Dermal transforming growth factor-beta responsiveness mediates wound contraction and epithelial closure.

Stromal-epithelial interactions are important during wound healing. Transforming growth factor-beta (TGF-beta) signaling at the wound site has been implicated in re-epithelization, inflammatory infiltration, wound contraction, and extracellular matrix deposition and remodeling. Ultimately, TGF-beta is central to dermal scarring. Because scarless embryonic wounds are associated with the lack of dermal TGF-beta signaling, we studied the role of TGF-beta signaling specifically in dermal fibroblasts through the development of a novel, inducible, conditional, and fibroblastic TGF-beta type II receptor knockout (Tgfbr2(dermalKO)) mouse model. Full thickness excisional wounds were studied in control and Tgfbr2(dermalKO) back skin. The Tgfbr2(dermalKO) wounds had accelerated re-epithelization and closure compared with controls, resurfacing within 4 days of healing. The loss of TGF-beta signaling in the dermis resulted in reduced collagen deposition and remodeling associated with a reduced extent of wound contraction and elevated macrophage infiltration. Tgfbr2(dermalKO) and control skin had similar numbers of myofibroblastic cells, suggesting that myofibroblastic differentiation was not responsible for reduced wound contraction. However, several mediators of cell-matrix interaction were reduced in the Tgfbr2(dermalKO) fibroblasts, including alpha1, alpha2, and beta1 integrins, and collagen gel contraction was diminished. There were associated deficiencies in actin cytoskeletal organization of vasodilator-stimulated phosphoprotein-containing lamellipodia. This study indicated that paracrine and autocrine TGF-beta dermal signaling mechanisms mediate macrophage recruitment, re-epithelization, and wound contraction.

Urothelial transdifferentiation to prostate epithelia is mediated by paracrine TGF-beta signaling.

The embryonic urogenital sinus mesenchyme (UGM) induces prostate epithelial morphogenesis in development. The molecular signals that drive UGM-mediated prostatic induction have not been defined. We hypothesized that the TGF-beta signaling directed the prostatic induction. UGM from TGF-beta type II receptor stromal conditional knockout mice (Tgfbr2(fspKO)) or control mice (Tgfbr2(floxE2/floxE2)) was recombined with wild-type adult mice bladder urothelial cells. The resulting urothelium associated with Tgfbr2(floxE2/floxE2) UGM was instructively differentiated into prostatic epithelium, as expected. In contrast, the urothelium associated with Tgfbr2(fspKO) UGM permissively maintained the phenotype of bladder epithelial cells. Microarray analysis of UGM tissues suggested the down-regulation of multiple Wnt ligands and the up-regulation of the Wnt antagonist, Wif 1, by the Tgfbr2(fspKO) UGM compared with Tgfbr2(floxE2/floxE2) UGM. The overexpression of Wif-1 by wild-type UGM resulted in the inhibition of prostatic induction. These data suggest that the stromal TGF-beta activity mediated by paracrine Wnt is necessary for the induction of prostatic differentiation. As Wnt ligands mediate differentiation and maintain the stem cell phenotype, the contribution of mouse stem cells and somatic cells to prostatic epithelium in the tissue recombination models was tested. The directed differentiation of mouse embryonic stem cells by UGM is suggested by a threshold number of mouse stem cells required in prostatic differentiation. To determine the contribution of somatic cells, the adult bladder epithelial compartment was labeled with green-fluorescent vital dye (CMFDA) and the stem-like cells marked by bromodeoxyuridine (BrdU) label-retention. The resulting prostatic epithelia of the tissue recombinants maintained the CMFDA dye, suggesting minimal cell division. Thus, the UGM can induce endoderm-derived epithelia and stem cells to form prostate through a transdifferentiation mechanism that requires stromal TGF-beta signaling to mediate epithelial Wnt activity.

Chemokine markers predict biochemical recurrence of prostate cancer following prostatectomy.

PURPOSE: Stratifying patients who have a high risk of prostate cancer recurrence following prostatectomy can potentiate the use of adjuvant therapy at an early stage. Inflammation has emerged as a mediator of prostate cancer metastatic progression. We hypothesized that chemokines can be biomarkers for distinguishing patients with high risk for biochemical recurrence of prostate cancer. EXPERIMENTAL DESIGN: In a nested case-control study, 82 subjects developed biochemical recurrence within 5 years of prostatectomy. Prostate tissues from 98 age-matched subjects who were recurrence-free following prostatectomy in the same period were the controls. A high-throughput lectin-based enrichment of prostate tissue enabled multiplex ELISA to identify the expression of three chemokines to discriminate the two patient populations. RESULTS: The expression of CX3CL1 and IL-15 in prostate tissue was associated with 5-year biochemical recurrence-free survival following prostatectomy. However, the expression of chemokine ligand 4 (CCL4) was associated with biochemical recurrence. Multivariable logistic regression model combining preoperative prostate-specific antigen, Gleason score, surgical margin, and seminal vesicle status with the three chemokines doubled the specificity of prediction at 90% sensitivity compared with use of the clinicopathologic variables alone (P < 0.0001). Survival analysis yielded a nomogram that supported the use of CX3CL1, IL-15, and CCL4 in predicting 1-, 3-, and 5-year recurrence-free survival after prostatectomy. CONCLUSIONS: Each of the three chemokines can serve as independent predictors of biochemical recurrence. However, the combination of chemokine biomarkers plus clinicopathologic variables discriminated prostatectomy subjects for the probability of biochemical recurrence significantly better than clinicopathologic variables alone.

Nicotinic signaling ameliorates acute bladder inflammation induced by protamine sulfate or cyclophosphamide.

PURPOSE: Nicotinic afferent pathways may be involved in the regulation of bladder inflammation. Based on that hypothesis we investigated the role of nicotinic signaling in a comparative analysis of 2 models of experimental bladder inflammation using protamine sulfate and cyclophosphamide. MATERIALS AND METHODS: Protamine sulfate and cyclophosphamide were used to induce acute bladder inflammation. Nicotinic agonists and antagonists were given concomitant to the bladder inflammatory agents. Changes in bladder inflammation were measured histologically by a pathologist and through the expression of inflammatory genes. RESULTS: Histologically cyclophosphamide induced more inflammatory changes than protamine sulfate during acute bladder inflammation. Antagonizing nicotinic signaling with mecamylamine induced further inflammatory changes on histology when used with cyclophosphamide but not with protamine sulfate. However, antagonizing nicotinic signaling in combination with protamine sulfate induced greater increases in mRNA expression of the inflammatory cytokine interleukin-6 compared to cyclophosphamide and mecamylamine combination treatments. The activation of nicotinic signaling attenuated acute bladder inflammation by protamine sulfate and cyclophosphamide independently through the down-regulation of increased interleukin-6 expression. CONCLUSIONS: Acutely cyclophosphamide treatment results in a greater frank bladder inflammation model in mice than protamine sulfate. However, cholinergic signaling can inhibit inflammation by either mechanism of induced bladder injury. Interleukin-6 gene expression is present and it can be regulated by afferent neuronal signaling even in the absence of observed histological changes in acute bladder inflammatory models.

Role of nicotinic and estrogen signaling during experimental acute and chronic bladder inflammation.

Inflammation is a physiological process that characterizes many bladder diseases. We hypothesized that nicotinic and estrogen signaling could down-regulate bladder inflammation. Cyclophosphamide was used to induce acute and chronic bladder inflammation. Changes in bladder inflammation were measured histologically and by inflammatory gene expression. Antagonizing nicotinic signaling with mecamylamine further aggravated acute and chronic inflammatory changes resulting from cyclophosphamide treatment. Estrogen and nicotinic signaling independently attenuated acute bladder inflammation by decreasing neutrophil recruitment and down-regulating elevated lipocalin-2 and cathepsin D expression. However, the combined signaling by the estrogen and nicotinic pathways, as measured by macrophage infiltration and up-regulation of interleukin-6 expression in the bladder, synergistically reduced chronic bladder inflammation. The elevated expression of p65 nuclear localization in bladders treated with cyclophosphamide or cyclophosphamide with mecamylamine suggested nuclear factor-kappa B activation in the chronic inflammatory process. The complementary treatment of 17 beta-estradiol and the nicotinic agonist anabasine resulted in the translocation of p65 to the cytoplasm, again greater than either alone. Activation of nuclear factor-kappaB can result in macrophage activation and/or elevation in epithelial proliferation. These data suggest that 17 beta-estradiol and anabasine reduce chronic bladder inflammation through reduction of nuclear translocation of p65 to suppress cytokine expression.

Stromal transforming growth factor-beta signaling mediates prostatic response to androgen ablation by paracrine Wnt activity.

Mechanisms of androgen dependence of the prostate are critical to understanding prostate cancer progression to androgen independence associated with disease mortality. Transient elevation of transforming growth factor-beta (TGF-beta) occurs after androgen ablation. To determine the role of TGF-beta on prostate response to androgen ablation, conditional TGF-beta type II receptor knockout mouse models of the epithelia (Tgfbr2(NKX3.1KO)) and stromal fibroblasts (Tgfbr2(fspKO)) were used. After castration, the prostates of Tgfbr2(NKX3.1KO) mice had apoptosis levels similar to those expected for control Tgfbr2(floxE2/floxE2) mice. Prostates of Tgfbr2(fspKO) mice, however, had reduced regression and high levels of proliferation associated with canonical Wnt activity throughout the glandular epithelia regardless of androgen status. In contrast, Tgfbr2(floxE2/floxE2) prostates had epithelial canonical Wnt activity only in the surviving proximal ducts after castration. In vitro studies showed that androgen antagonist, bicalutamide, transiently elevated both Tgfbr2(floxE2/floxE2) and Tgfbr2(fspKO) stromal expression of Wnt-2, Wnt-3a, and Wnt-5a. The neutralization of Wnt signaling by the expression of secreted frizzled related protein-2 (SFRP-2) resulted in decreased LNCaP prostate epithelial cell proliferation in stromal conditioned media transfer experiments. In vivo tissue recombination studies using Tgfbr2(fspKO) prostatic stromal cells in combination with wild-type or SV40 large T antigen expressing epithelia resulted in prostates that were refractile to androgen ablation. The expression of SFRP-2 restored the Tgfbr2(fspKO)-associated prostate responsiveness to androgen ablation. These studies reveal a novel TGF-beta, androgen, and Wnt paracrine signaling axis that enables prostatic regression of the distal ducts after androgen ablation while supporting proximal duct survival.