Effects of cytokines in burn blister fluids on fibroblast proliferation and their inhibition with the use of neutralizing antibodies

Recent studies have shown that tissue exudates, such as burn blister fluid and donor site wound fluid, have promotive effects on wound healing. In the present study, results obtained with enzyme-linked immunosorbent assays showed that at least three cytokines, transforming growth factor-beta1, transforming growth factor-alpha, and interleukin-6, exist at high concentrations in burn blister fluids. It was also found that these exudates were able to greatly enhance the rate of human fibroblast proliferation. However, neutralizing antibodies to transforming growth factor-beta1, transforming growth factor-alpha, interleukin-6, and platelet-derived growth factor failed to prevent this proliferative effect. Ultrafiltration of the exudates showed these cytokines to be in the high molecular weight fractions (30 to 300 kDa and >300 kDa) and that these fractions retained mitogenic activity toward fibroblasts. Therefore it was postulated that the cytokines were bound to high molecular weight substances such as serum proteins in these exudates and could escape neutralization by antibodies directed against them.     

High urine sIL-6R as a predictor of late graft failure in renal transplant recipients

BACKGROUND: Chronic allograft nephropathy is an important cause of late renal transplant failure. Although numerous studies on cytokines have been carried out, the pathogenetic role of cytokines in chronic renal allograft nephropathy remains unclear. METHODS: In a retrospective study, the authors compared posttransplant plasma and urine cytokine levels (interleukin [IL]-1alpha, IL-1beta, soluble [s] IL-1 receptor [R] antagonist [A], IL-2, sIL-2R, IL-3, IL-4, IL-6, sIL-6R, IL-10, tumor necrosis factor-alpha, transforming growth factor-beta2, and interferon-gamma) in 34 matched pairs of patients with or without late graft failure and in 50 matched pairs with either normal or increased serum creatinine levels and continued stable graft function. RESULTS: Twelve and 6 months before late graft failure, urine levels of sIL-6R were significantly increased (P=0.003 and P=0.01, respectively). Serum creatinine levels were not associated with increased urine sIL-6R. CONCLUSION: High urine sIL-6R appears to be predictive of late graft failure in renal transplant recipients.     

Regulation by IGF-I and TGF-beta1 of Swarm-rat chondrosarcoma chondrocytes.

The growth factors transforming growth factor-beta 1 and insulin-like growth factor-I influence a wide range of cellular actions, including the growth of several neoplastic cell types. Their role in the regulation of neoplastic chondrocytes remains unclear. We tested the hypotheses that transforming growth factor-beta 1 and insulin-like growth factor-I differentially regulate neoplastic chondrocytes and interact to modulate the mitotic and matrix synthetic activities of neoplastic chondrocytes. We used Swarm-rat chondrosarcoma chondrocytes to investigate the effect of each factor individually and of both factors in combination on [(3)H]thymidine incorporation into DNA and on [(35)S]sulfate incorporation into glycosaminoglycans. Each factor increased [(3)H]thymidine incorporation 2.7-fold: transforming growth factor-beta 1 achieved this effect at a 20-fold lower concentration than insulin-like growth factor-I. In contrast, insulin-like growth factor-I stimulated [(35)S]sulfate incorporation 3.5-fold; this was twice the maximal effect of transforming growth factor-beta 1. Transforming growth factor-beta 1 and insulin-like growth factor-I each decreased the proportion of newly synthesized glycosaminoglycans that were retained in the cells and pericellular matrix, indicating that the anabolic effect of these factors is only partly directed toward cell-associated matrix production. The mitogenic and matrix synthetic actions of insulin-like growth factor-I and transforming growth factor-beta 1 were synergistic. In concert, they increased [(3)H]thymidine incorporation approximately 12-fold, an effect three times greater than the sum of the maximal stimulation achieved by each factor individually. Similarly, transforming growth factor-beta 1 and insulin-like growth factor-I together increased glycosaminoglycan synthesis approximately two times more than the sum of their maximal individual effects. Taken together, these data indicate that these chondrosarcoma chondrocytes are positively regulated by insulin-like growth factor-I and transforming growth factor-beta 1 and that these growth factors interact to augment the mitotic and matrix synthetic actions of the chondrocytes. If supported in human models, the sensitivity to growth factors of these cells suggests that interventions directed toward growth factor inhibition may be of therapeutic value.     

Wound healing in the fetus

Macrophages are believed to play a crucial role in wound healing by synthesizing and secreting numerous cytokines. Some of these cytokines, such as transforming growth factor-beta and tumor necrosis factor-alpha, promote fibrosis and repair. We have shown that macrophages are recruited to sterile fetal wounds and have the potential to regulate repair by synthesizing transforming growth factor-beta(1), transforming growth factor-beta(2), and tumor necrosis factor-alpha. Transforming growth factor-beta was present in fetal lamb wounds in higher amounts than in adult sheep wounds. Furthermore, the concentrations and ratios of the transforming growth factor-beta isoforms in wounds that healed without scarring were different from those in wounds that scarred; transforming growth factor-beta(2) was highest in fetal wounds that did not scar and lowest in adult wounds. These data suggest that concentrations of transforming growth factor-beta isoforms rather than total transforming growth factor-beta concentration may be important in the regulation of fibrosis in prenatal and postnatal wound healing.     

Differential regulation of collagen gene expression in granulation tissue and nonrepair connective tissues in vitamin C-deficient guinea pigs

Poor wound healing during vitamin C deficiency is thought to be due to decreased hydroxylation of proline residues in collagen. In non-repair connective tissues of guinea pigs, however, procollagen gene expression is not decreased until weight loss occurs during the third and fourth weeks of scurvy (phase II) with only a moderate decrease in proline hydroxylation. Decreased procollagen gene expression is related to the induction of insulin-like growth factor binding proteins 1 and 2 that inhibit insulin-like growth factor-I action. We examined wound healing and granulation tissue formation during phase I of vitamin C deficiency. Synthetic sponges were implanted on day 7 of vitamin C deficiency and analyzed at 6 and 10 days after surgery, when there was no weight loss or induction of insulin-like growth factor binding proteins. Healing of incisions was almost complete at 10 days after surgery in normal controls but not in scorbutic animals. The area around the incision and implant exhibited excessive angiogenesis and hemorrhaging of vessels in the scorbutic animals at 6 and 10 days after surgery. At 10 days after surgery, collagen synthesis in the implants of scorbutic guinea pigs was 36% lower than control values, with a normal extent of proline hydroxylation. Concentrations of messenger RNAs for types I and III procollagens were slightly increased by scurvy at 6 days after surgery but were decreased by 26% and 40%, respectively, at 10 days. Fibronectin mRNA levels were unaffected by scurvy at both time points. Our results suggest that poor wound healing in phase I of scurvy may be related to defective interstitial procollagen gene expression and defective blood vessel formation, but it does not involve inhibition of proline hydroxylation or induction of insulin-like growth factor binding proteins. mRNA for insulin-like growth factor-II, transforming growth factor-beta(1), and transforming growth factor-beta(2) were significantly expressed in implants, but their patterns of expression did not correlate with changes in procollagen gene expression.     

Inflammatory leukocytes associated with increased immunosuppression by glioblastoma.

In order to determine the in vivo immune response in glioblastoma, monoclonal and polyclonal antibodies specific for inflammatory leukocytes and immunoregulatory products were utilized to stain tissue from four surgical specimens. The more activated the inflammatory cells, the more activated the tumors appeared to be. In the tumor with the largest infiltration (Case 3), inflammatory cells were stained for interferon-gamma, interleukin-2, interleukin-1 beta, lymphotoxin, tumor necrosis factor-alpha, and transforming growth factor-beta. The tumor cells also expressed interleukin-1 beta, interleukin-6, transforming growth factor-beta, tumor necrosis factor-alpha, and prostaglandin E. In contrast, in the tumor with the least inflammatory response (Case 1), the tumor cells did not express any cytokines. Expression of cytokines by glioma cells was modest in the two cases with modest inflammatory responses. Cellular inflammation, primarily consisting of T cells and macrophages with few or no B cells or natural killer cells, was two- to 15-fold greater outside the tumor than within. In contrast to leukocytes outside the tumor, which were activated and expressing class II major histocompatibility antigens, leukocytes within the tumor parenchyma or at the tumor's edge were negative for these antigens. In the four specimens studied here, the tumor cells themselves were also negative for class II major histocompatibility antigens. These findings, although preliminary, suggest that inflammatory cells within gliomas are inactivated and that glioma cells may increase the expression of immunosuppressive cytokines in response to an increased lymphocyte infiltrate. This observation, if corroborated by more extensive studies, may help to explain the failure of immune treatments in glioblastoma multiforme.     

碱性成纤维细胞生长因子拮抗转化生长因子—β1对人α1（I）胶原基因的启动激活

目的　探讨碱性成纤维细胞生长因子 (b FGF)对人α1 ( )胶原基因启动子活性的影响 ,以及与转化生长因子 - β1 (TGF- β1 )之间的相互作用 ,为防治增生性瘢痕提供依据。　方法　正常皮肤及瘢痕成纤维细胞原代、传代培养。采用 Fu GENE转染试剂 ,分别瞬间转染含人α1 ( )胶原基因 5'端序列 - 2 .5 kb与报告基因氯霉素乙酰基转移酶(CAT)的重组体 ph COL2 .5至正常皮肤及瘢痕成纤维细胞。 ELISA法测定 b FGF及 TGF- β1 作用 2 4小时后 ,转染ph COL2 .5的两种成纤维细胞的报告基因 CAT表达量。　结果　b FGF能抑制转染 ph COL2 .5重组体的正常皮肤及瘢痕成纤维细胞 CAT表达量 ,且能拮抗 TGF-β1 对转染 ph COL2 .5重组体的两种成纤维细胞 CAT表达的上调作用。与对照组相比有统计学意义 (P<0 .0 5)。　结论　正常皮肤及瘢痕成纤维细胞中 ,b FGF均能抑制人 α1 ( )胶原基因的启动转录 ,且能拮抗 TGF-β1 对人α1 ( )胶原基因启动活性的上调作用 ,b FGF抗纤维机制有望为增生性瘢痕的防治提供新思路     

Acceleration of wound healing in aged rats by topical application of transforming growth factor-beta(1).

The impaired wound healing associated with aging may reflect inadequate secretion or delivery of cytokines. Transforming growth factor-beta(1) is a mitogenic polypeptide with beneficial effects on wound healing. In the present study we questioned whether topical administration of transforming growth factor-beta(1) could improve the wound healing process in aged rats in vivo. Wound repair (from 1 to 14 days) was analyzed in full-thickness incisional wounds from 2-year-old rats with or without a single topical application of transforming growth factor-beta(1) (1 microg/wound) at the time of wounding. Identical wounds from 3-month-old, untreated rats served as controls. Histologic analysis showed a marked delay in several aspects of wound repair in the aged rats in comparison with that noted in the younger animals. Immunostaining of the wounds for proliferating cell nuclear antigen showed a reduction in the number of cycling fibroblasts in old rats. In addition, the number of capillaries per unit area of the wound as determined by a stain for Griffonin (Bandeiraea) simplicifolia lectin, and the number of inflammatory cells as identified by an antibody specific for macrophages, were also reduced in the wound area in old rats. Treatment with transforming growth factor-beta(1) resulted in marked enhancement of the following parameters: cell proliferation, inflammatory cell and fibroblast influx, wound closure, and angiogenesis. As seen with in situ hybridization, a similar temporal pattern of expression of messenger RNAs corresponding to type I procollagen and Secreted Protein, Acidic and Rich in Cysteine (osteonectin), known to be prevalent in healing wounds, was observed in both young and aged rats. However, the levels of mRNA corresponding to these secreted proteins appeared to be reduced in wound tissue from aged rats. Treatment with transforming growth factor-beta(1) subsequently resulted in an increase in the expression of both type I procollagen and Secreted Protein, Acidic and Rich in Cysteine mRNA in the wound tissue from aged rats. In summary, a single topical application of transforming growth factor-beta(1) to the wounds of aged rats at the time of wounding was associated with a healing response that, in all the parameters of wound repair examined, was similar to that of young rats. Topical transforming growth factor-beta(1) might therefore be beneficial in the treatment of dermal wounds in the aged.     

Cytokines associated with the pathophysiology of aggressive fibromatosis.

The rare benign extra-abdominal desmoid tumor is characterized by aggressive invasion of normal tissue. Treatment is complicated by its recurrence, invasiveness, and persistence. The etiology is unknown and the pathophysiology is obscure. Because of exuberant fibroblastic proliferation with collagenous tissue being the primary tissue component, this desmoid tumor has been compared with keloids arising from excessive scar formation in healing wounds. Numerous cytokines are associated with signaling for growth and maintenance of mesenchymal cells. Altered expression of these proteins is associated with many pathologic conditions. It has been proposed that the enhanced expression of platelet-derived growth factor and its receptor characterize desmoid tumors. We tested the hypothesis that the exuberant fibrosis of desmoid tumors may have resulted from the initiation of the cascade of molecular events producing increased expression of cytokines. We used immunohistochemical analysis of cytokines in desmoid tumors compared with keloids and skin to localize the expression of cytokines. The results showed localized increased expression of the cytokines epidermal growth factor, transforming growth factor-beta, tumor necrosis factor-alpha, vascular endothelial growth factor, interleukin-1beta, and interleukin-6 in the endothelial cells of blood vessels in the tumors. Production of tumor necrosis factor-alpha and interleukin-1beta in tumor tissue was increased, but we did not find increased expression of platelet-derived growth factor. We concluded that the increased expression of cytokines associated with angiogenesis usually found in wound healing and invasive tumors may contribute to the pathophysiology of the desmoid tumor.     

Suggestive linkage of the parathyroid receptor type 1 to osteoporosis.

We have investigated the role of 23 candidate genes in the control of bone mineral density (BMD) by linkage studies in families of probands with osteoporosis (lumbar spine [LS] or femoral neck [FN] BMD T score < -2.5) and low BMD relative to an age- and gender-matched cohort (Z score < -2.0). One hundred and fifteen probands (35 male, 80 female) and 499 of their first- or second-degree relatives (223 males and 276 females) were recruited for the study. BMD was measured at the LS and FN using dual-energy X-ray absorptiometry and expressed as age- and gender-matched Z scores corrected for body mass index. The candidate genes studied were the androgen receptor, type I collagen A1 (COLIA1), COLIA2, COLIIA1, vitamin D receptor (VDR), colony-stimulating factor 1, calcium-sensing receptor, epidermal growth factor (EGF), estrogen receptor 1 (ESR1), fibrillin type 1, insulin-like growth factor 1, interleukin-1 alpha (IL-1alpha), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-11 (IL-11), osteopontin, parathyroid hormone (PTH), PTH-related peptide, PTH receptor type 1 (PTHR1), transforming growth factor-beta 1, and tumor necrosis factors alpha and beta. Sixty-four microsatellites lying close to or within these genes were investigated for linkage with BMD. Using the program MapMaker/Sibs there was suggestive evidence of linkage between BMD and PTHR1 (maximum LOD score obtained [MLS] 2.7-3.5). Moderate evidence of linkage was also observed with EGF (MLS 1.8), COLIA1 (MLS 1.7), COLIIA1/VDR (MLS 1.7), ESR1 (MLS 1.4), IL-1alpha (MLS 1.4), IL-4 (MLS 1.2), and IL-6 (MLS 1.2). Variance components analysis using the program ACT, correcting for proband-wise ascertainment, also showed evidence of linkage (p 相似文献   

Comparison of the type-2 insulin-like growth factor receptor in normal osteoblasts and osteosarcoma-derived osteoblast-like cells

Insulin-like growth factor-II is known to stimulate the proliferation and differentiation of osteoblasts in part through activation of the type-2 insulin-like growth factor receptor. The present study examined the type-2 insulin-like growth factor receptors of three normal osteoblast-like cells and three osteosarcoma-derived osteoblast-like cells (OGA, SU, and IMAI) from humans. [¹²⁵I]insulin-like growth factor-II was used for the binding studies. All of the cell types had high affinity binding sites for insulin-like growth factor-II (dissociation constants [Kd] ? 1 nM). The concentration of these sites was 10 to 24-fold higher in normal osteoblasts than in the osteosarcoma cells studied. Unlabeled insulin-like growth factor-II inhibited the binding of [¹²⁵I]insulin-like growth factor-II to the cells in a dose-dependent manner; however, unlabeled insulin-like growth factor-I and insulin were less effective. Covalent crosslinking of insulin-like growth factor-II binding sites gave molecular mass estimates of M_r 250,000 in human osteoblast cells, 250,000 and 130,000 in OGA cells. 240,000 in SU cells, and 250,000 and 130,000 in IMAI cells. Unlabeled insulin-like growth factor-II inhibited all affinity labeling. In Northern blot analysis, the type-2 insulin-like growth factor receptor mRNA of normal osteoblasts was seen in greater abundance than it was in osteosarcoma cells. These results indicate that the numbers of type-2 insulin-like growth factor receptors differ between normal and transformed osteoblasts and that the differential expression of the receptor may be due to the differentiation of osteoblasts.