Synergistic Effects of Activin A and Fibroblast Growth Factor 2 in the Modulation of Insulin Expression

Diabetes is the most prevalent and serious metabolic disease, and the number of diabetic patients worldwide is increasing. The reduction of insulin biosynthes is in pancreatic E-cells is closely associated with the onset and progression of diabetes, therefore, it is important to search for ways to induce insulin-producing cells in non-E-cells. In the present study, it has been reported that activin A and a basic fibroblast growth factor 2 （ FGF2）, can synergistically increase the insulin mRNA level, in both mouse El4 striatal primary cell cultures and the hippocampal neuronal cell line HT22. Activin A and FGF2 can jointly stimulate the nuclear translocation of Smad3 and specifically activate ERK1/2. It is interesting to note that a specific inhibitor for MEK, U0126, can efficiently block the induction of an insulin promoter activity by activin A and FGF2. This indicates that activin A collaborates with FGF2, giving a signal to induce the insulin gene through selective activation of the ERK-type MAP kinase and Smad3 in mouse striatal and HT22 cells. These data suggest that activin A may act in concert with FGF2 for the development of insulin -positive neurons

Nintedanib induces apoptosis in human pterygium cells through the FGFR2-ERK signalling pathway

AIM:To investigate whether nintedanib can inhibit pterygium cells through the fibroblast growth factor receptor 2(FGFR2)/extracellular-signal-regulated kinase(ERK)pathway.METHODS:Human primary pterygium cells were cultured in vitro.After treatment with nintedanib,the cell morphology was observed under microscopy,the morphological changes of the nucleus were observed after DAPI staining,apoptosis was analyzed by Annexin-V FITC/PI double staining,and the changes of apoptosis-associated proteins were detected by Western blot.The binding ability of nintedanib to FGFR2 was predicted by molecular docking.Finally,by silencing FGFR2,we explored whether nintedanib inhibited FGFR2/ERK pathway.RESULTS:The results showed that nintedanib inhibited the growth of pterygium cells and caused nuclear pyknosis.The results of Annexin-VFITC/PI double staining showed that nintedanib was able to induce early and late apoptosis of pterygium cells,significantly increasing the expression of apoptosis-associated proteins Bax and cleaved-Caspase3(P<0.05),and reducing the expression of Bcl-2(P<0.05).In addition,nintedanib significantly inhibited ERK1/2 phosphorylation through FGFR2(P<0.05).After silencing the expression of FGFR2,there was no significant difference in the inhibition of ERK1/2 phosphorylation by nintedanib(P>0.05).CONCLUSION:Nintedanib induces apoptosis of pterygium cells by inhibiting FGFR2/ERK pathway.

Wnt pathway in the formation of ischemic brain injury Interventional pathway of basic fibroblast growth factor

BACKGROUND： Basic fibroblast growth factor （bFGF） can reduce neuronal apoptosis following ischemia/reperfusion （I/R） injury. Mechanism of the phenomenon should be elucidated.OBJECTIVE： The goal of this study was to observe the effect of bFGF on the expressions of Dickkopf-1（DKK-1） and β-catenin in the Wnt pathway in hippocampal tissue of rats following brain I/R injury, in order to investigate the role of Wnt pathway in the formation ofischemic brain injury.DESIGN： Randomized controlled experiment.SETTING： Shenyang Medical College.MATERIALS： Thirty healthy 3 months old male Wistar rats, weighing 300 - 350 g, were provided by the Experimental Animal Center of Shenyang Medical College. Thirty rats were randomized into sham-operation group, model group and treatment group. Goat anti-rat monoclonal antibody β-catenin was purchased from SANTA CRUZ Company. BFGF was developed by Beijing SL Pharmaceutical Co., Ltd.METHODS： This experiment was carried out in the Shenyang Medical College between November 2005 and May 2006. ①Focal brain I/R by suture-occluded method was modeled in rats in the treatment group and model group. Their middle cerebral artery was occluded 1 hour and reperfused for 24 hours. While in the sham-operation group, only the right common carotid artery and external carotid artery of rats were occluded for 90 minutes. ② The rats in the treatment group were intraperitoneally injected with 10 μg/kg bFGF,and those in the other groups were intraperitoneally injected with the same amount of saline.MAIN OUTCOME MEASURES： Following I/R 48 hours, the expressions of β-catenin and Dickkopf-1 mRNA in the neurons of hippocampal CA1 region by immunohistochemical SABC and RT-PCR.RESULTS： Following I/R 48 hours, the expressions of β-catenin and Dickkopf-1 mRNA in the neurons of hippocampal CA1 region was evaluated by means of immunohistochemical SABC and RT-PCR. ① Expression of DKK-1 mRNA in the sham-operation group was at low level, it was significantly higher in the model group compared to the sham-operation group; Expression of DKK-1 mRNA in the treatment group was significantly lower than that in the model group. ②Expression of β-catenin in the cerebral cortex and hippocampal cytoplasm of rats： The mean gray scale of β-catenin of model group was significantly lower than that of sham-operation group （74.27±2.65 vs. 111.36±5.39, P 〈 0.05）; The mean gray scale of β -catenin of treatment group was significantly higher than that of model group （86.18±7.41 vs. 74.27±2.65, P〈0.05）.CONCLUSION： bFGF may influence Wnt pathway by participating in the regulation of DKK-1 mRNA and β-catenin expressions, and thereby protect neurons.

FGF2 is overexpressed in asthma and promotes airway in airway epithelial cells

Background: Airway inflammation is the core pathological process of asthma, with the key inflammatory regulators incompletely defined. Recently, fibroblast growth factor 2(FGF2) has been reported to be an inflammatory regulator;however, its role in asthma remains elusive. This study aimed to investigate the immunomodulatory role of FGF2 in asthma.Methods: First, FGF2 expression was characterised in clinical asthma samples and the house dust mite(HDM)-induced mouse chronic asthma model. Second, recombinant mouse FGF2(rm-FGF2) protein was intranasally delivered to determine the effect of FGF2 on airway inflammatory cell infiltration. Third, human airway epithelium-derived A549 cells were stimulated with either HDM or recombinant human interleukin-1β(IL-1β) protein combined with or without recombinant human FGF2. IL-1β-induced IL-6 or IL-8 release levels were determined using enzyme-linked immunosorbent assay, and the involved signalling transduction was explored via Western blotting.Results: Compared with the control groups, the FGF2 protein levels were significantly upregulated in the bronchial epithelium and alveolar areas of clinical asthma samples [(6.70±1.79) vs.(16.32±2.40), P=0.0184;(11.20±2.11) vs.(21.00±3.00), P=0.033, respectively] and HDM-induced asthmatic mouse lung lysates [(1.00±0.15) vs.(5.14±0.42),P<0.001]. Moreover, FGF2 protein abundance was positively correlated with serum total and anti-HDM IgE levels in the HDM-induced chronic asthma model(R^(2)=0.857 and 0.783, P=0.0008 and 0.0043, respectively). Elevated FGF2protein was mainly expressed in asthmatic bronchial epithelium and alveolar areas and partly co-localised with infiltrated inflammatory cell populations in HDM-induced asthmatic mice. More importantly, intranasal instillation of rm-FGF2 aggravated airway inflammatory cell infiltration [(2.45±0.09) vs.(2.88±0.14), P=0.0288] and recruited more subepithelial neutrophils after HDM challenge [(110.20±29.43) cells/mm^(2) vs.(238.10±42.77) cells/mm^(2), P=0.0392]without affecting serum IgE levels and Th2 cytokine transcription. In A549 cells, FGF2 was upregulated through HDM stimulation and promoted IL-1β-induced IL-6 or IL-8 release levels [up to(1.41±0.12)-or(1.44±0.14)-fold change vs.IL-1β alone groups, P=0.001 or 0.0344, respectively]. The pro-inflammatory effect of FGF2 is likely mediated through the fibroblast growth factor receptor(FGFR)/mitogen-activated protein kinase(MAPK)/nuclear factor kappa B(NF-κB)pathway.Conclusions: Our findings suggest that FGF2 is a potential inflammatory modulator in asthma, which can be induced by HDM and acts through the FGFR/MAPK/NF-κB pathway in the airway epithelial cells.

Protective effects of a novel drug RC28-E blocking both VEGF and FGF2 on early diabetic rat retina

AIM： To investigate protective effects of a novel recombinant decoy receptor drug RC28-E on retinal damage in early diabetic rats. METHODS： The streptozotocin （STZ）-induced diabetic rats were randomly divided into 6 groups： diabetes mellitus （DM） group （saline, 3 μL/eye）; RC28-E at low （0.33 μg/μL, 3 μL）, medium （1 μg/μL, 3 μL）, and high （3 μg/μL, 3 μL） dose groups; vascular endothelial growth factor （VEGF） Trap group （1 μg/μL, 3 μL）; fibroblast growth factor （FGF） Trap group （1 μg/μL, 3 μL）. Normal control group was included. At week 1 and 4 following diabetic induction, the rats were intravitreally injected with the corresponding solutions. At week 6 following the induction, apoptosis in retinal vessels was detected by TUNEL staining. Glial fibrillary acidic protein （GFAP） expression was examined by immunofluorescence. Blood-retinal barrier （BRB） breakdown was assessed by Evans blue assay. Ultrastructural changes in choroidal and retinal vessels were analyzed by transmission electron microscopy （TEM）. Content of VEGF and FGF proteins in retina was measured by enzyme linked immunosorbent assay （ELISA）. The retinal expression of intercellular cell adhesion molecule-1 （ICAM-1）, tumor necrosis factor-α （TNF-α）, VEGF and FGF genes was examined by quantitative polymerase chain reaction （qPCR）. RESULTS： TUNEL staining showed that the aberrantly increased apoptotic cells death in diabetic retinal vascular network was significantly reduced by treatments of medium and high dose RC28-E, VEGF Trap, and FGF Trap （all P〈0.05）, the effects of medium and high dose RC28-E or FGF Trap were greater than VEGF Trap （P〈0.01）. GFAP staining suggested that reactive gliosis was substantially inhibited in all RC28-E and VEGF Trap groups, but the inhibition in FGF Trap group was not as prominent. Evans blue assay demonstrated that only high dose RC28-E could significantly reduce vascular leakage in early diabetic retina （P〈0.01）. TEM revealed that the ultrastructures in choroidal and retinal vessels were damaged in early diabetic retina, which was ameliorated to differential extents by each drug. The expression of VEGF and FGF2 proteins was significantly upregulated in early diabetic retina, and normalized by RC28-E at all dosages and by the corresponding Traps. The upregulation of ICAM-1 and TNF-α in diabetic retina was substantially suppressed by RC28-E and positive control drugs. CONCLUSION： Dual blockade of VEGF and FGF2 by RC28-E generates remarkable protective effects, including anti-apoptosis, anti-gliosis, anti-leakage, and improving ultrastructures and proinflammatory microenvironment, in early diabetic retina, thereby supporting further development of RC28-E into a novel and effective drug to diabetic retinopathy （DR）.

Application of neurotrophic and proangiogenic factors as therapy after peripheral nervous system injury

The intrinsic ability of peripheral nerves to regenerate after injury is extremely limited,especially in case of severe injury.This often leads to poor motor function and permanent disability.Existing approaches for the treatment of injured nerves do not provide appropriate conditions to support survival and growth of nerve cells.This drawback can be compensated by the use of gene therapy and cell therapy-based drugs that locally provide an increase in the key regulators of nerve growth,including neurotrophic factors and extracellular matrix proteins.Each growth factor plays its own specific angiotrophic or neurotrophic role.Currently,growth factors are widely studied as accelerators of nerve regeneration.Particularly noteworthy is synergy between various growth factors,that is essential for both angiogenesis and neurogenesis.Fibroblast growth factor 2 and vascular endothelial growth factor are widely known for their proangiogenic effects.At the same time,fibroblast growth factor 2 and vascular endothelial growth factor stimulate neural cell growth and play an important role in neurodegenerative diseases of the peripheral nervous system.Taken together,their neurotrophic and angiogenic properties have positive effect on the regeneration process.In this review we provide an in-depth overview of the role of fibroblast growth factor 2 and vascular endothelial growth factor in the regeneration of peripheral nerves,thus demonstrating their neurotherapeutic efficacy in improving neuron survival in the peripheral nervous system.

Twist 1 correlates with poor differentiation and progression in gastric adenocarcinoma via elevation of FGFR2 expression

AIM: To explore the correlation between Twist-related protein (Twist)1, fibroblast growth factor receptor (FGFR)2 and gastric adenocarcinoma differentiation and progression.

Expressions of TGF-β2, bFGF and ICAM-1 in lens epithelial cells of complicated cataract with silicone oil tamponade

AIM： To investigate the expression differences of transforming growth factor-β2（TGF-β2）, basic fibroblast growth factor（b FGF） and intercellular cell-adhesion molecule-1（ICAM-1） in lens epithelial cells（LECs） of complicated cataract with silicone oil tamponade and agerelated cataract. METHODS： Totally 150 eyes of 150 patients（aged 35 to 77y） were investigated, including 75 patients with complicated cataract after silicone oil tamponade and 75 patients with age-related cataract. The central piece of anterior capsules was collected during cataract surgery. TGF-β2, b FGF and ICAM-1 were detected in the 60 specimens of the two groups by immunohistochemistry. The expression levels of the three kinds of messenger ribonucleic acid（m RNA） were determined by real-time quantitative reverse transcriptionpolymerase chain reaction in the 90 specimens of the two groups.RESULTS： TGF-β2 was detected in the cytomembrane and cytoplasm of the LECs and b FGF was detected in the nucleus. ICAM-1 was positive in the cytomembrane of the LECs and the distribution of positive cells was uneven. The m RNA genes expression of the TGF-β2, b FGF and ICAM-1 was significant differences between the two groups and markedly increased in complicated cataract group（P〈0.05）.CONCLUSION： The up-regulated TGF-β2, b FGF and ICAM-1 maybe associate with the occurrence and development of complicated cataract with silicone oil tamponade.

Paradigm shift of chemotherapy and systemic treatment for biliary tract cancer

Biliary tract cancers(BTC)are frequently identified at late stages and have a poor prognosis due to limited systemic treatment regimens.For more than a decade,the combination of gemcitabine and cis-platin has served as the first-line standard treatment.There are few choices for second-line chemo-therapy.Targeted treatment with fibroblast growth factor receptor 2 inhibitors,neurotrophic tyrosine receptor kinase inhibitors,and isocitrate dehydrogenase 1 inhibitors has had important results.Immune checkpoint inhibitors(ICI)such as pembrolizumab are only used in first-line treatment for microsatellite instability high patients.The TOPAZ-1 trial's outcome is encouraging,and there are several trials underway that might soon put targeted treatment and ICI combos into first-line options.Newer targets and agents for existing goals are being studied,which may represent a paradigm shift in BTC management.Due to a scarcity of targetable mutations and the higher toxicity profile of the current medications,the new category of drugs may occupy a significant role in BTC therapies.

Efficacy of Ciji Hua'ai Baosheng formula on the expressions of vascular endothelial growth factor,kinase insert domain-containing receptor and basic fibroblast growth factor in mouse models of H22 hepatocellular carcinoma

OBJECTIVE: To investigate the efficacy of Ciji Hua'ai Baosheng formula(CHBF) on microvessel density(MVD) and vascular endothelial growth factor(VEGF), kinase insert domain-containing receptor(KDR) and basic fibroblast growth factor(b FGF) expression in serum and tumor tissue of mice receiving chemotherapy for the treatment of H22 hepatocellular carcinoma.METHODS: Sixty Kunming mice were injected subcutaneously with H22 hepatoma carcinoma cell suspensions into the right anterior armpit. Seven days later, all transplanted tumor were formed and the mice were intraperitoneally injected 200 mg/kg cytoxan(CTX) to establish the models of tumor-bearing mouse chemotherapy, then they were randomly divided into model group, continuing CTX chemotherapy group(CTX group), and three CHBF(117, 58.5 and 29.25 g/kg) groups. After ten days of treatments, histology was observed, contents of VEGF, KDR and b FGF in serum and tumor tissue were measured by enzyme-linked immunosorbent assay(ELISA), VEGF and b FGF protein expression and MVD tagged by CD34 were detected by immunohistochemisty.RESULTS: MVD in CHBF(117, 58.5 g/kg) and CTX groups was significantly lower than that in model group(P < 0.01); expressions of VEGF, KDR and b FGF in serum and tumor tissue in CHBF(117 g/kg)group were less than those in model group(P <0.05; P < 0.01); the expressions of MVD, VEGF and b FGF in tumor tissue of CHBF(117 g/kg) groupwere also less than those in CTX group(P < 0.05;P < 0.01).CONCLUSION: CHBF can effectively reduce the expression of VEGF, KDR and b FGF in serum and tumor tissue, and decrease MVD and delay tumor progression.

Healing of chronic cutaneous wounds by topical treatment with basic fibroblast growth factor

OBJECTIVE: To evaluate the safety and efficacy of topical application of recombinant bovine basic fibroblast growth factor (rbFGF) on the healing of chronic cutaneous wounds. METHODS: Twenty-eight patients with thirty-three chronic cutaneous wounds resulting from trauma, diabetes mellitus, pressure sore and radiation injuries were enrolled in this prospective, open-label crossover trial. Prior to treatment with rbFGF, all wounds failed to heal with conventional therapies within 4 weeks. All wounds were locally treated with rbFGF at a dose of 150 AU/cm(2). Healing time and the quality of wounds were used to evaluate the efficacy of the treatment. RESULTS: Healing of all chronic wounds was expedited. During the study, eighteen wounds completely healed within 2 weeks, four healed within 3 weeks, and another eight completely healed within 4 weeks. Only three wounds failed to heal within 4 weeks, but healed at 30, 40 and 42 days after treatment with rbFGF. Thus, compared with conventional therapies, the effective rate of rbFGF treatment within 4 weeks was 90.9%. Histological assessment showed more abundant capillary sprouts or tubes and that fibroblasts were differentiated in wounds treated with rbFGF. No adverse side effects related to basic fibroblast growth factor were observed. CONCLUSIONS: Our results indicate that rbFGF could be used to accelerate healing in chronic wounds. It is our belief that this may be a more effective method of chronic wound management.

Expression and effect of basic fibroblast growth factor on human cataract lens epithelial cells

OBJECTIVE: To detect the expression of basic fibroblast growth factor (bFGF) in human ocular tissues, and to assess the effect of bFGF on the proliferation of human cataract lens epithelial cells (LECs) and its correlation with age. METHODS: Enucleated eyes were subjected to immunostaining for bFGF protein. Human cataract LECs were cultured in vitro, and treated with bFGF for 48 hr. Proliferation was estimated by the positive area ratio of proliferating cell nuclear antigen (PCNA) in immunohistochemistry. RESULTS: bFGF protein was found in various human ocular tissues. bFGF stimulated human cataract LEC proliferation, and there was an age-related decrease in responsiveness of human cataract LECs to bFGF (P

Involvement of MAPK/ERK kinase-ERK pathway in exogenous bFGF-induced Egr-1 binding activity enhancement in anoxia-reoxygenation injured astrocytes

Objective Intravenous administration of basic fibroblast growth factor （bFGF） is effective to reduce the volume of cerebral infract due to ischemia. This study was designed to investigate the molecular mechanism, especially the signal transduction pathways, involved in this protective role of bFGF. Methods Anoxia-reoxygenation treated atrocytes were used to study the role of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase （MAPK/ERK kinase, MEK）-ERK signaling pathway after exogenous bFGF administration by Western blot. Electrophoretic mobile shift assay was used to detect the binding activity of early growth response factor-1 （Egr-1）, an important transcription factor for endogenous bFGF. Results bFGF could protect some signal transduction proteins from the oxygen-derived free radicals induced degradation. ERK1/2 was activated and involved in Egr-1 binding activity enhancement induced by exogenous bFGF. Conclusion MEK-ERK MAPK cascade may be an important signal transduction pathway contributed to bFGF induced enhancement of Egr-1 binding activity in anoxia-reoxygenation injured astrocytes.

Effect of basic fibroblast growth factor on the expression of glial fibrillary acidic protein after tractive spinal cord injury in rats

OBJECTIVE: To investigate the effects of basic fibroblast growth factor (bFGF) on the expression of glial fibrillary acidic protein (GFAP) after tractive spinal cord injury in rats and to explore the recovery of spinal cord function. METHODS: The rats were subjected to tractive spinal cord injury at T13-L2. Cortical somatosensory-evoked potential (CSEP) was closely monitored and when P1-N1 wave amplitude decreased to 70% of that before operation, a small-bore catheter was inserted below the injured plane through subarachnoid cavity. In the treatment groups, 20 microl of bFGF solution (containing 20 microg of bFGF) was injected through the catheter right after the operation and 1, 2, 3, 4, 8, 12 and 24 h postoperatively. In the control group, same volume of normal saline was injected and every four rats were killed at 1, 4, 7, 14 and 21 d after the operation. Combined behavior score (CBS) and electro-physiological examination were adopted to evaluate function recovery. Expression of GFAP was observed by immuno-histochemical staining and was analyzed quantitatively by computer image analysis. RESULTS: There was statistically significant difference in GFAP-positive cells between bFGF treatment group and the control group (P

Molecular Detection of FGFR2 Rearrangements in Resected Intrahepatic Cholangiocarcinomas:FISH Could Be An Ideal Method in Patients with Histological Small Duct Subtype

Background and Aims:Intrahepatic cholangiocarcinoma(ICC)is a subtype of primary liver cancer for which effective therapeutic agents are lacking.Fibroblast growth factor receptor 2(FGFR2)has become a promising therapeutic target in ICC;however,its incidence and optimum testing method have not been fully assessed.This study investigated the rearrangement of FGFR2 in intrahepatic cholangiocarcinoma using multiple molecular detection methods.Methods:The samples and clinical data of 167 patients who underwent surgical resection of intrahepatic cholangiocarcinoma in Zhongshan hospital,Fudan university were collected.The presence of FGFR2 gene rearrangement was confirmed using fluorescence in situ hybridization(FISH)and targeted next-generation sequencing(NGS).FGFR2 protein expression was determined using immunohistochemistry(IHC).The concordance between the methods was statistically compared.PD-L1 expression was also assessed in this cohort.The clinicopathological characteristics and genomic profile related to FGFR2 rearrangements were also analyzed to assist candidatescreening for targeted therapies.Results:FGFR2 rearrangement was detected in 21 of the 167 ICC cases(12.5%)using FISH.NGS analysis revealed that FGFR2 rearrangement was present in 16 of the 20 FISH-positive cases,which was consistent with the FISH results(kappa value=0.696,p<0.01).IHC showed that 80 of the 167 cases(48%)were positive for FGFR2 expression,which was discordant with both FISH and NGS results.By comparison,FGFR2-positivity tended to correlate with unique clinicopathological subgroups,featuring early clinical stage,histologically small duct subtype,and reduced mucus production(P<0.05),with improved overall survival(p<0.05).FGFR2-positivity was not associated with PD-L1 expression in ICCs.In genome research,we identified eight partner genes fused with FGFR2,among which FGFR2-BICC1 was the most common fusion type.BAP1,CDKN2A,and CDKN2B were the most common concomitant genetic alterations of FGFR2,whereas KRAS and IDH1 mutations were mutually exclusive to FGFR2 rearrangements.Conclusions:FISH achieved satisfactory concordance with NGS,has potential value for FGFR2 screening for targeted therapies.FGFR2 detection should be prioritized for unique clinical subgroups in ICC,which features a histological small duct subtype,early clinical stage,and reduced mucus production.

Crouzon syndrome in a fraternal twin:A case report and review of the literature

BACKGROUND Crouzon syndrome(CS;OMIM 123500)is an autosomal dominant inherited craniofacial disorder caused by mutations in the fibroblast growth factor receptor 2(FGFR2)gene.CS is characterized by craniofacial dysostosis,exophthalmos,and facial anomalies with hypoplastic maxilla and relative mandibular prognathism.CASE SUMMARY Our report involves a 6-year-old fraternal twin boy with many caries in the oral cavity who presented with characteristic features of CS based on clinical and radiographic examinations along with Sanger sequencing.The fraternal girl did not show any abnormalities indicating CS.Carious teeth and poor oral hygiene were managed promptly through administering appropriate behavior guidance,orthodontic treatment was planned,and preventive procedures were described.CONCLUSION CS could occur in a fraternal twin caused by a de novo mutation of the FGFR2 gene.Oral hygiene instruction,preventive programs on oral hygiene,orthodontic treatment,and maxillary osteotomy were required for treatment.

Endothelin-1, an important mitogen of smooth muscle cells of spontaneously hypertensive rats

OBJECTIVE: To study the features of vascular smooth muscle cell (VSMC) proliferation induced by endothelin-1 (ET-1). METHODS: VSMCs of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats were cultured and treated with ET-1. Basic fibroblast growth factor (bFGF) gene expression was measured using both Northern blot and an enzyme-linked immunoassay. RESULTS: ET-1 resulted in an increase in bFGF transcripts at 8 - 24 h; bFGF levels were significantly higher in VSMCs treated with ET-1 than in those not treated. However, VSMCs growth responses in SHR and WKY were different. Smooth muscle cells of SHR were hyper-responsive to ET-1. Maximal bFGF mRNA levels were elevated 3.5-fold at 4 h of stimulation in WKY and 8-fold at 8h in SHR4. Moreover, the proliferation of VSMCs induced by ET-1 was inhibited by antisense phosphorothioate oligodeoxynucleotides (10 micromol/L AS-bFGF) but not sense bFGF oligomers at the same concentrations, being reduced by 80% in SHR and 40% in WKY vs control, respectively. Furthermore, the effect of AS-bFGF oligomers on SHR SMC proliferation is significantly greater than on WKY SMC proliferation. CONCLUSION: ET-1 may be required for exaggerated vascular growth responses in SHR and bFGF may be involved.