Evaluation of the Therapeutic Effects of the Hydroethanolic Extract of Portulaca oleracea on Surgical-Induced Peritoneal Adhesion

Objective. Peritoneal adhesion (PA) is an abnormal connective tissue that usually occurs between tissues adjacent to damaged organs during processes such as surgery. In this study, the anti-inflammatory and antioxidant effects of Portulaca oleracea (PO) were investigated against postoperative-induced peritoneal adhesion. Methods. Thirty healthy male Wistar rats ( 220 ± 20 g , 6-8 weeks) were randomly divided into four groups: (1) normal, (2) control (induced peritoneal adhesion), and (3) and (4) PO extracts (induced peritoneal adhesion and received 100 or 300 mg/kg/day of PO extract for seven days). Finally, macroscopic and microscopic examinations were performed using different scoring systems and immunoassays in the peritoneal lavage fluid. Results. We found that the levels of adhesion scores and interleukin- (IL-) 1β, IL-6, IL-10, tumour necrosis factor- (TNF-) α, transforming growth factor- (TGF-) β1, vascular endothelial growth factor (VEGF), and malondialdehyde (MDA) were increased in the control group. However, PO extract (100 and 300 mg/kg) notably reduced inflammatory (IL-1β, IL-6, and TNF-α), fibrosis (TGF-β1), angiogenesis (VEGF), and oxidative (MDA) factors, while increased anti-inflammatory cytokine IL-10, antioxidant factor glutathione (GSH), compared to the control group. Conclusion. Oral administration of PO improved postoperational-induced PA by alleviating the oxidative factors, fibrosis, inflammatory cytokines, angiogenesis biomarkers, and stimulating antioxidative factors. Hence, PO can be considered a potential herbal medicine to manage postoperative PA. However, further clinical studies are required to approve the effectiveness of PO.

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Intraperitoneal Lavage with Crocus sativus Prevents Postoperative-Induced Peritoneal Adhesion in a Rat Model: Evidence from Animal and Cellular Studies

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/5945101 ◽

2021 ◽

Vol 2021 ◽

pp. 1-22

Author(s):

Pouria Rahmanian-Devin ◽

Hassan Rakhshandeh ◽

Vafa Baradaran Rahimi ◽

Zahra Sanei-Far ◽

Maede Hasanpour ◽

...

Keyword(s):

Cell Proliferation ◽

Growth Factor ◽

Plasminogen Activator ◽

Macrophage Polarization ◽

Crocus Sativus ◽

Dependent Manner ◽

Peritoneal Adhesion ◽

Tnf Α ◽

Anti Inflammatory ◽

Tgf Β1

Postoperative peritoneal adhesions are considered the major complication following abdominal surgeries. The primary clinical complications of peritoneal adhesion are intestinal obstruction, infertility, pelvic pain, and postoperative mortality. In this study, regarding the anti-inflammatory and antioxidant activities of Crocus sativus, we aimed to evaluate the effects of Crocus sativus on the prevention of postsurgical-induced peritoneal adhesion. Male Wistar-Albino rats were used to investigate the preventive effects of C. sativus extract (0.5%, 0.25% and 0.125% w / v ) against postsurgical-induced peritoneal adhesion compared to pirfenidone (PFD, 7.5% w / v ). We also investigated the protective effects of PFD (100 μg/ml) and C. sativus extract (100, 200, and 400 μg/ml) in TGF-β1-induced fibrotic macrophage polarization. The levels of cell proliferation and oxidative, antioxidative, inflammatory and anti-inflammatory, fibrosis, and angiogenesis biomarkers were evaluated both in vivo and in vitro models. C. sativus extract ameliorates postoperational-induced peritoneal adhesion development by attenuating oxidative stress [malondialdehyde (MDA)]; inflammatory mediators [interleukin- (IL-) 6, tumour necrosis factor- (TNF-) α, and prostaglandin E2 (PGE2)]; fibrosis [transforming growth factor- (TGF-) β1, IL-4, and plasminogen activator inhibitor (PAI)]; and angiogenesis [vascular endothelial growth factor (VEGF)] markers, while propagating antioxidant [glutathione (GSH)], anti-inflammatory (IL-10), and fibrinolytic [tissue plasminogen activator (tPA)] markers and tPA/PAI ratio. In a cellular model, we revealed that the extract, without any toxicity, regulated the levels of cell proliferation and inflammatory (TNF-α), angiogenesis (VEGF), anti-inflammatory (IL-10), M1 [inducible nitric oxide synthase (iNOS)] and M2 [arginase-1 (Arg 1)] biomarkers, and iNOS/Arg-1 ratio towards antifibrotic M1 phenotype of macrophage, in a concentration-dependent manner. Taken together, the current study indicated that C. sativus reduces peritoneal adhesion formation by modulating the macrophage polarization from M2 towards M1 cells.

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The Effects of Rice Husk Liquid Smoke in Porphyromonas gingivalis-Induced Periodontitis

European Journal of Dentistry ◽

10.1055/s-0041-1727554 ◽

2021 ◽

Author(s):

Theresia Indah Budhy ◽

Ira Arundina ◽

Meircurius Dwi Condro Surboyo ◽

Anisa Nur Halimah

Keyword(s):

Growth Factor ◽

Porphyromonas Gingivalis ◽

Rice Husk ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Control Group ◽

Proliferation Markers ◽

Liquid Smoke ◽

Tnf Α ◽

Factor Α

Abstract Objectives The purpose of this study is to analyze the effects of rice husk liquid smoke in Porphyromonas gingivalis-induced periodontitis in the inflammatory and proliferation marker such as nuclear factor kappa β (NF-kB), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), transforming growth factor-β (TGF-β), fibroblast growth factor 2 (FGF2), collagen type 1 (COL-1) expression, and the number of macrophages, lymphocytes, and fibroblasts. Materials and Methods Rice husk liquid smoke is obtained by the pyrolysis process. Porphyromonas gingivalis-induced periodontitis in 20 μL phosphate-buffered saline containing 1 × 109 CFU was injected into the lower anterior gingival sulcus of Wistar rats. The periodontitis was then treated with 20 μL/20 g body weight of rice husk liquid smoke once a day for 2 and 7 days, respectively. After treatment, the bone and lower anterior gingival sulcus were analyzed with immunohistochemistry and hematoxylin–eosin staining. Results The treatment of periodontitis with rice husk liquid smoke showed a lower NF-kB, TNF-α, and IL-6 expression and a higher TGF-β, FGF2, and COL-1 expression than the control after treatment for 2 and 7 days (p < 0.05), respectively. The number of macrophages and fibroblasts was also higher when compared with the control group (p < 0.05), but the number of lymphocytes was lower than the control (p < 0.05). Conclusion Rice husk liquid smoke showed its effects on Porphyromonas gingivalis-induced periodontitis with a decrease in inflammatory markers and an increase in proliferation markers. The development of a rice husk liquid smoke periodontitis treatment is promising.

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Pro- and Anti-Inflammatory Cytokines in the First Trimester—Comparison of Missed Miscarriage and Normal Pregnancy

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18168538 ◽

2021 ◽

Vol 18 (16) ◽

pp. 8538

Author(s):

Maciej Kwiatek ◽

Tomasz Gęca ◽

Anna Kwaśniewska

Keyword(s):

Immune Response ◽

Inflammatory Cytokines ◽

First Trimester ◽

Normal Pregnancy ◽

Control Group ◽

Study Group ◽

Tnf Α ◽

Cytokine Levels ◽

Anti Inflammatory ◽

Tgf Β1

The advantage in response of Th2 over Th1 is observed in normal pregnancy in peripheral blood. A disturbance of this balance can lead to symptoms of miscarriage and pregnancy loss. The aim of this study was to evaluate the pro- and anti-inflammatory cytokines in sera of women who were diagnosed with missed miscarriage in the first trimester and to compare this systemic immune response to the response in women with normal pregnancy. The study group consisted of 61 patients diagnosed with missed miscarriage. In total, 19 healthy women with uncomplicated first trimester created the control group. Cytokines were determined in the maternal serum by ELISA. The analysis included INF-γ, TNF-α, Il-1β, Il-4, Il-5, Il-6, Il-9, Il-10, Il-13 and TGF-β1. Th1 cytokine levels in the study group reached slightly higher values for INF-γ, Il-1β and slightly lower for IL-6 and TNF-α. In turn, Th2 cytokine levels in the study group were slightly higher (Il-9, Il-13), significantly higher (Il4, p = 0.015; Il-5, p = 0.0003) or showed no differences with the control group (Il-10). Slightly lower concentration involved only TGF-β1. Analysis of the correlation between levels of pro- and anti-inflammatory cytokines resulted in some discrepancies, without showing predominance of a specific immune response. The results did not confirm that women with missed miscarriage had an advantage in any type of immune response in comparison to women with normal pregnancy.

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Increased Expression of Granzyme B and Transforming Growth Factor-β in Intralesional Plasma of Oral Lichenoid Reactions: A Preliminary Study

10.21203/rs.3.rs-112771/v1 ◽

2020 ◽

Author(s):

Kai Sun ◽

Lei Pan ◽

Yi-wen Deng ◽

Jun Chen ◽

Guan-huan Du ◽

...

Keyword(s):

Transforming Growth Factor ◽

Inflammatory Diseases ◽

Granzyme B ◽

Large Population ◽

Therapeutic Effects ◽

Peripheral Plasma ◽

Cytokine Profiles ◽

Tnf Α ◽

Lichenoid Reactions ◽

Tgf Β1

Abstract Background: Oral lichenoid reactions are intractable inflammatory diseases of oral mucosa. The cytokine profiles of intralesional blood remain unclear. We aim at revealing the intralesional cytokine profiles and providing some actual and stable intralesional cytokine biomarkers to evaluate the severity and therapeutic effects of oral lichenoid reactions.Methods: Paired intralesional and peripheral plasma from 26 patients with oral lichenoid reactions were collected. The concentration of 15 cytokines of granzyme B, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL17A, TNF-α, IFN-α, IFN-β, IFN-γ, TGF-β1, TGF-β2 and TGF-β3 was measured by Luminex assays. REU score was used for evaluating the severity of the disease. Results: Eleven cytokines including IL-10, IFN-α, IL-6, IL-17A, granzyme B, TGF-β1, TGF-β2, TGF-β3, IL-2, TNF-α, IL-12p70 were detected within the reliable working range. IL-10 was detected in less intralesional samples (19/26) than peripheral samples (26/26, p=0.01). The cytokine concentrations from intralesional plasma were significantly elevated in granzyme B (median 108.94 vs. 16.00), TGF-β1 (mean 30448.92 vs. 10199.04), TGF-β2 (mean 1659.73 vs. 1308.49) and TGF-β3 (mean 914.33 vs. 573.13) than that in peripheral plasma (p=0.001, p＜0.001, p＜0.001 and p＜0.001, respectively). The concentration of IL-12p70 in peripheral plasma was positively correlated with REU score (coefficient of correlation=0.463, p=0.02).Conclusions: The concentration of granzyme B and TGF-β are more abundant in intralesional microenvironment than in peripheral plasma of oral lichenoid reactions. IL-12p70 may be a potential molecular biomarker for evaluating the severity of oral lichenoid reactions. Cohort study of large population is required.

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Centrifugation Conditions in the L-PRP Preparation Affect Soluble Factors Release and Mesenchymal Stem Cell Proliferation in Fibrin Nanofibers

Molecules ◽

10.3390/molecules24152729 ◽

2019 ◽

Vol 24 (15) ◽

pp. 2729 ◽

Cited By ~ 4

Author(s):

Melo ◽

Luzo ◽

Lana ◽

Santana

Keyword(s):

Growth Factor ◽

Transforming Growth Factor ◽

Platelet Rich Plasma ◽

Clinical Practices ◽

Soluble Factors ◽

Tnf Α ◽

Platelet Concentration ◽

Tgf Β1

Leukocyte and platelet-rich plasma (L-PRP) is an autologous product that when activated forms fibrin nanofibers, which are useful in regenerative medicine. As an important part of the preparation of L-PRP, the centrifugation parameters may affect the release of soluble factors that modulate the behavior of the cells in the nanofibers. In this study, we evaluated the influences of four different centrifugation conditions on the concentration of platelets and leukocytes in L-PRP and on the anabolic/catabolic balance of the nanofiber microenvironment. Human adipose-derived mesenchymal stem cells (h-AdMSCs) were seeded in the nanofibers, and their viability and growth were evaluated. L-PRPs prepared at 100× g and 100 + 400× g released higher levels of transforming growth factor (TGF)-β1 and platelet-derived growth factor (PDGF)-BB due to the increased platelet concentration, while inflammatory cytokines interleukin (IL)-8 and tumor necrosis factor (TNF)-α were more significantly released from L-PRPs prepared via two centrifugation steps (100 + 400× g and 800 + 400× g) due to the increased concentration of leukocytes. Our results showed that with the exception of nanofibers formed from L-PRP prepared at 800 + 400× g, all other microenvironments were favorable for h-AdMSC proliferation. Here, we present a reproducible protocol for the standardization of L-PRP and fibrin nanofibers useful in clinical practices with known platelet/leukocyte ratios and in vitro evaluations that may predict in vivo results.

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Amelioration of paraquat-induced pulmonary fibrosis in mice by regulating miR-140-5p expression with the fibrogenic inhibitor Xuebijing

International Journal of Immunopathology and Pharmacology ◽

10.1177/2058738420923911 ◽

2020 ◽

Vol 34 ◽

pp. 205873842092391 ◽

Cited By ~ 1

Author(s):

Min-na Dong ◽

Yun Xiao ◽

Yun-fei Li ◽

Dong-mei Wang ◽

Ya-ping Qu ◽

...

Keyword(s):

Growth Factor ◽

Treatment Group ◽

Pulmonary Fibrosis ◽

Transforming Growth Factor ◽

Lavage Fluid ◽

Tissue Growth ◽

Control Treatment ◽

Enzyme Linked Immunosorbent Assay ◽

Control Group ◽

Tgf Β1

Intravenous Xuebijing (XBJ) therapy suppresses paraquat (PQ)-induced pulmonary fibrosis. However, the mechanism underlying this suppression remains unknown. This work aimed to analyze the miR-140-5p-induced effects of XBJ injection on PQ-induced pulmonary fibrosis in mice. The mice were arbitrarily assigned to four groups. The model group was administered with PQ only. The PQ treatment group was administered with PQ and XBJ. The control group was administered with saline only. The control treatment group was administered with XBJ only. The miR-140-5p and miR-140-5p knockout animal models were overexpressed. The gene expression levels of miR-140-5p, transglutaminase-2 (TG2), β-catenin, Wnt-1, connective tissue growth factor (CTGF), mothers against decapentaplegic homolog (Smad), and transforming growth factor-β1 (TGF-β1) in the lungs were assayed with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis. The levels of TGF-β1, CTGF, and matrix metalloproteinase-9 (MMP-9) in the bronchoalveolar lavage fluid were assessed by enzyme-linked immunosorbent assay (ELISA). Hydroxyproline (Hyp) levels and pulmonary fibrosis were also scored. After 14 days of PQ induction of pulmonary fibrosis, AdCMV-miR-140-5p, and XBJ upregulated miR-140-5p expression; blocked the expressions of TG2, Wnt-1, and β-catenin; and decreased p-Smad2, p-Smad3, CTGF, MMP-9, and TGF-β1 expressions. In addition, Hyp and pulmonary fibrosis scores in XBJ-treated mice decreased. Histological results confirmed that PQ-induced pulmonary fibrosis in XBJ-treated lungs was attenuated. TG2 expression and the Wnt-1/β-catenin signaling pathway were suppressed by the elevated levels of miR-140-5p expression. This inhibition was pivotal in the protective effect of XBJ against PQ-induced pulmonary fibrosis. Thus, XBJ efficiently alleviated PQ-induced pulmonary fibrosis in mice.

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Evaluation of the Effects of Peritoneal Lavage with Rosmarinus officinalis Extract against the Prevention of Postsurgical-Induced Peritoneal Adhesion

Planta Medica ◽

10.1055/a-1118-3918 ◽

2020 ◽

Vol 86 (06) ◽

pp. 405-414 ◽

Cited By ~ 1

Author(s):

Yasamin Roohbakhsh ◽

Vafa Baradaran Rahimi ◽

Samaneh Silakhori ◽

Hamed Rajabi ◽

Pouria Rahmanian-Devin ◽

...

Keyword(s):

Vascular Endothelial Growth Factor ◽

Growth Factor ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β1 ◽

Vehicle Group ◽

Vascular Endothelial ◽

Abdominal Adhesions ◽

Peritoneal Adhesion ◽

Tnf Α ◽

Endothelial Growth Factor

AbstractPostoperative adhesions are regarded as the major complication following abdominal surgery. Rosmarinus officinalis has shown antioxidative and anti-inflammatory effects. Therefore, we aimed to assess the influence of 70% v/v hydro-ethanolic extract of the aerial parts of R. officinalis against postoperative abdominal adhesions in a rat model. Forty-eight male Wistar rats (190 ± 20 g) were divided into six groups of eight: group 1 = normal group, without any surgical procedures, group 2 = control group, group 3 = vehicle group, and groups 3, 4, and 5 = experimental groups receiving 2 mL of 4, 2, or 1% w/v R. officinalis treatment. Adhesion levels were macroscopically examined. Additionally, the levels of inflammatory cytokines (interleukin-6, interleukin-1β, and TNF-α), growth factors (transforming growth factor-β1, and vascular endothelial growth factor), oxidative (NO, nitric oxide and MDA, malondialdehyde), and antioxidative (GSH, glutathione) factors were evaluated. Our results revealed that the adhesion score, interleukin-6, interleukin-1β, TNF-α, transforming growth factor-β1, vascular endothelial growth factor, NO, and MDA levels were significantly increased in the vehicle group, while the GSH level was diminished. R. officinalis treatment notably ameliorated the adhesion score following postoperative abdominal adhesions compared with the vehicle group. Our results also revealed that R. officinalis markedly reduced inflammatory cytokines, oxidative factors, fibrosis, and angiogenesis biomarkers, whereas it increased the antioxidative factor. Therefore, R. officinalis may be a potential candidate for the management of postoperative peritoneal adhesion.

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Role of the Hippo signaling pathway in safflower yellow pigment treatment of paraquat-induced pulmonary fibrosis

Journal of International Medical Research ◽

10.1177/0300060520905425 ◽

2020 ◽

Vol 48 (9) ◽

pp. 030006052090542

Author(s):

Hai Li ◽

Baotian Kan ◽

Lingli Song ◽

Yufa Liu ◽

Xiangdong Jian

Keyword(s):

Growth Factor ◽

Pulmonary Fibrosis ◽

Quantitative Polymerase Chain Reaction ◽

Tissue Growth ◽

Enzyme Linked Immunosorbent Assay ◽

Control Group ◽

Therapeutic Effects ◽

Hippo Signaling ◽

Exposure Group ◽

Tgf Β1

Objective To elucidate the molecular mechanisms by which safflower yellow (SY) mediates therapeutic effects in rats with paraquat intoxication-induced pulmonary fibrosis. Methods Rats received combinations of paraquat, SY, and SB431542, a transforming growth factor (TGF)-β1 receptor antagonist. Survival over 28 days was assessed by Kaplan–Meier analysis. Rat tissue and serum samples were assessed by hematoxylin and eosin staining, Masson’s Trichrome staining, immunoblotting, quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and transmission electron microscopy. Results Survival rates were higher in SY and SB431542 groups (treatment and paraquat) than in the exposure group (paraquat alone). In the exposure group, serum TGF-β1 levels increased between days 3 and 14; mammalian STE20-like (MST) levels increased between days 3 and 7; TGF-β1 and Smad3 levels increased between days 3 and 14; and Yap and connective tissue growth factor levels increased between days 3 and 28. TGF-β1 levels were lower in SY and SB431542 groups than in the exposure group. Pathology scores were higher in exposure, SY, and SB431542 groups than in the control group throughout the experiment. Conclusions In rats with paraquat intoxication-induced pulmonary fibrosis, Hippo signaling could be activated by the MST-Yap pathway; SY and SB431542 could alleviate pulmonary fibrosis via Hippo signaling.

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Therapeutic Effects of an Inhibitor of Thioredoxin Reductase on Liver Fibrosis by Inhibiting the Transforming Growth Factor-β1/Smads Pathway

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2021.690170 ◽

2021 ◽

Vol 8 ◽

Author(s):

Wenxuan Jiao ◽

Man Bai ◽

Hanwei Yin ◽

Jiayi Liu ◽

Jing Sun ◽

...

Keyword(s):

Growth Factor ◽

Liver Fibrosis ◽

Molecular Mechanisms ◽

Transforming Growth Factor ◽

Smooth Muscle Actin ◽

Thioredoxin Reductase ◽

Transforming Growth Factor Β1 ◽

Therapeutic Effects ◽

Pathological State ◽

Tgf Β1

Liver fibrosis is an important stage in the progression of liver injury into cirrhosis or even liver cancer. Hepatic stellate cells (HSCs) are induced by transforming growth factor-β1 (TGF-β1) to produce α-smooth muscle actin (α-SMA) and collagens in liver fibrosis. Butaselen (BS), which was previously synthesized by our group, is an organic selenium compound that exerts antioxidant and tumor cell apoptosis–promoting effects by inhibiting the thioredoxin (Trx)/thioredoxin reductase (TrxR) system. The aim of this study was to investigate the potential effects of BS on liver fibrosis and explore the underlying molecular mechanisms of its action. Liver fibrosis models were established using male BALB/c mice through intraperitoneal injection of CCl4. BS was administered orally once daily at a dose of 36, 90, or 180 mg/kg. Silymarin (Si), which is a drug used for patients with nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, was administered at a dose of 30 mg/kg per day as a control. The action mechanisms of BS against liver fibrosis progression were examined in HSCs. The study revealed that the activity and expression levels of TrxR were elevated in the mouse liver and serum after CCl4-induced liver fibrosis. Oral administration of BS relieved the pathological state of mice with liver fibrosis, showing significant therapeutic effects against liver fibrosis. Moreover, BS not only induced HSC apoptosis but also inhibited the production of α-SMA and collagens by HSCs by downregulating the TGF-β1 expression and blocking the TGF-β1/Smads pathway. The results of the study indicated that BS inhibited liver fibrosis by regulating the TGF-β1/Smads pathway.

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Cytokines modulate the sensitivity of human fibroblasts to stimulation with insulin-like growth factor-I (IGF-I) by altering endogenous IGF-binding protein production

Journal of Endocrinology ◽

10.1677/joe.0.1370151 ◽

1993 ◽

Vol 137 (1) ◽

pp. 151-159 ◽

Cited By ~ 60

Author(s):

M. E. Yateman ◽

D. C. Claffey ◽

S. C. Cwyfan Hughes ◽

V. J. Frost ◽

J. A. H. Wass ◽

...

Keyword(s):

Growth Factor ◽

Transforming Growth Factor ◽

Human Fibroblasts ◽

Dermal Fibroblasts ◽

Insulin Like Growth Factor ◽

Tnf Α ◽

Igf I ◽

Dose Dependent ◽

Tgf Β1 ◽

Igfbp 3

ABSTRACT Human dermal fibroblasts produce a number of insulin-like growth factor-binding proteins (IGFBPs) including the main circulating form, IGFBP-3. It has been suggested that the regulation of IGFBP secretion may play a major role in modulating insulin-like growth factor (IGF) bioactivity. We have quantified the effects of two cytokines, transforming growth factor-β1 (TGF-β1) and tumour necrosis factor-α (TNF-α) which have opposing actions on fibroblast IGFBP-3 production, and examined their subsequent role in IGF-I mitogenesis. TGF-β1 caused a dose-dependent increase in IGFBP-3 in serum-free fibroblast-conditioned media. TGF-β1 (1 μg/l) resulted in immunoreactive IGFBP-3 levels reaching 286·5 ± 22·4% of control after 20 h, the increase being confirmed by Western ligand blot. TNF-α caused a dose-dependent decrease in fibroblast IGFBP-3 secretion, 1 μg TNG-α/l reducing IGFBP-3 levels to 32·1 ± 11·% of control. This effect was not due to cytotoxicity and was not cell-density-dependent. Fibroblast proliferation was examined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric cytochemical bioassay. The addition of IGF-I resulted in dose-dependent growth stimulation after 48 h, the effective range being 20–100 μg/l. The IGF-I analogue Long-R3-IGF-I which has little affinity for the IGFBPs was approximately 20-fold more potent in this assay, and was unaffected by exogenous IGFBP-3. While the addition of 1 μg TGF-β1/l to increasing doses of IGF-I resulted in a fourfold decrease in mitogenic sensitivity to the IGF-I, no such effect was seen with Long-R3-IGF-I. Conversely, 1 μg TNF-α/l increased fibroblast IGF-I sensitivity five-fold, an effect not observed with the IGF-I analogue. Such data suggest that endogenous IGFBP-3 inhibits IGF-I bioactivity and that the regulation of IGF mitogenesis by TGF-β1 and TNF-α can occur via local IGFBP modulation. This may represent a mechanism by which complex growth signals are co-ordinated in vivo. Journal of Endocrinology (1993) 137, 151–159

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