. Intriguingly, knocking out peptidylarginine deiminase 4 (PAD4, a key enzyme for NET formation) or DNase 1 treatment (which cleaves NETs) also prolonged allograft survival. In summary, rhADAMTS13 lessens inflammation in allografts by reducing NET burden, resulting in enhanced allograft survival. RhADAMTS13 and anti‐NET treatments could be new therapeutic strategies to promote skin allograft longevity and, hence, the survival of patients with severe burns.     

β1-integrins shedding in a guinea-pig model of chronic asthma with remodelled airways

Background A hallmark of airway remodelling in asthma is subepithelial fibrosis, but its relation with airway dysfunction is still controversial.
Objective To describe airway functional abnormalities and subepithelial remodelling induced by repetitive antigenic challenges.
Methods Nine inhaled antigenic challenges were applied every 10 days to guinea-pigs sensitized to ovalbumin (OVA). Antigen-induced airway hyperresponsiveness (AI-AHR) to histamine and its immunohistopathological relationship was evaluated at the first, third and ninth OVA challenges.
Results From the first challenge on, OVA induced acute transient bronchoobstruction followed by development of AI-AHR. A progressive rise in baseline Penh (a bronchoobstruction index) and granulocyte airway infiltration was also observed. After the ninth OVA challenge, the amount of extracellular matrix in the subepithelial region (SER) of bronchi and bronchioles was increased. Immunohistochemistry analysis showed that this SER fibrosis was associated to β1-integrin subunit overexpression, even in acellular areas. Immunoelectronmicroscopy corroborated the location of β1-integrin in extracellular matrix, essentially in types l and II collagen fibres. Presence of α1- and α2-integrin subunits in these areas was also corroborated. AI-AHR was correlated with degree of SER increment, cell infiltration, and β1-integrin expression.
Conclusion Our data suggested that β1-integrin shedding produced by repetitive allergen challenges in guinea-pigs was associated with collagen deposition in SER of bronchi and bronchioles, along with inflammatory cells infiltration and AI-AHR development.     

β1‐integrin restricts astrocytic differentiation of adult hippocampal neural stem cells

Integrins are transmembrane receptors that mediate cell‐extracellular matrix and cell–cell interactions. The β1‐integrin subunit is highly expressed by embryonic neural stem cells (NSCs) and is critical for NSC maintenance in the developing nervous system, but its role in the adult hippocampal niche remains unexplored. We show that β1‐integrin expression in the adult mouse dentate gyrus (DG) is localized to radial NSCs and early progenitors, but is lost in more mature progeny. Although NSCs in the hippocampal subgranular zone (SGZ) normally only infrequently differentiate into astrocytes, deletion of β1‐integrin significantly enhanced astrocyte differentiation. Ablation of β1‐integrin also led to reduced neurogenesis as well as depletion of the radial NSC population. Activation of integrin‐linked kinase (ILK) in cultured adult NSCs from β1‐integrin knockout mice reduced astrocyte differentiation, suggesting that at least some of the inhibitory effects of β1‐integrin on astrocytic differentiation are mediated through ILK. In addition, β1‐integrin conditional knockout also resulted in extensive cellular disorganization of the SGZ as well as non‐neurogenic regions of the DG. The effects of β1‐integrin ablation on DG structure and astrogliogenesis show sex‐specific differences, with the effects following a substantially slower time‐course in males. β1‐integrin thus plays a dual role in maintaining the adult hippocampal NSC population by supporting the structural integrity of the NSC niche and by inhibiting astrocytic lineage commitment. GLIA 2016;64:1235–1251