transforming-growth-factor-beta and Arterial-Occlusive-Diseases

Limb ischemia occurs due to obstruction of blood perfusion to lower limbs, a manifestation that is associated with peripheral artery disease (PAD). Angiogenesis is important for adequate oxygen delivery. The present study investigated a potential role for chrysin, a naturally occurring flavonoid, in promoting angiogenesis in hindlimb ischemia (HLI) rat model. Rats were allocated into four groups: (1) sham-operated control, (2) HLI: subjected to unilateral femoral artery ligation, (3) HLI + chrysin: received 100 mg/kg, i.p. chrysin immediately after HLI, and (4) HLI + chrysin + rapamycin: received 6 mg/kg/day rapamycin i.p. for 5 days then subjected to HLI and dosed with 100 mg/kg chrysin, i.p. Rats were killed 18 h later and gastrocnemius muscles were collected and divided into parts for (1) immunohistochemistry detection of CD31 and CD105, (2) qRT-PCR analysis of eNOS and VEGFR2, (3) colorimetric analysis of NO, (4) ELISA estimation of TGF-β, VEGF, ATG5 and Beclin-1, and (5) Western blot analysis of p-PI3K, PI3K, p-Akt, Akt, p-mTOR, mTOR, and HIF-1α. Chrysin significantly enhanced microvessels growth in HLI muscles as indicated by increased CD31 and CD105 levels and decreased TGF-β. Chrysin's proangiogenic effect is potentially mediated by increased VEGF, VEGFR2 and activation of PI3K/AKT/mTOR pathway, which promoted eNOS and NO levels as it was reversed by the mTOR inhibitor, rapamycin. Chrysin also inhibited autophagy as it decreased ATG5 and Beclin-1. The current study shows that chrysin possesses a proangiogenic effect in HLI rats and might be useful in patients with PAD.

Topics: Angiogenesis Inducing Agents; Animals; Arterial Occlusive Diseases; Autophagy; Beclin-1; Flavonoids; Hindlimb; Ischemia; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

One current concept suggests that unchecked proliferation of clonally selected precursors of endothelial cells (ECs) contribute to severe pulmonary arterial hypertension (PAH). We hypothesized that clonally selected ECs expressing the progenitor marker CD117 promote severe occlusive pulmonary hypertension (PH). The remodelled pulmonary arteries of PAH patients harboured CD117

Topics: Animals; Apoptosis; Arterial Occlusive Diseases; Bone Morphogenetic Proteins; Cell Lineage; Cell Separation; Cells, Cultured; Chronic Disease; Clone Cells; Endothelial Cells; Flow Cytometry; Humans; Hypertension, Pulmonary; Hypoxia; Male; Mesoderm; Proto-Oncogene Proteins c-kit; Pulmonary Artery; Rats; Rats, Sprague-Dawley; Receptor, Transforming Growth Factor-beta Type I; Signal Transduction; Transcriptome; Transforming Growth Factor beta

To characterize and compare primary and restenotic lesions of the superficial femoral artery and analyze the contribution of TGF-beta/Smad3 signaling to the pathophysiology of peripheral artery occlusive disease.. Immunohistochemical studies were performed on specimens retrieved from the superficial femoral artery of patients undergoing either atherectomy for primary atherosclerotic or recurrent disease after stenting and/or prior angioplasty. Immunohistochemical analysis revealed a significantly higher smooth muscle cell (SMC) content (alpha-actin+) and expression of Smad3 in restenotic lesions while primary lesions contained significantly more leukocytes (CD45+) and macrophages (CD68+). Further studies demonstrated colocalization of Smad3 with alpha-actin and PCNA, suggesting a role for Smad3 in the proliferation observed in restenotic lesions. To confirm a role for Smad3 in SMC proliferation, we both upregulated Smad3 via adenoviral mediated gene transfer (AdSmad3) and inhibited Smad3 through transfection with siRNA in human aortic SMCs, then assessed cell proliferation with tritiated thymidine. Overexpression of Smad3 enhanced whereas inhibition of Smad3 decreased cell proliferation.. Differences in cellular composition and cell proliferation in conjunction with the finding that Smad3 is expressed exclusively in restenotic disease suggest that TGF-beta, through Smad3 signaling, may play an essential role in SMC proliferation and the pathophysiology of restenosis in humans.

Topics: Angioplasty; Apoptosis; Arterial Occlusive Diseases; Atherectomy; Atherosclerosis; Cell Proliferation; Cells, Cultured; Constriction, Pathologic; Femoral Artery; Humans; Hyperplasia; Myocytes, Smooth Muscle; Recurrence; Signal Transduction; Smad3 Protein; Stents; Transfection; Transforming Growth Factor beta; Treatment Outcome

The purpose of the present study was to assess the course of adhesion molecules (intercellular adhesion molecule (ICAM), vascular cell adhesion molecule (VCAM), e-selectin, p-selectin and monocyte chemoatlractant protein 1 (MCP-1)), growth factors (transforming growth factor beta (TGFbeta) and basic fibroblast growth factor (bFGF)) and the cytokine tumour necrosis factor alpha (TNFalpha) after both angioplasty and cryoplasty. Recently cryoplasty has been suggested as a new method to oppose neointimal hyperplasia resulting in restenosis formation. While in vitro models have shown that the application of cryothermal energy to the endothelium during angioplasty leads to apoptosis induction and reduced proliferation rates, no human in vivo proof for an inhibition of neointimal hyperplasia exists. For restenosis initiation adhesion molecules, growth factors and cytokines play an important role. One possibility to investigate the endothelial response to angioplasty is the measurement of the soluble forms of adhesion molecules, growth factors and cytokines that are released into the circulation after denuding the vessel wall. In the present study we assessed the distribution pattern of the soluble forms of e-selectin, p-selectin, ICAM, VCAM, MCP-1, TGFbeta, bFGF and TNFalpha after angiography, angioplasty and cryoplasty of the femoropopliteal artery in the early course of 4 weeks in 29 patients with peripheral arterial occlusive disease. During the 4 weeks after intervention levels of e-selectin, ICAM, VCAM and MCP-1 increased after both angioplasty and cryoplasty. The course of the screened biomarkers was similar between angioplasty and cryoplasty. P-selectin and TGFbeta both decreased after cryoplasty, but not significantly. The present results show that the release of adhesion molecules, growth factors and cytokines is similar between balloon angioplasty and cryoplasty.

Topics: Aged; Angioplasty, Balloon; Arterial Occlusive Diseases; Cell Adhesion Molecules; Chemokine CCL2; Cryotherapy; E-Selectin; Endothelium; Female; Femoral Artery; Fibroblast Growth Factor 2; Humans; L-Lactate Dehydrogenase; Male; P-Selectin; Pilot Projects; Popliteal Artery; Prospective Studies; Radiography; Recurrence; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

Vascular endothelial growth factor (VEGF) and transforming growth factor beta (TGF-beta1) play an important role in angiogenesis. We wanted to determine if concentrations of growth factors in the coronary sinus (CS) and right atrium (RA) are higher in coronary artery disease patients with total occlusions than in those with partial occlusions. Fifty-one patients scheduled for coronary artery angiography were evaluated for possible recruitment. A 6F Goodale-Lubin catheter was used to collect blood from the CS and RA. Data for all but four patients were gathered successfully, leaving 47 study patients. The reviewer was blinded to growth factor data when interpreting coronary angiographic findings. Of the 47 enrolled patients, 32 had at least one diseased vessel, seven of whom had at least one major total epicardial coronary occlusion. In all 32 patients, the concentrations of VEGF in the CS were higher than those in the RA (31.5 +/- 2.7 vs 27.1 +/- 1.8 pg/mL; p = 0.005). Patients with total occlusions had higher VEGF concentrations in the CS than those with non-total occlusions (38.9 +/- 8.0 vs 29.5 +/- 2.6 pg/mL; p = 0.037). The differences in TGF-beta1 in the two groups were not statistically significant. The higher CS VEGF concentrations in patients with total occlusion indicate that VEGF may play a part in the development of angiogenesis.

Topics: Aged; Arterial Occlusive Diseases; Coronary Angiography; Coronary Disease; Coronary Stenosis; Coronary Vessels; Enzyme-Linked Immunosorbent Assay; Female; Heart Atria; Humans; Hypertension; Male; Middle Aged; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Topics: Animals; Arterial Occlusive Diseases; Arteries; Carbonic Anhydrases; Collateral Circulation; DNA-Binding Proteins; Early Growth Response Protein 1; Endothelial Cells; Gene Expression; Humans; Immediate-Early Proteins; MAP Kinase Signaling System; Mice; Neoplasms; Neovascularization, Pathologic; Nerve Tissue Proteins; Stress, Mechanical; Transcription Factors; Transforming Growth Factor beta; Tunica Intima

Collateral artery growth (arteriogenesis) can be induced in rabbit and mice by occlusion of the femoral artery. We aimed to identify genes that are differentially expressed during arteriogenesis.. 24 h after femoral ligation or sham operation collateral arteries were isolated from New Zealand white rabbits, mRNAs were extracted and amplified using the SMART technique. cDNAs were subjected to suppression subtractive hybridization. The differential expression was confirmed by Northern blot, Real time PCR and Western blot. Additionally, the gene expression was modulated in vivo by application of cytokines via osmotic minipumps.. We found the cardiac ankyrin repeat protein (carp) mRNA to be upregulated at 24 h and already at 6 h and 12 h after surgery as shown by Northern blot hybridization and real time PCR. The carp mRNA was also increased in our mouse model of arteriogenesis. Western blot results on nuclear extracts of rabbit collaterals 24 h after surgery indicated that carp, which we showed to be expressed in endothelial cells and smooth muscle cells of collateral arteries by immunohistochemistry, was also upregulated on the protein level. We infused MCP-1, TGF-beta1 or doxorubicin for 24 h in rabbits and found that only TGF-beta1 led to an additional increase of carp mRNA. Overexpression of carp in cos-1 cells resulted in a 3.7-fold increase of the immediate early gene egr-1.. Our results implicate that carp is associated with the initiation and regulation of arteriogenesis.

Topics: Animals; Arterial Occlusive Diseases; Arteries; Blotting, Western; Chemokine CCL2; Collateral Circulation; COS Cells; DNA-Binding Proteins; Doxorubicin; Early Growth Response Protein 1; Gene Expression; Immediate-Early Proteins; In Situ Hybridization; Models, Animal; Muscle Proteins; Neovascularization, Physiologic; Nuclear Proteins; Polymerase Chain Reaction; Rabbits; Repressor Proteins; RNA, Messenger; Transcription Factors; Transforming Growth Factor beta

Vascular endothelial growth factor (VEGF) has been implicated in the reendothelialization of the vascular wall after balloon injury. This study investigated whether thrombin, which is formed during activation of the coagulation cascade at sites of vascular injury, upregulates VEGF expression in vascular smooth muscle cells (VSMCs). VEGF expression was assessed in native and cultured VSMCs by Northern blot analysis and reverse transcription-polymerase chain reaction and the release of VEGF protein by immunoassay. alpha-Thrombin time- and concentration-dependently increased VEGF mRNA levels, mainly that mRNA coding for the soluble splice variant VEGF(164/165), and stimulated the release of VEGF protein. These effects required the proteolytic activity of thrombin and were mimicked by a thrombin receptor activating-peptide. Upregulation of VEGF expression was also induced by conditioned medium from alpha-thrombin-stimulated VSMCs. Both the early and the delayed alpha-thrombin-induced VEGF expressions were attenuated by antioxidants and by diphenyleneiodonium. alpha-Thrombin-induced VEGF release was significantly reduced by a platelet-derived growth factor (PDGF)-, a transforming growth factor (TGF)-beta-, and a basic fibroblast growth factor (bFGF)-neutralizing antibody. Thrombin caused a redox-sensitive upregulation of expression of VEGF in VSMCs through a direct and an indirect effect, which was dependent on the endogenous formation of PDGF, TGF-beta, and bFGF. Upregulation of VEGF expression may represent an important mechanism by which the coagulation cascade contributes to the regeneration of the endothelial lining at sites of balloon injury.

Topics: Acetylcysteine; Angioplasty, Balloon; Animals; Antioxidants; Arterial Occlusive Diseases; Ascorbic Acid; Cells, Cultured; Endothelial Growth Factors; Fibroblast Growth Factor 2; Humans; Kinetics; Lymphokines; Male; Muscle, Smooth, Vascular; Platelet-Derived Growth Factor; Rats; Rats, Wistar; Reactive Oxygen Species; RNA, Messenger; Thrombin; Transcriptional Activation; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Inhibition of glutamate carboxypeptidase (GCP) II (EC 3.4.17.21), also termed N-acetylated alpha-linked acidic dipeptidase (NAALADase), has been shown to protect against ischemic injury presumably via decreasing glutamate and increasing N-acetyl-aspartyl-glutamate (NAAG). NAAG is a potent and selective mGlu3 receptor agonist. Activation of glial mGlu3 receptors has been shown to protect against NMDA toxicity by releasing transforming growth factors, TGF-betas. We hypothesized that GCP II inhibition could be neuroprotective also via TGF-betas, due to increased NAAG. To verify this, Enzyme-Linked Immunosorbent Assays (ELISAs) were performed on media from both control and ischemic cultures treated with the GCP II inhibitor, 2-(phosphonomethyl)-pentanedioic acid (2-PMPA). We found that 2-PMPA attenuated ischemia-induced declines in TGF-beta. To further assess the role of TGF-betas in 2-PMPA-mediated neuroprotection, a neutralizing antibody to TGF-beta (TGF-beta Ab) was used. In both in vitro and in vivo models of cerebral ischemia, TGF-beta Ab reversed the neuroprotection by 2-PMPA. Antibodies to other growth factors had no effect. Data suggests that neuroprotection by GCP II inhibition may be partially mediated by promoting TGF-beta release.

Topics: Animals; Antibodies; Arterial Occlusive Diseases; Brain; Carboxypeptidases; Cells, Cultured; Cerebral Arteries; Disease Models, Animal; Enzyme Inhibitors; Glutamate Carboxypeptidase II; Neuroprotective Agents; Precipitin Tests; Rats; Rats, Sprague-Dawley; Receptors, Metabotropic Glutamate; Transforming Growth Factor beta

The mechanisms underlying the neuroprotective effects of the group II metabotropic glutamate receptor (mGluR) agonist LY379268 were investigated in a gerbil model of global ischemia. LY379268 (10 mg/kg i.p.) 30 or 60 min after 5-min bilateral carotid artery occlusion (BCAO) attenuated the ischemia-induced hyperactivity and provided protection in the CA1 hippocampal cells. This neuroprotective effect was maintained (P <.001) when histological analysis was performed 14 and 28 days after BCAO. Furthermore, 24- or 48-h pretreatment with LY379268, 10 mg/kg i.p., before 5-min BCAO markedly reduced (P <.001 and P <.05, respectively) the damage to CA1 hippocampal neurons. This result is consistent with the induction of neuroprotective factors or a very long brain half-life. To study the possible induction of neuroprotective factors as contributing to this action of LY379268, brains were examined for expression of neurotrophic factors. Results indicated that LY379268 (10 mg/kg i.p.) failed to alter the expression of transforming growth factor-beta, brain-derived neurotrophic factor, nerve growth factor, and basic fibroblast growth factor in the hippocampal regions of brains taken from gerbils sacrificed at 6, 24, 72, and 120 h postinjection. The new group II mGlu antagonist, LY341495, administered 1 h before 5-min BCAO, attenuated the neuroprotective effect of LY379268 administered 24 h before 5-min BCAO. Complementary pharmacokinetic studies showed that a significant receptor-active concentration persisted in the brain 24 h after LY379268 10 mg/kg i.p. We conclude that group II mGluR occupancy, rather than induction of neuroprotective factors, explains the long-lasting neuroprotective effect of LY379268 in the gerbil model of global ischemia.

Topics: Amino Acids; Animals; Arterial Occlusive Diseases; Brain Ischemia; Brain-Derived Neurotrophic Factor; Bridged Bicyclo Compounds, Heterocyclic; Carotid Artery Diseases; Excitatory Amino Acid Agonists; Gerbillinae; Hippocampus; Immunohistochemistry; Male; Motor Activity; Nerve Growth Factor; Neurons; Neuroprotective Agents; Receptors, Metabotropic Glutamate; Transforming Growth Factor beta

Osteogenic protein-1 (OP1) not only possesses trophic activity on bone tissue but also influences neuronal survival and differentiation in vitro. Specific receptors for OP1 are present in brain and spinal cord and can be upregulated during cerebral contusion. OP1 is a member of the transforming growth factor-beta superfamily, several of whose members possess neuroprotective activity. In this study, the neuroprotective effect of OP1 in cerebral ischemia was evaluated in adult animals.. Adult male Sprague-Dawley rats were anesthetized with chloral hydrate. OP1 or vehicle was administered intracortically or intracerebroventricularly to the rats. Thirty minutes, 24 hours, or 72 hours after OP1 injection, the right middle cerebral artery (MCA) was ligated for 90 minutes. Twenty-four hours after reperfusion, animals were tested for motor behavior. The animals were subsequently anesthetized with urethane and perfused intracardially with saline. Brain tissue was removed, sliced, and incubated with 2% triphenyltetrazolium chloride to localize the area of infarction.. Only animals pretreated with OP1 24 hours before MCA ligation showed a reduction in motor impairment. OP1, given 30 minutes or 72 hours before MCA ligation, did not reduce cortical infarction. In contrast, pretreatment with OP1 24 hours before MCA ligation significantly attenuated the volume of infarction in the cortex, in agreement with the behavioral findings.. Intracerebral administration of OP1 24 hours before MCA ligation reduces ischemia-induced injury in the cerebral cortex.

Topics: Animals; Arterial Occlusive Diseases; Behavior, Animal; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Brain Ischemia; Cerebral Infarction; Ligation; Male; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

Two patterns of transforming growth factor-beta1 (TGF-beta1) expression were identified in brains of normotensive rats following permanent occlusion of the middle cerebral artery (MCAO). First, a relative increase of TGF-beta1 mRNA by 37% was found at 12 h after MCAO in the ipsilateral cingulate cortex as compared to the homotopic contralateral region. The cingulate cortex is located distant from the ischemic territory. Treatment with the glutamate receptor antagonists MK-801 and NBQX did not reduce this expression (34% and 26% increase, respectively). Therefore, peri-infarct depolarization waves were probably not responsible for induction. Secondly, an increase of TGF-beta1 mRNA by 116% was found at 7 days after MCAO within infarcted tissue. This expression was not reduced by the glutamate receptor antagonists MK-801 (increase 140%) and NBQX (increase 137%), either. TGF-beta1 mRNA expression in the cingulate cortex at 12 h after MCAO is possibly mediated by neurons and astroglia and may support cell survival. Expression in the infarcted tissue at 7 days after MCAO is most likely related to the invasion of monocytes and may be involved in the downregulation of inflammatory events, in neoangiogenesis, and in formation of a glial scar around the infarct.

Topics: Animals; Arterial Occlusive Diseases; Brain; Cerebral Arteries; Chronic Disease; Dizocilpine Maleate; Excitatory Amino Acid Antagonists; Male; Quinoxalines; Rats; Rats, Inbred F344; RNA, Messenger; Transforming Growth Factor beta

Tranilast (N(3,4-dimethoxycinnamoyl)anthranilic acid), an agent which in cell culture inhibits transforming growth factor-beta (TGF-beta) secretion and antagonises the effects of TGF-beta and platelet-derived growth factor (PDGF) on cell migration and proliferation, has been reported to reduce the incidence of restenosis after angioplasty in angiographically validated human clinical trials. We investigated in a rat model of balloon angioplasty whether tranilast's effects in vivo could be attributed to inhibition of expression of TGF-beta and/or its receptor types. Using a standardised reverse transcriptase-polymerase chain reaction (RT-PCR) assay, we examined the effects of three doses of tranilast (25, 50 and 100 mg/kg) on the expression of two TGF-beta isoforms, the types I and II TGF-beta receptors and two putative TGF-beta responses, induction of integrins alpha(v) and beta3 mRNA, 2 h after oral administration and 26 h after vessel injury. Tranilast attenuated in a dose-dependent and reversible manner the injury-induced increases in mRNA levels encoding TGF-beta1, TGF-beta3, two type I TGF-beta receptors ALK-5 and ALK-2, and the type II receptor TbetaRII. At the highest dose mRNA levels encoding TGF-beta1 and TbetaRII were attenuated to levels approaching or below those observed in uninjured vessels. Messenger RNAs encoding TGF-beta3, ALK-5 and ALK-2 were all attenuated by between 70 and 74% (all P < 0.05). Tranilast also attenuated in a reversible manner the elevations in mRNA levels for integrins alpha(v) and beta3 observed after vessel injury, by 90 and 72%, respectively. We also investigated, in cultured smooth muscle cells derived from injured carotid arteries, the extent to which tranilast (300 mg/l) attenuated any increases in expression of type I and type II receptors stimulated by PDGF-BB and TGF-beta1, growth factors implicated in smooth muscle cell migration and proliferation in injured vessels. Increases in mRNA levels of the type I receptors ALK-5 and ALK-2 induced by PDGF-BB and TGF-beta1 were almost completely prevented by tranilast. Tranilast also prevented the PDGF-BB induced increases in TbetaRII but only partially inhibited the TGF-beta1 induced upregulation of TbetaRII. We conclude that tranilast can inhibit transcriptional mechanisms associated with the upregulation of TGF-beta and its receptor types in balloon catheter injured vessels. It is possible that these mechanisms contribute to its ability to reduce the frequency of reste

Topics: Angioplasty, Balloon; Animals; Arterial Occlusive Diseases; Carotid Arteries; Carotid Artery Injuries; Cell Division; Cell Movement; Cells, Cultured; DNA Primers; Dose-Response Relationship, Drug; Integrins; Male; Muscle, Smooth, Vascular; ortho-Aminobenzoates; Platelet Aggregation Inhibitors; Polymerase Chain Reaction; Rats; Rats, Sprague-Dawley; Receptors, Transforming Growth Factor beta; RNA, Messenger; Transforming Growth Factor beta

The restenosis rate in vein bypass grafts is higher than in native coronary arteries, and both the cascade of regulatory factors and the vessel reaction may be altered. In this study, vein bypass atherectomy specimens were classified as primary (n = 10) or restenotic (n = 12). Immunohistochemistry with 11 primary antibodies showed low levels of proliferation in both tissues and similar amounts of extracellular matrix components in both primary and restenotic specimens at the time points at which tissue was removed for clinical reasons. Inflammation appeared increased in restenotic specimens. Using in situ hybridization, transforming growth factor-beta1 messenger RNA was detected in both primary and restenotic tissue, with a trend to higher expression in restenosis (8.4 +/- 5.3 vs. 9.4 +/- 7.4 grains/nucleus) and further increased expression in multiple compared with single restenoses (15.1 +/- 6.1 vs. 5.6 +/- 5.1 grains/nucleus, P < 0.05). Hence, there were no great differences in cell proliferation or extracellular matrix formation between primary and restenosis vein graft tissue, in contrast to previously described findings in arterial tissue. This suggests that primary vein graft tissue is already in a chronic 'restenosis-like' state and subsequent injury creates minimal additional upregulation.

Topics: Antigens, CD; Antigens, Differentiation, Myelomonocytic; Arterial Occlusive Diseases; Atherectomy; Cell Division; Extracellular Matrix; Graft Occlusion, Vascular; Humans; Immunohistochemistry; In Situ Hybridization; Inflammation; Proteins; RNA, Messenger; Transforming Growth Factor beta; Up-Regulation; Veins

The potentially neurotrophic cytokine transforming growth factor-beta1 (TGF-beta1) is locally expressed following human stroke and experimental ischemic lesions, but the cellular source(s) and profile of induction have so far not been established in experimental focal cerebral ischemia. This study presents the time course and a cellular localization of TGF-beta1 mRNA, visualized by in situ hybridization combined with immunohistochemical staining for microglia, macrophages, or astrocytes, on brain sections from adult spontaneously hypertensive rats subjected to transient proximal occlusion of their middle cerebral artery. Six hours after ischemia, an early and transient neuronal and microglial expression of TGF-beta1 mRNA was observed in the extraischemic cingulate and frontal cortices. Both early and protracted expression of TGF-beta1 mRNA in the caudate-putamen and neocortical infarcts and in the caudate-putamen penumbra colocalized with OX42/ED1-immunoreactive microglia and macrophages, whereas TGF-beta1 mRNA in the neocortical penumbra colocalized with OX42/ED1-immunoreactive cells of a microglial morphology. No astrocytes were double-labeled. The number of TGF-beta1 mRNA-expressing microglia and macrophages increased strongly during the first week. Thereafter, TGF-beta1 mRNA became increasingly restricted to the neocortical penumbra (3 weeks), and after 3 months it was confined to activated microglia in the anterior commissure. Our data establish activated microglia and macrophages as the major source of TGF-beta1 mRNA following experimental focal cerebral ischemia. Consequently, TGF-beta1-mediated functions may be exerted by microglia both in the early degenerative phase, and later in combination with blood-borne macrophages, in the remodeling and healing phase after focal cerebral ischemia.

Topics: Animals; Arterial Occlusive Diseases; Cerebral Arteries; Gene Expression; Ischemic Attack, Transient; Macrophages; Male; Microglia; Rats; Rats, Inbred SHR; RNA, Messenger; Transforming Growth Factor beta

Vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) proliferate faster and are more sensitive to transforming growth factor-beta 1 (TGF-beta 1) than those of normotensive Wistar-Kyoto rats. We studied the in vitro effects of tranilast, an anti-allergic drug, on the proliferation, migration and extracellular matrix synthesis in the SHR-VSMC. There were many inhibitory effects of tranilast (30-300 microM) on SHR-VSMC. One is the effect on the proliferation stimulated with fetal bovine serum (FBS), TGF-beta 1 and platelet-derived growth factor-BB (PDGF-BB). Another is the effect on the PDGF-BB-induced migration. Lastly, tranilast exhibited inhibitory effects on spontaneous collagen synthesis and TGF-beta 1-induced collagen and glycosaminoglycan synthesis. On the other hand, collagen induced the VSMC migration concentration-dependently. These results suggest that tranilast may prevent restenosis after percutaneous transluminal coronary angioplasty.

Topics: Angioplasty, Balloon, Coronary; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arterial Occlusive Diseases; Cell Division; Chemotaxis, Leukocyte; Collagen; Drug Evaluation, Preclinical; Endothelium, Vascular; Extracellular Matrix; Glycosaminoglycans; Humans; Male; Muscle, Smooth, Vascular; ortho-Aminobenzoates; Platelet-Derived Growth Factor; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Recombinant Proteins; Recurrence; Transforming Growth Factor beta