ACOD1 deficiency offers protection in a mouse model of diet-induced obesity by maintaining a healthy gut microbiota.

Aconitate decarboxylase 1 (ACOD1) is the enzyme synthesizing itaconate, an immuno-regulatory metabolite tuning host-pathogen interactions. Such functions are achieved by affecting metabolic pathways regulating inflammation and microbe survival. However, at the whole-body level, metabolic roles of itaconate remain largely unresolved. By using multiomics-integrated approaches, here we show that ACOD1 responds to high-fat diet consumption in mice by promoting gut microbiota alterations supporting metabolic disease. Genetic disruption of itaconate biosynthesis protects mice against obesity, alterations in glucose homeostasis and liver metabolic dysfunctions by decreasing meta-inflammatory responses to dietary lipid overload. Mechanistically, fecal metagenomics and microbiota transplantation experiments demonstrate such effects are dependent on an amelioration of the intestinal ecosystem composition, skewed by high-fat diet feeding towards obesogenic phenotype. In particular, unbiased fecal microbiota profiling and axenic culture experiments point towards a primary role for itaconate in inhibiting growth of Bacteroidaceae and Bacteroides, family and genus of Bacteroidetes phylum, the major gut microbial taxon associated with metabolic health. Specularly to the effects imposed by Acod1 deficiency on fecal microbiota, oral itaconate consumption enhances diet-induced gut dysbiosis and associated obesogenic responses in mice. Unveiling an unrecognized role of itaconate, either endogenously produced or exogenously administered, in supporting microbiota alterations underlying diet-induced obesity in mice, our study points ACOD1 as a target against inflammatory consequences of overnutrition.

Pyruvate transamination and NAD biosynthesis enable proliferation of succinate dehydrogenase-deficient cells by supporting aerobic glycolysis.

Succinate dehydrogenase (SDH) is the mitochondrial enzyme converting succinate to fumarate in the tricarboxylic acid (TCA) cycle. SDH acts as a tumor suppressor with germline loss-of-function mutations in its encoding genes predisposing to aggressive familial neuroendocrine and renal cancer syndromes. Lack of SDH activity disrupts the TCA cycle, imposes Warburg-like bioenergetic features, and commits cells to rely on pyruvate carboxylation for anabolic needs. However, the spectrum of metabolic adaptations enabling SDH-deficient tumors to cope with a dysfunctional TCA cycle remains largely unresolved. By using previously characterized Sdhb-deleted kidney mouse cells, here we found that SDH deficiency commits cells to rely on mitochondrial glutamate-pyruvate transaminase (GPT2) activity for proliferation. We showed that GPT2-dependent alanine biosynthesis is crucial to sustain reductive carboxylation of glutamine, thereby circumventing the TCA cycle truncation determined by SDH loss. By driving the reductive TCA cycle anaplerosis, GPT2 activity fuels a metabolic circuit maintaining a favorable intracellular NAD+ pool to enable glycolysis, thus meeting the energetic demands of SDH-deficient cells. As a metabolic syllogism, SDH deficiency confers sensitivity to NAD+ depletion achieved by pharmacological inhibition of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme of the NAD+ salvage pathway. Beyond identifying an epistatic functional relationship between two metabolic genes in the control of SDH-deficient cell fitness, this study disclosed a metabolic strategy to increase the sensitivity of tumors to interventions limiting NAD availability.

SKP2 drives the sensitivity to neddylation inhibitors and cisplatin in malignant pleural mesothelioma.

BACKGROUND: The combination of pemetrexed and cisplatin remains the reference first-line systemic therapy for malignant pleural mesothelioma (MPM). Its activity is moderate because of tumor aggressiveness, immune-suppressive environment and resistance to chemotherapy-induced immunogenic cell death (ICD). Preliminary and limited findings suggest that MPM cells have deregulated ubiquitination and proteasome activities, although proteasome inhibitors achieved disappointing clinical results. METHODS: Here, we investigated the role of the E3-ubiquitin ligase SKP/Cullin/F-box (SCF) complex in cell cycle progression, endoplasmic reticulum (ER)/proteostatic stress and ICD in MPM, and the therapeutic potential of the neddylation/SCF complex inhibitor MLN4924/Pevonedistat. RESULTS: In patient-derived MPM cultures and syngenic murine models, MLN4924 and cisplatin showed anti-tumor effects, regardless of MPM histotype and BAP1 mutational status, increasing DNA damage, inducing S- and G2/M-cell cycle arrest, and apoptosis. Mechanistically, by interfering with the neddylation of cullin-1 and ubiquitin-conjugating enzyme UBE2M, MLN4924 blocks the SCF complex activity and triggers an ER stress-dependent ICD, which activated anti-MPM CD8+T-lymphocytes. The SKP2 component of SCF complex was identified as the main driver of sensitivity to MLN4924 and resistance to cisplatin. These findings were confirmed in a retrospective MPM patient series, where SKP2 high levels were associated with a worse response to platinum-based therapy and inferior survival. CONCLUSIONS: We suggest that the combination of neddylation inhibitors and cisplatin could be worth of further investigation in the clinical setting for MPM unresponsive to cisplatin. We also propose SKP2 as a new stratification marker to determine the sensitivity to cisplatin and drugs interfering with ubiquitination/proteasome systems in MPM.

Short-term outcomes with the Ajust™ system: a new single incision sling for the treatment of stress urinary incontinence.

INTRODUCTION AND HYPOTHESIS: To evaluate the efficacy and safety of the minimally invasive Ajust™ system in the treatment of stress urinary incontinence. METHODS: This was a prospective multicentre study. All patients with primary urodynamic stress urinary incontinence were prospectively selected to receive the Ajust™ procedure. The International Consultation on Incontinence-Short Form (ICI-SF), Women Irritative Prostate Symptoms Score (W-IPSS), PGI-S, and PGI-I questionnaires were used to evaluate the impact of incontinence and voiding dysfunction on QoL and to measure patient's perception of incontinence severity and improvement. RESULTS: From January 2009 to October 2009, 111 consecutive subjects were enrolled in the study. At 6 months, 102 were available for outcomes analysis. The subjective and objective cure rates were 85.7% and 91.4%, respectively. The ICI-SF and W-IPSS questionnaires showed a statistical significant improvement in symptom scores. CONCLUSIONS: In the short-term follow-up, the Ajust™ system was effective in restoring continence in more than 85% of subjects with a highly significant improvement in QoL.

D-mannose suppresses macrophage IL-1ß production.

D-mannose is a monosaccharide approximately a hundred times less abundant than glucose in human blood. Previous studies demonstrated that supraphysiological levels of D-mannose inhibit tumour growth and stimulate regulatory T cell differentiation. It is not known whether D-mannose metabolism affects the function of non-proliferative cells, such as inflammatory macrophages. Here, we show that D-mannose suppresses LPS-induced macrophage activation by impairing IL-1ß production. In vivo, mannose administration improves survival in a mouse model of LPS-induced endotoxemia as well as decreases progression in a mouse model of DSS-induced colitis. Phosphomannose isomerase controls response of LPS-activated macrophages to D-mannose, which impairs glucose metabolism by raising intracellular mannose-6-phosphate levels. Such alterations result in the suppression of succinate-mediated HIF-1α activation, imposing a consequent reduction of LPS-induced Il1b expression. Disclosing an unrecognized metabolic hijack of macrophage activation, our study points towards safe D-mannose utilization as an effective intervention against inflammatory conditions.

The Transcriptional Regulator Sin3A Contributes to the Oncogenic Potential of STAT3.

Epigenetic silencing of promoter and enhancer regions is a common phenomenon in malignant cells. The transcription factor STAT3 is aberrantly activated in several tumors, where its constitutive acetylation accounts for the transcriptional repression of a number of tumor suppressor genes (TSG) via molecular mechanisms that remain to be understood. Using nucleophosmin-anaplastic lymphoma kinase-positive (NPM-ALK+) anaplastic large-cell lymphoma (ALCL) as model system, we found in cells and patient-derived tumor xenografts that STAT3 is constitutively acetylated as a result of ALK activity. STAT3 acetylation relied on intact ALK-induced PI3K- and mTORC1-dependent signaling and was sensitive to resveratrol. Resveratrol lowered STAT3 acetylation, rescued TSG expression, and induced ALCL apoptotic cell death. STAT3 constitutively bound the Sin3A transcriptional repressor complex, and both STAT3 and Sin3A bound the promoter region of silenced TSG via a resveratrol-sensitive mechanism. Silencing SIN3A caused reexpression of TSG, induced ALCL apoptotic cell death in vitro, and hindered ALCL tumorigenic potential in vivo. A constitutive STAT3-Sin3A interaction was also found in breast adenocarcinoma cells and proved critical for TSG silencing and cell survival. Collectively, these results suggest that oncogene-driven STAT3 acetylation and its constitutive association with Sin3A represent novel and concomitant events contributing to STAT3 oncogenic potential. SIGNIFICANCE: This study delineates the transcriptional regulatory complex Sin3A as a mediator of STAT3 transcriptional repressor activity and identifies the STAT3/Sin3A axis as a druggable target to antagonize STAT3-addicted tumors. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/12/3076/F1.large.jpg.See related commentary by Monteleone and Poli, p. 3031.

Loss of C/EBP-ß LIP drives cisplatin resistance in malignant pleural mesothelioma.

OBJECTIVES: Cisplatin-based chemotherapy is moderately active in malignant pleural mesothelioma (MPM) due to intrinsic drug resistance and to low immunogenicity of MPM cells. CAAT/enhancer binding protein (C/EBP)-ß LIP is a pro-apoptotic and chemosensitizing transcription factor activated in response to endoplasmic reticulum (ER) stress. MATERIALS AND METHODS: We investigated if LIP levels can predict the clinical response to cisplatin and survival of MPM patients receiving cisplatin-based chemotherapy. We studied the LIP-dependent mechanisms determining cisplatin-resistance and we identified pharmacological approaches targeting LIP, able to restore cisplatin sensitiveness, in patient-derived MPM cells and animal models. Results were analyzed by a one-way analysis of variance test. RESULTS: We found that LIP was degraded by constitutive ubiquitination in primary MPM cells derived from patients poorly responsive to cisplatin. LIP ubiquitination was directly correlated with cisplatin chemosensitivity and was associated with patients' survival after chemotherapy. Overexpression of LIP restored cisplatin's pro-apoptotic effect by activating CHOP/TRB3/caspase 3 axis and up-regulating calreticulin, that triggered MPM cell phagocytosis by dendritic cells and expanded autologous anti-tumor CD8+CD107+T-cytotoxic lymphocytes. Proteasome inhibitor carfilzomib and lysosome inhibitor chloroquine prevented LIP degradation. The triple combination of carfilzomib, chloroquine and cisplatin increased ER stress-triggered apoptosis and immunogenic cell death in patients' samples, and reduced tumor growth in cisplatin-resistant MPM preclinical models. CONCLUSION: The loss of LIP mediates cisplatin resistance, rendering LIP a possible predictor of cisplatin response in MPM patients. The association of proteasome and lysosome inhibitors reverses cisplatin resistance by restoring LIP levels and may represent a new adjuvant strategy in MPM treatment.

ß3-Adrenoreceptors Control Mitochondrial Dormancy in Melanoma and Embryonic Stem Cells.

The early phases of embryonic development and cancer share similar strategies to improve their survival in an inhospitable environment: both proliferate in a hypoxic and catecholamine-rich context, increasing aerobic glycolysis. Recent studies show that ß3-adrenergic receptor (ß3-AR) is involved in tumor progression, playing an important role in metastasis. Among ß-adrenergic receptors, ß3-AR is the last identified member of this family, and it is involved in cancer cell survival and induction of stromal reactivity in the tumor microenvironment. ß3-AR is well known as a strong activator of uncoupling protein 1 (UCP1) in brown fat tissue. Interestingly, ß3-AR is strongly expressed in early embryo development and in many cancer tissues. Induction of uncoupling protein 2 (UCP2) has been related to cancer metabolic switch, leading to accelerated glycolysis and reduced mitochondrial activity. In this study, for the first time, we demonstrate that ß3-AR is able to promote this metabolic shift in both cancer and embryonic stem cells, inducing specific glycolytic cytoplasmic enzymes and a sort of mitochondrial dormancy through the induction of UCP2. The ß3-AR/UCP2 axis induces a strong reduction of mitochondrial activity by reducing ATP synthesis and mitochondrial reactive oxygen species (mtROS) content. These effects are reverted by SR59230A, the specific ß3-AR antagonist, causing an increase in mtROS. The increased level of mtROS is neutralized by a strong antioxidant activity in embryonic stem cells, but not in cancer stem cells, where it causes a dramatic reduction in tumor cell viability. These results lead to the possibility of a selective antitumor therapeutic use of SR59230A. Notably, we demonstrate the presence of ß3-AR within the mitochondrial membrane in both cell lines, leading to the control of mitochondrial dormancy.

TVT-secur: a minimally invasive procedure for the treatment of primary stress urinary incontinence. One year data from a multi-centre prospective trial.

The objective of this study is to evaluate the efficacy and morbidity of the new minimally invasive TVT-secur procedure. This was a prospective multi-centre trial. All patients with primary urodynamic stress urinary incontinence were prospectively selected to receive the TVT-secur procedure. The International Consultation on Incontinence-Short Form (ICIQ-SF), Women Irritative Prostate Symptoms Score (W-IPSS), Patient Global Impression of Severity (PGI-S) and Patient Global Impression of Improvement (PGI-I) questionnaires were used to evaluate the impact of incontinence and voiding dysfunction on quality of life (QoL) and to measure patient's perception of incontinence severity and improvement. The SPSS software was used for data analysis. From November 2006 to September 2007, 95 consecutive patients were enrolled in the study. At 1 year, 91 patients were available for the analysis. The subjective and objective cure rates were 78% and 81%, respectively. The ICIQ-SF and W-IPSS symptoms score showed a statistically significant decrease. Post-operative complications included voiding difficulty, recurrent UTI, de novo urgency incontinence and dyspareunia. Our data show that TVT-secur is associated with an 80% success rate at 1 year.

Chemically assisted dissection of tissues in laparoscopic excision of endometriotic cysts.

STUDY OBJECTIVE: To evaluate the capacity of chemical dissection of tissues using a mucolytic substance, Mesna, in improving laparoscopic excision of endometriotic cysts. DESIGN: Randomized, double-blind, controlled trial (Canadian Task Force classification I). SETTING: University-affiliated training hospital. PATIENTS: Forty-four women with symptomatic ovarian endometriotic cysts. Intervention. Laparoscopic excision of endometriotic cysts in 22 women with the aid of Mesna solution and in 22 with the aid of saline solution. MEASUREMENTS AND MAIN RESULTS: In comparison with saline solution, Mesna as a chemical dissector resulted in significant reductions in operating time, in difficulty encountered by the surgeon to enucleate the cysts, and in less bleeding. No differences were found in length of hospital stay, costs of surgeries, analgesic requirement, and fever. Postoperatively, patients treated with Mesna achieved more pregnancies than those treated with saline. CONCLUSION: Chemical dissection of tissues with Mesna proved to be a safe and suitable support in laparoscopic surgery for ovarian endometriotic cysts.