Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cytodifferentiation of peritubular myoid cells was studied in developing rats from fetal day 18 through approachment of puberty. The parameters taken into consideration were 1) the presence of desmin, a component of intermediate filaments in contractile cells; 2) the expression of alkaline phosphatase, a cell surface enzyme present in no other cell type of the seminiferous tubule; 3) the expression of the smooth muscle specific isoform of alpha-actin, a marker of terminal differentiation in smooth muscle cells; 4) cell proliferation rate, evaluated in radioautography as labeling index after incorporation of 3H-thymidine in short-term organ culture; and 5) cytoarchitectural changes detected with scanning electron microscopy. By means of immunofluorescence and cytochemistry it was observed that the three markers are expressed early during life, long before the onset of the first spermatogenic wave; in particular desmin is already present in fetal samples and alkaline phosphatase activity appears a few days after birth, whereas alpha-smooth muscle isoactin is first detected around birth. As for myoid cell replication, the high prenatal labeling index was found to drop soon after birth and to further slow down during the first month of postnatal life, suggesting that myoid cell proliferation is not a major factor in peritubular expansion. SEM examination of developing peritubulum has shown that, when approaching puberty, the myoid cell undergoes a dramatic change in cytoarchitecture, consisting in extreme flattening and cytoplasmic expansion resulting in an apparent increase in peritubular surface.
 ...
PMID:Development and cytodifferentiation of peritubular myoid cells in the rat testis. 160 76

Vinculin- and caldesmon-immunoreactive forms and actin isoform patterns were studied in samples of normal and atherosclerotic human aorta. After removal of adventitia and endothelium, the remaining tissue was divided into three layers: media, muscular-elastic (adjacent to media) intima, and subendothelial (juxtaluminal) intima. In media of normal aorta, meta-vinculin accounted for 41.0 +/- 0.9% (mean +/- SEM) of total immunoreactive vinculin (meta-vinculin + vinculin); 150-kDa caldesmon accounted for 78.2 +/- 5.1% of immunoreactive caldesmon (150-kDa + 70-kDa); the fractional contents of alpha-smooth muscle actin, beta-nonmuscle, and gamma-isoactins were 49.0 +/- 0.6%, 30.4 +/- 0.6%, and 20.8 +/- 0.8%, respectively. Muscular-elastic intima was very similar to media by these criteria. In subendothelial intima, the fractional content of meta-vinculin and 150-kDa caldesmon was significantly lower (6.9 +/- 1.5% and 32.7 +/- 7.0%, respectively) than in muscular-elastic intima and media, whereas the isoactin pattern was identical to that in adjacent layers, demonstrating the smooth muscle origin of subendothelial intima cells. In atherosclerotic fibrous plaque, the fractional content of alpha-actin was decreased in subendothelial intima, rather than in media and muscular-elastic intima. Additionally, the proportion of subendothelial intima cells [i.e., the cells that express low amounts of smooth muscle phenotype markers (meta-vinculin, 150-kDa caldesmon, and alpha-actin)] in the total intima cell population increased dramatically in atherosclerotic fibrous plaque. The results suggest that changes in the relative content of meta-vinculin and 150-kDa caldesmon as well as alpha-actin in human aortic intima are associated with atherosclerosis although, in subendothelial intima of normal aorta, a certain smooth muscle cell population exists that expresses reduced amounts of "contractile" phenotype markers, even in the absence of the disease.
 ...
PMID:Modulation of human aorta smooth muscle cell phenotype: a study of muscle-specific variants of vinculin, caldesmon, and actin expression. 314 99

Clinical and experimental studies have established the accelerating role of cytomegalovirus (CMV) infection on cardiac allograft arteriosclerosis, ie, chronic rejection. We have investigated the mechanisms behind the interaction between CMV infection and chronic rejection. In the first part of the study, 762 endomyocardial biopsy specimens obtained from 47 heart allograft recipients were analyzed. Of these, 28 patients developed CMV infection during the first postoperative year. In 24 of 28 CMV patients, mononuclear inflammatory cells (endothelialitis) were seen in the subendothelium of small intramyocardial arterioles. In CMV-free recipients, only five of 19 had any subendothelial inflammation in the vascular structures P < 0.0001 when compared with CMV patients). The subendothelial inflammation demonstrated an intensive peak at the onset of CMV infection, subsiding slowly thereafter. Morphologically, the inflammatory cells in the subendothelium were small lymphocytes. Only few activated pyroninophilic lymphocytes were seen. Immunohistochemistry revealed that the lymphocytes were mostly T cells (UCHL1+). In the second part of the study, we investigated if a similar endothelialitis could be induced experimentally in allografted rats. We performed rat aortic allografts from the DA (AG-B4, RT1a) donors to the WF (AG-B2, RT1v) recipients and infected the recipients with 10(5) plaque-forming units of rat CMV Maastricht strain 1 day after transplantation. In rat CMV-infected aortic allografts, the frequency of subendothelial leukocyte common antigen (LCA, OX1) positive leukocytes, 1.7 +/- 0.1 (SEM) point score units, was significantly higher when compared to noninfected allografts, 0.8 +/- 0.1 point score units (P < 0.05), and they were most prominent in the intimal space during and following acute infection. During subsequent weeks, the LCA-positive leukocytes were replaced by alpha-actin-positive smooth muscle cells. Instead, most of the cells in intima of CMV-free grafted rats stained positively to alpha-actin from the beginning and were smooth muscle cells. Practically no leukocytes were seen. In rat CMV-infected aortic allografts most subendothelial inflammatory cells represented T cells (W3/25+) and cells of the monocyte/macrophage lineage (OX42+). In conclusion, acute CMV infection is associated with an subendothelial inflammation (endothelialitis) of allograft vascular structures both in human and in rat. Nonactivated T lymphocytes and monocytes predominate the inflammatory lesion in the subendothelium. The results suggest that the virus-linked vascular wall inflammation may play a role in the immune injury toward allograft vascular structures, particularly to endothelium, and thus contribute to allograft arteriosclerosis.
 ...
PMID:Acute cytomegalovirus infection induces a subendothelial inflammation (endothelialitis) in the allograft vascular wall. A possible linkage with enhanced allograft arteriosclerosis. 829 11

In the human heart, we have previously shown the predominance of endothelin (ET) ETA receptors, in addition to the presence of ET-1, ET-2, ET-3, and big ET-1. ET-1 is a potent constrictor of isolated epicardial coronary arteries, and this action is mediated via ETA receptors. To determine the source of ET in the heart, our aims were to obtain cell cultures from human left ventricle, identify the cell type, and characterize ET secretion and receptor expression. We explanted human left ventricular tissue. Positive staining with alpha-actin antibodies confirmed the presence of smooth-muscle cells, whereas negative staining for sarcomeric actin and von Willebrand factor indicated an absence of cardiac myocytes and endothelial cells, respectively. Therefore, the cultures were identified as human left ventricular smooth-muscle cells (HLVSMCs). Because blood vessels were not macroscopically visible in the ventricular tissue, the HLVSMCs most likely originated from intramyocardial resistance vessels. The cells secreted immunoreactive mature ET and big ET-1 (102 +/- 29 and 73 +/- 10 pM/24 h, respectively; mean of three individuals +/- SEM). Saturation binding studies showed that [125I]ET-1 bind with high affinity in this preparation (Kd 0.21 +/- 0.06 nM; Bmax 15 +/- 4 fmol/mg protein; mean of three individuals +/- SEM). A competition binding study using the ETA-selective antagonist FR139317 (10 pM-10 microM) revealed the predominance of ETA receptors (Kd 0.33 +/- 0.10 nM, n = 3). We have shown that smooth-muscle cells isolated from human left ventricle secrete immunoreactive mature ET and big ET-1, and express mainly ETA receptors. These cells may provide a useful model for studying the effects of ET in the regulation of vascular tone and of the blood supply in the myocardium.
 ...
PMID:Delineation of endothelin receptors in human left ventricular smooth-muscle cells. 858 13

The growth response of aortic vascular smooth muscle cells (VSMCs) to chronic hypertension includes vascular hypertrophy. We have shown previously that angiotensin II positively regulates the expression of the human vascular smooth muscle (SM) alpha-actin gene. To further expand our understanding of vasoactive peptide-induced vascular hypertrophy, we studied endothelin-1 (ET-1) regulation of total protein synthesis and cytoskeletal gene expression in VSMCs. In a concentration-dependent manner ET-1 increased [3H] leucine incorporation by VSMCs (122.4 +/- 5.5%, mean +/- SEM, n = 5). ET-1 (0.1 microM) induced expression of SM alpha-actin mRNA as detected by Northern blot analysis. Also, ET-1 in a concentration-dependent manner (0.1 nM-0.1 microM) induced expression of the chloramphenicol acetyl transferase gene driven by 896 bp of the human SM alpha-actin promoter when transiently transfected into rat aortic VSMCs by the calcium phosphate method (141.2 +/- 9.8%, mean +/- SEM, n = 10). These data suggest that part of ET-1-induced increase in protein synthesis is achieved through transcriptional regulation of the SM alpha-actin gene via activation of cis-acting element(s) in the promoter. Such findings help elucidate the role of ET-1 in regulation of vascular growth.
 ...
PMID:Endothelin-1 induces an increase in total protein synthesis and expression of the smooth muscle alpha-actin gene in vascular smooth muscle cells. 876 40

Interstitial fibrosis is significantly correlated with the progression of renal impairment for most causes of renal insufficiency. Transforming growth factor beta 1 (TGF-beta 1) and basic fibroblast growth factor (bFGF) are two of a group of profibrotic cytokines that have been associated with the development of renal interstitial fibrosis. We have previously demonstrated that alterations in D-glucose concentrations modulate the synthesis of TGF-beta 1 by human renal proximal tubular cells (HPTC) in vitro. The aim of the present study was to examine the influence of bFGF on TGF-beta 1 synthesis by HPTC in culture and to examine any modulation of this response by changes in ambient glucose concentration. Incubation of growth-arrested HPTC (72 hours in serum-free medium) with bFGF resulted in a dose-dependent increase in latent TGF-beta 1 secretion. Maximal release of TGF-beta 1 was seen at a bFGF dose of 50 ng/ml in cells incubated in 5 mM D-glucose (7.48 +/- 2.5 ng/ml, mean +/- SEM; n = 3; p = 0.04). This release of TGF-beta 1 in response to bFGF was unaffected by increasing the concentration of glucose in the culture media to 25 mM (7.76 +/- 1.3, mean +/- SEM; n = 3; p < 0.02). It was also unaffected by pretreatment of cells with either actinomycin-D or cycloheximide. TGF-beta 1 secretion was, however, inhibited in a dose-dependent manner by the exposure of cells to the microtubule-disrupting agent vinblastine, indicating that the generation of TGF-beta 1 was dependent on the secretion of preformed, stored TGF-beta 1. In a separate series of experiments, exposure of HPTC to TGF-beta 1 (10 ng/ml) led to the induction of bFGF mRNA, which was first apparent at 12 hours and reached maximal levels 24 hours after stimulation (normalized bFGF/alpha-actin mRNA ratio was 1.5 times that of the control). This increase in bFGF mRNA was accompanied by a time-dependent increase in bFGF protein production, which was maximal after 24 hours (19.83 +/- 12.7 pg/ml versus 2.49 +/- 0.34 pg/ml, mean +/- SEM, stimulated versus control; n = 3; p = 0.03). These findings demonstrate that bFGF stimulates the secretion of preformed, latent TGF-beta 1 by HPTC but does not induce de novo TGF-beta 1 gene transcription or TGF-beta 1 protein synthesis. We have also demonstrated a positive-feedback loop involving TGF-beta 1 and bFGF and postulate that this may be involved in the progressive nature of renal fibrosis in vivo.
 ...
PMID:Basic fibroblast growth factor stimulates the release of preformed transforming growth factor beta 1 from human proximal tubular cells in the absence of de novo gene transcription or mRNA translation. 911 19

Thiazolidinediones, insulin-sensitizing agents that lower insulin and lipid levels in insulin-resistant states, block agonist-induced Ca2+ entry into vascular smooth muscle (VSM) cells in vitro and lower blood pressure in animals and humans in vivo. In this study, we investigated the effects of ciglitazone and troglitazone on cell growth and DNA synthesis (as thymidine incorporation), and differentiation in cultured human aorta (haVSM) and human coronary artery (hcaVSM) VSM cells. Mitotically quiescent haVSM cells were stimulated with serum or platelet-derived growth factor (PDGF). Ciglitazone (40 micromol/L) inhibited haVSM cell proliferation by 84 +/- 16% (mean +/- SEM) (P < .05, n = 3), and serum and PDGF stimulated [3H]-thymidine incorporation by 91 +/- 18% (P < .03, n = 3) and 73 +/- 14% (P < .03, n = 4), respectively. Troglitazone (5 micromol/L) inhibited proliferation of haVSM cells by 78 +/- 14% (P < .05, n = 3) and hcaVSM cells by 91 +/- 18% (P < .05, n = 3). Proliferating VSM cells (synthetic phenotype) expressed small amounts of alpha-actin, whereas nonproliferating VSM cells (contractile phenotype) exhibited abundant alpha-actin. Exposure of proliferating haVSM cells to 40 micromol/L ciglitazone induced a marked increase in alpha-actin staining, consistent with transition to the well differentiated, contractile phenotype. To the extent that thiazolidinediones similarly affect growth factor-induced proliferation and differentiation of arterial myocytes in vivo, these agents may be useful in treating atherosclerosis and in preventing restenosis after angioplasty.
 ...
PMID:Effects of thiazolidinediones on growth and differentiation of human aorta and coronary myocytes. 912 11

Human parturition is effected by a cascade of factors, of which many are unknown. We aim to identify the genes that are changed by labor in the human myometrium by suppression subtractive hybridization. We also seek to ascertain whether these genes are differentially expressed in the myometrium at the upper or fundal and lower segments of the uterus. Term myometrial tissues were obtained from laboring and nonlaboring women undergoing cesarean section after obtaining informed consent. Total RNA was used in suppression subtractive hybridization (CLONTECH PCR Select) to produce two subtracted cDNA libraries enriched for genes expressed during or before labor, labor and not-in-labor libraries, respectively. Dot blot screening of 400 positive clones, constituting 20% of the two subtracted libraries, revealed 30 differentially expressed clones, 14 of which were up-regulated by labor. Among the 10 known genes that were up-regulated in labor, 6 had apparent immune regulatory and inflammatory roles. Three are well-known inflammatory mediators and modulators that were previously linked with parturition: IL-8, manganese superoxide dismutase (MnSOD), and metalloproteinase-9. Three others, interferon-inducible 1-8d gene, elongation factor 1alpha, and nucleophosmin, have not been previously linked with labor. Constitutively expressed genes, including cyclophilin and alpha-actin, were found to be altered by labor. Quantitative real-time RT-PCR using Taqman probes further confirmed the up-regulation of some of these genes. The amounts of the specific genes assayed were standardized to 18S ribosomal RNA and are expressed as mean +/- SEM. Quantitative real-time RT-PCR showed that IL-8 mRNA rose from 0.003 +/- 0.002 in nonlaboring samples (n = 38) to 0.24 +/- 0.11 (n = 20) in gestational-age-matched spontaneously laboring women (P = 0.035). Similarly, MnSOD rose from 0.11 +/- 0.02 (n = 24) to 1.23 +/- 0.56 (n = 24) in gestational-age-matched women (P = 0.047). Additionally, cyclophilin, often used as a constitutive or housekeeping gene marker, increased from 0.0008 +/- 0.0002 (n = 6) to 0.002 +/- 0.0004 (n = 6; P = 0.008) during labor. Notably, MnSOD mRNA was differentially distributed between the upper (0.63 +/- 0.18) and lower (0.15 +/- 0.05; n = 15; P = 0.022) segments of the uterus, but IL-8 was not (n = 17; P = 0.97). Induced labor further showed significantly higher levels of IL-8 (0.63 +/- 0.21; n = 14) than spontaneous labor (0.22 +/- 0.11; n = 20; P = 0.046), but not MnSOD (P = 0.1). This work identifies novel as well as known genes that were not previously associated with parturition. It extends previous data indicating that there is differential expression of some, but not all genes within the gravid human uterus. Inflammatory genes constitute a major proportion of the known genes found to be up-regulated in labor, lending support to the hypothesis of an inflammatory mechanism for human parturition. This work further indicates that many factors associated with human labor and their complex interactions remain to be elucidated.
 ...
PMID:Human myometrial genes are differentially expressed in labor: a suppression subtractive hybridization study. 1205 Jan 94

Several implants for orbital wall fracture treatment are available at the present, but they have drawbacks: resorption, risk for migration and foreign body reaction. Alloplastic resorbable implants would be advantageous: no removal operation and no donor side morbidity. The purpose of this study was to evaluate the foreign body reaction, capsule formation and mechanical properties of two bioresorbable implants. PDS and SR-P(L/DL)LA mesh sheet (70/30) with solid frame (96/4) implants (SR-P(L/DL)LA 70,96) were placed into subcutaneous tissue of 24 rats. Immunohistochemistry was used to evaluate reactivity for Tn-C, alpha-actin, type I and III collagens and two mononuclear cells: T-cells and monocyte/ macrophage. GPC, DSC and SEM were performed. Student's t-test or nonparametric Kruskall-Wallis test were used for statistical analysis. Histology of peri-implant capsule exhibited an inner cell-rich zone and an outer connective tissue zone around both materials. Tn-C reactivity was high in the inner and alpha-actin in the outer zone. At the end of the study, the difference of type I collagen versus type III collagen reactivity in inner zone was statistically significant (P<0.0001) as was the difference of type I collagen versus type III collagen reactivity in outer zone (P<0.0001). Immunohistochemistry did not reveal any statistical differences of T-cell and monocyte/macrophage reactivity around PDS versus SR-P(L/DL)LA 70,96 implants, nor any differences as a function of time. PDS were deformed totally after 2 months. SR-P(L/DL)LA 70,96 implants were only slightly deformed during the follow up of 7 months. PDS degraded rapidly in SEM observation. Particles were detaching from surface. SEM observation revealed that polylactide implant was degrading from the surface and the inner porous core became visible. The degradation came visible at 7 months. There were cracks in perpendicular direction towards to the long axis of the filaments. M(w) of PDS decreased fast compared to the polylactide implant. Foreign body reaction was minimal to both materials but continued throughout the whole observation period. Mechanically PDS was poor, it looses its shape totally within 2 months. It cannot be recommended for orbital wall reconstruction. New mesh sheet-frame structure (SR-P(L/DL)LA 70,96) approved to be mechanically adequate for orbital wall reconstruction. It seems not to possess intrinsic memory and retains its shape. The resorption time is significantly longer compared to PDS and is comparable to other studied P(L/DL)LA copolymers. Thus, the new polylactide copolymer implant may support the orbital contents long enough to give way to bone growth over the wall defect.
 ...
PMID:Biodegradable polydioxanone and poly(l/d)lactide implants: an experimental study on peri-implant tissue response. 1597 53