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Growth differentiation factor 11 (GDF11) has been implicated in the regulation of islet development and a variety of aging conditions, but little is known about the physiological functions of GDF11 in adult pancreatic islets. Here, we showed that systematic replenishment of GDF11 not only preserved insulin secretion but also improved the survival and morphology of β-cells and improved glucose metabolism in both nongenetic and genetic mouse models of type 2 diabetes (T2D). Conversely, anti-GDF11 monoclonal antibody treatment caused β-cell failure and lethal T2D. In vitro treatment of isolated murine islets and MIN6 cells with recombinant GDF11 attenuated glucotoxicity-induced β-cell dysfunction and apoptosis. Mechanistically, the GDF11-mediated protective effects could be attributed to the activation of transforming growth factor-β/Smad2 and phosphatidylinositol-4,5-bisphosphate 3-kinase-AKT-FoxO1 signaling. These findings suggest that GDF11 repletion may improve β-cell function and mass and thus may lead to a new therapeutic approach for T2D.

Using a mouse model of multiple sclerosis (MS), experimental autoimmune encephalitis (EAE), we evaluated the role of gut microbiota in modulating chronic-progressive (CP) versus relapse-remitting (RR) forms of the disease. We hypothesized that clinical courses of EAE may be shaped by differential gut microbiota. Metagenomic sequencing of prokaryotic 16S rRNA present in feces from naïve mice and those exhibiting CP-EAE or RR-EAE revealed significantly diverse microbial populations. Microbiota composition was considerably different between naïve strains of mice, suggesting microbial components present in homeostatic conditions may prime mice for divergent courses of disease. Additionally, there were differentially abundant bacteria in CP and RR forms of EAE, indicating a potential role for gut microbiota in shaping tolerant or remittance-favoring, and pathogenic or pro-inflammatory-promoting conditions. Furthermore, immunization to induce EAE led to significant alterations in gut microbiota, some were shared between disease courses and others were course-specific, supporting a role for gut microbial composition in EAE pathogenesis. Moreover, using Linear Discriminant Analysis (LDA) coupled with effect size measurement (LEfSe) to analyze microbial content, biomarkers of each naïve and disease states were identified. Our findings demonstrate for the first time that gut microbiota may determine the susceptibility to CP or RR forms of EAE.

Purpose: Approximately 10% of patients with mismatch repair-proficient (MMRp) colorectal cancer showed clinical benefit to anti-PD-1 monotherapy (NCT01876511). We sought to identify biomarkers that delineate patients with immunoreactive colorectal cancer and to explore new combinatorial immunotherapy strategies that can impact MMRp colorectal cancer. Experimental Design: We compared the expression of 44 selected immune-related genes in the primary colon tumor of 19 patients with metastatic colorectal cancer (mCRC) who responded (n ¼ 13) versus those who did not (n ¼ 6) to anti-PD-1 therapy (NCT01876511). We define a 10 gene-based immune signature that could distinguish responder from nonresponder. Resected colon specimens (n ¼ 14) were used to validate the association of the predicted status (responder and nonresponder) with the immune-related gene expression, the phenotype, and the function of tumor-infiltrating lymphocytes freshly isolated from the same tumors. Results: Although both IL17 Low and IL17 High immunoreactive MMRp colorectal cancers are associated with intratumor correlates of adaptive immunosuppression (CD8/ IFNg and PD-L1/IDO1 colocalization), only IL17 Low MMRp tumors (3/14) have a tumor immune microenvironment (TiME) that resembles the TiME in primary colon tumors of patients with mCRC responsive to anti-PD-1 treatment. Conclusions: The detection of a preexisting antitumor immune response in MMRp colorectal cancer (immunoreactive MMRp colorectal cancer) is not sufficient to predict a clinical benefit to T-cell checkpoint inhibitors. Intratumoral IL17-mediated signaling may preclude responses to immunotherapy. Drugs targeting the IL17 signaling pathway are available in clinic, and their combination with T-cell checkpoint inhibitors could improve colorectal cancer immunotherapy. See related commentary by Willis et al., p. 5185

Based on the results that activation in the PTSD patients in the presence of negative distractors increased in the emotion-related brain regions but decreased in the working memory-related brain regions, we may conclude that the neural basis of working memory is impaired by negative emotion in PTSD patients.

Background Similar to other local therapeutic methods, local interstitial radiotherapy (IRT) also suffers from insufficient systematic immune activation, resulting in tumor metastasis. Results Mn-based IRT radiosensitizers consisting of 131I, MnO2 and bovine serum albumin (BSA) (131I-MnO2-BSA) were engineered. Such Mn-based IRT radiosensitizers successfully unlocked radiogenetics to magnify systematic immune responses of local IRT via remodeling hypoxic and immunosuppressive microenvironments and resist tumor metastasis. The MnO2 in 131I-MnO2-BSA caused decomposition of H2O2 enriched in tumors to generate O2 for alleviating hypoxic microenvironment and removing tumor resistances to IRT. Concurrently, hypoxia mitigation by such radiosensitizers-unlocked radiogenetics can effectively remodel immunosuppressive microenvironment associated with regulatory T (Treg) cells and tumor-associated macrophages (TAMs) infiltration inhibition to induce immunogenic cell death (ICD), which, along with hypoxia mitigation, activates systematic immune responses. More intriguingly, 131I-MnO2-BSA-enabled radiogenetics can upregulate PD-L1 expression, which allows anti-PD-L1-combined therapy to exert a robust antitumor effect on primary tumors and elicit memory effects to suppress metastatic tumors in both tumor models (4T1 and CT26). Conclusions IRT radiosensitizer-unlocked radiogenetics and the corresponding design principle provide a general pathway to address the insufficient systematic immune responses of local IRT. Graphical Abstract

Background Although men presenting with clinically localized prostate cancer (PrCA) often are treated with radical prostatectomy or radiation therapy with curative intent, about 25–40% develop biochemically recurrent PrCA within 5 years of treatment, which has no known cure. Studies suggest that carotenoid and tocopherol intake may be associated with PrCA risk and progression. We examined plasma carotenoid and tocopherol levels in relation to prostate-specific antigen (PSA) levels among men with PSA-defined biochemical recurrence of PrCA. Methods Data analyzed were from a 6-month diet, physical activity and stress-reduction intervention trial conducted in South Carolina among biochemically recurrent PrCA patients (n=39). Plasma carotenoids and tocopherol levels were measured using high-performance liquid chromatography (HPLC). Linear regression was used to estimate least-square means comparing PSA levels of men with high versus low carotenoid/tocopherol levels, adjusting for covariates. Results After adjusting for baseline PSA level, plasma cis-lutein/zeaxanthin level at 3 months was related inversely to PSA level at 3 months (P=0.0008), while α-tocopherol (P=0.01), β-cryptoxanthin (P=0.01), and all-trans-lycopene (P=0.004) levels at 3 months were related inversely to PSA levels at 6-months. Percent increase in α-tocopherol and trans-β-carotene levels from baseline to month 3 were associated with lower PSA levels at 3 and 6 months. Percent increase in β−cryptoxanthin, cislutein/zeaxanthin and all-trans-lycopene were associated with lower PSA levels at 6 months only. Conclusions Certain plasma carotenoids and tocopherols were related inversely to PSA levels at various timepoints, suggesting that greater intake of foods containing these micronutrients might be beneficial to men with PSA-defined PrCA recurrence.