Clinical and genetic characterization of a cohort of proteinuric patients with biallelic CUBN variants.

BACKGROUND: Proteinuria is a well-known risk factor for progressive kidney impairment. Recently, C-terminal cubilin (CUBN) variants have been associated with isolated proteinuria without progression of kidney disease. METHODS: Genetic testing of 347 families with proteinuria of suspected monogenic cause was performed by next-generation sequencing of a custom-designed kidney disease gene panel. Families with CUBN biallelic proteinuria-causing variants were studied at the clinical, genetic, laboratory and pathologic levels. RESULTS: Twelve families (15 patients) bearing homozygous or compound heterozygous proteinuria-causing variants in the C-terminal CUBN gene were identified, representing 3.5% of the total cohort. We identified 14 different sequence variants, five of which were novel. The median age at diagnosis of proteinuria was 4 years (range 9 months to 44 years), and in most cases proteinuria was detected incidentally. Thirteen patients had moderate to severe proteinuria at diagnosis without nephrotic syndrome. These patients showed lack of response to angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blocker (ARB) treatment, normal kidney biopsy and preservation of normal kidney function over time. The two remaining patients presented a more severe phenotype, likely caused by associated comorbidities. CONCLUSIONS: Identification of C-terminal pathogenic CUBN variants is diagnostic of an entity characterized by glomerular proteinuria, normal kidney histology and lack of response to ACEi/ARB treatment. This study adds evidence and increases awareness about albuminuria caused by C-terminal variants in the CUBN gene, which is a benign condition usually diagnosed in childhood with preserved renal function until adulthood.

Clinical utility of genetic testing in early-onset kidney disease: seven genes are the main players.

BACKGROUND: Inherited kidney diseases are one of the leading causes of chronic kidney disease (CKD) that manifests before the age of 30 years. Precise clinical diagnosis of early-onset CKD is complicated due to the high phenotypic overlap, but genetic testing is a powerful diagnostic tool. We aimed to develop a genetic testing strategy to maximize the diagnostic yield for patients presenting with early-onset CKD and to determine the prevalence of the main causative genes. METHODS: We performed genetic testing of 460 patients with early-onset CKD of suspected monogenic cause using next-generation sequencing of a custom-designed kidney disease gene panel in addition to targeted screening for c.428dupC MUC1. RESULTS: We achieved a global diagnostic yield of 65% (300/460), which varied depending on the clinical diagnostic group: 77% in cystic kidney diseases, 76% in tubulopathies, 67% in autosomal dominant tubulointerstitial kidney disease, 61% in glomerulopathies and 38% in congenital anomalies of the kidney and urinary tract. Among the 300 genetically diagnosed patients, the clinical diagnosis was confirmed in 77%, a specific diagnosis within a clinical diagnostic group was identified in 15%, and 7% of cases were reclassified. Of the 64 causative genes identified in our cohort, 7 (COL4A3, COL4A4, COL4A5, HNF1B, PKD1, PKD2 and PKHD1) accounted for 66% (198/300) of the genetically diagnosed patients. CONCLUSIONS: Two-thirds of patients with early-onset CKD in this cohort had a genetic cause. Just seven genes were responsible for the majority of diagnoses. Establishing a genetic diagnosis is crucial to define the precise aetiology of CKD, which allows accurate genetic counselling and improved patient management.

IDH mutation status trumps the Pignatti risk score as a prognostic marker in low-grade gliomas.

Management of low-grade gliomas (LGG) is based on clinical and radiologic features, including the Pignatti prognostic scoring system, which classifies patients as low- or high-risk. To determine whether molecular data can offer advantages over these features, we have examined the prognostic impact of several molecular alterations in LGG. In a cohort of 58 patients with LGG, we have retrospectively analyzed clinical and molecular characteristics, including the Pignatti criteria, IDH mutations, TP53 mutations, the 1p/19q deletion, and MGMT methylation, and correlated our findings with progression-free survival (PFS) and overall survival (OS). Mean age of patients was 45 years; 71% were classified as low-risk by the Pignatti system. IDH mutations were detected in 62%, p53 mutations in 17%, the 1p/19q codeletion in 46%, and MGMT methylation in 40% of patients. Survival analyses were performed in the 49 patients without contrast enhancement. In the univariate analysis, IDH mutations, the 1p/19q codeletion, and the combination of IDH mutations with the 1p/19q codeletion were associated with both longer PFS (P = 0.006, P = 0.037, and P = 0.003, respectively) and longer OS (P < 0.001, P = 0.02, and P < 0.001, respectively). The multivariate analysis identified absence of IDH mutations as a factor for greater risk of progression [hazard ratio (HR) = 3.1; P = 0.007]and death (HR = 6.4; P < 0.001). We suggest that IDH mutations may be more effective than the Pignatti score in discriminating low- and high-risk patients with LGG.

Insulin-like Growth Factor 2 Overexpression Induces ß-Cell Dysfunction and Increases Beta-cell Susceptibility to Damage.

The human insulin-like growth factor 2 (IGF2) and insulin genes are located within the same genomic region. Although human genomic studies have demonstrated associations between diabetes and the insulin/IGF2 locus or the IGF2 mRNA-binding protein 2 (IGF2BP2), the role of IGF2 in diabetes pathogenesis is not fully understood. We previously described that transgenic mice overexpressing IGF2 specifically in ß-cells (Tg-IGF2) develop a pre-diabetic state. Here, we characterized the effects of IGF2 on ß-cell functionality. Overexpression of IGF2 led to ß-cell dedifferentiation and endoplasmic reticulum stress causing islet dysfunction in vivo. Both adenovirus-mediated overexpression of IGF2 and treatment of adult wild-type islets with recombinant IGF2 in vitro further confirmed the direct implication of IGF2 on ß-cell dysfunction. Treatment of Tg-IGF2 mice with subdiabetogenic doses of streptozotocin or crossing these mice with a transgenic model of islet lymphocytic infiltration promoted the development of overt diabetes, suggesting that IGF2 makes islets more susceptible to ß-cell damage and immune attack. These results indicate that increased local levels of IGF2 in pancreatic islets may predispose to the onset of diabetes. This study unravels an unprecedented role of IGF2 on ß-cells function.

Outcome prognostic factors in inoperable malignant bowel obstruction.

PURPOSE: Inoperable malignant bowel obstruction (MBO), a severe complication of peritoneal carcinomatosis, has a low desobstruction rate (30-40 %) and end-of-life decision-making is hampered by the lack of known prognostic factors. This study aimed to explore prognostic factors for desobstruction in MBO. METHODS: All patients with inoperable MBO admitted in our large oncology hospital between 2010 and 2013 were treated following a clinical protocol based on antiemetics, steroids and two antisecretories, octreotide, and hyoscine butylbromide. Two prognostic factor analyses using logistic regressions were performed, one based on data from day 1 of admission and the other on data from day 8. RESULTS: Forty-five patients were included. Frequency of desobstruction was 48.9 %. In the analysis of prognostic factors on day 1, MBO episodes derived from functional physiopathologic mechanisms (vs. mechanic or mixed) were more prone to resolve (p < 0.001 corrected for multiple comparisons). Considering patients alive with persistent obstruction on day 8, a better clinical condition was the variable more associated with desobstruction, but without statistical significance after correction for multiple comparisons. CONCLUSIONS: A functional physiopathologic mechanism of MBO development may be an early prognostic factor for desobstruction. A high proportion of desobstruction was observed, suggesting that the combination of antisecretories with different mechanism of action warrants further investigation.

Treatment of infantile-onset Pompe disease in a rat model with muscle-directed AAV gene therapy.

OBJECTIVE: Pompe disease (PD) is caused by deficiency of the lysosomal enzyme acid α-glucosidase (GAA), leading to progressive glycogen accumulation and severe myopathy with progressive muscle weakness. In the Infantile-Onset PD (IOPD), death generally occurs <1 year of age. There is no cure for IOPD. Mouse models of PD do not completely reproduce human IOPD severity. Our main objective was to generate the first IOPD rat model to assess an innovative muscle-directed adeno-associated viral (AAV) vector-mediated gene therapy. METHODS: PD rats were generated by CRISPR/Cas9 technology. The novel highly myotropic bioengineered capsid AAVMYO3 and an optimized muscle-specific promoter in conjunction with a transcriptional cis-regulatory element were used to achieve robust Gaa expression in the entire muscular system. Several metabolic, molecular, histopathological, and functional parameters were measured. RESULTS: PD rats showed early-onset widespread glycogen accumulation, hepato- and cardiomegaly, decreased body and tissue weight, severe impaired muscle function and decreased survival, closely resembling human IOPD. Treatment with AAVMYO3-Gaa vectors resulted in widespread expression of Gaa in muscle throughout the body, normalizing glycogen storage pathology, restoring muscle mass and strength, counteracting cardiomegaly and normalizing survival rate. CONCLUSIONS: This gene therapy holds great potential to treat glycogen metabolism alterations in IOPD. Moreover, the AAV-mediated approach may be exploited for other inherited muscle diseases, which also are limited by the inefficient widespread delivery of therapeutic transgenes throughout the muscular system.

Spatially Preserved Multi-Region Transcriptomic Subtyping and Biomarkers of Chemoimmunotherapy Outcome in Extensive-Stage Small Cell Lung Cancer.

PURPOSE: Transcriptomic subtyping holds promise for personalized therapy in extensive-stage small cell lung cancer (ES-SCLC). In this study, we aimed to assess intratumoral transcriptomic subtype diversity and to identify biomarkers of long-term chemoimmunotherapy benefit in human ES-SCLC. EXPERIMENTAL DESIGN: We analyzed tumor samples from 58 patients with ES-SCLC enrolled in two multicenter single-arm phase IIIb studies evaluating frontline chemoimmunotherapy in Spain: n = 32 from the IMfirst trial and n = 26 from the CANTABRICO trial. We used the GeoMx Digital Spatial Profiler system to perform multi-region transcriptomic analysis. For subtype classification, we performed hierarchical clustering using the relative expression of ASCL1 (SCLC-A), NEUROD1 (SCLC-N), POU2F3 (SCLC-P), and YAP1 (SCLC-Y). RESULTS: Subtype distribution was found to be similar between bothcohorts, except for SCLC-P, which was not identified in the CANTABRICO_DSP cohort. A total of 44% of the patients in both cohorts had tumors with multiple coexisting transcriptional subtypes. Transcriptional subtypes or subtype heterogeneity was not associated with outcomes. Most potential targets did not show subtype-specific expression. Consistently in both cohorts, tumors from patients with long-term benefit (time to progression ≥12 months) contained an IFNγ-dominated mRNA profile, including enhanced capacity for antigen presentation. Hypoxia and glycolytic pathways were associated with resistance to chemoimmunotherapy. CONCLUSIONS: This work suggests that intratumoral heterogeneity, inconsistent association with outcome, and unclear subtype-specific target expression might be significant challenges for subtype-based precision oncology in SCLC. Preexisting IFNγ-driven immunity and mitochondrial metabolism seem to be correlates of long-term efficacy in this study, although the absence of a chemotherapy control arm precludes concluding that these are predictive features specific for immunotherapy.

The S-REAL study: Spanish real-world data on unresectable stage III NSCLC patients treated with durvalumab after chemoradiotherapy.

OBJECTIVES: The S-REAL study aimed to assess the effectiveness of durvalumab as consolidation therapy after definitive chemoradiotherapy (CRT) in a real-world cohort of patients with locally advanced, unresectable stage III non-small cell lung cancer (LA-NSCLC) included in a Spanish early access program (EAP). METHODS: In this multicentre, observational, retrospective study we analysed data from patients treated in 39 Spanish hospitals, who started intravenous durvalumab (10 mg/kg every 2 weeks) between September 2017 and December 2018. The primary endpoint was progression-free survival (PFS). Secondary endpoints included patient characterization and adverse events of special interest (AESI). RESULTS: A total of 244 patients were followed up for a median of 21.9 months [range 1.2-34.7]. Median duration of durvalumab was 45.5 weeks (11.4 months) [0-145]. Median PFS was 16.7 months (95% CI 12.2-25). No remarkable differences in PFS were observed between patients with programmed cell death-ligand 1 (PD-L1) expression ≥ 1% or < 1% (16.7 versus 15.6 months, respectively). However, PFS was higher in patients who had received prior concurrent CRT (cCRT) versus sequential CRT (sCRT) (20.6 versus 9.4 months). AESIs leading to durvalumab discontinuation were registered in 11.1% of patients. CONCLUSIONS: These results are in line with prior published evidence and confirm the benefits of durvalumab in the treatment of LA-NSCLC patients in a real-world setting. We also observed a lower incidence of important treatment-associated toxicities, such as pneumonitis, compared with the pivotal phase III PACIFIC clinical study.

Teleoncology: A Solution for Everyone? A Single-Center Experience with Telemedicine during the Coronavirus Disease 2019 (COVID-19) Pandemic.

Since the beginning of the COVID-19 pandemic, the use of telehealth was rapidly implemented without previous evidence. The ONCOTELEMD study aimed to evaluate the opinion of patients attended via telemedicine during this period and to study factors that condition patient preferences on its use. Included patients had a confirmed cancer diagnosis and were contacted by telephone between 13 March and 30 April 2020, in the Medical Oncology Service of Hospital Parc Taulí, Sabadell. A 12-question survey was presented to them between 4 February and 19 April 2021. Statistical analysis was carried out using chi-square and multivariable logistic regression tests. Six hundred forty-six patients were included; 487 responded to the survey. The median age was 68 years (27-90), 55.2% were female. Most patients had a surveillance visit (65.3%) and were diagnosed with colorectal or breast cancer (43% and 26.5%, respectively); 91.8% of patients were satisfied, and 60% would accept the use of telemedicine beyond the pandemic. Patients aged more than 50 years (OR 0.40; 95% CI, 0.19-0.81; p = 0.01) and diagnosed with breast cancer (OR 0.45; 95% CI, 0.26-0.69; p < 0.001) were less predisposed to adopt telehealth in the future. Patients agreed to be informed via telehealth of scan or lab results (62% and 84%, respectively) but not of new oral or endovenous treatments (52% and 33.5%, respectively). Additionally, 75% of patients had a medium or low-null technologic ability, and 51.3% would only use the telephone or video call to contact health professionals. However, differences were found according to age groups (p < 0.0001). In total, patients surveyed were satisfied with telemedicine and believed telehealth could have a role following the COVID-19 pandemic. Moreover, our results remark on the importance of individualizing the use of telehealth, showing relevant data on patient preferences and digital literacy.

Reduction of liver fructokinase expression and improved hepatic inflammation and metabolism in liquid fructose-fed rats after atorvastatin treatment.

Consumption of beverages that contain fructose favors the increasing prevalence of metabolic syndrome alterations in humans, including non-alcoholic fatty liver disease (NAFLD). Although the only effective treatment for NAFLD is caloric restriction and weight loss, existing data show that atorvastatin, a hydroxymethyl-glutaryl-CoA reductase inhibitor, can be used safely in patients with NAFLD and improves hepatic histology. To gain further insight into the molecular mechanisms of atorvastatin's therapeutic effect on NAFLD, we used an experimental model that mimics human consumption of fructose-sweetened beverages. Control, fructose (10% w/v solution) and fructose+atorvastatin (30 mg/kg/day) Sprague-Dawley rats were sacrificed after 14 days. Plasma and liver tissue samples were obtained to determine plasma analytes, liver histology, and the expression of liver proteins that are related to fatty acid synthesis and catabolism, and inflammatory processes. Fructose supplementation induced hypertriglyceridemia and hyperleptinemia, hepatic steatosis and necroinflammation, increased the expression of genes related to fatty acid synthesis and decreased fatty acid ß-oxidation activity. Atorvastatin treatment completely abolished histological signs of necroinflammation, reducing the hepatic expression of metallothionein-1 and nuclear factor kappa B binding. Furthermore, atorvastatin reduced plasma (x 0.74) and liver triglyceride (x 0.62) concentrations, decreased the liver expression of carbohydrate response element binding protein transcription factor (x 0.45) and its target genes, and increased the hepatic activity of the fatty acid ß-oxidation system (x 1.15). These effects may be related to the fact that atorvastatin decreased the expression of fructokinase (x 0.6) in livers of fructose-supplemented rats, reducing the metabolic burden on the liver that is imposed by continuous fructose ingestion.

"High Tumor Burden" in Metastatic Non-Small Cell Lung Cancer: Defining the Concept.

PURPOSE: Identifying patient characteristics that define a worse disease prognosis or "high tumor burden" (HTB) status is essential for clinical decision-making and treatment selection in metastatic non-small cell lung cancer (mNSCLC). We aimed to define this concept based on the experience of oncologists in clinical practice. PATIENTS AND METHODS: A representative sample of Spanish experts was selected and asked to complete an online survey regarding the definition of HTB according to their personal experience. RESULTS: HTB was identified by the oncologists (N = 81) as one of the principle factors influencing first-line treatment decision-making. According to the experts, HTB is mainly defined by the number of metastatic lesions (n = 45, 56%), location (n = 34, 42%), tumor size (sum of diameters of target lesions; n = 26, 32%) and liver involvement (n = 24, 30). High lactate dehydrogenase (LDH) levels were also associated with HTB. Almost half of respondents (n = 33, 41%) believed that one metastatic lesion was sufficient to consider a patient as presenting HTB, 72% (n = 58) considered that two were necessary and 99% (n = 80) three. Liver (n = 76, 100%) followed by brain (n = 65, 86%) were the main metastatic sites associated with HTB. Tumor size ranging from 6 cm to 10 cm as well as high LDH levels (three times the upper limit) defined the concept for 82% (n = 62) and 100% (n = 76) of oncologists, respectively. CONCLUSION: In the real-world setting, according to experts, HTB is defined by the number of metastatic lesions, location of metastases, tumor size and by high LDH levels. Given the relevance of this concept, efforts should be made to unify its definition and to further explore its potential as a prognostic factor for mNSCLC patients.

Vitamin D Receptor Overexpression in ß-Cells Ameliorates Diabetes in Mice.

Vitamin D deficiency has been associated with increased incidence of diabetes, both in humans and in animal models. In addition, an association between vitamin D receptor (VDR) gene polymorphisms and diabetes has also been described. However, the involvement of VDR in the development of diabetes, specifically in pancreatic ß-cells, has not been elucidated yet. Here, we aimed to study the role of VDR in ß-cells in the pathophysiology of diabetes. Our results indicate that Vdr expression was modulated by glucose in healthy islets and decreased in islets from both type 1 diabetes and type 2 diabetes mouse models. In addition, transgenic mice overexpressing VDR in ß-cells were protected against streptozotocin-induced diabetes and presented a preserved ß-cell mass and a reduction in islet inflammation. Altogether, these results suggest that sustained VDR levels in ß-cells may preserve ß-cell mass and ß-cell function and protect against diabetes.

Suppressor of cytokine signaling-3 (SOCS-3) and a deficit of serine/threonine (Ser/Thr) phosphoproteins involved in leptin transduction mediate the effect of fructose on rat liver lipid metabolism.

UNLABELLED: There is controversy regarding whether fructose in liquid beverages constitutes another dietary ingredient of high caloric density or introduces qualitative changes in energy metabolism that further facilitate the appearance of metabolic diseases. Central to this issue is the elucidation of the molecular mechanism responsible for the metabolic alterations induced by fructose ingestion. Fructose administration (10% wt/vol) in the drinking water of Sprague-Dawley male rats for 14 days induced hyperleptinemia and hepatic leptin resistance. This was caused by impairment of the leptin-signal transduction mediated by both janus-activated kinase-2 and the mitogen-activated protein kinase pathway. The subsequent increase in activity in the liver of the unphosphorylated and active form of the forkhead box O1 nuclear factor, which transrepresses peroxisome proliferator-activated receptor alpha activity, and a lack of activation of the adenosine monophosphate-activated protein kinase, led to hypertriglyceridemia and hepatic steatosis. These alterations are attributable to two key events: (1) an increase in the amount of suppressor of cytokine signaling-3 protein, which blocks the phosphorylation and activation of janus-activated kinase-2 and Tyr(985) on the long form of the leptin receptor; and (2) a common deficit of phosphorylation in serine/threonine residues of key proteins in leptin-signal transduction pathways. The latter is probably produced by the early activation of protein phosphatase 2A, and further sustained by the accumulation in liver tissue of ceramide, an activator of protein phosphatase 2A, due to incomplete oxidation of fatty acids. CONCLUSION: Our data indicate that fructose ingestion as a liquid solution induces qualitative changes in liver metabolism that lead to metabolic diseases.

Treatment in esophagogastric junction cancer: Past, present and future. / Tratamientos oncológicos en el cáncer de unión esofagogástrica: pasado, presente y futuro.

Adenocarcinomas of the gastroesophageal junction represent 27% of all gastric tumors. n recent years, it has been classified as an entity of its own, with specific treatments that are sometimes differentiated from gastric treatments. Treatment can be based on chemotherapy (CTx) or chemoradiotherapy (CRTx) that is administered preoperatively (neoadjuvant), postoperatively (adjuvant) or perioperatively. There are studies that have tested several treatment modalities, but there is currently no single protocolized sequence. The results point to an improvement in survival when we administer preoperative treatment, with evidence in favor of CRTx and CTx. Studies are already underway with targeted treatment that aim to increase the activity of traditional chemotherapy. In the next few years, we should know the role of immunotherapy in this group of patients.

A Single-Center Retrospective Study of Patients with Double Primary Cancers: Breast Cancer and EGFR-Mutant Non-Small Cell Lung Cancer.

BACKGROUND: Second primary malignancies (SPM) in the lung are not common in breast cancer (BC) patients. EGFR-mutant lung cancer (LC) is a separate molecular subset, and the co-existence of EGFR-mutant LC and BC has not been explored. We hypothesized that EGFR-mutant LC patients could have higher rates of primary BC than those with EGFR-wild type (WT). METHODS: We collected data on clinical and molecular characteristics and outcomes of female patients with LC and a previous or simultaneous history of primary BC treated in our hospital from 2008 to 2014. RESULTS: Data on treatment, follow-up, and EGFR mutation status were available for 356 patients. 17.7% (11/62) of patients with EGFR mutations had BC, compared to 1.02% (3/294) of EGFR-WT patients (p < 0.001). Both tumors were metachronous in 81.8%, with LC diagnosed 9 years after the diagnosis of BC. 5 of the 6 (83.3%) BC patients treated with radiotherapy developed LC in an area within the radiation field. No EGFR mutations were detected in BC tissue and no HER2 expression was detected in LC samples. CONCLUSION: SPM in the lung and breast occur more frequently among EGFR-mutant compared to EGFR-WT LC patients. Radiotherapy for BC may increase the risk of developing primary LC.

Hepatic gene expression changes in an experimental model of accelerated senescence: the SAM-P8 mouse.

The senescence-accelerated mouse (SAM) is an experimental model of aging, established through phenotypic selection from a common genetic pool of AKR/J mice. Here we use complementary DNA microarray, Western blot, and electrophoretic mobility shift assay to consider whether changes in liver gene expression observed in 5-month-old SAM-prone 8 (P8) mice, compared to SAM-R1 controls, are similar to those reported in aged rodents. Livers from SAM-P8 mice presented 88 differentially expressed transcripts, 59% of which were upregulated and 41% were downregulated. Of these, 14% were related to inflammatory/immunity processes, 10% were related to the xenobiotic metabolism (XM) and 3% to nervous system pathophysiology (NSP). Depressed expression and activity of genes related to XM, and altered expression of genes related to NSP, are similar to changes observed in aged rodents. Increased expression of heat shock protein 1 and Jun-B, reduced activity of activator protein 1 and absence of nuclear factor-kappaB activation indicate the lack of a strong liver inflammatory response in 5-month-old SAM-P8 mice.

Hypertriglyceridemia and hepatic steatosis in senescence-accelerated mouse associate to changes in lipid-related gene expression.

Aged rodents show increasing plasma and tissue triglycerides, and reductions in liver peroxisome proliferator-activated receptor alpha (PPARalpha) and its target genes. We determined whether a similar situation is present in a model of accelerated aging, the senescence-accelerated prone (SAM-P8) mouse. Five-month-old SAM-P8 mice were hypertriglyceridemic, and exhibited hepatic steatosis and reduced fatty acid oxidation versus control 5-month-old senescence-accelerated resistant (SAM-R1) mice, with no differences in PPARalpha expression and binding activity; in fact, fenofibrate administration to SAM-P8 mice induced a clear PPARalpha-driven response. Complementary DNA (cDNA) microarray analysis (Affymetrix Mouse Genome 430A 2.0 GeneChip array), Western blot, and electrophoretic mobility shift assay (EMSA) experiments indicated, among other changes, a deficit in farnesoid X receptor (FXR) expression and binding activity in the livers of SAM-P8 mice with respect to SAM-R1 controls. Triglyceride accretion and a deficit in hepatic fatty acid oxidation, features of the aging process in mammals, associate to a deficit in hepatic FXR activity in the SAM-P8 mice.

AAV-mediated pancreatic overexpression of Igf1 counteracts progression to autoimmune diabetes in mice.

OBJECTIVE: Type 1 diabetes is characterized by autoimmune destruction of ß-cells leading to severe insulin deficiency. Although many improvements have been made in recent years, exogenous insulin therapy is still imperfect; new therapeutic approaches, focusing on preserving/expanding ß-cell mass and/or blocking the autoimmune process that destroys islets, should be developed. The main objective of this work was to test in non-obese diabetic (NOD) mice, which spontaneously develop autoimmune diabetes, the effects of local expression of Insulin-like growth factor 1 (IGF1), a potent mitogenic and pro-survival factor for ß-cells with immunomodulatory properties. METHODS: Transgenic NOD mice overexpressing IGF1 specifically in ß-cells (NOD-IGF1) were generated and phenotyped. In addition, miRT-containing, IGF1-encoding adeno-associated viruses (AAV) of serotype 8 (AAV8-IGF1-dmiRT) were produced and administered to 4- or 11-week-old non-transgenic NOD females through intraductal delivery. Several histological, immunological, and metabolic parameters were measured to monitor disease over a period of 28-30 weeks. RESULTS: In transgenic mice, local IGF1 expression led to long-term suppression of diabetes onset and robust protection of ß-cell mass from the autoimmune insult. AAV-mediated pancreatic-specific overexpression of IGF1 in adult animals also dramatically reduced diabetes incidence, both when vectors were delivered before pathology onset or once insulitis was established. Transgenic NOD-IGF1 and AAV8-IGF1-dmiRT-treated NOD animals had much less islet infiltration than controls, preserved ß-cell mass, and normal insulinemia. Transgenic and AAV-treated islets showed less expression of antigen-presenting molecules, inflammatory cytokines, and chemokines important for tissue-specific homing of effector T cells, suggesting IGF1 modulated islet autoimmunity in NOD mice. CONCLUSIONS: Local expression of Igf1 by AAV-mediated gene transfer counteracts progression to diabetes in NOD mice. This study suggests a therapeutic strategy for autoimmune diabetes in humans.

Long-Term Efficacy and Safety of Insulin and Glucokinase Gene Therapy for Diabetes: 8-Year Follow-Up in Dogs.

Diabetes is a complex metabolic disease that exposes patients to the deleterious effects of hyperglycemia on various organs. Achievement of normoglycemia with exogenous insulin treatment requires the use of high doses of hormone, which increases the risk of life-threatening hypoglycemic episodes. We developed a gene therapy approach to control diabetic hyperglycemia based on co-expression of the insulin and glucokinase genes in skeletal muscle. Previous studies proved the feasibility of gene delivery to large diabetic animals with adeno-associated viral (AAV) vectors. Here, we report the long-term (∼8 years) follow-up after a single administration of therapeutic vectors to diabetic dogs. Successful, multi-year control of glycemia was achieved without the need of supplementation with exogenous insulin. Metabolic correction was demonstrated through normalization of serum levels of fructosamine, triglycerides, and cholesterol and remarkable improvement in the response to an oral glucose challenge. The persistence of vector genomes and therapeutic transgene expression years after vector delivery was documented in multiple samples from treated muscles, which showed normal morphology. Thus, this study demonstrates the long-term efficacy and safety of insulin and glucokinase gene transfer in large animals and especially the ability of the system to respond to the changes in metabolic needs as animals grow older.

AAV-mediated Sirt1 overexpression in skeletal muscle activates oxidative capacity but does not prevent insulin resistance.

Type 2 diabetes is characterized by triglyceride accumulation and reduced lipid oxidation capacity in skeletal muscle. SIRT1 is a key protein in the regulation of lipid oxidation and its expression is reduced in the skeletal muscle of insulin resistant mice. In this tissue, Sirt1 up-regulates the expression of genes involved in oxidative metabolism and improves mitochondrial function mainly through PPARGC1 deacetylation. Here we examined whether Sirt1 overexpression mediated by adeno-associated viral vectors of serotype 1 (AAV1) specifically in skeletal muscle can counteract the development of insulin resistance induced by a high fat diet in mice. AAV1-Sirt1-treated mice showed up-regulated expression of key genes related to ß-oxidation together with increased levels of phosphorylated AMP protein kinase. Moreover, SIRT1 overexpression in skeletal muscle also increased basal phosphorylated levels of AKT. However, AAV1-Sirt1 treatment was not enough to prevent high fat diet-induced obesity and insulin resistance. Although Sirt1 gene transfer to skeletal muscle induced changes at the muscular level related with lipid and glucose homeostasis, our data indicate that overexpression of SIRT1 in skeletal muscle is not enough to improve whole-body insulin resistance and that suggests that SIRT1 has to be increased in other metabolic tissues to prevent insulin resistance.