A novel inhibitor of the mitochondrial respiratory complex I with uncoupling properties exerts potent antitumor activity.

Cancer cells are highly dependent on bioenergetic processes to support their growth and survival. Disruption of metabolic pathways, particularly by targeting the mitochondrial electron transport chain complexes (ETC-I to V) has become an attractive therapeutic strategy. As a result, the search for clinically effective new respiratory chain inhibitors with minimized adverse effects is a major goal. Here, we characterize a new OXPHOS inhibitor compound called MS-L6, which behaves as an inhibitor of ETC-I, combining inhibition of NADH oxidation and uncoupling effect. MS-L6 is effective on both intact and sub-mitochondrial particles, indicating that its efficacy does not depend on its accumulation within the mitochondria. MS-L6 reduces ATP synthesis and induces a metabolic shift with increased glucose consumption and lactate production in cancer cell lines. MS-L6 either dose-dependently inhibits cell proliferation or induces cell death in a variety of cancer cell lines, including B-cell and T-cell lymphomas as well as pediatric sarcoma. Ectopic expression of Saccharomyces cerevisiae NADH dehydrogenase (NDI-1) partially restores the viability of B-lymphoma cells treated with MS-L6, demonstrating that the inhibition of NADH oxidation is functionally linked to its cytotoxic effect. Furthermore, MS-L6 administration induces robust inhibition of lymphoma tumor growth in two murine xenograft models without toxicity. Thus, our data present MS-L6 as an inhibitor of OXPHOS, with a dual mechanism of action on the respiratory chain and with potent antitumor properties in preclinical models, positioning it as the pioneering member of a promising drug class to be evaluated for cancer therapy. MS-L6 exerts dual mitochondrial effects: ETC-I inhibition and uncoupling of OXPHOS. In cancer cells, MS-L6 inhibited ETC-I at least 5 times more than in isolated rat hepatocytes. These mitochondrial effects lead to energy collapse in cancer cells, resulting in proliferation arrest and cell death. In contrast, hepatocytes which completely and rapidly inactivated this molecule, restored their energy status and survived exposure to MS-L6 without apparent toxicity.

Reduced lactic acidosis risk with Imeglimin: Comparison with Metformin.

The global prevalence of type 2 diabetes (T2D) is expected to exceed 642 million people by 2040. Metformin is a widely used biguanide T2D therapy, associated with rare but serious events of lactic acidosis, in particular with predisposing conditions (e.g., renal failure or major surgery). Imeglimin, a recently approved drug, is the first in a new class (novel mode of action) of T2D medicines. Although not a biguanide, Imeglimin shares a chemical moiety with Metformin and also modulates mitochondrial complex I activity, a potential mechanism for Metformin-mediated lactate accumulation. We interrogated the potential for Imeglimin to induce lacticacidosis in relevant animal models and further assessed differences in key mechanisms known for Metformin's effects. In a dog model of major surgery, Metformin or Imeglimin (30-1000 mg/kg) was acutely administered, only Metformin-induced lactate accumulation and pH decrease leading to lactic acidosis with fatality at the highest dose. Rats with gentamycin-induced renal insufficiency received Metformin or Imeglimin (50-100 mg/kg/h), only Metformin increased lactatemia and H+ concentrations with mortality at higher doses. Plasma levels of Metformin and Imeglimin were similar in both models. Mice were chronically treated with Metformin or Imeglimin 200 mg/kg bid. Only Metformin produced hyperlactatemia after acute intraperitoneal glucose loading. Ex vivo measurements revealed higher mitochondrial complex I inhibition with Metformin versus slight effects with Imeglimin. Another mechanism implicated in Metformin's effects on lactate production was assessed: in isolated rat, liver mitochondria exposed to Imeglimin or Metformin, only Metformin (50-250 µM) inhibited the mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH). In liver samples from chronically treated mice, measured mGPDH activity was lower with Metformin versus Imeglimin. These data indicate that the risk of lactic acidosis with Imeglimin treatment may be lower than with Metformin and confirm that the underlying mechanisms of action are distinct, supporting its potential utility for patients with predisposing conditions.

Regulation of citrulline synthesis in human enterocytes: Role of hypoxia and inflammation.

Intensive care unit patients and chronic airway inflammatory disease are characterized by chronic systemic hypoxia and inflammation inducing a decrease in nitric oxide release due to impaired l-arginine (ARG) homeostasis. As ARG is synthesized from circulating l-citrulline (CIT), an alteration of CIT production in small intestine by ornithine carbamoyltransferase could be involved. Here, we posit that hypoxia and/or inflammation has effects on ornithine carbamoyltransferase regulation in enterocytes. A duodenal explant incubation model was used. Biopsy specimens taken from 25 selected patients were incubated for 6 h in 4 groups: control, inflammation, hypoxia, and hypoxia + inflammation. At the end of the incubation period, we measured CIT concentration in culture media, ornithine carbamoyltransferase activity, ornithine carbamoyltransferase protein and gene expression, protein expression of enzymes involved in the CIT production pathway, and expression of energy status proteins. Inflammation and/or hypoxia conditions did not affect CIT production. Ornithine carbamoyltransferase activity was increased in hypoxia conditions (p = 0.023). Expression of enzymes implicated in the CIT crossroads pathway and enzymes reflecting energy status variation was not affected by inflammation and hypoxia. Data sets were pooled to evaluate the variability of the four quartiles for each parameter. CIT production was found to increase over the quartiles whereas other parameters remained stable. Our results showed that intestinal CIT production is preserved during inflammation and/or hypoxia, thus confirming the significance of this metabolic pathway. This suggests that the CIT deficiency observed in clinical hypercatabolic states could be a consequence of high utilization for ARG synthesis.

The mitochondrially-localized nucleoside diphosphate kinase D (NME4) is a novel metastasis suppressor.

BACKGROUND: Mitochondrial nucleoside diphosphate kinase (NDPK-D, NME4, NM23-H4) is a multifunctional enzyme mainly localized in the intermembrane space, bound to the inner membrane. RESULTS: We constructed loss-of-function mutants of NDPK-D, lacking either NDP kinase activity or membrane interaction and expressed mutants or wild-type protein in cancer cells. In a complementary approach, we performed depletion of NDPK-D by RNA interference. Both loss-of-function mutations and NDPK-D depletion promoted epithelial-mesenchymal transition and increased migratory and invasive potential. Immunocompromised mice developed more metastases when injected with cells expressing mutant NDPK-D as compared to wild-type. This metastatic reprogramming is a consequence of mitochondrial alterations, including fragmentation and loss of mitochondria, a metabolic switch from respiration to glycolysis, increased ROS generation, and further metabolic changes in mitochondria, all of which can trigger pro-metastatic protein expression and signaling cascades. In human cancer, NME4 expression is negatively associated with markers of epithelial-mesenchymal transition and tumor aggressiveness and a good prognosis factor for beneficial clinical outcome. CONCLUSIONS: These data demonstrate NME4 as a novel metastasis suppressor gene, the first localizing to mitochondria, pointing to a role of mitochondria in metastatic dissemination.

The mechanism by which imeglimin inhibits gluconeogenesis in rat liver cells.

Aims: To understand the mechanism by which imeglimin (a new oral hypoglycemic agent whose phase 3 development program in Japan has now been completed) decreases hepatic glucose production. Materials and methods: We compared the effect of imeglimin and metformin on glucose production, ATP/ADP ratio, oxygen consumption rate, mitochondrial redox potential and membrane potential in primary rat hepatocytes. Results: We found that both imeglimin and metformin dose-dependently decreased glucose production and the ATP/ADP ratio. Moreover, they both increased mitochondrial redox potential (assessed by mitochondrial NAD(P)H fluorescence) and decreased membrane potential (assessed by TMRM fluorescence). However, contrary to metformin, which inhibits mitochondrial Complex I, imeglimin did not decrease the oxygen consumption rate in intact cells. By measuring the oxygen consumption of in situ respiratory chain as a function of the concentration of NADH, we observed that imeglimin decreased the affinity of NADH for the respiratory chain but did not affect its Vmax (ie competitive inhibition) whereas metformin decreased both the Vmax and the affinity (ie uncompetitive inhibition). Conclusions: We conclude that imeglimin induces a kinetic constraint on the respiratory chain that does not affect its maximal activity. This kinetic constraint is offset by a decrease in the mitochondrial membrane potential, which induces a thermodynamic constraint on the ATPase responsible for a decrease in the ATP/ADP ratio.

The centenary of the Harris-Benedict equations: How to assess energy requirements best? Recommendations from the ESPEN expert group.

BACKGROUND & AIMS: The year 2019 marked the centenary of the publication of the Harris and Benedict equations for estimation of energy expenditure. In October 2019 a Scientific Symposium was organized by the European Society for Clinical Nutrition and Metabolism (ESPEN) in Vienna, Austria, to celebrate this historical landmark, looking at what is currently known about the estimation and measurement of energy expenditure. METHODS: Current evidence was discussed during the symposium, including the scientific basis and clinical knowledge, and is summarized here to assist with the estimation and measurement of energy requirements that later translate into energy prescription. RESULTS: In most clinical settings, the majority of predictive equations have low to moderate performance, with the best generally reaching an accuracy of no more than 70%, and often lead to large errors in estimating the true needs of patients. Generally speaking, the addition of body composition measurements did not add to the accuracy of predictive equations. Indirect calorimetry is the most reliable method to measure energy expenditure and guide energy prescription, but carries inherent limitations, greatly restricting its use in real life clinical practice. CONCLUSIONS: While the limitations of predictive equations are clear, their use is still the mainstay in clinical practice. It is imperative to recognize specific patient populations for whom a specific equation should be preferred. When available, the use of indirect calorimetry is advised in a variety of clinical settings, aiming to avoid under-as well as overfeeding.

Nutrition and physical activity: French intergroup clinical practice guidelines for diagnosis, treatment and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, AFC, SFP-APA, SFNCM, AFSOS).

This document is a summary of the French intergroup guidelines regarding the nutrition and physical activity (PA) management in digestive oncology. This collaborative work was produced under the auspices of all French medical and surgical societies involved in digestive oncology, nutrition and supportive care. It is based on published guidelines, recent literature review and expert opinions. Recommendations are graded according to the level of evidence. Malnutrition affects more than half of patients with digestive cancers and is often underdiagnosed. It has multiple negative consequences on survival, quality of life and risk of treatment complications. Consequently, in addition to anticancer treatments, supportive care including nutritional support and PA plays a central role in the management of digestive cancers. It is crucial to detect malnutrition (diagnostic criteria updated in 2019) early, to prevent it and to act against it at all stages of the cancer and at all times of the care pathway. In this context, we proposed recommendations for the evaluation and management in nutrition and PA in digestive oncology for each stage of the disease (perioperative setting, during radiation therapy, during systemic treatments, at the palliative phase, after cancer). Guidelines for nutrition and PA management aim at increasing awareness about malnutrition in oncology. They are continuously evolving and need to be regularly updated.

Citrulline stimulates muscle protein synthesis, by reallocating ATP consumption to muscle protein synthesis.

BACKGROUND: Animal studies and clinical data support the interest of citrulline as a promising therapeutic for sarcopenia. Citrulline is known to stimulate muscle protein synthesis, but how it affects energy metabolism to support the highly energy-dependent protein synthesis machinery is poorly understood. METHODS: Here, we used myotubes derived from primary culture of mouse myoblasts to study the effect of citrulline on both energy metabolism and protein synthesis under different limiting conditions. RESULTS: When serum/amino acid deficiency or energy stress (mild uncoupling) were applied, citrulline stimulated muscle protein synthesis by +22% and +11%, respectively. Importantly, this increase was not associated with enhanced energy status (ATP/ADP ratio) or mitochondrial respiration. We further analysed the share of mitochondrial respiration and thus of generated ATP allocated to different metabolic pathways by using specific inhibitors. Our results indicate that addition of citrulline allocated an increased share of mitochondrially generated ATP to the protein synthesis machinery under conditions of both serum/amino acid deficiency (+28%) and energy stress (+21%). This reallocation was not because of reduced ATP supply to DNA synthesis or activities of sodium and calcium cycling ion pumps. CONCLUSIONS: Under certain stress conditions, citrulline increases muscle protein synthesis by specifically reallocating mitochondrial fuel to the protein synthesis machinery. Because ATP/ADP ratios and thus Gibbs free energy of ATP hydrolysis remained globally constant, this reallocation may be linked to decreased activation energies of one or several ATP (and GTP)-consuming reactions involved in muscle protein synthesis.

Human mesenchymal stem cells improve rat islet functionality under cytokine stress with combined upregulation of heme oxygenase-1 and ferritin.

BACKGROUND: Islets of Langerhans transplantation is a promising therapy for type 1 diabetes mellitus, but this technique is compromised by transplantation stresses including inflammation. In other tissues, co-transplantation with mesenchymal stem cells has been shown to reduce damage by improving anti-inflammatory and anti-oxidant defences. Therefore, we probed the protection afforded by bone marrow mesenchymal stem cells to islets under pro-inflammatory cytokine stress. METHODS: In order to evaluate the cytoprotective potential of mesenchymal stem cells on rat islets, co-cultures were exposed to the interleukin-1, tumour necrosis factor α and interferon γ cocktail for 24 h. Islet viability and functionality tests were performed. Reactive oxygen species and malondialdehyde were measured. Expression of stress-inducible genes acting as anti-oxidants and detoxifiers, such as superoxide dismutases 1 and 2, NAD(P)H quinone oxidoreductase 1, heme oxygenase-1 and ferritin H, was compared to non-stressed cells, and the corresponding proteins were measured. Data were analysed by a two-way ANOVA followed by a Holm-Sidak post hoc analysis. RESULTS: Exposure of rat islets to cytokines induces a reduction in islet viability and functionality concomitant with an oxidative status shift with an increase of cytosolic ROS production. Mesenchymal stem cells did not significantly increase rat islet viability under exposure to cytokines but protected islets from the loss of insulin secretion. A drastic reduction of the antioxidant factors heme oxygenase-1 and ferritin H protein levels was observed in islets exposed to the cytokine cocktail with a prevention of this effect by the presence of mesenchymal stem cells. CONCLUSIONS: Our data evidenced that MSCs are able to preserve islet insulin secretion through a modulation of the oxidative imbalance mediated by heme and iron via heme oxygenase-1 and ferritin in a context of cytokine exposure.

Performing an early systematic Doppler-ultrasound fails to prevent hemorrhagic complications after complex partial nephrectomy.

BACKGROUND: The aim of this work was to assess the clinical relevance of a systematic postoperative Doppler-ultrasound (DU) after complex partial nephrectomy (PN). MATERIALS AND METHODS: All patients who underwent open, laparoscopic or robotic PN from 2014 to 2017 at our institution were included. Postoperative hemorrhagic complications (HCs) were defined as the occurrence of blood transfusion, hemorrhagic shock, arterial embolization, or re-hospitalization for hematoma. DU was systematically performed between post-op day 4 and 7 for every complex tumor (RENAL score ⩾ 7). DU was considered positive in the presence of pseudoaneurysm (PA) or arteriovenous fistula (AVF). RESULTS: Among 194 patients, 117 underwent DU (60.3%). We reported 22 HCs (11.3%) requiring 8 selective embolization procedures (4.1%). HCs occurred during the hospital stay in 17 patients (77.3%), thus directly diagnosed on a computed tomography scan. Among the five patients (22.7%) with HC occurring after hospital discharge, between day 7 to 15, four had a previously negative systematic DU. Overall, systematic DU was positive in only five patients (4.3%) with only one patient of 194 (0.5%) undergoing preventive embolization of a PA-AVF. The negative predictive values (NPVs) and positive predictive values of DU were respectively 96.5% and 5%, with 20% sensitivity and 96.5% specificity. CONCLUSIONS: Our results may suggest offering systematic DU in patients under antiplatelet therapies, with high tumor size (>T1b), or early postoperative hemoglobin variations. A high NPV of DU might be counterbalanced by its low sensibility. Since all secondary HCs occurred between postoperative day 7 to 15, our results may suggest differing DU in selected cases.

Impact of maternal low-level cadmium exposure on glucose and lipid metabolism of the litter at different ages after weaning.

Cadmium (Cd) is a metal which may participate in the development of type II diabetes even if Cd exposure levels are mild. However, experimental studies focusing on daily environmentally relevant doses are scarce, particularly for glucose metabolism of the offspring of chronically exposed mothers. The aim is to measure the impact of maternal low level Cd exposure on glucose and lipid metabolism of offspring. Female rats were exposed to 0, 50 or 500 µg.kg-1.d-1 of CdCl2, 21 days before mating and during 21 days of gestation and 21 days of lactation. Pups exposure was organized in 3 groups (control, Cd1, Cd2) according to renal dams' Cd burden. Parameters of glucose and lipid metabolisms were measured for the pups on post-natal day 21, 26 and 60. Maternal Cd exposure led to significant amounts of Cd in the liver and kidney of pups. At weaning, insulin secretion upon glucose stimulation was unchanged, but the removal of circulating glucose was slower for pups born from the lowest impregnated dams (Cd1). Five days after, glucose tolerance of all groups was identical. Thus, this loss of insulin sensitivity was reversed, in part by increased adiponectin secretion for the Cd1 group. Furthermore, pups from dams accumulating the highest levels of Cd (Cd2) exhibited a compensatory increased insulin pancreatic secretion, together with increased circulating non-esterified fatty acids, indicating the establishment of insulin resistance, 2 months after birth. This study has demonstrated the influence of maternal exposure to low levels of Cd on glucose homeostasis in the offspring that might increase the risk of developing type II diabetes later in life.

[Even the Warburg effect can be oxidized: metabolic cooperation and tumor development]. / Même l'effet Warburg est oxydable - Coopération métabolique et développement tumoral.

During tumor development, malignant cells rewire their metabolism to meet the biosynthetic needs required to increase their biomass and to overcome their microenvironment constraints. The sustained activation of aerobic glycolysis, also called Warburg effect, is one of these adaptative mechanisms. The progresses in this area of research have revealed the flexibility of cancer cells that alternate between glycolytic and oxidative metabolism to cope with their conditions of development while sharing their energetic resources. In this survey, we review these recent breakthroughs and discuss a model that likens tumor to an evolutive metabolic ecosystem. We further emphasize the ensuing therapeutic applications that target metabolic weaknesses of neoplastic cells.

New Automatized Method of 3D Multiculture Viability Analysis Based on Confocal Imagery: Application to Islets and Mesenchymal Stem Cells Co-Encapsulation.

Co-encapsulation of pancreatic islets with mesenchymal stem cells in a three-dimensional biomaterial's structure is a promising technique to improve transplantation efficacy and to decrease immunosuppressant therapy. Currently, evaluation of graft quality after co-encapsulation is only based on insulin secretion. Viability measurement in a 3D conformation structure involving two different cell types is complex, mainly performed manually, highly time consuming and examiner dependent. Standardization of encapsulated graft viability analysis before transplantation is a key point for the translation of the method from the bench side to clinical practice. In this study, we developed an automated analysis of islet viability based on confocal pictures processing of cells stained with three probes (Hoechst, propidium iodide, and PKH67). When compared with results obtained manually by different examiners, viability results show a high degree of similarity (under 3% of difference) and a tight correlation (r = 0.894; p < 0.001) between these two techniques. The automated technique offers the advantage of reducing the analysis time by 6 and avoids the examiner's dependent variability factor. Thus, we developed a new efficient tool to standardize the analysis of islet viability in 3D structure involving several cell types, which is a key element for encapsulated graft analysis in clinical practice.

Impact of chronic and low cadmium exposure of rats: sex specific disruption of glucose metabolism.

BACKGROUND: Several epidemiological and animal studies suggest a positive association between cadmium (Cd) exposure and incidence of type 2 diabetes, but the association remains controversial. Besides, the experimental data have mainly been obtained with relatively high levels of Cd, over various periods of time, and with artificial routes of administration. OBJECTIVES: Do environmental exposures to Cd induce significant disruption of glucose metabolism? METHODS: Adults Wistar rats were exposed for three months to 0, 5, 50 or 500 µg.kg-1.d-1 of CdCl2 in drinking water. Relevant parameters of glucose homeostasis were measured. RESULTS: Cd accumulated in plasma, kidney and liver of rats exposed to 50 and 500 µg.kg-1.d-1, without inducing signs of organ failure. In rats drinking 5 µg.kg-1.d-1 for 3 months, Cd exposure did not lead to any significant increase of Cd in these organs. At 50 and 500 µg.kg-1.d-1 of Cd, glucose and insulin tolerance were unchanged in both sexes. However, females exhibited a significant increase of both fasting and glucose-stimulated plasma insulin that was assigned to impaired hepatic insulin extraction as indicated by unaltered fasting C-peptide plasma levels. CONCLUSIONS: Glucose homeostasis is sensitive to chronic Cd exposure in a gender-specific way. Moreover, this study proves that an environmental pollutant such as Cd can have, at low concentrations, an impact on the glucose homeostatic system and it highlights the importance of a closer scrutiny of the underlying environmental causes to understand the increased incidence of type 2 diabetes.

Malnutrition and refeeding syndrome prevention in head and neck cancer patients: from theory to clinical application.

PURPOSE: The goal of this review is to raise awareness about refeeding syndrome (RFS) and to give a comprehensive presentation of recent guidelines and latest scientific data about nutritional management among head and neck cancer (HNC) patients while focusing on RFS prevention. METHODS: A review of literature for nutritional assessment and RFS management was conducted. Electronic searches of Medline, Cochrane, PubMed and Embase databases for articles published in peer-reviewed journals were conducted from February to September 2017 using the keywords: "nutrition assessment", "head and neck cancer", "refeeding syndrome" and "guidelines". Articles, reviews, book references as well as national and international guidelines in English and French were included. RESULTS: The prevalence of malnutrition is high in HNC patients and a large number of them will need artificial nutritional support or refeeding intervention. RFS is characterized by fluid and electrolyte imbalance associated with clinical manifestations induced by rapid refeeding after a period of malnutrition or starvation. Regarding risk factors for malnutrition and RFS, HNC patients are particularly vulnerable. However, RFS remains unrecognized among head and neck surgeons and medical teams. Practical data are summarized to help organizing nutritional assessment and refeeding interventions. It also summarizes preventive measures to reduce RFS incidence and morbidity in HNC population. CONCLUSION: Nutritional assessment and early refeeding interventions are crucial for HNC patients care. As prevention is the key for RFS management, early identification of patients with high risks is crucial and successful nutritional management requires a multidisciplinary approach.

Metformin-Induced Mitochondrial Complex I Inhibition: Facts, Uncertainties, and Consequences.

Metformin is the most widely prescribed drug to treat patients with type II diabetes, for whom retrospective studies suggest that metformin may have anticancer properties. However, in experiments performed with isolated cells, authors have reported both pro- and anti-apoptotic effects of metformin. The exact molecular mechanism of action of metformin remains partly unknown despite its use for over 60 years and more than 17,000 articles in PubMed. Among the various widely recognized or recently proposed targets, it has been reported consistently that metformin is capable of inhibiting mitochondrial respiratory chain Complex I. Since most of the effects of metformin have been replicated by other inhibitors of Complex I, it has been suggested that the mechanism of action of metformin involved the inhibition of Complex I. However, compared to conventional Complex I inhibitors, the metformin-induced inhibition of Complex I has unique characteristics. Among these, the most original one is that the concentrations of metformin required to inhibit Complex I are lower in intact cells than in isolated mitochondria. Experiments with isolated mitochondria or Complex I were generally performed using millimolar concentrations of metformin, while plasma levels remain in the micromolar range in both human and animal studies, highlighting that metformin concentration is an important issue. In order to explain the effects in animals based on observations in cells and mitochondria, some authors proposed a direct effect of the drug on Complex I involving an accumulation of metformin inside the mitochondria while others proposed an indirect effect (the drug no longer having to diffuse into the mitochondria). This brief review attempts to: gather arguments for and against each hypothesis concerning the mechanism by which metformin inhibits Complex I and to highlight remaining questions about the toxicity mechanism of metformin for certain cancer cells.

Pathological heterogeneity in sporadic synchronous renal tumors: Is the histological concordance predictable?

OBJECTIVE: To evaluate the pathological concordance rate of multiple synchronous renal masses (MSRM) presumed to be sporadic and to analyze predictive factors of concordance. MATERIAL AND METHODS: We identified from our institutional database patients with sporadic MSRM treated at our center between January 2000 and December 2015. All tumors were reviewed by a dedicated uropathologist. Pathological concordance rate was analyzed regarding clinical characteristics and preoperative imaging. RESULTS: We included 112 patients: 50 had unilateral synchronous renal masses and 62 bilateral synchronous renal masses. A total of 291 tumors were analyzed, with an average of 2.6 tumors per patient. Overall, the malignant concordance rate was 91.6%, the pathological concordance rate was 67.3% and the grade concordance rate was 62.5%. In univariate analysis, predictive factors of histological concordance were bilateral synchronous renal masses (odds ratio [OR] = 3.39; 95% CI: 1.06-10.8; P = 0.04), age<60 years (OR = 3.04; 95% CI: 1.2-7.7; P = 0.02) and ≥3 lesions (OR = 2.41; 95% CI: 1.03-5.68; P = 0.04). In multivariate analysis, age<60 remained significantly associated with histological concordance (OR = 3.84; 95% CI: 1.24-11.9; P = 0.02). CONCLUSIONS: The histological concordance rate of MSRM is low. Age at diagnosis <60 years, bilateral lesions and ≥3 tumors are predictive factors of histological concordance, but the pathological diagnosis remains difficult to predict. This heterogeneity is important to take into account, particularly when choosing the treatment upon the renal biopsy results from a single lesion.

Protection of PC12 cells from cocaine-induced cell death by inhibiting mitochondrial permeability transition.

Cocaine abuse induces brain injury and neurodegeneration by a mechanism that has not yet been fully elucidated. Mitochondria play a key role in cell death processes, notably through the opening of the permeability transition pore (PTP). In this work, we examined the involvement of the PTP in cocaine-induced toxicity in PC12 cell lines. We used two different PTP inhibitors -i.e. cyclosporin A (CsA) and metformin-to assess their ability to counteract the cocaine induced effects. We first observed that a 48 h exposure to cocaine strongly sensitized cells to calcium overload, as measured by the calcium retention capacity. CsA and metformin significantly decreased the cocaine-induced PTP opening sensitization. We next showed by confocal microscopy that cocaine induced a permanent PTP opening in intact living cells, a phenomenon characterized by the collapse of the mitochondrial membrane potential and the relocation of the NAD(P)H from the mitochondrial matrix to the cytosol. As expected, a cocaine-induced PTP opening was prevented by PTP inhibitors. Finally, a flow cytometry analysis revealed that cocaine induced cell death while CsA and metformin promoted cell survival. Our results demonstrate that cocaine induces PC12 cell death through a mechanism involving permanent PTP opening.

Prospective assessment and histological analysis of adherent perinephric fat in partial nephrectomies.

OBJECTIVES: The complexity of partial nephrectomy (PN) is partly anticipated by morphometric tumor-based scores that do not consider patient-related issues such as adherent perinephric fat (APF). Also, the objective is to prospectively assess the predictive factors of APF during PN, its effect on complications, and to correlate it to the histological reality. METHODS: A total of 125 consecutive patients undergoing robotic or open PN were prospectively included. The Mayo adhesive probability score (MAP score) was compared to the peroperative presence of APF defined by a score≥2. Adipose tissue was analyzed histologically for fibrosis and inflammatory infiltrate of CD68+macrophages. Univariate and multivariate logistic regression analyses were performed to evaluate predictive factors of APF, and outcomes were compared using chi-square and Kruskal-Wallis tests. RESULTS: APF was present in 51 patients (40.8%) and associated with slight longer operating time and increased blood loss. Warm ischemia time, margins, transfusion, and the Clavien-Dindo score were not different. In multivariate analysis, only male sex, age, waist circumference, fat density on computed tomography, and MAP score were significant predictors of APF. A radioclinical score was more predictive of APF than MAP score alone. Histologically, there was no macrophage infiltration but larger adipocytes in APF without significant differences in fibrosis. CONCLUSIONS: APF can be accurately predicted using radioclinical data as the MAP score, combined with sex, age, and waist circumference. APF is associated with increased operative time and blood loss without postoperative complications. Histological analysis finds larger adipocytes in APF without inflammatory infiltrate, and no difference in fibrosis.