Lysosomal fusion and SNARE function are impaired by cholesterol accumulation in lysosomal storage disorders.

Partial Retraction of: The EMBO Journal (2010) 29: 3607-3620. DOI: 10.1038/emboj.2010.237 | Published online 24 September 2010 Journal statement The journal contacted the authors in February 2022 about potential image insertions and duplications in Fig 4A and 4E. In the absence of source data, the authors are retracting Fig 4A, the lower panel of Fig 4E (LAMP1 immunoblot), and the following statements in the text that rely on these data: "Quantitative analysis showed that the percentage of Flotillin-1 associated with DRMs was increased in LSD endolysosomal membranes (Figure 4A), indicating an increased amount of cholesterol-enriched regions in these membrane samples." "LAMP1 also displayed a similar distribution profile in WT and LSD cells (Figure 4E)". Author statement The authors could not verify the aberrations in panel A of Fig 4 and the lower immunoblot (LAMP1) of 4E because the original source data are no longer available (12 years after publication, which is beyond the institute's 10-year data retention policy). The authors wish to clarify that the main conclusions of the paper are not affected by the retraction of Figure panels 4A and 4E for the following reasons: Figure panel 4A supports the observation that there are increased cholesterol-enhanced regions in LSD samples. This finding is also supported by data provided in figs 4B, 4C and 4D. Figure panel 4E: The LAMP1 blot in Fig 4E shows that the distribution of protein normally excluded from DRMs is not altered between Wt and LSD samples. This result is also supported by the upper blot in this panel (Transferrin receptor). The authors apologize for these errors and agree with this corrigendum; no response could be obtained from AL.

Identification of sixteen novel candidate genes for late onset Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is a neurodegenerative movement disorder affecting 1-5% of the general population for which neither effective cure nor early diagnostic tools are available that could tackle the pathology in the early phase. Here we report a multi-stage procedure to identify candidate genes likely involved in the etiopathogenesis of PD. METHODS: The study includes a discovery stage based on the analysis of whole exome data from 26 dominant late onset PD families, a validation analysis performed on 1542 independent PD patients and 706 controls from different cohorts and the assessment of polygenic variants load in the Italian cohort (394 unrelated patients and 203 controls). RESULTS: Family-based approach identified 28 disrupting variants in 26 candidate genes for PD including PARK2, PINK1, DJ-1(PARK7), LRRK2, HTRA2, FBXO7, EIF4G1, DNAJC6, DNAJC13, SNCAIP, AIMP2, CHMP1A, GIPC1, HMOX2, HSPA8, IMMT, KIF21B, KIF24, MAN2C1, RHOT2, SLC25A39, SPTBN1, TMEM175, TOMM22, TVP23A and ZSCAN21. Sixteen of them have not been associated to PD before, were expressed in mesencephalon and were involved in pathways potentially deregulated in PD. Mutation analysis in independent cohorts disclosed a significant excess of highly deleterious variants in cases (p = 0.0001), supporting their role in PD. Moreover, we demonstrated that the co-inheritance of multiple rare variants (≥ 2) in the 26 genes may predict PD occurrence in about 20% of patients, both familial and sporadic cases, with high specificity (> 93%; p = 4.4 × 10- 5). Moreover, our data highlight the fact that the genetic landmarks of late onset PD does not systematically differ between sporadic and familial forms, especially in the case of small nuclear families and underline the importance of rare variants in the genetics of sporadic PD. Furthermore, patients carrying multiple rare variants showed higher risk of manifesting dyskinesia induced by levodopa treatment. CONCLUSIONS: Besides confirming the extreme genetic heterogeneity of PD, these data provide novel insights into the genetic of the disease and may be relevant for its prediction, diagnosis and treatment.

Analysis of Genetic and Non-genetic Predictors of Levodopa Induced Dyskinesia in Parkinson's Disease.

Background: Levodopa (L-Dopa), representing the therapeutic gold standard for the treatment of Parkinson disease (PD), is associated with side effects like L-Dopa induced dyskinesia (LID). Although several non-genetic and genetic factors have been investigated for association with LID risk, contrasting results were reported and its genetic basis remain largely unexplored. Methods: In an Italian PD cohort (N = 460), we first performed stepwise multivariable Cox Proportional Hazard regressions modeling LID risk as a function of gender, PD familiarity, clinical subtype, weight, age-at-onset (AAO) and years-of-disease (YOD), L-Dopa dosage, severity scores, and scales assessing motor (UPDRS-III), cognitive (MoCA), and non-motor symptoms (NMS). Then we enriched the resulting model testing two variants-rs356219 and D4S3481-increasing the expression of the SNCA gene, previously suggested as a potential mechanism of LID onset. To account for more complex (non-linear) relations of these variables with LID risk, we built a survival random forest (SRF) algorithm including all the covariates mentioned above. Results: Among tested variables (N = 460 case-complete, 211 LID events; total follow-up 31,361 person-months, median 61 months), disease duration showed significant association (p < 0.005), with 6 (3-8)% decrease of LID risk per additional YOD. Other nominally significant associations were observed for gender-with women showing a 39 (5-82)% higher risk of LID-and AAO, with 2 (0.3-3)% decrease of risk for each year increase of PD onset. The SRF algorithm confirmed YOD as the most prominent feature influencing LID risk, with a variable importance of about 8% in the model. In genetic models, no statistically significant effects on incident LID risk was observed. Conclusions: This evidence supports a protective effect of late PD onset and gender (men) against LID risk and suggests a new independent protective factor, YOD. Moreover, it underlines the importance of personalized therapeutic protocols for PD patients in the future.

Do consumers understand health claims on extra-virgin olive oil?

Health claims have been introduced in food labelling to support consumers' awareness of healthy food choices and to enhance a healthy diet. Even though many countries around the world have developed legislation and guidelines to regulate the introduction of health claims on food labels, there is the evidence that many consumers do not understand the meaning of these claims. This study analyses whether Italian consumers really understand authorized health claims on extra-virgin olive oil and what are the drivers of such understanding. An Olive Oil Health Claims Understanding index was constructed and embedded in a structured questionnaire, which was then administered to a representative sample of Italian household members who are responsible for food shopping (N = 1,030). Results from the survey showed that only 36% of the respondents understood the meaning of the authorized health claims on extra-virgin olive oil. Moreover, the findings confirmed that the understanding of health claims is related to socio-demographic, personal and psychographic characteristics of consumers, as well as to their attitudes toward using food as medicine. Outcomes also proved the central role of nutrition knowledge in affecting understanding of health claims.

The "Land of Fires" Toxic Waste Scandal and Its Effect on Consumer Food Choices.

The present study focused on an environmental scandal that occurred in Italy, the Land of Fires toxic waste scandal, which caused consumer concerns related to the safety of food produced in the affected region, as well as massive market reduction in products associated with the polluted area. Based on a representative sample of Italian households (N = 1134), this study applied an extended Theory of Planned Behavior (TPB) model to analyze consumer purchases of regional food products after this environmental hazard. In addition to attitudes, subjective norms and perceived behavioral control, the model included risk perception, trust, and actual purchases. Using a structural equation model, our results provided support to the hypothesis that consumer perceptions of risk negatively impacted their purchase behaviors and suggested that increasing Italians' trust in government information could reduce their perceived risk and, consequently, increase their intention to purchase regional food.

Whole Exome Sequencing Study of Parkinson Disease and Related Endophenotypes in the Italian Population.

Parkinson Disease (PD) is a complex neurodegenerative disorder characterized by large genetic heterogeneity and missing heritability. Since the genetic background of PD can partly vary among ethnicities and neurological scales have been scarcely investigated in a PD setting, we performed an exploratory Whole Exome Sequencing (WES) analysis of 123 PD patients from mainland Italy, investigating scales assessing motor (UPDRS), cognitive (MoCA), and other non-motor symptoms (NMS). We performed variant prioritization, followed by targeted association testing of prioritized variants in 446 PD cases and 211 controls. Then we ran Exome-Wide Association Scans (EWAS) within sequenced PD cases (N = 113), testing both motor and non-motor PD endophenotypes, as well as their associations with Polygenic Risk Scores (PRS) influencing brain subcortical volumes. We identified a variant associated with PD, rs201330591 in GTF2H2 (5q13; alternative T allele: OR [CI] = 8.16[1.08; 61.52], FDR = 0.048), which was not replicated in an independent cohort of European ancestry (1,148 PD cases, 503 controls). In the EWAS, polygenic analyses revealed statistically significant multivariable associations of amygdala- [ß(SE) = -0.039(0.013); FDR = 0.039] and caudate-PRS [0.043(0.013); 0.028] with motor symptoms. All subcortical PRSs in a multivariable model notably increased the variance explained in motor (adjusted-R2 = 38.6%), cognitive (32.2%) and other non-motor symptoms (28.9%), compared to baseline models (~20%). Although, the small sample size warrants further replications, these findings suggest shared genetic architecture between PD symptoms and subcortical structures, and provide interesting clues on PD genetic and neuroimaging features.

Functional Antagonism between OTX2 and NANOG Specifies a Spectrum of Heterogeneous Identities in Embryonic Stem Cells.

Embryonic stem cells (ESCs) cultured in leukemia inhibitory factor (LIF) plus fetal bovine serum (FBS) exhibit heterogeneity in the expression of naive and primed transcription factors. This heterogeneity reflects the dynamic condition of ESCs and their versatility to promptly respond to signaling effectors promoting naive or primed pluripotency. Here, we report that ESCs lacking Nanog or overexpressing Otx2 exhibit an early primed identity in LIF + FBS and fail to convert into 2i-induced naive state. Conversely, Otx2-null ESCs possess naive identity features in LIF + FBS similar to Nanog-overexpressing ESCs and convert poorly into FGF-induced early primed state. When both Nanog and Otx2 are inactivated, ESCs cultured in LIF + FBS exhibit primed identity and weakened ability to convert into naive state. These data suggest that, through mutual antagonism, NANOG and OTX2 specify the heterogeneous identity of ESCs cultured in LIF + FBS and individually predispose them for optimal response to naive or primed inducing factors.

Dysregulation of the Expression of Asparagine-Linked Glycosylation 13 Short Isoform 2 Affects Nephrin Function by Altering Its N-Linked Glycosylation.

BACKGROUND: N-linked glycosylation, which is a post-translational modification process, plays an important role in protein folding, intracellular trafficking and membrane targeting, as well as in regulating the protein function. Recently, we identified a missense variant (p.T141L) in the short isoform 2 of the X-linked gene asparagine-linked glycosylation 13 (ALG13-is2), which segregated with focal segmental glomerulosclerosis and PCCD in a large Australian pedigree; however, any evidence of its pathogenicity was demonstrated. ALG13 gene encodes, through alternative splicing, 2 glycosyltransferase isoforms, which catalyse the second sugar addition of the highly conserved oligosaccharide precursor in the endoplasmic reticulum (ER). Mutations in the long isoform 1 were associated with epilepsy. METHODS AND RESULTS: Here, we show a different expression of the 2 isoforms depending on the tissue. Specifically, the long isoform is highly expressed in lungs, ovaries, testes, cerebellum, cortex, retina, pituitary gland, and olfactory bulbs, while the short isoform is highly expressed in mouse podocytes and in human podocyte cell lines, at both mRNA and protein levels. The silencing of ALG13-is2 by specific siRNAs induces an altered N-linked glycosylation pattern of nephrin, as demonstrated by the presence of an additional immunostaining band of about 130 kD. In knock-down cells, immunofluorescence analysis shows perturbed organization of the cytoskeleton and altered localization of nephrin on the cellular membrane. We also demonstrated that the altered pattern of N-linked glycosylation induces an over-expression of binding immunoglobulin protein and calreticulin, suggesting ER stress. CONCLUSIONS: These results provide preliminary evidence that ALG13-is2 could be an important modifier of renal filtration defects.

The Seven Challenges for Transitioning into a Bio-based Circular Economy in the Agri-food Sector.

BACKGROUND: Closed-loop agri-food supply chains have a high potential to reduce environmental and economic costs resulting from food waste disposal. This paper illustrates an alternative to the traditional supply chain of bread based on the principles of a circular economy. METHODS: Six circular interactions among seven actors (grain farmers, bread producers, retailers, compostable packaging manufacturers, insect breeders, livestock farmers, consumers) of the circular filière are created in order to achieve the goal of "zero waste". In the model, two radical technological innovations are considered: insects used as animal feed and polylactic acid compostable packaging. RESULTS: The main challenges for the implementation of the new supply chain are identified. Finally, some recent patents related to bread sustainable production, investigated in the current paper, are considered. CONCLUSION: Recommendations are given to academics and practitioners interested in the bio-based circular economy model approach for transforming agri-food supply chains.

Lysosomal fusion and SNARE function are impaired by cholesterol accumulation in lysosomal storage disorders.

The function of lysosomes relies on the ability of the lysosomal membrane to fuse with several target membranes in the cell. It is known that in lysosomal storage disorders (LSDs), lysosomal accumulation of several types of substrates is associated with lysosomal dysfunction and impairment of endocytic membrane traffic. By analysing cells from two severe neurodegenerative LSDs, we observed that cholesterol abnormally accumulates in the endolysosomal membrane of LSD cells, thereby reducing the ability of lysosomes to efficiently fuse with endocytic and autophagic vesicles. Furthermore, we discovered that soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptors (SNAREs), which are key components of the cellular membrane fusion machinery are aberrantly sequestered in cholesterol-enriched regions of LSD endolysosomal membranes. This abnormal spatial organization locks SNAREs in complexes and impairs their sorting and recycling. Importantly, reducing membrane cholesterol levels in LSD cells restores normal SNARE function and efficient lysosomal fusion. Our results support a model by which cholesterol abnormalities determine lysosomal dysfunction and endocytic traffic jam in LSDs by impairing the membrane fusion machinery, thus suggesting new therapeutic targets for the treatment of these disorders.

Multistep, sequential control of the trafficking and function of the multiple sulfatase deficiency gene product, SUMF1 by PDI, ERGIC-53 and ERp44.

Sulfatase modifying factor 1 (SUMF1) encodes for the formylglicine generating enzyme, which activates sulfatases by modifying a key cysteine residue within their catalytic domains. SUMF1 is mutated in patients affected by multiple sulfatase deficiency, a rare recessive disorder in which all sulfatase activities are impaired. Despite the absence of canonical retention/retrieval signals, SUMF1 is largely retained in the endoplasmic reticulum (ER), where it exerts its enzymatic activity on nascent sulfatases. Part of SUMF1 is secreted and paracrinally taken up by distant cells. Here we show that SUMF1 interacts with protein disulfide isomerase (PDI) and ERp44, two thioredoxin family members residing in the early secretory pathway, and with ERGIC-53, a lectin that shuttles between the ER and the Golgi. Functional assays reveal that these interactions are crucial for controlling SUMF1 traffic and function. PDI couples SUMF1 retention and activation in the ER. ERGIC-53 and ERp44 act downstream, favoring SUMF1 export from and retrieval to the ER, respectively. Silencing ERGIC-53 causes proteasomal degradation of SUMF1, while down-regulating ERp44 promotes its secretion. When over-expressed, each of three interactors favors intracellular accumulation. Our results reveal a multistep control of SUMF1 trafficking, with sequential interactions dynamically determining ER localization, activity and secretion.

Functional correction of CNS lesions in an MPS-IIIA mouse model by intracerebral AAV-mediated delivery of sulfamidase and SUMF1 genes.

Mucopolysaccharidosis type IIIA (MPS-IIIA or Sanfilippo syndrome) is a lysosomal storage disorder caused by the congenital deficiency of sulfamidase (SGSH) enzyme and consequent accumulation of partially degraded heparan sulfate (HS) in lysosomes. The central nervous system (CNS) is the predominant site of tissue damage in MPS-IIIA. Here we describe a gene therapy approach for MPS-IIIA in a mouse model using recombinant adeno-associated virus serotype 5 (AAV2/5) as a vehicle to deliver therapeutic genes to the CNS. SUMF1 (SUlfatase Modifying Factor 1) exhibits an enhancing effect on sulfatase activity when co-expressed with sulfatases. Consistent with these findings, we demonstrated that co-delivery of SUMF1 and SGSH (via an AAV2/5-CMV-SGSH-IRES-SUMF1 vector) resulted in a synergistic increase in SGSH activity, both in primary neural cells and in murine brain. A study aimed at testing the therapeutic efficacy of simultaneous brain administration of SUMF1 and SGSH was then performed by injecting the lateral ventricles of newborn MPS-IIIA/normal mice with either AAV2/5-CMV-SGSH-IRES-SUMF1 or AAV2/5-CMV-GFP vectors. Widespread GFP expression was observed within the GFP-injected brain, and a stable and significant increase of SGSH activity was detected in several brain regions following SGSH-IRES-SUMF1 administration. Treatment with AAV2/5-CMV-SGSH-IRES-SUMF1 vectors resulted in a visible reduction in lysosomal storage and inflammatory markers in transduced brain regions. Finally, the MPS-IIIA mice treated with therapeutic genes displayed an improvement in both motor and cognitive functions. Our results suggest that early treatment of CNS lesions by AAV-mediated intraventricular injection of both SGSH and SUMF1 genes may represent a feasible therapy for MPS-IIIA.

Multiple sulfatase deficiency is due to hypomorphic mutations of the SUMF1 gene.

Sulfatases catalyze the hydrolysis of sulfate ester bonds from a wide variety of substrates and are implicated in several human inherited diseases. Multiple sulfatase deficiency (MSD) is a rare autosomal recessive disorder characterized by the simultaneous deficiency of all known sulfatases. MSD is caused by mutations in the Sulfatase Modifying Factor 1 (SUMF1) gene encoding the alpha-formylglycine generating enzyme (FGE), which is responsible for the post-translational modification of sulfatases. In all MSD patients, residual sulfatase activities are detectable, at variable levels. To correlate the nature of the residual sulfatase activities detected in MSD patients with residual FGE activity, four FGE mutants (i.e. p.S155P, p.R224W, p.R345C, p.R349W) found in homozygosis in MSD patients were analyzed. Using viral-mediated gene delivery, these mutants were over-expressed in mouse embryonic fibroblasts (MEFs) from a recently developed Sumf1 KO mouse line which is completely devoid of all sulfatase activities. The results obtained indicate that mutant SUMF1 cDNAs encode stable SUMF1 proteins which are of the appropriate molecular weight and are properly localized in the endoplasmic reticulum. Expression of these cDNAs in Sumf1-/- MEFs results in partial rescue of sulfatase activities. These data indicate that MSD is due to hypomorphic SUMF1 mutations and suggest that complete loss of SUMF1 function is likely to be lethal in humans.

Role of a molecular variant of rat atrial natriuretic Peptide gene in vascular remodeling.

Previous studies in a hypertensive animal model of stroke and in humans showed that mutations of the atrial natriuretic peptide (ANP) gene are associated with increased risk of stroke. To elucidate the vascular disease mechanisms that result from structural modifications of the ANP gene, we investigated a coding mutation of the ANP gene in stroke-prone spontaneously hypertensive rats (SHRsp). This mutation leads to a Gly/Ser transposition in the prosegment of ANP. We found that presence of this mutation is associated with increased immunostaining of ANP in the wall of SHRsp cerebral vessels. The mutation causes a major inhibitory effect on endothelial cell proliferation, as assessed by thymidine incorporation, and on angiogenesis, as determined by an endothelial cell tube formation assay, in human umbilical vein endothelial cells (HUVEC) exposed to ANP/SHRsp. These in vitro findings show that the SHRsp-derived form of ANP has an inhibitory effect on vascular remodeling and they provide further support for a role of the ANP gene in the pathogenesis of cerebrovascular disease in the animal model.

SUMF1 enhances sulfatase activities in vivo in five sulfatase deficiencies.

Sulfatases are enzymes that hydrolyse a diverse range of sulfate esters. Deficiency of lysosomal sulfatases leads to human diseases characterized by the accumulation of either GAGs (glycosaminoglycans) or sulfolipids. The catalytic activity of sulfatases resides in a unique formylglycine residue in their active site generated by the post-translational modification of a highly conserved cysteine residue. This modification is performed by SUMF1 (sulfatase-modifying factor 1), which is an essential factor for sulfatase activities. Mutations in the SUMF1 gene cause MSD (multiple sulfatase deficiency), an autosomal recessive disease in which the activities of all sulfatases are profoundly reduced. In previous studies, we have shown that SUMF1 has an enhancing effect on sulfatase activity when co-expressed with sulfatase genes in COS-7 cells. In the present study, we demonstrate that SUMF1 displays an enhancing effect on sulfatases activity when co-delivered with a sulfatase cDNA via AAV (adeno-associated virus) and LV (lentivirus) vectors in cells from individuals affected by five different diseases owing to sulfatase deficiencies or from murine models of the same diseases [i.e. MLD (metachromatic leukodystrophy), CDPX (X-linked dominant chondrodysplasia punctata) and MPS (mucopolysaccharidosis) II, IIIA and VI]. The SUMF1-enhancing effect on sulfatase activity resulted in an improved clearance of the intracellular GAG or sulfolipid accumulation. Moreover, we demonstrate that the SUMF1-enhancing effect is also present in vivo after AAV-mediated delivery of the sulfamidase gene to the muscle of MPSIIIA mice, resulting in a more efficient rescue of the phenotype. These results indicate that co-delivery of SUMF1 may enhance the efficacy of gene therapy in several sulfatase deficiencies.

Contribution of genetic factors to renal lesions in the stroke-prone spontaneously hypertensive rat.

Stroke-prone spontaneously hypertensive rats (SHRSP) develop renal lesions more frequently than the closely related control strain, the stroke-resistant SHR. The aim of this study was to investigate the contribution of genetic factors to the enhanced susceptibility to renal damage of SHRSP in an SHRSP/SHR F2 intercross by means of a genotype/phenotype cosegregation analysis. For this purpose, 154 6-week-old F2-SHRSP/SHR rats (79 male, 75 female) were fed a stroke-permissive Japanese diet for 4 weeks. Systolic blood pressure (SBP) was recorded at the end of the dietary period. Renal damage was scored from 0 to 3, and 274 genetic markers polymorphic between SHR and SHRSP were genotyped. Linkage of genotype markers to the degree of renal disease was determined by chi2 test. Experimental threshold level to declare linkage was calculated by QTL cartographer. SBP was not correlated to renal damage (rho coefficient, 0.201; P=NS). Grade 2 and grade 3 lesions were more frequent in male than in female rats (P=0.01). Two loci, D1Rat238, on chromosome 1 and the IGF receptor-binding protein 4 (Rbp4g) on chromosome 10, were significantly linked to the degree of renal damage, with SHRSP allele being aggressive at D1Rat238 locus and protective at Rbp4g locus. In male rats only, the SHRSP allele at one locus on chromosome 16, D16Mit2, was associated with a more severe degree of renal disease. Our results demonstrate that in this intercross, susceptibility to renal damage is influenced by several genetic loci acting independently from high blood pressure levels and also shows a sexual dimorphism.

Functional cross-talk between angiotensin II and epidermal growth factor receptors in NIH3T3 fibroblasts.

BACKGROUND: The main angiotensin (Ang) II subtype receptors (AT1R and AT2R) are involved in cellular growth processes and exert functionally antagonistic effects. OBJECTIVE: To characterize the mechanisms by which Ang II receptors influence growth, by investigating the interactions between Ang II subtype receptors and epidermal growth factor (EGF) receptors on mitogen-activated protein kinase (MAPK) pathway activation. DESIGN AND METHODS: The experiments were performed using a mouse fibroblast cell line, NIH3T3, by transient co-transfection with rat AT1R or AT2R expression vectors, or both. Extracellular-signal-regulated kinase (ERK)1/2 phosphorylation was analysed by western blot and the ERK activity was evaluated using PathDetect, an in-vivo signal transduction pathway trans-reporting system. Selective Ang II receptor antagonists (losartan for AT1R and PD123319 for AT2R) were used to investigate the contributions of each receptor to the response observed. RESULTS: Our data show that, in this cellular model, both Ang II receptors phosphorylate ERK1/2. However, in the cells expressing AT1R, the EGF-induced MAPK pathway was enhanced in the presence of Ang II in a synergistic fashion. In contrast, a reduction of EGF-induced MAPK activation was observed in the cells expressing AT2R. In cells expressing both Ang II subtype receptors, Ang II promoted an enhancement of EGF-induced MAPK activation. However, in the presence of the AT1R antagonist, losartan, the effect of EGF was reduced. CONCLUSION: These data indicate the existence of an opposite cross-talk of AT1R and AT2R with EGF receptors, and suggest a complex functional interaction between these pathways in the regulation of cellular growth processes.