Caloric Restriction Impairs Regulatory T cells Within the Tumor Microenvironment After Radiation and Primes Effector T cells.

Outcomes for triple negative breast cancer (TNBC) are poor and may be improved by increasing CD8+ tumor infiltrating lymphocytes (TIL) to augment antitumor immunity. Radiation (RT) can promote immunogenic cell death with increased antitumor T cell activity but also stimulates suppressive regulatory T cells (Tregs). Because metabolic alterations affect immune homeostasis and prior studies show caloric restriction (CR) combined with RT improves preclinical TNBC outcomes, we hypothesized that CR augments RT, in part, by altering intratumoral immunity. Using an in vivo model of TNBC, we treated mice with ad libitum (AL) diet, radiation, a CR diet, or CR + RT, and demonstrated an immune suppressive environment with a significant increase in CD4+ CD25+Foxp3+ Tregs after RT but not in CR-fed mice. CD8:Treg ratio in CR + RT TIL increased 4-fold compared with AL + RT mice. In vivo CD8 depletion was performed to assess the role of effector T cells in mitigating the effects of CR, and it was found that in mice undergoing CR, depletion of CD8 T cells resulted in increased tumor progression and decreased median survival compared with isotype control-treated mice. In addition, PD-1 expression on CD3+CD8+ T cells within the tumor microenvironment was significantly increased in CR + RT versus AL + RT treated mice as per immunofluorescence. Serum from breast cancer patients undergoing RT alone or CR and RT was collected pre- and postintervention, and a cytokine array demonstrated that patients treated with CR + RT had notable decreases in immunosuppressive cytokines such as IL-2Rγ, IL-10Rß, and TGF-ß2 and 3 compared with patients receiving RT alone. In conclusion, combining CR with RT decreases intratumoral Tregs, increases CD8:Treg, and increases PD-1 expression via a process dependent on CD8 T cells in a TNBC model. Breast cancer patients undergoing CR concurrently with RT also had significant reduction in immunosuppressive cytokine levels compared with those receiving RT alone.

Increased Stromal Infiltrating Lymphocytes Are Associated with the Risk of Disease Progression in Mesenchymal Circulating Tumor Cell-Positive Primary Breast Cancer Patients.

Circulating tumor cells (CTCs) and the immune infiltration of tumors are closely related to clinical outcomes. This study aimed to verify the influence of stromal lymphocyte infiltration and the immune context of tumor microenvironment on the hematogenous spread and prognosis of 282 chemotherapy naïve primary BC patients. To detect the presence of mesenchymal CTCs, RNA extracted from CD45-depleted peripheral blood was interrogated for the expression of mesenchymal gene transcripts. Tumor-infiltrating lymphocytes (TILs) were detected in the stromal areas by immunohistochemistry, using CD3, CD8, and CD45RO antibodies. The concentrations of 51 plasma cytokines were measured by multiplex bead arrays. TILs infiltration in mesenchymal CTC-positive patients significantly decreased their progression-free survival (HR = 4.88, 95% CI 2.30-10.37, p < 0.001 for CD3high; HR = 6.17, 95% CI 2.75-13.80, p < 0.001 for CD8high; HR = 6.93, 95% CI 2.86-16.81, p < 0.001 for CD45ROhigh). Moreover, the combination of elevated plasma concentrations of transforming growth factor beta-3 (cut-off 662 pg/mL), decreased monocyte chemotactic protein-3 (cut-off 52.5 pg/mL) and interleukin-15 (cut-off 17.1 pg/mL) significantly increased the risk of disease recurrence (HR = 4.838, 95% CI 2.048-11.427, p < 0.001). Our results suggest a strong impact of the immune tumor microenvironment on BC progression, especially through influencing the dissemination and survival of more aggressive, mesenchymal CTC subtypes.

Circulating extracellular vesicle-associated TGFß3 modulates response to cytotoxic therapy in head and neck squamous cell carcinoma.

Management of locally advanced head and neck squamous cell carcinoma (HNSCC) requires a multi-prong approach comprising surgery, radiation and/or chemotherapy, yet outcomes are limited. This is largely due to a paucity of biomarkers that can predict response to specific treatment modalities. Here, we evaluated TGFß3 protein levels in extracellular vesicles (EVs) released by HNSCC cells as a predictor for response to chemoradiation therapy (CRT). To this end, specific EV-fractions were isolated from cell lines or HNSCC patient plasma, and TGFß3 protein was quantified. In patients treated with CRT, TGFß3 levels were found to be significantly higher in plasma EV-fractions or non-responders compared with responders. High levels of TGFß3 levels in Annexin V-EVs were associated with the worst progression-free survival. In vitro experiments demonstrated that TGFß3 silencing sensitized HNSCC cells to cytotoxic therapies, and this phenotype could be rescued by treatment with exogenous. In addition, specific EV-fractions shed by cisplatin-resistant cells were sufficient to transfer the resistant phenotype to sensitive cells through activation of TGFß-signaling pathway. Therefore, our data show that TGFß3 transmitted through EV plays a significant role in response to cytotoxic therapy, which can be exploited as a potential biomarker for CRT response in HNSCC patients treated with curative intent.

Ulipristal acetate decreases transforming growth factor ß3 serum and tumor tissue concentrations in patients with uterine fibroids.

OBJECTIVE: To evaluate and compare transforming growth factor ß3 (TGF-ß3) serum concentration in patients with uterine fibroids (UFs) without hormone treatment, treated with ulipristal acetate (UPA), and controls; to evaluate TGF-ß3 concentrations in UF tissue in patients without hormone treatment and those treated with UPA; and to evaluate the correlations of age and body mass index (BMI) with TGF-ß3 serum and UF tissue levels between the groups. DESIGN: Retrospective cohort study. SETTING: University teaching hospital. PATIENT(S): A total of 141 patients divided into three groups: UFs non-UPA, UFs, and UPA, controls. INTERVENTION(S): Medical history and examination, genital ultrasound scan, blood and tissue sampling, and measurement of TGF-ß3 serum and tissue concentrations. MAIN OUTCOME MEASURE(S): Evaluation of the impact of UPA (3 months treatment), age and BMI on TGF-ß3 serum and UF tissue levels. RESULT(S): The values of TGF-ß3 serum and tissue concentrations statistically significantly differed between the non-UPA and UPA groups. The mean TGF-ß3 serum concentrations were non-UPA group 32.24 ± 34.55 pg/mL, UPA group 10.88 ± 7.15 pg/mL, and controls 11.97 ± 10.30 pg/mL. The mean TGF-ß3 tissue concentrations were non-UPA group 171.29 ± 91.81 pg/mg and UPA group 99.99 ± 60.63 pg/mg. Statistically significantly lower mean TGF-ß3 serum and tissue concentrations were observed in patients treated with UPA. No statistically significant correlations between TGF-ß3 concentrations and age or BMI were found. CONCLUSION(S): Reduction of serum and tissue TGF-ß3 concentrations in UFs may be an important component of the effect of UPA on UF biology. Further research in this area is necessary.

Ethnic differences in TGFß-signaling pathway may contribute to prostate cancer health disparity.

Epidemiological studies show that the incidence and mortality rates of prostate cancer (PCa) are significantly higher in African-American (AA) men when compared with Caucasian (CA) men in the United States. Transforming growth factor ß (TGFß) signaling pathway is linked to health disparities in AAs. Recent studies suggest a role of TGFß3 in cancer metastases and its effect on the migratory and invasive behavior; however, its role in PCa in AA men has not been studied. We determined the circulating levels of TGFß3 in AA and CA men diagnosed with PCa using ELISA. We analyzed serum samples from both AA and CA men diagnosed with and without PCa. We show that AA PCa patients had higher levels of TGFß3 protein compared with AA controls and CA patients. In fact, TGFß3 protein levels in serum were higher in AA men without PCa compared with the CA population, which may correlate with more aggressive disease seen in AA men. Studies on AA-derived PCa cell lines revealed that TGFß3 protein levels were also higher in these cells compared with CA-derived PCa cell lines. Our studies also reveal that TGFß does not inhibit cell proliferation in AA-derived PCa cell lines, but it does induce migration and invasion through activation of PI3K pathway. We suggest that increased TGFß3 levels are responsible for development of aggressive PCa in AA patients as a consequence of development of resistance to inhibitory effects of TGFß on cell proliferation and induction of invasive metastatic behavior.

Maternal plasma angiogenic and inflammatory factor profiling in foetal Down syndrome.

OBJECTIVE AND DESIGN: Angiogenic factors are proteins that are related to certain foetal chromosomal abnormalities. The aim of this study was to determine the concentration of 60 angiogenic factors in the plasma of women with offspring possessing trisomy 21/Down syndrome (DS). METHOD: After analysing karyotyping results, we selected 20 patients with foetuses possessing DS, and for the control group, we selected 28 healthy patients with uncomplicated pregnancies who delivered healthy newborns at term (i.e., 15-18 weeks of gestation). To assess the concentration of proteins in the blood plasma, we used a protein macroarray which enabled simultaneous determination of 60 angiogenic factors per sample. RESULTS: We observed a statistically significant increase in the concentration of these five angiogenic and inflammatory factors: TGFb1 (p = 0.039), angiostatin (p = 0.0142), I-309 (p = 0.0476), TGFb3 (p = 0.0395), and VEGF-D (p = 0.0173)-compared to concentrations in patients with healthy foetuses. CONCLUSION: Our findings suggest that angiogenic factors may play role in DS pathogenesis.

Stellate Cell Activation and Imbalanced Expression of TGF-ß1/TGF-ß3 in Acute Autoimmune Liver Lesions Induced by ConA in Mice.

Objective. To study the pathogenic feature of liver injury, activation of hepatic stellate cells, and dynamic expression of TGF-ß1/TGF-ß3 to reveal their role in liver injury induced by ConA. Methods. Mice were randomly divided into control group and ConA treatment group. ConA (20 mg/kg) was injected through vena caudalis in ConA treatment group; the controls received the same volume of saline injection. After injection for 2 h, 8 h, 24 h, and 48 h, animals were terminated. Blood, liver, and spleen were harvested. Liver function and histopathology were studied. α-SMA, vimentin, TGF-ß1, and TGF-ß3 were detected. Results. After ConA injection, liver damage started to increase. Expression of α-SMA, vimentin, TGF-ß1, and TGF-ß3 was significantly enhanced; all above indicators reached peak at 8 h; but from 24 h after ConA injection, TGF-ß3 expression began to decline, while the TGF-ß1/TGF-ß3 ratio at 48 h was significantly lower than control. Conclusion. (1) Autoimmune liver injury induced by ConA showed time-based features, in which the most serious liver lesions happened at 8 h after ConA injection. (2) Early activation of HSC and imbalance expression of TGF-ß1 and TGF-ß3 existed in ConA-induced acute autoimmune liver injury, which may be associated with liver dysfunction and the mechanisms of progression to fibrosis.

Influence of vitamin D and transforming growth factor ß3 serum concentrations, obesity, and family history on the risk for uterine fibroids.

OBJECTIVE: To evaluate the influence of 25-hydroxyvitamin D and transforming growth factor ß3 (TGF-ß3) serum concentrations, weight, and family history on the risk of developing uterine fibroids. DESIGN: Retrospective cohort study. SETTING: University hospital. PATIENT(S): A total of 188 women, including patients admitted for uterine fibroid surgery (n = 105) as the study group and healthy women of similar age (n = 83) as controls. INTERVENTION(S): Medical history and completion of specially designed questionnaire, transvaginal or transabdominal genital ultrasound scan, blood sampling, and measurement of vitamin D and TGF-ß3 serum concentrations. MAIN OUTCOME MEASURE(S): Evaluation of the impact of family history, vitamin D, and TGF-ß3 serum concentrations on the risk of developing uterine fibroids. RESULT(S): Mean 25-hydroxyvitamin D serum concentrations were 21.9 ± 8.9 ng/mL and 26.7 ± 11.9 ng/mL in patients with uterine fibroids and controls, respectively. The difference was statistically significant. The TGF-ß3 serum concentrations in the fibroid-positive group ranged from 1.20 to 436.15 pg/mL (half the patients had concentrations >16.25 pg/mL). Concentrations in the control group ranged from 0.96 to 49.08 pg/mL (half the women had concentrations of >11.80 pg/mL). The differences were statistically significant. Higher body mass index (BMI) and positive family history were also found to be among the risk factors for uterine fibroids. CONCLUSION(S): Our study confirmed higher BMI, positive family history, and lower vitamin D and higher TGF-ß3 serum concentrations as risk factors for uterine fibroids.

Simtuzumab treatment of advanced liver fibrosis in HIV and HCV-infected adults: results of a 6-month open-label safety trial.

BACKGROUND: Chronic liver injury can result in fibrosis that may progress over years to end-stage liver disease. The most effective anti-fibrotic therapy is treatment of the underlying disease, however when not possible, interventions to reverse or slow fibrosis progression are needed. AIM: The aim of this study was to study the safety and tolerability of simtuzumab, a monoclonal antibody directed against lysyl oxidase-like 2 (LOXL2) enzyme, in subjects with hepatitis C virus (HCV), human immunodeficiency virus (HIV), or HCV-HIV co-infection and advanced liver disease. METHODS: Eighteen subjects with advanced liver fibrosis received simtuzumab 700 mg intravenously every 2 weeks for 22 weeks. Transjugular liver biopsies were performed during screening and at the end of treatment to measure hepatic venous pressure gradient (HVPG) and to stage fibrosis. RESULTS: Treatment was well-tolerated with no discontinuations due to adverse events. No significant changes were seen in HVPG or liver biopsy fibrosis score after treatment. Exploratory transcriptional and protein profiling using paired pre- and post-treatment liver biopsy and serum samples suggested up-regulation of TGF-ß3 and IL-10 pathways with treatment. CONCLUSION: In this open-label, pilot clinical trial, simtuzumab treatment was well-tolerated in HCV- and HIV-infected subjects with advanced liver disease. Putative modulation of TGF-ß3 and IL-10 pathways during simtuzumab treatment merits investigation in future trials.

Prognostic significance of in situ and plasma levels of transforming growth factor ß1, -2 and -3 in cutaneous melanoma.

Melanoma is an aggressive type of cutaneous malignancy. Transforming growth factor (TGF)­ß has been demonstrated to be an important mediator of tumor progression. However, to the best of our knowledge, the systemic roles of plasma TGF­ß and TGF­ß in situ have not been investigated in Han Chinese melanoma patients. The results of the present study demonstrated that the in situ and plasma levels of TGF­ß1, TGF­ß2 and TGF­ß3 protein and messenger RNA were significantly elevated in tumor tissues compared with those of normal tissues. The survival rates of the patients which were triple­positive (TGF­ß1+, TGF­ß2+ and TGF­ß3+) were found to be markedly decreased compared to those which were single­ (TGF­ß1+, TGF­ß2+ or TGF­ß3+) or double­positive (TGF­ß1+, TGF­ß2+; TGF­ß2+, TGF­ß3+; or TGF­ß1+, TGF­ß3+). These results may therefore contribute to the use of TGF­ß as a prognostic biomarker, and to the development of novel therapies for melanoma treatment.

Transforming growth factor (TGF)-ß levels and unprovoked recurrent venous thromboembolism.

Prediction of recurrence in patients with unprovoked venous thromboembolism (VTE) remains a challenge. Studies of atherosclerosis suggest a protective role of transforming growth factor (TGF)-ß. However, the role of TGF-ß has not been studied in VTE. The aim of this study was to investigate TGF-ß as a predictive marker of recurrent VTE in patients with a first episode of unprovoked VTE. Patients in the Malmö Thrombophilia Study (MATS) were followed after the discontinuation of anticoagulant treatment until the diagnosis of recurrent VTE or the end of the study in December 2008 (mean ± SD 38.5 months ± 27). Among patients with a first episode of unprovoked VTE, we identified 42 patients with recurrent VTE during the follow-up period. Two age- and sex-matched control subjects without recurrent VTE were selected for each patient (n = 84). Plasma levels of the three isoforms of TGF-ß (TGF-ß1, TGF-ß2 and TGF-ß3) were quantified simultaneously by TGF-ß 3-plex immunoassay. Compared to controls, plasma levels of TGF-ß1 and TGF-ß2 were significantly lower in patients with recurrent VTE (p < 0.05), whereas no difference was found for TGF-ß3. In a multivariate Cox regression analyses, adjusted for inherited thrombophilia, age, sex and BMI, low levels of TGF-ß1 [hazard ratio (HR) = 2.2, 95% confidence interval (CI) 1.1-4.3; p = 0.02] and TGF-ß2 (HR = 2.4, 95% CI 1.2-4.7; p = 0.01) were independently associated with a higher risk of recurrent VTE. We propose TGF-ß1 and TGF-ß2 as potential predictive markers for recurrence in patients with unprovoked VTE.

Injury-activated transforming growth factor ß controls mobilization of mesenchymal stem cells for tissue remodeling.

Upon secretion, transforming growth factor ß (TGFß) is maintained in a sequestered state in extracellular matrix as a latent form. The latent TGFß is considered as a molecular sensor that releases active TGFß in response to the perturbations of the extracellular matrix at the situations of mechanical stress, wound repair, tissue injury, and inflammation. The biological implication of the temporal discontinuity of TGFß storage in the matrix and its activation is obscure. Here, using several animal models in which latent TGFß is activated in vascular matrix in response to injury of arteries, we show that active TGFß controls the mobilization and recruitment of mesenchymal stem cells (MSCs) to participate in tissue repair and remodeling. MSCs were mobilized into the peripheral blood in response to vascular injury and recruited to the injured sites where they gave rise to both endothelial cells for re-endothelialization and myofibroblastic cells to form thick neointima. TGFßs were activated in the vascular matrix in both rat and mouse models of mechanical injury of arteries. Importantly, the active TGFß released from the injured vessels is essential to induce the migration of MSCs, and cascade expression of monocyte chemotactic protein-1 stimulated by TGFß amplifies the signal for migration. Moreover, sustained high levels of active TGFß were observed in peripheral blood, and at the same time points following injury, Sca1+ CD29+ CD11b- CD45- MSCs, in which 91% are nestin+ cells, were mobilized to peripheral blood and recruited to the remodeling arteries. Intravenously injection of recombinant active TGFß1 in uninjured mice rapidly mobilized MSCs into circulation. Furthermore, inhibitor of TGFß type I receptor blocked the mobilization and recruitment of MSCs to the injured arteries. Thus, TGFß is an injury-activated messenger essential for the mobilization and recruitment of MSCs to participate in tissue repair/remodeling.

Serum TGF-beta2 and TGF-beta3 are increased and positively correlated to pain, functionality, and radiographic staging in osteoarthritis.

The goal of this study was to verify or reject the hypothesis that systematic differences exist in various profibrotic or antifibrotic factors between osteoarthritic patients and controls, as well as between different stages of osteoarthritis. The study group comprised 63 patients with knee osteoarthritis and 18 controls. Transforming growth factor-beta (TGF-beta)1, -2, -3; tissue inhibitor of metalloproteinase (TIMP)-1 protein levels; and gelatinolytic activity of matrix metalloproteinase (MMP)-1, -2, -3, -9 activities were measured by enzyme-linked immunosorbent assay and gelatin zymography, respectively. Visual analog scale scores, Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores, Lequesne clinical osteoarthritis scales, and Kellgren-Lawrence radiographic grading were recorded for each patient.Transforming growth factor-beta2 and -3 (in contrast to TGF-beta1 and TIMP-1) serum protein levels were significantly higher in osteoarthritic patients compared to controls (210%+/-14% [P<.001] and 232%+/-7% [P<10(-7)], respectively). Additionally, TGF-beta2 and -3 were strongly positively correlated to Kellgren-Lawrence radiographic grading of the disease (P<10(-5) and P<10(-7), respectively). Moreover, TGF-beta2 correlated positively with the WOMAC scale (P=.007). However, TIMP-1 decreased as osteoarthritis progressed clinically, but remained irrelevant to radiographic staging. Furthermore, activities of MMP-2 and -9, but not MMP-1+/-3, were lower in patients with osteoarthritis.

Studies of TGF-beta(1-3) in serosal fluid during abdominal surgery and their effect on in vitro human mesothelial cell proliferation.

BACKGROUND: Increased transforming growth factor-beta (TGF-beta) levels are associated with fibrosis, affected cell proliferation, and postsurgical adhesion development, but the knowledge regarding TGF-beta response to the surgical trauma is limited. This study investigated TGF-beta(1-3) isoforms and fibrinolytical factors in peritoneal serosal fluid during abdominal surgery, together with the in vitro effect of TGF-beta(1-3) on human mesothelial cell proliferation. MATERIALS AND METHODS: Total as well as biologically active TGF-beta(1-3) and fibrinolytic factors: t-PA, uPA, and PAI-1 were measured in serosal fluid and plasma from 23 patients undergoing colorectal cancer surgery. In vitro proliferation of human primary mesothelial cell cultures upon TGF-beta(1-3) stimulation was also investigated. RESULTS: Total TGF-beta1 and TGF-beta2 levels were similar in serosal fluid and plasma while active fractions were increased in serosal fluid. In contrast, total fraction of TGF-beta3 was higher in serosal fluid compared with plasma, while levels of active fractions did not differ. Plasminogen activators (t-PA, uPA) were elevated while the inhibitor (PAI-1) was decreased in serosal fluid compared with plasma. The in vitro mesothelial cell proliferation studies revealed that high TGF-beta(1-3) concentrations decreased cell proliferation, while lower concentrations of TGF-beta1 increased mesothelial cell proliferation. CONCLUSIONS: This human study shows increased active TGF-beta levels in peritoneal serosal fluid, compared with plasma, during abdominal surgery and that TGF-beta1 at physiological concentrations increased human mesothelial cell proliferation in vitro. TGF-beta cytokines may be involved in postsurgical adhesion formation.

Alterations in circulating activin A, GDF-15, TGF-beta3 and MMP-2, -3, and -9 during one year of left ventricular reverse remodelling in patients operated for severe aortic stenosis.

BACKGROUND: Patients with aortic stenosis (AS) develop left ventricular remodelling with cardiomyocyte hypertrophy and increased fibrosis. Following aortic valve replacement (AVR) reverse remodelling usually takes place. AIMS: To examine circulating levels of members of the transforming growth factor (TGF) beta superfamily and matrix metalloproteinases (MMP), known to have important effects on hypertrophy and extracellular matrix, in patients operated for AS. METHODS: Circulating levels of activin A, GDF-15, TGF-beta3, MMP-2, -3, and -9 were measured in twenty-two patients undergoing AVR preoperatively, and 2 days, six months and 12 months postoperatively. Echocardiography and a six minute walking test evaluated reverse remodelling and physical performance. RESULTS: Activin A increased at six (1081.00+/-98.05 pg/ml, p<0.05) and twelve months (1263.09+/-141.43 pg/ml, p<0.05) compared to the preoperative value (855.00+/-76.30 pg/ml) and correlated negatively to physical performance. The preoperative value was also increased compared to controls (639.54+/-63.05 pg/ml, p<0.05). GDF-15, MMP-3 and -9 were all increased at two days postoperatively (p<0.05). MMP-3 correlated with left ventricular end diastolic dimension (p<0.05). MMP-2 did not change during the study period. TGF-beta3 was only slightly reduced at six months postoperatively. CONCLUSION: The observed alteration in circulating levels of members of the TGF-beta superfamily and MMPs might play a role in the reverse remodelling process following AVR for AS.

Transforming growth factor-beta in the brain enhances fat oxidation via noradrenergic neurons in the ventromedial and paraventricular hypothalamic nucleus.

We have previously reported that intracisternal administration of TGF-beta induces an increase in fat oxidation and that intracisternal administration of anti-TGF-beta antibody partially inhibits an increase in fat oxidation during treadmill running in rats. These results indicate a regulatory role of that TGF-beta in the brain on fat oxidation during exercise. However, it is not clear how TGF-beta in the brain enhance fat oxidation. We hypothesized that TGF-beta in the brain elicits its regulatory effects on fat oxidation via hypothalamic noradrenergic neurons, because some reports have demonstrated the important role of hypothalamic noradrenergic neurons in the regulation of fat oxidation during and after exercise. To examine this hypothesis, we measured the extracellular noradrenaline (NA) levels in the paraventricular hypothalamic nucleus (PVH), ventromedial hypothalamic nucleus (VMH) and lateral hypothalamic area, which are especially important in the regulation of energy metabolism, after intracisternal administration of TGF-beta by using an in vivo brain microdialysis. Microdialysis study revealed that intracisternal administration of TGF-beta3 caused increases in the NA levels in the PVH and VMH. Then, we investigated the impact of impairment of noradrenergic neurons in the PVH and VMH by neurotoxin 6-hydroxydopamine microinjection (NA-lesion) on the action of intracisternal administration of TGF-beta. The NA lesion completely abolished the regulatory effect of TGF-beta on fat oxidation. These results suggest that TGF-beta in the brain enhances fat oxidation via noradrenergic neurons in the PVH and VMH.

Testosterone treatment promotes tubular damage in experimental diabetes in prepubertal rats.

Puberty unmasks or accelerates progressive kidney diseases, including diabetes mellitus (DM), perhaps through effects of sex steroids. To test the hypothesis that rising androgen levels at puberty permit diabetic kidney damage, we studied four groups of male rats with and without streptozocin-induced DM: adult onset (A), adult onset after castration (AC), juvenile onset (J), and juvenile onset with testosterone treatment (JT). Profibrotic markers were measured after 6 wk with blood glucose levels 300-450 mg/dl. JT permitted increased expression of mRNA for two isoforms of transforming growth factor-beta and connective tissue growth factor compared with J animals with DM; prior castration did not provide protection in adult-onset DM. JT also permitted greater tubular staining for alpha-smooth muscle actin and fibroblast-specific protein, two markers of cell damage and potential epithelial mesenchymal transition. Once again, castration was not protective for these effects of DM in the AC group. These data indicate that puberty permits detrimental effects in the tubulointerstitium in the diabetic kidney, an effect mimicked by testosterone treatment of juvenile animals and partially blunted by castration of adults, but damage does not correlate with testosterone levels, suggesting a less direct mechanism.