The Effects of Insulin-Like Growth Factor I and BTP-2 on Acute Lung Injury

Acute lung injury (ALI) afflicts approximately 200,000 patients annually and has a 40% mortality rate. The COVID-19 pandemic has massively increased the rate of ALI incidence. The pathogenesis of ALI involves tissue damage from invading microbes and, in severe cases, the overexpression of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). This study aimed to develop a therapy to normalize the excess production of inflammatory cytokines and promote tissue repair in the lipopolysaccharide (LPS)-induced ALI. Based on our previous studies, we tested the insulin-like growth factor I (IGF-I) and BTP-2 therapies. IGF-I was selected, because we and others have shown that elevated inflammatory cytokines suppress the expression of growth hormone receptors in the liver, leading to a decrease in the circulating IGF-I. IGF-I is a growth factor that increases vascular protection, enhances tissue repair, and decreases pro-inflammatory cytokines. It is also required to produce anti-inflammatory 1,25-dihydroxyvitamin D. BTP-2, an inhibitor of cytosolic calcium, was used to suppress the LPS-induced increase in cytosolic calcium, which otherwise leads to an increase in proinflammatory cytokines. We showed that LPS increased the expression of the primary inflammatory mediators such as toll like receptor-4 (TLR-4), IL-1β, interleukin-17 (IL-17), TNF-α, and interferon-γ (IFN-γ), which were normalized by the IGF-I + BTP-2 dual therapy in the lungs, along with improved vascular gene expression markers. The histologic lung injury score was markedly elevated by LPS and reduced to normal by the combination therapy. In conclusion, the LPS-induced increases in inflammatory cytokines, vascular injuries, and lung injuries were all improved by IGF-I + BTP-2 combination therapy.

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Constitutive pro- and anti-inflammatory cytokine and growth factor response to exercise in leukocytes

Journal of Applied Physiology ◽

10.1152/japplphysiol.00562.2005 ◽

2006 ◽

Vol 100 (4) ◽

pp. 1124-1133 ◽

Cited By ~ 80

Author(s):

Frank Zaldivar ◽

Jessica Wang-Rodriguez ◽

Dan Nemet ◽

Christina Schwindt ◽

Pietro Galassetti ◽

...

Keyword(s):

Growth Factors ◽

Growth Factor ◽

Inflammatory Cytokines ◽

Fluorescence Intensity ◽

Healthy Humans ◽

Intracellular Cytokines ◽

Tnf Α ◽

Igf I ◽

Ifn Γ ◽

Anti Inflammatory

Leukocytosis following exercise is a well-described phenomenon of stress/inflammatory activation in healthy humans. We hypothesized that, despite this increase in circulating inflammatory cells, exercise would paradoxically induce expression of both pro- and anti-inflammatory cytokines and growth factors within these cells. To test this hypothesis, 11 healthy adult men, 18–30 yr old, performed a 30-min bout of heavy cycling exercise; blood sampling was at baseline, end-exercise, and 60 min into recovery. The percentage of leukocytes positive for intracellular cytokines and growth factors and mean fluorescence intensity was obtained by flow cytometry. Proinflammatory cytokines (IL-1α, IL-2, IFN-γ, and TNF-α), a pleiotropic cytokine (IL-6), and anti-inflammatory cytokines and growth factors [IL-4, IL-10, growth hormone (GH), and IGF-I] were examined. Median fluorescence intensity was not affected by exercise; however, we found a number of significant changes ( P < 0.05 by mixed linear model and modified t-test) in the numbers of circulating cells positive for particular mediators. The pattern of expression reflected both pro- and anti-inflammatory functions. In T-helper lymphocytes, TNF-α, but also IL-6, and IL-4 were significantly increased. In monocytes, both IFN-γ and IL-4 increased. B-lymphocytes positive for GH and IGF-I increased significantly. GH-positive granulocytes also significantly increased. Collectively, these observations indicate that exercise primes an array of pro- and anti-inflammatory and growth factor expression within circulating leukocytes, perhaps preparing the organism to effectively respond to a variety of stressors imposed by exercise.

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Inhibition by Interleukin-1β and Tumor Necrosis Factor-α of the Insulin-Like Growth Factor I Messenger Ribonucleic Acid Response to Growth Hormone in Rat Hepatocyte Primary Culture*

Endocrinology ◽

10.1210/endo.138.3.4966 ◽

1997 ◽

Vol 138 (3) ◽

pp. 1078-1084 ◽

Cited By ~ 80

Author(s):

Jean-Paul Thissen ◽

Josiane Verniers

Keyword(s):

Gene Expression ◽

Growth Factor ◽

Tumor Necrosis Factor ◽

Tumor Necrosis ◽

Mrna Levels ◽

Factor I ◽

Tnf Α ◽

Igf I ◽

Necrosis Factor ◽

I Gene

Abstract The cytokines are the putative mediators of the catabolic reaction that accompanies infection and trauma. Evidence suggests that their catabolic actions are indirect and potentially mediated through changes in hormonal axis such as the hypothalamo-pituitary-adrenal axis. Insulin-like growth factor I (IGF-I) is a GH-dependent growth factor that regulates the protein metabolism. To determine whether cytokines can directly inhibit the production of IGF-I by the liver, we investigated the regulation of IGF-I gene expression by interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α (10 ng/ml) in a model of rat primary cultured hepatocytes. Hepatocytes were isolated by liver collagenase perfusion and cultured on Matrigel 48 h before experiments. Each experiment was performed in at least three different animals. In the absence of GH, IL-1β and TNF-α did not affect the IGF-I messenger RNA (mRNA) basal levels, whereas IL-6 increased it by a factor of 2.5 after 24 h (P < 0.05). GH (500 ng/ml) alone stimulated the IGF-I gene expression markedly (5- to 10-fold increase) after 24 h (P < 0.001). IL-1β, and TNF-α to a lesser extent, dramatically inhibited the IGF-I mRNA response to GH (IL-1β: −82%, P < 0.001 and TNF-α: −47%, P < 0.01). The half-maximal inhibition of the IGF-I mRNA response to GH was observed for a concentration of IL-1β between 0.1 and 1 ng/ml. Moreover, IL-1β abolished the IL-6-induced IGF-I mRNA response. In contrast, IL-6 did not impair the IGF-I mRNA response to GH. To determine the potential role of the GH receptor (GHR) and the GH-binding protein (GHBP) in this GH resistance, we assessed the GHR and GHBP mRNAs response to these cytokines. GH alone did not affect the GHR/GHBP mRNA levels. IL-1β markedly decreased the GHR and GHBP mRNA levels (respectively, −68% and −60%, P < 0.05). Neither TNF-α nor IL-6 affected the GHR/GHBP gene expression. In conclusion, our results show that IL-1β, and TNF-α to a lesser extent, blunt the IGF-I mRNA response to GH. The resistance to GH induced by IL-1β might be mediated by a decrease of GH receptors, as suggested by the marked reduction of GHR mRNA. These findings suggest that decreased circulating IGF-I, in response to infection and trauma, may be caused by a direct effect of cytokines at the hepatocyte level.

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Inhibition of Inflammation and Regulation of AQPs/ENaCs/Na+-K+-ATPase Mediated Alveolar Fluid Transport by Total Flavonoids Extracted From Nervilia fordii in Lipopolysaccharide-induced Acute Lung Injury

Frontiers in Pharmacology ◽

10.3389/fphar.2021.603863 ◽

2021 ◽

Vol 12 ◽

Author(s):

Shuomiao Yin ◽

Meizhu Ding ◽

Long Fan ◽

Xuhua Yu ◽

Ziyao Liang ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Pulmonary Edema ◽

Active Transport ◽

Inflammatory Cytokines ◽

Fluid Transport ◽

Oxygenation Index ◽

Total Flavonoids ◽

Sd Rats ◽

Tnf Α

Aims: The occurrence of vascular permeability pulmonary edema in acute lung injury (ALI) is related to the imbalance of alveolar fluid transport. Regulating the active transport of alveolar fluid by aquaporins (AQPs), epithelial sodium channels (ENaCs), and Na+-K+-ATPase can effectively reduce the edema fluid in the alveolar cavity and protect against ALI. We evaluated the therapeutic effects of total flavonoids, extracted from Nervilia fordii (TFENF), and investigated its potential mechanisms of alveolar fluid transport in a rat ALI model.Materials and methods: A model of lipopolysaccharide (LPS, 5 mg/kg)-induced ALI was established in Sprague-Dawley (SD) rats through the arteriae dorsalis penis. SD rats were divided into six groups, including the vehicle, LPS model, TFENF (6 mg/kg, 12 mg/kg, 24 mg/kg), and dexamethasone group (DEX group, 5 mg/kg). The wet-to-dry (W/D) lung weight ratio, oxygenation index, and histopathological observation were used to evaluate the therapeutic effect of TFENF. The mRNA expression of AQPs, ENaCs, and pro-inflammatory cytokines was determined using real-time polymerase chain reaction, whereas protein expression was determined using immunohistochemistry. The Na+-K+-ATPase activity was assessed using enzyme-linked immunosorbent assay.Results: LPS significantly stimulated the production of inflammatory mediators including tumor necrosis factor (TNF)-α and interleukin (IL)-1β, and disrupted the water transport balance in the alveolar cavity by inhibiting AQPs/ENaCs/Na+-K+-ATPase. Pretreatment with TFENF reduced the pathological damage and W/D ratio of the lungs and ameliorated the arterial blood oxygen partial pressure (PaO2) and oxygenation index. TFENF further decreased the mRNA level of TNF-α and IL-1β; increased the expression of AQP-1, AQP-5, αENaC, and βENaC; and increased Na+-K+-ATPase activity. Moreover, the regulation of AQPs, βENaC, and Na+-K+-ATPase and the inhibition of TNF-α and IL-1β by TFENF were found to be dose dependent.Conclusion: TFENF protects against LPS-induced ALI, at least in part, through the suppression of inflammatory cytokines and regulation of the active transport capacity of AQPs/ENaCs/Na+-K+-ATPase. These findings suggest the therapeutic potential of TFENF as phytomedicine to treat inflammation and pulmonary edema in ALI.

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Effect of tumor necrosis factor-α on the expression of insulin-like growth factor I and insulin-like growth factor binding protein 4 in mouse osteoblasts

Acta Endocrinologica ◽

10.1530/eje.0.1310293 ◽

1994 ◽

Vol 131 (3) ◽

pp. 293-301 ◽

Cited By ~ 29

Author(s):

Stephan H Scharla ◽

Donna D Strong ◽

Subburaman Mohan ◽

Thierry Chevalley ◽

Thomas A Linkhart

Keyword(s):

Growth Factor ◽

Tumor Necrosis Factor ◽

Tumor Necrosis ◽

Tumor Necrosis Factor Α ◽

Insulin Like Growth Factor ◽

Factor I ◽

Tnf Α ◽

Igf I ◽

Factor Α ◽

Necrosis Factor

Scharla SH, Strong DD, Mohan S, Chevalley T, Linkhart TA. Effect of tumor necrosis factor-α on the expression of insulin-like growth factor I and insulin-like growth factor binding protein 4 in mouse osteoblasts. Eur J Endocrinol 1994;131:293–301. ISSN 0804–4643 Tumor necrosis factor-α (TNF-α) is a cytokine produced by immune cells, which has multiple effects on bone cells and is therefore thought to mediate changes in bone metabolism occurring during inflammation. In the present study we have investigated the effect of TNF-α on the secretion of insulin-like growth factor I (IGF-I) and IGF binding protein 4 (IGFBP-4) by clonal mouse osteoblasts (MC3T3-E1 cells) using subconfluent in vitro cultures and serum-free conditions. The IGF-I was determined by radioimmunoassay under conditions eliminating the interference of IGFBPs. Treatment of MC3T3-E1 cultures with TNF-α for 24 h resulted in a dose-dependent decrease in IGF-I secretion (maximally to 34 ± 9.7% of control with 60 pmol/l TNF-α; mean ± sd). The TNF-α treatment also resulted in decreased messenger ribonucleic acid (mRNA) levels of IGF-I at 4 and 24 h, as detected by Northern analysis. Because basal secretion of IGFBPs is very low in MC3T3-E1 cells, effects of TNF-α on IGFBP secretion were studied in cultures in which IGFBP-4 expression was increased by calcitriol (1,25(OH)2D3) treatment. The presence of TNF-α (600 pmol/l) inhibited this calcitriol-induced stimulation of IGFBP-4 mRNA levels from 4 h onwards, with complete inhibition of the calcitriol effect occurring at 24 h. We also observed a dose-dependent inhibition of calcitriol-stimulated IGFBP-4 secretion into the culture medium (as detected by Western ligand blot), with the maximal inhibition occurring with 600 pmol/l TFN-α to 25 ± 7% of control levels. These TNF-α effects were not prevented by indomethacin treatment, suggesting that they are not dependent on prostaglandins. The DNA synthesis was reduced to 62 ± 8% of the control value by 600 pmol/l TNF-α. We conclude that secretion of IGFs and IGFBPs by osteoblasts can be modulated by TNF-α, which in turn may be responsible for some of the known effects of TNF-α on osteoblastic cell proliferation and differentiation. Stephan H Scharla, Klinik am Kurpark, Schussenrieder Strasse 5, D-88326 Anlendorf, Germany

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IL-6 knockout alleviates inflammatory response and improve acute lung injury via regulating macrophage polarization in sepsis

10.21203/rs.3.rs-618570/v1 ◽

2021 ◽

Author(s):

Jinxin Zhang ◽

Kuo Shen ◽

Jiangang Xie ◽

Shanshou Liu ◽

Xiaozhi Bai ◽

...

Keyword(s):

Flow Cytometry ◽

Acute Lung Injury ◽

Lung Injury ◽

Western Blot ◽

Bronchoalveolar Lavage ◽

Inflammatory Cytokines ◽

Death Rate ◽

Bronchoalveolar Lavage Fluid ◽

Lavage Fluid ◽

Tnf Α

Abstract Background Sepsis is a fatal disease with a high rate of morbidity and mortality, during which acute lung injury is the earliest and most serious complication. Macrophage plays a crucial role in the initiation and progress of sepsis. This study meant to explore the effect of IL-6 knockout in CLP induced sepsis. Methods In this study, cecal ligation and puncture (CLP) was performed on wildtype and interleukin 6 (IL-6) knockout C57 mice. General condition and death rate of sepsis mice were observed. organ samples (lungs, livers, kidneys and hearts) and serum were collected for histology observation and inflammatory cytokine detection. Lung tissue injury detection were conducted via lung injury score, wet/dry ration and protein concentrations measurement of Bronchoalveolar lavage fluid (BALF). In in vivo studies, RAW264.7 macrophages were transfected with IL-6 specific siRNA and treated with LPS. After exposed to IL-6 specific siRNA and LPS, expression of inflammatory cytokines interleukin 1 (IL-1), tumor necrosis factor-α (TNF-α), IL-6 and interleukin 10 (IL-10) were detected by RT-qPCR, concentration of IL-1 and TNF-α in culture supernatant were detected by ELISA and M1 and M2 markers were detected by western blot and flow cytometry. Results We constructed CLP induced sepsis models and found that inhibition of IL-6 could improve general condition and death rate of sepsis mice. Mice in IL-6 knockout group display improved tissue damage, especially in the lung tissue. IL-6 knockout relieved inflammatory cytokines storm in both serum and bronchoalveolar lavage fluid while polarized macrophage to an anti-inflammatory M2 phenotype. In cell model, inhibition of IL-6 could alleviate LPS induced expression of inflammatory cytokines IL-1, TNF-α, and IL-6 in macrophages. Western blot and Flow cytometry results indicated that expression of M1 markers (iNOS and CD86) in LPS stimulated macrophages were significantly declined while M2 (Arg-1 and CD206) were enhanced when expression of IL-6 was blocked. Conclusion Inhibition of IL-6 alleviated LPS induced inflammation and exerted protective effect in sepsis via regulating macrophage function and polarization.

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