2-Deoxy-d-Glucose Ameliorates PKD Progression Chiaravalli, Marco; Rowe, Isaline; Mannella, Valeria ...
Journal of the American Society of Nephrology,
07/2016, Volume:
27, Issue:
7
Journal Article
Peer reviewed
Open access
Autosomal dominant polycystic kidney disease (ADPKD) is an important cause of ESRD for which there exists no approved therapy in the United States. Defective glucose metabolism has been identified as ...a feature of ADPKD, and inhibition of glycolysis using glucose analogs ameliorates aggressive PKD in preclinical models. Here, we investigated the effects of chronic treatment with low doses of the glucose analog 2-deoxy-d-glucose (2DG) on ADPKD progression in orthologous and slowly progressive murine models created by inducible inactivation of the Pkd1 gene postnatally. As previously reported, early inactivation (postnatal days 11 and 12) of Pkd1 resulted in PKD developing within weeks, whereas late inactivation (postnatal days 25-28) resulted in PKD developing in months. Irrespective of the timing of Pkd1 gene inactivation, cystic kidneys showed enhanced uptake of (13)C-glucose and conversion to (13)C-lactate. Administration of 2DG restored normal renal levels of the phosphorylated forms of AMP-activated protein kinase and its target acetyl-CoA carboxylase. Furthermore, 2DG greatly retarded disease progression in both model systems, reducing the increase in total kidney volume and cystic index and markedly reducing CD45-positive cell infiltration. Notably, chronic administration of low doses (100 mg/kg 5 days per week) of 2DG did not result in any obvious sign of toxicity as assessed by analysis of brain and heart histology as well as behavioral tests. Our data provide proof of principle support for the use of 2DG as a therapeutic strategy in ADPKD.
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The identification of alternative biocompatible magnetic NPs for advanced clinical application is becoming an important need due to raising concerns about iron accumulation in soft ...issues associated to the administration of superparamagnetic iron oxide nanoparticles (NPs). Here, we report on the performance of previously synthetized iron-doped hydroxyapatite (FeHA) NPs as contrast agent for magnetic resonance imaging (MRI). The MRI contrast abilities of FeHA and Endorem® (dextran coated iron oxide NPs) were assessed by 1H nuclear magnetic resonance relaxometry and their performance in healthy mice was monitored by a 7 Tesla scanner. FeHA applied a higher contrast enhancement, and had a longer endurance in the liver with respect to Endorem® at iron equality. Additionally, a proof of concept of FeHA use as scintigraphy imaging agent for positron emission tomography (PET) and single photon emission computed tomography (SPECT) was given labeling FeHA with 99mTc-MDP by a straightforward surface functionalization process. Scintigraphy/x-ray fused imaging and ex vivo studies confirmed its dominant accumulation in the liver, and secondarily in other organs of the mononuclear phagocyte system. FeHA efficiency as MRI-T2 and PET-SPECT imaging agent combined to its already reported intrinsic biocompatibility qualifies it as a promising material for innovative nanomedical applications.
The ability of iron-doped hydroxyapatite nanoaprticles (FeHA) to work in vivo as imaging agents for magnetic resonance (MR) and nuclear imaging is demonstrated. FeHA applied an higher MR contrast in the liver, spleen and kidneys of mice with respect to Endorem®. The successful radiolabeling of FeHA allowed for scintigraphy/X-ray and ex vivo biodistribution studies, confirming MR results and envisioning FeHA application for dual-imaging.
Obesity is a chronic, complex pathology associated with a risk of developing secondary pathologies, including cardiovascular diseases, cancer, type 2 diabetes (T2DM) and musculoskeletal disorders. ...Since skeletal muscle accounts for more than 70% of total glucose disposal, metabolic alterations are strictly associated with the onset of insulin resistance and T2DM. The present study relies on the proteomic analysis of gastrocnemius muscle from 15 male and 15 female C56BL/J mice fed for 14 weeks with standard, 45% or 60% high-fat diets (HFD) adopting a label-free LC-MS/MS approach followed by bioinformatic pathway analysis. Results indicate changes in males due to HFD, with increased muscular stiffness (Col1a1, Col1a2, Actb), fiber-type switch from slow/oxidative to fast/glycolytic (decreased Myh7, Myl2, Myl3 and increased Myh2, Mylpf, Mybpc2, Myl1), increased oxidative stress and mitochondrial dysfunction (decreased respiratory chain complex I and V and increased complex III subunits). At variance, females show few alterations and activation of compensatory mechanisms to counteract the increase of fatty acids. Bioinformatics analysis allows identifying upstream molecules involved in regulating pathways identified at variance in our analysis (Ppargc1a, Pparg, Cpt1b, Clpp, Tp53, Kdm5a, Hif1a). These findings underline the presence of a gender-specific response to be considered when approaching obesity and related comorbidities.
Pulmonary infections caused by
(MA) have increased over recent decades, affecting individuals with underlying pathologies such as chronic obstructive pulmonary disease, bronchiectasis and, ...especially, cystic fibrosis. The lack of a representative and standardized model of chronic infection in mice has limited steps forward in the field of
pulmonary infection. To overcome this challenge, we refined the method of agar beads to establish
chronic infection in immunocompetent mice. We evaluated bacterial count, lung pathology and markers of inflammation and we performed longitudinal studies with magnetic resonance imaging (MRI) up to three months after
infection. In this model,
was able to establish a persistent lung infection for up to two months and with minimal systemic spread. Lung histopathological analysis revealed granulomatous inflammation around bronchi characterized by the presence of lymphocytes, aggregates of vacuolated histiocytes and a few neutrophils, mimicking the damage observed in humans. Furthermore,
lung lesions were successfully monitored for the first time by MRI. The availability of this murine model and the introduction of the successfully longitudinal monitoring of the murine lung lesions with MRI pave the way for further investigations on the impact of
pathogenesis and the efficacy of novel treatments.
Ceruloplasmin (Cp) is a ferroxidase that plays a role in cellular iron homeostasis and is mainly expressed in the liver and secreted into the blood. Cp is also produced by adipose tissue, which ...releases it as an adipokine. Although a dysfunctional interaction of iron with the metabolism of lipids has been associated with several metabolic diseases, the role of Cp in adipose tissue metabolism and in the interplay between hepatocytes and adipocytes has been poorly investigated. We previously found that Cp-deficient (CpKO) mice become overweight and demonstrate adipose tissue accumulation together with liver steatosis during aging, suggestive of lipid dysmetabolism. In the present study, we investigated the lipid alterations which occur during aging in adipose tissue and liver of CpKO and wild-type mice both in vivo and ex vivo. During aging of CpKO mice, we observed adipose tissue accumulation and liver lipid deposition, both of which are associated with macrophage infiltration. Liver lipid deposition was characterized by accumulation of triglycerides, fatty acids and ω-3 fatty acids, as well as by a switch from unsaturated to saturated fatty acids, which is characteristic of lipid storage. Liver steatosis was preceded by iron deposition and macrophage infiltration, and this was observed to be already occurring in younger CpKO mice. The accumulation of ω-3 fatty acids, which can only be acquired through diet, was associated with body weight increase in CpKO mice despite food intake being equal to that of wild-type mice, thus underlining the alterations in lipid metabolism/catabolism in Cp-deficient animals.
Polycystic kidney disease (PKD) is a genetic disorder characterized by bilateral cyst formation. We showed that PKD cells and kidneys display metabolic alterations, including the Warburg effect and ...glutaminolysis, sustained in vitro by the enzyme asparagine synthetase (ASNS). Here, we used antisense oligonucleotides (ASO) against
Asns
in orthologous and slowly progressive PKD murine models and show that treatment leads to a drastic reduction of total kidney volume (measured by MRI) and a prominent rescue of renal function in the mouse. Mechanistically, the upregulation of an ATF4–ASNS axis in PKD is driven by the amino acid response (AAR) branch of the integrated stress response (ISR). Metabolic profiling of PKD or control kidneys treated with
Asns
-ASO or
Scr
-ASO revealed major changes in the mutants, several of which are rescued by
Asns
silencing in vivo. Indeed, ASNS drives glutamine-dependent de novo pyrimidine synthesis and proliferation in cystic epithelia. Notably, while several metabolic pathways were completely corrected by
Asns
-ASO, glycolysis was only partially restored. Accordingly, combining the glycolytic inhibitor 2DG with
Asns
-ASO further improved efficacy. Our studies identify a new therapeutic target and novel metabolic vulnerabilities in PKD.
Synopsis
Metabolic Reprogramming, such as glycolysis and glutaminolysis, are key features of polycystic kidney disease (PKD). Asparagine synthetase drives glutamine utilization in this disease and it is upregulated in human and mouse tissues. Its inhibition retards disease progression and rescues metabolic derangement in PKD mice.
Glutamine utilization and cyst expansion are driven by ASNS upregulation in PKD.
PKD cystic phenotype and metabolic rewiring are hampered by Asns-ASO.
Glutaminolysis, pyrimidine biosynthesis and proliferation are driven by a GCN2-ATF4-ASNS axis.
PKD is further delayed by co-targeting glutaminolysis and glycolysis with Asns-ASO and 2DG.
Metabolic Reprogramming, such as glycolysis and glutaminolysis, are key features of polycystic kidney disease (PKD). Asparagine synthetase drives glutamine utilization in this disease and it is upregulated in human and mouse tissues. Its inhibition retards disease progression and rescues metabolic derangement in PKD mice.
Fatty liver may be involved in the pathogenesis of type 2 diabetes. Physical exercise is a tool to improve insulin sensitivity, but little is known about its effect on intrahepatic fat (IHF) content. ...The purpose of this study was to examine the association of habitual physical activity, insulin resistance, and adiponectin with IHF content.
Participants were 191 (77 female and 114 male) apparently healthy, nonalcoholic individuals (aged 19-62 years; BMI 17.0-35.5 kg/m2). IHF content was assessed in a quantitative fashion and noninvasively as a continuous variable by means of 1H magnetic resonance spectroscopy (MRS), and habitual physical activity was assessed by means of a questionnaire. Fatty liver was defined as IHF content of >5% wet weight, and insulin sensitivity was estimated using the computer homeostasis model assessment (HOMA)-2 indexes.
A reduced prevalence of fatty liver in the quartile of the most physically active individuals (25, 11, 25, and 2% in quartile 1, 2, 3, and 4, respectively; chi2 = 15.63; P = 0.001) was found along with an inverse correlation between the physical activity index and the IHF content when plotted as continuous variables (Pearson's r = -0.27; P < 0.000). This association was not attenuated when adjusted for age, sex, BMI, HOMA-2, and adiponectin (partial correlation r = -0.25; P < 0.001).
This study demonstrated that a higher level of habitual physical activity is associated with a lower IHF content and suggested that this relationship may be due to the effect of exercise per se.
Magnetic resonance imaging (MRI) provides non-invasive, repetitive measures in the same individual, allowing the study of a physio-pathological event over time. In this study, we tested the ...performance of 7 Tesla multi-parametric MRI to monitor the dynamic changes of mouse skeletal muscle injury and regeneration upon acute ischemia induced by femoral artery dissection. T2-mapping (T2 relaxation time), diffusion-tensor imaging (Fractional Anisotropy) and perfusion by Dynamic Contrast-Enhanced MRI (K-trans) were measured and imaging results were correlated with histological morphometric analysis in both Gastrocnemius and Tibialis anterior muscles. We found that tissue damage positively correlated with T2-relaxation time, while myofiber regeneration and capillary density positively correlated with Fractional Anisotropy. Interestingly, K-trans positively correlated with capillary density. Accordingly, repeated MRI measurements between day 1 and day 28 after surgery in ischemic muscles showed that: 1) T2-relaxation time rapidly increased upon ischemia and then gradually declined, returning almost to basal level in the last phases of the regeneration process; 2) Fractional Anisotropy dropped upon ischemic damage induction and then recovered along with muscle regeneration and neoangiogenesis; 3) K-trans reached a minimum upon ischemia, then progressively recovered. Overall, Gastrocnemius and Tibialis anterior muscles displayed similar patterns of MRI parameters dynamic, with more marked responses and less variability in Tibialis anterior. We conclude that MRI provides quantitative information about both tissue damage after ischemia and the subsequent vascular and muscle regeneration, accounting for the differences between subjects and, within the same individual, between different muscles.
Signals of tissue necrosis, damage-associated molecular patterns (DAMPs), cause inflammation. Leukocytes migrating into injured tissues tonically release DAMPs, including the high mobility group box ...1 protein (HMGB1). In the absence of suitable models, the relative role of DAMPs released because of necrosis or leukocyte activation has not, so far, been dissected. We have generated a mouse model lacking Hmgb1 in the hematopoietic system and studied the response to acute sterile injury of the skeletal muscle. Regenerating fibers are significantly less numerous at earlier time points and smaller at the end of the process. Leukocyte Hmgb1 licenses the skeletal muscle to react to hypoxia, to express angiopoietin-2, and to initiate angiogenesis in response to injury. Vascularization of the regenerating tissue is selectively jeopardized in the absence of leukocyte Hmgb1, revealing that it controls the nutrient and oxygen supply to the regenerating tissue. Altogether, our results reveal a novel nonredundant role for leukocyte Hmgb1 in the repair of injured skeletal muscle.
Defective functionality of thymic epithelial cells (TECs), due to genetic mutations or injuring causes, results in altered T‐cell development, leading to immunodeficiency or autoimmunity. These ...defects cannot be corrected by hematopoietic stem cell transplantation (HSCT), and thymus transplantation has not yet been demonstrated to be fully curative. Here, we provide proof of principle of a novel approach toward thymic regeneration, involving the generation of thymic organoids obtained by seeding gene‐modified postnatal murine TECs into three‐dimensional (3D) collagen type I scaffolds mimicking the thymic ultrastructure. To this end, freshly isolated TECs were transduced with a lentiviral vector system, allowing for doxycycline‐induced Oct4 expression. Transient Oct4 expression promoted TECs expansion without drastically changing the cell lineage identity of adult TECs, which retain the expression of important molecules for thymus functionality such as Foxn1, Dll4, Dll1, and AIRE. Oct4‐expressing TECs (iOCT4 TEC) were able to grow into 3D collagen type I scaffolds both in vitro and in vivo, demonstrating that the collagen structure reproduced a 3D environment similar to the thymic extracellular matrix, perfectly recognized by TECs. In vivo results showed that thymic organoids transplanted subcutaneously in athymic nude mice were vascularized but failed to support thymopoiesis because of their limited in vivo persistence. These findings provide evidence that gene modification, in combination with the usage of 3D biomimetic scaffolds, may represent a novel approach allowing the use of postnatal TECs for thymic regeneration. Stem Cells Translational Medicine 2019;8:1107–1122
Transient Oct4 expression promoted thymic epithelial cells expansion without drastically changing the cell lineage identity of adult thymic epithelial cells. iOCT4 thymic epithelial cells were able to grow into three‐dimensional collagen type I scaffolds both in vitro and in vivo demonstrating that the collagen structure reproduced a three‐dimensional environment similar to the thymic extracellular matrix, perfectly recognized by thymic epithelial cells. in vivo results showed that thymic organoids transplanted subcutaneously in athymis nude mice were vascularized but failed to support thymopoiesis because of the limited in vivo persistence. These findings provide evidence that gene modification, in combination with the usage of three‐dimensional biomimetic scaffolds, represents a novel approach allowing the use of postnatal thymic epithelial cells for thymic regeneration.
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