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Bullous pemphigoid (BP) is an organ-specific disease. Its pathogenesis has not been clearly studied yet; However, studies in recent years have shown that its pathogenesis is related to T helper cells. The pathogenesis of BP is mainly related to Th2 and Th17-related cytokines. IL-4, IL-5 and IL-13 cause eosinophil recruitment, promote antibody production, trigger pruritus and promote blister formation and other symptoms. IL-17 and IL-23 promote the production of matrix metalloproteinase-9 (MMP-9) by related cells, which causes dermo-epidermal junction (DEJ) separation to form bullae and blisters, and can persist in BP inflammation. The serum concentrations of IL-17 and IL-23 are related to the prognosis of BP. In this paper, we focus on the role of related cytokines in the pathogenesis of bullous pemphigoid and the relationship between the related cytokine populations secreted by three major T helper cells—helper T lymphocytes 1 (Th1), Th2, and Th17. A better understanding of the biological and immunological functions of cytokines associated with BP patients will provide opportunities for therapeutic targets in BP. [ABSTRACT FROM AUTHOR]

Aim: Bullous pemphigoid (BP) is an organ-specific autoimmune bullous disease characterized by autoantibodies that target the cellular adhesion molecules BP180 and BP230. Both immunoglobulin (Ig)G and IgE are involved in the induction of subepidermal blisters. Specifically, IgE autoantibodies are presumed to be responsible for the pruritic and erythematous features of BP. Histologically, eosinophil infiltration is a prominent feature in BP. Eosinophils and IgE are mostly associated with the Th2 immune response. Th2 cytokines, particularly interleukin (IL)-4 and IL-13, are presumed to contribute to the pathology of BP. The aim of this review is to discuss the role of IL-4/13 in the pathogenesis of BP and the potential of using IL-4/13 antagonists for treatment.Methods: After searching in PubMed and Web of Science databases using 'bullous pemphigoid', 'interleukin-4/13', and 'dupilumab' as keywords, studies related was compiled and examined.Results: Overall, IgE, eosinophils, IL-4, and IL-13 may interact with each other in the pathogenesis of BP; these potential interactions provide clues concerning targets for molecular treatment.Conclusion: Anti-IL-4/13 treatment has been experimentally used in patients with BP, with satisfactory outcomes and few side effects. However, before this novel therapy can be approved for regular usage, further studies are needed concerning the long-term safety and systemic usage of IL-4/13 monoclonal antibody treatment in BP. BP is an autoimmune skin disease with Th2-mediated autoimmune response involvement. As typical Th2 cytokines, IL-4 and IL-13 may contribute to the pathogenesis of BP in multiple ways, such as promoting Th2 cell polarization, driving the immunoglobulin class switching, recruiting eosinophils and basophils, and inducing pruritus. As a promising therapeutic approach for BP, IL-4/13 antagonists have shown satisfactory outcomes in preliminary clinical studies. [ABSTRACT FROM AUTHOR]

Introduction: Gastroesophageal reflux disease is defined as bothersome symptoms and/or complications caused by the reflux of stomach contents. About 40–50% of patients develop refractory gastroesophageal reflux disease (R-GERD), with poor improvement of symptoms with treatment. Many pathogenic mechanisms share in development of R-GERD, among which is the important role of T-helper 1 and T-helper 2 response mediated by cytokines. The interleukin-4 is a cytokine known of its anti-inflammatory effect. In this study, we aimed to evaluate the level of interleukin-4 in Egyptian patients with R-GERD versus those with GERD. PATIENTS AND Methods: Our study included 25 patients with reflux symptoms who received PPIs for less than 8 weeks with improvement of symptoms, versus 25 patients with refractory reflux symptoms who received PPIs for more than 8 weeks without improvement of symptoms. Interleukin-4 levels were assessed in both groups by ELISA. Results: There was a statistically significant difference between the two groups as regard interleukin-4 levels (p < 0.012) which was higher in the patients with (R-GERD), the mean level of IL-4 was 37.31 ± 56.07 in GERD group while in R-GERD group, it was 102.78 ± 112.29. The diagnostic accuracy of interleukin-4 revealed a sensitivity of 56% and specificity of 76% at cutoff value >58.25 pg/ml, with an acceptable accuracy of 0.6. Conclusions: The present study concluded that IL-4 is significantly higher in patients with R GERD with cut off value > 58.25 pg/ml. Therapeutic strategies that modulate the production of IL-4 may provide a good solution for treatment of R GERD. [ABSTRACT FROM AUTHOR]

We co-cultured Caco-2 cells with Lactobacillus salivarius and L. plantarum in vitro to investigate their immunoregulatory mechanisms and detected Lactobacillus strains adhering to Caco-2 cells expressing mRNAs of cytokines and Toll-like receptors (TLRs) by fluorescent quantitative reverse transcription–polymerase chain reaction. The strains were intragastrically administered to mice. Thymus/spleen indexes were measured on different days. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, flow cytometry, and enzyme-linked immunosorbent assay were performed to assess different variables. Results showed increased mRNA expressions of T helper 1 (Th1), various cytokines, surface receptors, TLRs (2, 4, and 9), thymus/spleen indexes, spleen lymphocyte transformation rate, macrophage energy metabolism and phagocytosis, CD11c+CD80+ cell number, interferon-γ secretion, and sIgA secretion levels; inhibition of nuclear factor-κB inflammation signal pathway; and downregulated mRNA expression of specific interleukins. Both Lactobacillus strains can promote naive T cell differentiation (Th1) and participate in immunomodulatory responses, featuring a potential in prevention and management approaches for foodborne diseases. [ABSTRACT FROM AUTHOR]

We recently demonstrated that the polysaccharide component of the Korean medicinal herb Angelica gigas (immuno-stimulatory fraction of A. gigas; ISAg) induces anticancer effects in mice by activating natural killer (NK) and natural killer T (NKT) cells. However, it is unclear whether the use of ISAg in vivo can affect the differentiation of conventional T cells. Here, we investigated the effects of ISAg on the activation of conventional CD4+ and CD8+ T cells. We found that the administration of ISAg induced the polarization of CD4+ T cells toward the acquisition of the Th1 phenotype in vivo. Additionally, in mice treated with ISAg, CD8+ T cells produced more IFNγ than in control mice treated with PBS. Moreover, treatment with ISAg activated CD4+ and CD8+ T cells as well as NK and NKT cells, resulting in the secretion of Th1-type cytokines in a toll-like receptor 4 (TLR4)-dependent manner, implying that TLR4 is critical for an optimal Th1 response. Interestingly, ISAg treatment increased the number of Foxp3+ Treg cells, but not of Th2 cells, compared to control mice treated with PBS, indicating that ISAg possesses an immunomodulatory capacity that can control adaptive immune responses. Taken together, our results indicate that ISAg possesses a Th1-enhancing activity that could be used to treat Th2-mediated allergic immune diseases such as atopic dermatitis. [ABSTRACT FROM AUTHOR]

5-Hydroxymethylfurfural (5-HMF) is one of the most important products of maillard reaction. This study sought to elucidate the immunomodulatory effect of 5-HMF by evaluating IFN-γ and IL-4 production in BALB/c mice sensitized with ovalbumin (OVA). Four groups of BALB/c mice (n = 5 for each group) including control, vehicle and two 5-HMF (188 and 750 mg/kg bw) treatment groups were studied. Interleukin-4(IL-4) and interferon gamma (IFN-γ) levels were measured in culture supernatants of spleen cells using enzyme-linked immunosorbent assay. It was found that the IL-4 level was significantly suppressed in 5-HMF treatment groups compared with the vehicle group (P < .05). Moreover, the IFN-γ/IL-4 ratio was significantly increased in a dose-independent manner compared with the vehicle group (P < .05). Oral administration of 5-HMF inhibited IL-4 but not IFN-γ production by splenocytes of mice immunized with OVA. These changes may reflect that 5-HMF could be a novel therapeutic approach for prevention of (Th2) cytokine-dominant disease. [ABSTRACT FROM AUTHOR]

Context: Thyme has been used in traditional medicine for medicinal purposes since ancient times. Objective: The objective of this study was to investigate the effects of thymol and carvacrol as two major constituents of thyme on dendritic cells (DCs) maturation and T cell activation. Materials and methods: Splenic DCs were treated with non-cytotoxic concentrations of the components and then analyzed for MHC II, CD86, and CD40 expression by flow cytometry. The effects of compounds on mitogenic, as well as allogenic T cell responses in mixed lymphocyte culture (MLR) and the release of cytokines were investigated. Results: At 0.1 µg/ml, reduced mean fluorescent intensity (MFI) of CD86 for thymol (80.3 ± 0.2% of untreated control) and CD40 for carvacrol (79.5 ± 0.14%) was observed (p < 0.001). Decreased mitogenic T cell proliferation by thymol [proliferation index (PI) from 0.93 ± 0.11 at 1 µg/ml to 0.42 ± 0.16 at 100 µg/ml (p < 0.01)] and carvacrol [PI from 1.08 ± 0.3 at 1 µg/ml to 0.28 ± 0.1 at 100 µg/ml (p < 0.001)] was seen. Ten micrograms/ml thymol (PI, 0.85 ± 0.04) and carvacrol (PI, 0.89 ± 0.03) inhibited allogenic T cell response (p < 0.05). Decreased IFN-γ level in MLR supernatant from 1441 ± 27.7 pg/ml in untreated cells to 944 ± 32.1 at 10 µg/ml of thymol and of carvacrol (886 ± 31.7 pg/ml) (p < 0.01) was found. IL-4 levels were decreased in the presence of both compounds (p < 0.01). Conclusion: These data showed the suppressive effects of thymol and carvacrol on DCs maturation and function, as well as T cell responses. [ABSTRACT FROM AUTHOR]

Macrophages can undergo cell-cell fusion, leading to the formation of multinucleated giant cells and osteoclasts. This process is believed to promote the proteolytic activity of macrophages toward pathogens, foreign bodies, and extracellular matrices. Here, we examined the role of PTP-PEST (PTPN12), a cytoplasmic protein tyrosine phosphatase, in macrophage fusion. Using a macrophage-targeted PTP-PEST-deficient mouse, we determined that PTP-PEST was not needed for macrophage differentiation or cytokine production. However, it was necessary for interleukin-4-induced macrophage fusion into multinucleated giant cells in vitro. It was also needed for macrophage fusion following implantation of a foreign body in vivo. Moreover, in the RAW264.7 macrophage cell line, PTP-PEST was required for receptor activator of nuclear factor kappa-B ligand (RANKL)-triggered macrophage fusion into osteoclasts. PTP-PEST had no impact on expression of fusion mediators such as β-integrins, E-cadherin, and CD47, which enable macrophages to become fusion competent. However, it was needed for polarization of macrophages, migration induced by the chemokine CC chemokine ligand 2 (CCL2), and integrin-induced spreading, three key events in the fusion process. PTP-PEST deficiency resulted in specific hyperphosphorylation of the protein tyrosine kinase Pyk2 and the adaptor paxillin. Moreover, a fusion defect was induced upon treatment of normal macrophages with a Pyk2 inhibitor. Together, these data argue that macrophage fusion is critically dependent on PTP-PEST. This function is seemingly due to the ability of PTP-PEST to control phosphorylation of Pyk2 and paxillin, thereby regulating cell polarization, migration, and spreading. [ABSTRACT FROM AUTHOR]

Dendritic cells (DCs) are among the most potent antigen-presenting cells (APC s), stimulating peripheral blood mononuclear cells (PBMCs) to generate antigen-specific cytotoxic T lymphocytes (CTLs). The objectives of this study were to determine if interleukin (IL)-4 is beneficial or detrimental for the generation of human DCs in vitro and to understand whether DCs generated in vitro in the presence or absence of IL-4 stimulate the killing of adenocarcinoma cells by CTLs in vivo. Mucin 1 (MUC1), a glycoprotein found on the surface of adenocarcinoma cells was used to load DCs. MUC1-loaded DCs generated in the absence of IL-4 were superior to their counterparts produced with IL-4 in stimulating PBMCs to kill human breast cancer MCF-7 cells in vitro. A corollary in vivo protection experiment was performed by injecting immunodeficient NOD-SC ID mice with MCF-7 cells s.c. and MUC1-loaded CTLs, PBMCs, or DCs generated in the absence of IL-4, i.p. Mice that received CTLs and MUC1-loaded DCs on days 0, 2, 4, 9, 14 and 19 were completely protected against the development of MCF-7-derived tumors, while other schedules conferred lower protection. Therefore, tumor antigen-loaded DCs enhance the efficacy of adoptive CTL transfer, and should thus be considered for combinatorial immunotherapeutic regimens. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effectiveness and possible mechanisms of an herbal prescription, Huangqi Maxingshigan decoction (Radix Astragali, Herba Ephedrae, Almond, Gypsum Fibrosum, Radix Glycytthizae) on infectious laryngotracheitis (ILT) in chickens. One hundred and sixty one-day-old chicks were randomly allocated into four groups, housed in isolated cages of 40 birds each: group­was Huangqi Maxingshigan decoction treatment group, group II as Ding Chuan San control group, group III as the model group, and group IV as the blank control group. Except for the blank control group, other groups were challenged with infectious laryngotracheitis virus via the intratracheal route on age day 52. Birds in Group I were administered Huangqi Maxingshigan decoction at a concentration of 0.4 mL, or with Ding Chuan San in group II for comparison at 48 h post virus challenge (day 54) when they showed clinical signs, 2 times daily for 5 days consecutively. Then, the superoxide dismutases (SOD) activity and malondialdehyde (MDA) contents in serum, the expression of IFN-γ, IL-4 mRNA in spleen, the sIgA contents in tracheal fluid, the sIgA secreting cells in trachea were determined on day 5, day 15, day 25 post infection. The results showed that Huangqi Maxingshigan decoction could correct Th2-dominant Th1/th2 imbalance through up-regulation of IFN-γ, and down-regulation of IL-4 at the transcriptional level, enhance cell-mediated immunity, ease inflammatory responses caused by ILTV. The results also showed that Huangqi Maxingshigan decoction provide an important antioxidant defense in the process of anti-ILT. Furthermore, it could induce the production of sIgA to enhance mucosal immunity. [ABSTRACT FROM AUTHOR]

Stimulation of the β2-adrenergic receptor (β2AR) on a CD40L/interleukin-4-activated B lymphocyte increases the level of immunoglobulin E (IgE) in a protein kinase A (PKA)- and p38 mitogen-activated protein kinase (MAPK)-dependent manner. However, the mechanism by which β2AR stimulation mediates the increase in the level of p38 MAPK activation has remained unclear. Here we show that the β2AR-induced increase in p38 MAPK activation occurred via a hematopoietic protein tyrosine phosphatase (HePTP)-mediated cross talk between PKA and p38 MAPK. β2AR agonists, cAMP-elevating agents, and PKA inhibitors were used to show that β2AR stimulation resulted in a PKA-dependent increase in p38 MAPK phosphorylation. Pharmacological agents and gene-deficient mice revealed that p38 MAPK phosphorylation was regulated by the G-stimulatory (Gs)/cAMP/PKA pathway independently of the G-inhibitory or β-arrestin-2 pathways. Coimmunoprecipitation and Western blot analysis showed that HePTP was phosphorylated in a PKA-dependent manner, which inactivated HePTP and allowed for increased free p38 MAPK to be phosphorylated by the MAPK cascade that was activated by CD40L. HePTP short hairpin RNA confirmed that HePTP played a role in regulating the level of p38 MAPK phosphorylation in a B cell. Thus, β2AR stimulation on a B cell phosphorylates and inactivates HePTP in a Gs/cAMP/PKA-dependent manner to release bound p38 MAPK, making more available for phosphorylation and subsequent IgE regulation. [ABSTRACT FROM AUTHOR]

Background Clinical studies require protocols where a sufficient number of well-characterized highly immunogenic DC are produced according to good manufacturing practice (GMP) guidelines. Methods In the present study, using leukapheresis products from 10 cancer patients, we validated an elutriation technology for large-scale clinical grade production of monocyte-derived DC. Results The elutriation method gave a very high purity (mean±SD) (86±5.3%) and recovery (66±10.4%) of monocytes. Specifically for the two monocyte-rich fractions (3 and 4,) the recovery was 42±13% of viable cells that could be further differentiated into immature DC in hydrophobic culture bags using GM-CSF and IL-4. The immature DC exhibited<1% CD83 + expression and >98% phagocytic activity. Maturation with TNF-α or poly I:C resulted in DC with expression of CD80 + , CD86 + and HLA-DR + (>99%) and CD83 + (80±11.9%), as well as producing IL-12p70 and lacking phagocytic activity (<5%). This cell product can be cryopreserved with cell viability >85% and cell recovery >80% after thawing. Discussion The elutriation procedure, when optimized and if the monocyte content of the starting material exceeds 5%, does not require further selection or depletion using affinity approaches. [ABSTRACT FROM AUTHOR]

Amino acid catabolizing enzymes emerged as a crucial mechanism used by tumors to dampen immune responses. TheL-phenylalanine oxidase IL-4 induced gene 1 (IL4I1) is expressed by tumor-associated myeloid cells of most solid tumors, including melanoma. We previously provided the only evidence that IL4I1 accelerates tumor growth by limiting the CD8+T cell mediated immune response, in a mouse model of melanoma cell transplantation. Here, we explored the role of IL4I1 in Ret mice, a spontaneous model of melanoma. We found that IL4I1 was expressed by CD11b+myeloid cells and that its activity correlated with disease aggressiveness. IL4I1 did not enhance tumor cell proliferation or angiogenesis, but orchestrated the remodeling of the immune compartment within the primary tumor. Indeed, the inactivation of IL4I1 limited the recruitment of polymorphonuclear myeloid-derived suppressor cells and enhanced the infiltration by Th1 and cytotoxic T cells, thus delaying tumor development and metastatic dissemination. Accordingly, human primary melanomas that were poorly infiltrated by IL4I1+cells exhibited a higher density of CD8+T cells. Collectively, our findings strengthen the rationale for therapeutic targeting of IL4I1 as one of the key immune regulators. [ABSTRACT FROM AUTHOR]

Scleroderma is an autoimmune disease characterized by extracellular matrix deposition and inflammation. Topical vitamin D analogs have been reported as effective treatments for scleroderma. We previously reported that a matricellular protein, periostin (POSTN), contributes to pathogenesis of scleroderma as POSTN knockout mice were resistant to bleomycin (BLM)-induced scleroderma. We investigated whether a vitamin D analog affects the expression of POSTN in dermal fibroblasts and in a BLM-induced scleroderma model. The vitamin D analog, maxacalcitol (22-oxacalcitriol [OCT]), was applied to dermal fibroblasts and POSTN expression was measured. The effect of OCT on Th2 cytokine- and TGFβ-induced POTSN and Collagen 1 α 1 (Col1A1) expression was also assessed. In vivo, OCT was administered to BLM-induced scleroderma model and outcomes were determined by dermal thickness, collagen density and POSTN expression. Treatment with OCT significantly decreased POSTN expression in dermal fibroblasts. Th2 cytokine- and TGFβ-induced expression of POSTN and Col1A1 was also suppressed by OCT. In vivo, OCT administration decreased the density of collagen bundles and POSTN expression in a BLM-induced scleroderma model. In addition to the previously reported immunosuppressive effect, the vitamin D analog OCT might be effective to treat scleroderma, in part through inhibition of Th2 cytokine- and TGFβ-induced POSTN expression. [ABSTRACT FROM PUBLISHER]

Interleukin-4 (IL4), a Th2 cytokine, signals through IL4 receptors (IL4Rs) to regulate increased lymphocyte proliferation and survival. We have recently discovered that IL4 also promotes these phenotypes in mammary cancer cells expressing IL4Rs to enhance their metastatic ability. Targeting IL4/IL4R signaling on cancer cells themselves may limit metastatic disease. [ABSTRACT FROM AUTHOR]

It is becoming clear that combination strategies will be necessary to augment cancer immunotherapy. We report that combination anti-OX40/anti-CTLA-4 mAb immunotherapy improves survival by enhancing effector T cell expansion and function, even while inducing Th2 cytokine production. Furthermore, IL-4 blockade in addition to combination therapy significantly improved anti-tumor efficacy. [ABSTRACT FROM PUBLISHER]

Endothelial cell activation and dysfunction underlie many vascular disorders, including atherosclerosis and inflammation. Here, we show that interleukin-4 (IL-4) markedly induced vascular cell adhesion molecule 1 (VCAM-1), both in cultured endothelial cells and in the intact endothelium in mice. Combined treatment with IL-4 and tumor necrosis factor alpha (TNF-α) resulted in further, sustained induction of VCAM-1 expression. IL-4-mediated induction of VCAM-1 and secondary monocyte adhesion was predominantly regulated by the transcription factor STAT6. Genome-wide survey of IL-4-mediated STAT6 binding from sequential chromatin-immunoprecipitation with deep sequencing (chromatin immunoprecipitation sequencing [ChIP-seq]) in endothelial cells revealed regions of transient and sustained transcription factor binding. Through the combination of DNA microarrays and ChIP-seq at the same time points, the majority of IL-4-responsive genes were shown to be STAT6 dependent and associated with direct STAT6 binding to their promoter. IL-4-mediated stable binding of STAT6 led to sustained target gene expression. Moreover, our strategy led to the identification of a novel functionally important STAT6 binding site within 16 kb upstream of the VCAM-1 gene. Taken together, these findings support a critical role for STAT6 in mediating IL-4 signal transduction in endothelial cells. Identification of a novel IL-4-mediated VCAM-1 enhancer may provide a foundation for targeted therapy in vascular disease. [ABSTRACT FROM AUTHOR]

Bronchial epithelial cells play a pivotal role in airway inflammation, but little is known about posttranscriptional regulation of mediator gene expression during the inflammatory response in these cells. Here, we show that activation of human bronchial epithelial BEAS-2B cells by proinflammatory cytokines interleukin-4 (IL-4) and tumor necrosis factor alpha (TNF-α) leads to an increase in the mRNA stability of the key chemokines monocyte chemotactic protein 1 and IL-8, an elevation of the global translation rate, an increase in the levels of several proteins critical for translation, and a reduction of microRNA-mediated translational repression. Moreover, using the BEAS-2B cell system and a mouse model, we found that RNA processing bodies (P bodies), cytoplasmic domains linked to storage and/or degradation of translationally silenced mRNAs, are significantly reduced in activated bronchial epithelial cells, suggesting a physiological role for P bodies in airway inflammation. Our study reveals an orchestrated change among posttranscriptional mechanisms, which help sustain high levels of inflammatory mediator production in bronchial epithelium during the pathogenesis of inflammatory airway diseases. [ABSTRACT FROM AUTHOR]

Mast cells and basophils are known to be a critical interleukin 4 (IL-4) source for establishing Th2 protective responses to parasitic infections. Chromatin structure and histone modification patterns in the Il13/Il4 locus of mast cells were similar to those of IL-4-producing type 2 helper T cells. However, using a transgenic approach, we found that Il4 gene expression was distinctly regulated by individual cis regulatory elements in cell types of different lineages. The distal 3' element contained conserved noncoding sequence 2 (CNS-2), which was a common enhancer for memory phenotype T cells, NKT cells, mast cells, and basophils. Targeted deletion of CNS-2 compromised production of IL-4 and several Th2 cytokines in connective-tissue-type and immature-type mast cells but not in basophils. Interestingly, the proximal 3' element containing DNase I-hypersensitive site 4 (HS4), which controls Il4 gene silencing in T-lineage cells, exhibited selective enhancer activity in basophils. These results indicate that CNS-2 is an essential enhancer for Il4 gene transcription in mast cell but not in basophils. The transcription of the Il4 gene in mast cells and basophils is independently regulated by CNS-2 and HS4 elements that may be critical for lineage-specific Il4 gene regulation in these cell types. [ABSTRACT FROM AUTHOR]

Serum response factor (SRF) is a crucial transcriptional factor for muscle-specific gene expression. We investigated SRF function in adult skeletal muscles, using mice with a postmitotic myofiber-targeted disruption of the SRF gene. Mutant mice displayed severe skeletal muscle mass reductions due to a postnatal muscle growth defect resulting in highly hypotrophic adult myofibers. SRF-depleted myofibers also failed to regenerate following injury. Muscles lacking SRF had very low levels of muscle creatine kinase and skeletal alpha-actin (SKA) transcripts and displayed other alterations to the gene expression program, indicating an overall immaturity of mutant muscles. This loss of SKA expression, together with a decrease in beta-tropomyosin expression, contributed to myofiber growth defects, as suggested by the extensive sarcomere disorganization found in mutant muscles. However, we observed a downregulation of interleukin 4 (IL-4) and insulin-like growth factor 1 (IGF-1) expression in mutant myofibers which could also account for their defective growth and regeneration. Indeed, our demonstration of SRF binding to interleukin 4 and IGF-1 promoters in vivo suggests a new crucial role for SRF in pathways involved in muscle growth and regeneration. [ABSTRACT FROM AUTHOR]