Metal Dyshomeostasis and Their Pathological Role in Prion and Prion-Like Diseases: The Basis for a Nutritional Approach

Metal ions are key elements in organisms' life acting like cofactors of many enzymes but they can also be potentially dangerous for the cell participating in redox reactions that lead to the formation of reactive oxygen species (ROS). Any factor inducing or limiting a metal dyshomeostasis, ROS production and cell injury may contribute to the onset of neurodegenerative diseases or play a neuroprotective action. Transmissible spongiform encephalopathies (TSEs), also known as prion diseases, are a group of fatal neurodegenerative disorders affecting the central nervous system (CNS) of human and other mammalian species. The causative agent of TSEs is believed to be the scrapie prion protein PrPSc, the β sheet-rich pathogenic isoform produced by the conformational conversion of the α-helix-rich physiological isoform PrPC. The peculiarity of PrPSc is its ability to self-propagate in exponential fashion in cells and its tendency to precipitate in insoluble and protease-resistance amyloid aggregates leading to neuronal cell death. The expression "prion-like diseases" refers to a group of neurodegenerative diseases that share some neuropathological features with prion diseases such as the involvement of proteins (α-synuclein, amyloid β, and tau) able to precipitate producing amyloid deposits following conformational change. High social impact diseases such as Alzheimer's and Parkinson's belong to prion-like diseases. Accumulating evidence suggests that the exposure to environmental metals is a risk factor for the development of prion and prion-like diseases and that metal ions can directly bind to prion and prion-like proteins affecting the amount of amyloid aggregates. The diet, source of metal ions but also of natural antioxidant and chelating agents such as polyphenols, is an aspect to take into account in addressing the issue of neurodegeneration. Epidemiological data suggest that the Mediterranean diet, based on the abundant consumption of fresh vegetables and on low intake of meat, could play a preventive or delaying role in prion and prion-like neurodegenerative diseases. In this review, metal role in the onset of prion and prion-like diseases is dealt with from a nutritional, cellular, and molecular point of view

The Triglycerides and Glucose (TyG) Index Is Associated with 1-Hour Glucose Levels during an OGTT

Background and Objectives: Among individuals with normal glucose tolerance (NGT), subjects with high levels of plasma glucose (≥155 mg/dL) at sixty minutes during an oral glucose tolerance test (1h-OGTT) are at an increased risk of developing type 2 diabetes. We investigated the association between the triglycerides and glucose (TyG) index, a novel marker of insulin resistance, with 1h-OGTT glucose plasma concentrations. Material and Methods: 1474 non-diabetic Caucasian subjects underwent a 75 g OGTT and were divided into two groups according to the cutoff 1h-OGTT plasma glucose < 155 mg/dL (NGT-1h-low) and ≥ 155 mg/dL (NGT-1h-high). The TyG index was calculated as ln [fasting triglycerides (milligrams per deciliter) × fasting blood glucose (milligrams per deciliter)/2]. Multivariable linear and logistic regression analyses were used to establish the contribution of the TyG index to the variability of 1h-OGTT glucose, and how the former affected the risk of being NGT-1h-high. Results: 1004 individuals were NGT-1h-low and 470 were NGT-1h-high. The TyG index was higher for NGT-1h-high (p = 0.001) individuals, and it was an independent factor influencing 1h-OGTT glycemia (β = 0.191, p < 0.001) after correcting for age, sex, and BMI. The TyG index was the strongest marker associated with the risk of being NGT-1h-high (OR = 1.703, CI 95% 1.34–2.17, p < 0.001) when compared with FPG (OR = 1.054, CI 95% 1.04–1.07, p < 0.001) and the HOMA-IR (OR = 1.156, CI 95% 1.08–1.23, p < 0.001). Conclusions: Our study demonstrated that the TyG index, an efficient and cost-effective marker of insulin resistance, is associated with the variability of early post-challenge glucose levels and is an independent marker of being NGT-1h-high

Riproduzione ovina in aree iodocarenti: effetti della iodoprofilassi

Nella regione Abruzzo sono presenti aree caratterizzate da iodocarenza e da elevata incidenza di patologie dovute all’insufficiente apporto di iodio (M. Olivieri et al. Atti VI Giorn. It. Tiroide 114, 1988). In questo contesto anche gli animali di interesse zootecnico possono essere suscettibili agli effetti negativi della iodocarenza. In particolare, alterazioni dello sviluppo sessuale potrebbero associarsi ad una ridotta capacità riproduttiva (E.A. Jannini et al. Endocr. Rev. 16:443, 1995). A tal fine gli obiettivi del presente studio, finanziato dal Ministero della Sanità (Ricerca Finalizzata 1998), sono stati: a) monitorare l’apporto alimentare di iodio in differenti allevamenti ovini distribuiti sul territorio abruzzese tramite la determinazione della ioduria; b) valutare le capacità riproduttive di animali sottoposti o meno ad un adeguato programma di iodoprofilassi. Nella prima fase dello studio l’apporto di iodio è stato valutato, in 11 differenti allevamenti ovini per un totale di 56 animali, mediante la determinazione della concentrazione di iodio urinario con metodo colorimetrico basato sulla reazione di Sandell-Kolthoff, dopo digestione dei campioni di urine con acido clorico. I risultati hanno evidenziato un apporto ottimale di iodio soltanto in 3 allevamenti (ioduria 300 g/L). In 3 allevamenti si è riscontrato un apporto di iodio discreto (ioduria 100-150 g/L) mentre in 5 allevamenti i livelli di iodio urinario erano decisamente insufficienti (ioduria 300 g/L per almeno 3 mesi. Dopo 6 mesi dall’inizio del trattamento sono stati valutati gli effetti della iodoprofilassi sulle capacità riproduttive. A tal fine le femmine di controllo e quelle trattate sono state sottoposte a sincronizzazione degli estri mediante apposizione intravaginale di pessari contenenti 40 mg di Fluorgesterone acetato e somministrazione intramuscolo di PGF2(250 g). Dopo 10 giorni le femmine trattate e quelle di controllo sono state messe in accoppiamento rispettivamente con maschi trattati o di controllo. Il successo degli accoppiamenti è stato valutato dopo 40-60 giorni accertando lo stato di gravidanza mediante ecografia. I risultati hanno dimostrato un aumento statisticamente significativo (p=0.007) della fertilità degli animali trattati rispetto ai controlli. In particolare, si è evidenziato come solo il 37% delle femmine di controllo accoppiate con maschi di controllo siano rimaste gravide, rispetto al 100% delle femmine trattate accoppiate con maschi trattati. Tale aumentata capacità riproduttiva è associata ad una più efficiente gametogenesi sia maschile che femminile, come evidenziato dall’analisi istologica delle gonadi. In conclusione, nel presente studio si è dimostrato come il deficitario apporto iodico in animali di interesse zootecnico possa essere ripristinato con un programma di iodoprofilassi basato sulla somministrazione di iodio per via parenterale. Tale trattamento oltre ad essere efficace nell’aumentare le capacità riproduttive degli animali può rivelarsi estremamente utile per la iodoprofilassi silente nell’uomo che si nutrirebbe di carni, latte e derivati a più elevato contenuto di iodio

Beneficial effects of iodoprophilaxis on ovine reproduction

Some area of Abruzzo are characterized by severe iodine deficiency and by high prevalence of iodine deficient disorders. The adverse effects of iodine deficiency are also present in farm animals, compromising local economy. In the present study, granted by the Ministero della Sanità, we attempted to: a) monitor sheep iodine intake in different sheep breeding farms distributed in the Abruzzo territory; b) monitor the effects of iodoprophylaxis on animal reproductive capacity. Eleven breeding farms, with a total of 56 animals, were examined. By measuring urinary iodine concentration (UIC), acceptable levels of iodine intake were present in animals bred in 3 farms, with a mean UIC 300 g/L; animals bred in 3 farms showed a mean UIC between 100-150 g/L, while values of UIC 50 g/L were observed in animals bred in the remaining 5 farms. In one of the farms, with low value of UIC, subcutaneous injections of 1 ml of Lipiodol were done in male and female animals. This single injection was able to maintain UIC well above 300 g/L for at least 3 months. After 6 months reproductive capacity were assessed by monitoring the rate of successful mating, compared to that of untreated animals. To this end, lipidiol-treated and untreated females were mated for 5 days with lipiodol treated and untreated males, respectively. Successful mating were evaluated by monitoring, 1 month later, the presence of embryos by ecographic analysis. The results showed that about 90% of treated females mated with treated males were pregnant while only 37% of the control females mated with control males were pregnant. In conclusion, the results of this study demonstrate that iodoprophylaxis improves ovine reproductive capacity. This may improve local economy and may also be beneficial for human iodoprophylaxis in the region

Detrimental effects of iodine deficiency on ovine gametogenesis and replication

Damaged reproduction, including miscarriages and stillbirths, represents a major issue of the iodine deficiency disorders (IDD) affecting humans and animals living in iodine deficient environment. Moreover, during the last decade, a number of different experimental findings suggested an important role for thyroid hormone in male and female gonadal development and gametogenesis. In the present study, we monitored the reproductive capacity of sheeps exposed to iodine deficiency or following iodine prophylaxis. To this end, 40 ewes and 20 rams, characterized by low urinary iodine concentrations (UIC) (78.2±6.3 g/L) were used. The animals were ramdomly divided into two groups. One group (20 ewes and 10 rams) received a subcutaneous injections of 1 ml of Lipiodol (containing 480 mg of iodine), while the remaining animals were used as control group. This single injection was able to maintain UIC well above 300 g/L for at least 3 months and to induce a statistically significant increase in both T4 (69.8±17.9 ng/ml vs 48.4±10.7 ng/ml, P<0.01) and T3 (1.13±0.27 ng/ml vs 0.69±0.30 ng/ml, P<0.01) serum levels. After 6 months reproductive capacity was assessed by monitoring the rate of successful matings, compared to that of untreated animals. To this end, treated and untreated ewes were mated for 5 days with lipiodol-treated and untreated rams, respectively. Successful matings were evaluated by monitoring, 1 month later, the presence of embryos by ecographic analysis. The results showed that 100% of treated ewes mated with treated rams were pregnant, while only 37% of the control ewes mated with control rams were pregnant (P=0.007). During pregnancy, 1 miscarriage in both control and treated animals was observed. At birth, body weight and height were similar in lambs born from control and treated ewes. One month after labor, control ewes showed an increased thyroid/body weight ratio with respect to treated ewes (8.5±0.7 x 10-5 vs 6.4±0.5 x 10-5, P<0.05). Histological analysis of adult male and female gonads showed that gametogenesis was impaired in control animals with respect to the treated ones. In conclusion, the results of the present study suggest that iodine deficiency may have adverse effects on ovine gametogenesis and explain the reduced animal fertility observed in iodine deficient environment

Generation and validation of novel adeno-associated viral vectors for the analysis of Ca2+ homeostasis in motor neurons

A finely tuned Ca2+ homeostasis in restricted cell domains is of fundamental importance for neurons, where transient Ca2+ oscillations direct the proper coordination of electro-chemical signals and overall neuronal metabolism. Once such a precise regulation is unbalanced, however, neuronal functions and viability are severely compromised. Accordingly, disturbed Ca2+ metabolism has often been claimed as a major contributor to different neurodegenerative disorders, such as amyotrophic lateral sclerosis that is characterised by selective motor neuron (MN) damage. This notion highlights the need for probes for the specific and precise analysis of local Ca2+ dynamics in MNs. Here, we generated and functionally validated adeno-associated viral vectors for the expression of gene-encoded fluorescent Ca2+ indicators targeted to different cell domains, under the transcriptional control of a MN-specific promoter. We demonstrated that the probes are specifically expressed, and allow reliable local Ca2+ measurements, in MNs from murine primary spinal cord cultures, and can also be expressed in spinal cord MNs in vivo, upon systemic administration to newborn mice. Preliminary analyses using these novel vectors have shown larger cytosolic Ca2+ responses following stimulation of AMPA receptors in the cytosol of primary cultured MNs from a murine genetic model of ALS compared to the healthy counterpart

YAP1 acts as oncogenic target of 11q22 amplification in multiple cancer subtypes

The transcriptional coactivator YAP1 is a critical effector of the human Salvador-Warts-Hippo pathway. Literature data report apparently discrepant results on the carcinogenic role of YAP1, which acts either as oncogene or as tumor suppressor in different in vitro and in vivo models. Furthermore, genomic amplification events of 11q22 locus encompassing YAP1 gene have been detected in multiple tumor types but there is limited direct evidence about the oncogenic role of endogenous YAP1 within in the amplicon. We screened a panel of human tumor samples and cancer cell lines and identified that the YAP1 amplification event is actually present in up to 23% of the cases. We exploited EKVX (lung cancer), CaSki (cervical cancer) and RO82 (thyroid cancer) cell lines harboring both genomic YAP1 amplification and YAP1 protein overexpression, in order to study the effects of downregulation of endogenous YAP1 by RNA-interference strategies. Class comparison analysis of gene expression profiling data identified 707 statistically significantly modulated genes (multivariable global test p-value = 0.002) that were functionally annotated for cell proliferation and cellular movement ontologies. Mechanistic studies of the identified perturbed pathways revealed that YAP1 silencing significantly decreased cell proliferation and cell cycle perturbation associated with upregulation of p21 and p27 cell-cycle inhibitors, reduced cell migration (p<0.048) and anchorage-independent growth (p<0.02). In CaSki cell line, YAP1 silencing induced significantly increased sensitivity and cell-death response to cisplatin treatment (p=0.011) as well as reduction of in-vivo tumorigenic potential (p=0.027). Overall, these results establish that YAP1 is a direct oncogenic target of the 11q22 amplicon in previously unreported cancer types and support the relevance of such genetic aberration in carcinogenesis in a fraction of multiple tumor types