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Spike protein (S protein) is the virus “key” to infect cells and is able to strongly bind to the human angiotensin-converting enzyme2 (ACE2), as has been reported. In fact, Spike structure and function is known to be highly important for cell infection as well as for entering the brain. Growing evidence indicates that different types of coronaviruses not only affect the respiratory system, but they might also invade the central nervous system (CNS). However, very little evidence has been so far reported on the presence of COVID-19 in the brain, and the potential exploitation, by this virus, of the lung to brain axis to reach neurons has not been completely understood. In this Article, we assessed the SARS-CoV and SARS-CoV-2 Spike protein sequence, structure, and electrostatic potential using computational approaches. Our results showed that the S proteins of SARS-CoV-2 and SARS-CoV are highly similar, sharing a sequence identity of 77%. In addition, we found that the SARS-CoV-2 S protein is slightly more positively charged than that of SARS-CoV since it contains four more positively charged residues and five less negatively charged residues which may lead to an increased affinity to bind to negatively charged regions of other molecules through nonspecific and specific interactions. Analysis the S protein binding to the host ACE2 receptor showed a 30% higher binding energy for SARS-CoV-2 than for the SARS-CoV S protein. These results might be useful for understanding the mechanism of cell entry, blood-brain barrier crossing, and clinical features related to the CNS infection by SARS-CoV-2.

It has long been known that there is decreased mitochondrial function in several tissues of Niemann–Pick C1 model mice and cultured cells. These defects contribute to the accumulation of Reactive Oxygen Species (ROS) and tissue damage. It is also well established that there is increased unesterified cholesterol, stored in late endosomes/lysosomes, in many tissues in mutant humans, mouse models, and mutant cultured cells. Using a mouse model with an NPC1 point mutation that is more typical of the most common form of the disease, and highly purified liver mitochondria, we find markedly decreased mitochondrial membrane cholesterol. This is compared to previous reports of increased mitochondrial membrane cholesterol. We also find that, although in wild-type or heterozygous mitochondria cytochrome c oxidase (COX) activity decreases with age as expected, surprisingly, COX activity in homozygous mutant mice improves with age. COX activity is less than half of wild-type amounts in young mutant mice but later reaches wild-type levels while total liver cholesterol is decreasing. Mutant mice also contain a decreased number of mitochondria that are morphologically abnormal. We suggest that the decreased mitochondrial membrane cholesterol is causative for the mitochondrial energy defects. In addition, we find that the mitochondrial stress regulator protein MNRR1 can stimulate NPC1 synthesis and is deficient in mutant mouse livers. Furthermore, the age curve of MNRR1 deficiency paralleled levels of total cholesterol. The role of such altered mitochondria in initiating the abnormal autophagy and neuroinflammation found in NPC1 mouse models is discussed.

Retinal degeneration is the major and principal cause behind many incurable blindness diseases. Several studies indicated the neuroprotective effect of Curcuma longa in eye pathologies, specifically retinopathy. However, the molecular mechanism behind its effect has not been completely elucidated. Using an

The loss of NPC1 or NPC2 function results in cholesterol and sphingolipid dyshomeostasis that impairs developmental trajectories, predisposing the postnatal brain to the appearance of pathological signs, including progressive and stereotyped Purkinje cell loss and microgliosis. Despite increasing evidence reporting the activation of pro-inflammatory microglia as a cardinal event of NPC1 disease progression at symptomatic stages both in patients and preclinical models, how microglia cells respond to altered neurodevelopmental dynamics remains not completely understood. To gain an insight on this issue, we have characterized patterns of microglia activation in the early postnatal cerebellum and young adult olfactory bulb of the hypomorphic Npc1

Administration of 1000–1500 mg/day D-Chiro-Inositol (DCIns) or a combination of Myo-Inositol (MyoIns) and DCIns in their plasma molar ratio (40:1) for three or more months are among recommended treatments for metabolic syndrome and/or Polycystic Ovary Syndrome (PCOS). We previously confirmed the efficacy of this formulation (8.2 mg/day MyoIns and 0.2 mg/day DCIns for 10 days) in a mouse PCOS model, but also observed negative effects on ovarian histology and function of formulations containing 0.4–1.6 mg/day DCIns. We therefore analyzed effects of higher doses of DCIns, 5, 10 and 20 mg/day, administered to young adult female mice for 21 days, on ovarian histology, serum testosterone levels and expression of the ovarian enzyme aromatase. Five mg/day DCIns (human correspondence: 1200 mg/day) altered ovarian histology, increased serum testosterone levels and reduced the amount of aromatase of negative controls, suggesting the induction of an androgenic PCOS model. In contrast, 10–20 mg/day DCIns (human correspondence: 2400–4800 mg/day) produced ovarian lesions resembling those typical of aged mice, and reduced serum testosterone levels without affecting aromatase amounts, suggesting a failure in steroidogenic gonadal activity. Notwithstanding physiological/biochemical differences between mice and humans, the observed pictures of toxicity for ovarian histology and function recommend caution when administering DCIns to PCOS patients at high doses and/or for periods spanning several ovulatory cycles.

Oxidative stress is a toxic cellular condition, strictly related to inflammation and known to be a common feature of many neurodegenerative diseases. The imbalanced redox state modifies several molecular processes including protein SUMOylation, JNK and Tau protein activation, important actors in Alzheimer's disease. In this study, we showed a strong interaction among SUMO-1-JNK-Tau proteins and their molecular targets in an in vitro model (SHSY5Y cell line) of oxidative stress in which a significant reduction of cell viability and an augmented cell death was induced by increased doses of H2O2. The evoked oxidative stress led to a deficiency in the degradation system showing altered levels of Caspase-3, LC3BII/I and Ubiquitin. Curcumin, a natural compound with anti-oxidant and anti-inflammatory effects, demonstrated to tackle oxidative stress re-equilibrating SUMO-1, JNK and Tau functions. Importantly, 5 μM of curcumin induced an efficient recovery of cell viability, a reduction of cell death and a normalization of altered protein degradation marker levels. Interestingly, we found that H2O2 treatment induced a strong co-localization of SUMO-1-p-JNK-Tau proteins in nuclear bodies (NBs) and that curcumin was able to reduce these nuclear aggregates. These results highlight the SUMO-1-JNK-Tau axis key role in oxidative stress and the protective effect of curcumin against this pathological event, focusing on the importance of SUMO/deSUMOylation balance to regulate essential cellular processes.

The dyshomeostasis of intracellular cholesterol trafficking is typical of the Niemann-Pick type C (NPC) disease, a fatal inherited lysosomal storage disorder presenting with progressive neurodegeneration and visceral organ involvement. In light of the well-established relevance of cholesterol in regulating the endocannabinoid (eCB) system expression and activity, this study was aimed at elucidating whether NPC disease-related cholesterol dyshomeostasis affects the functional status of the brain eCB system. To this end, we exploited a murine model of NPC deficiency for determining changes in the expression and activity of the major molecular components of the eCB signaling, including cannabinoid type-1 and type-2 (CB1 and CB2) receptors, their ligands, N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG), along with their main synthesizing/inactivating enzymes. We found a robust alteration of distinct components of the eCB system in various brain regions, including the cortex, hippocampus, striatum and cerebellum, of Npc1-deficient compared to wild-type pre-symptomatic mice. Changes of the eCB component expression and activity differ from one brain structure to another, although 2-AG and AEA are consistently found to decrease and increase in each structure, respectively. The thorough biochemical characterization of the eCB system was accompanied by a behavioral characterization of Npc1-deficient mice using a number of paradigms evaluating anxiety, locomotor activity, spatial learning/memory abilities, and coping response to stressful experience. Our findings provide the first description of an early and region-specific alteration of the brain eCB system in NPC and suggest that defective eCB signaling could contribute at producing and/or worsening the neurological symptoms of this disorder.

The Npc1nih/nih-null model and the Npc1nmf164/nmf164 hypomorph models of Niemann-Pick C1 (NPC1) disease show defects in olfaction. We have tested the effects of the life-prolonging treatment hydroxypropyl-beta-cyclodextrin (HPBCD) on olfaction and neural stem cell numbers when delivered either systemically or by nasal inhalation. Using the paradigm of finding a hidden cube of food after overnight food deprivation, Npc1nih/nih homozygous mice showed a highly significant delay in finding the food compared with wild-type mice. Npc1nmf164/nmf164 homozygous mice showed an early loss of olfaction which was mildly corrected by somatic delivery of HPBCD which also increased the number of neural stem cells in the mutant but did not change the number in wild-type mice. In contrast, nasal delivery of this drug, at 1/5 the dosage used for somatic delivery, to Npc1nmf164/nmf164 mutant mice delayed loss of olfaction but the control of nasal delivered saline did so as well. The nasal delivery of HPBCD to wild-type mice caused loss of olfaction but nasal delivery of saline did not. Neural stem cell counts were not improved by nasal therapy with HPBCD. We credit the delay in olfaction found with the treatment, a delay which was also found for time of death, to a large amount of stimulation the mice received with handling during the nasal delivery.

Among the extensive public and scientific interest in the use of phytochemicals to prevent or treat human diseases in recent years, natural compounds have been highly investigated to elucidate their therapeutic effect on chronic human diseases including cancer, cardiovascular disease, and neurodegenerative disease. Curcumin, an active principle of the perennial herb Curcuma longa, has attracted an increasing research interest over the last half-century due to its diversity of molecular targets, including transcription factors, enzymes, protein kinases, growth factors, inflammatory cytokines, receptors, and it’s interesting pharmacological activities. Despite that, the clinical effectiveness of the native curcumin is weak, owing to its low bioavailability and rapid metabolism. Preclinical data obtained from animal models and phase I clinical studies done in human volunteers confirmed a small amount of intestinal absorption, hepatic first pass effect, and some degree of intestinal metabolism, might explain its poor systemic availability when it is given via the oral route. During the last decade, researchers have attempted with new pharmaceutical methods such as nanoparticles, liposomes, micelles, solid dispersions, emulsions, and microspheres to improve the bioavailability of curcumin. As a result, a significant number of bioavailable curcumin-based formulations were introduced with a varying range of enhanced bioavailability. This manuscript critically reviews the available scientific evidence on the basic and clinical effects and molecular targets of curcumin. We also discuss its pharmacokinetic and problems for marketing curcumin as a drug.

Proteins belonging to the TGFβ-stimulated clone 22 domain (TSC22D) family display a repertoire of activities, regulating cell proliferation and differentiation. The tumor suppressor activity of the first identified member of the family, TSC22D1 (formerly named TSC-22), has been extensively studied, but afterward a longer isoform encoded by the same gene turned out to play an opposite role. We have previously characterized the role of TSC22D1 and TSC22D4 in cell differentiation using granule neurons (GNs) isolated from the mouse cerebellum. However, the possibility to study the role of these factors in cell proliferation was limited by the fact that GNs readily exit from the cell-cycle and differentiate upon isolation and in vitro culture. To overcome this limitation, we have now exploited DAOY medulloblastoma cells, which are ontogenetically similar to cerebellar GNs and can be efficiently transfected with interfering RNA for gene knockdown purposes. Our findings indicate that TSC22D4-TSC22D1 short isoform heterodimers are involved in the escape from cell proliferation and exit from the cell-cycle, whereas, the TSC22D1 long isoform is required for cell proliferation, acting independently from TSC22D4. We also show that the silencing of specific expression of TSC22D4 or TSC22D1 isoforms affects the cell-cycle progression. These findings add a novel insight on the function of TSC22D proteins, with particular reference to the tumor suppressor activity of the TSC22D1 short isoform, which is re-framed within the context of a functional interplay with TSC22D4 and the mutually exclusive expression with the TSC22D1 long isoform.

Mice exposed to continuous light undergo functional and histological changes that mimic those of human Polycystic Ovary Syndrome (PCOS). We herein induced the syndrome by exposing 30-day-old females to 10 weeks of permanent light. Ovarian morphology and histology, as well as reproductive parameters (time of observed pregnancy/delivery) were investigated. Ovaries of PCOS-modeled mice showed lack of tertiary follicles and corpora lutea, altered ovarian architecture, and increased thickness of the theca layer. When mice were returned to a normal light-dark regimen for 10 days, a slight, spontaneous improvement occurred, whereas a quick and almost complete recovery from PCOS signs and symptoms was obtained by treating animals with a daily supplementation of 420 mg/kg myo-inositol and D-chiro-inositol (MyoIns/DCIns) in a 40:1 molar ratio. Namely, ovaries from mice treated by this protocol recovered normal histological features and a proper ratio of theca/granulosa cell layer thickness (TGR), suggesting that the androgenic phenotype was efficiently reversed. Indeed, we identified TGR as a useful index of PCOS, as its increase in PCOS-modeled mice correlated linearly with reduced reproductive capability ( r = 0.75, p < 0.0001). Mice treated with a 40:1 formula regained low TGR values and faster recovery of their fertility, with a physiological delivery time after mating. On the other hand, a higher D-chiro-inositol treatment formula, such as MyoIns versus DCIns 5:1, was ineffective or even had a negative effect on clinical-pathological outcomes.

Niemann-Pick Type C1 disorder (NPC) is a rare lysosomal storage disease characterized by the accumulation of cholesterol in lysosomes. NPC has no FDA approved treatments yet, however 2-hydroxypropyl-β-cyclodextrin (HPβCD) has shown efficacy for treating the disease in both mouse and feline NPC models and is currently being investigated in late stage clinical trials. Despite promising results, therapeutic use of HPβCD is limited by the need for high doses, ototoxicity and intrathecal administration. These limitations can be attributed to its poor pharmacokinetic profile. In the attempt to overcome these limitations, we have designed a β-cyclodextrin (βCD) based polymer prodrugs (ORX-301) for an enhanced pharmacokinetic and biodistribution profile, which in turn can potentially provide an improved efficacy at lower doses. We demonstrated that subcutaneously injected ORX-301 extended the mean lifespan of NPC mice at a dosage 5-fold lower (800 mg/kg, body weight) the HPβCD dose proven efficacious (4000 mg/kg). We also show that ORX-301 penetrates the blood brain barrier and counteracts neurological impairment. These properties represent a substantial improvement and appear to overcome major limitations of presently available βCD-based therapy, demonstrating that this novel prodrug is a valuable alternative/complement for existing therapies.

Niemann-Pick type C1 (NPC1) disease is a lysosomal storage disorder caused by defective intracellular trafficking of exogenous cholesterol. Purkinje cell (PC) degeneration is the main sign of cerebellar dysfunction in both NPC1 patients and animal models. It has been recently shown that a significant decrease in Sonic hedgehog (Shh) expression reduces the proliferative potential of granule neuron precursors in the developing cerebellum of Npc1 −/− mice. Pursuing the hypothesis that this developmental defect translates into functional impairments, we have assayed Npc1-deficient pups belonging to the milder mutant mouse strain Npc1 nmf164 for sensorimotor development from postnatal day (PN) 3 to PN21. Npc1 nmf164 / Npc1 nmf164 pups displayed a 2.5-day delay in the acquisition of complex motor abilities compared to wild-type (wt) littermates, in agreement with the significant disorganization of cerebellar cortex cytoarchitecture observed between PN11 and PN15. Compared to wt, Npc1 nmf164 homozygous mice exhibited a poorer morphological differentiation of Bergmann glia (BG), as indicated by thicker radial shafts and less elaborate reticular pattern of lateral processes. Also BG functional development was defective, as indicated by the significant reduction in GLAST and Glutamine synthetase expression. A reduced VGluT2 and GAD65 expression also indicated an overall derangement of the glutamatergic/GABAergic stimulation that PCs receive by climbing/parallel fibers and basket/stellate cells, respectively. Lastly, Npc1-deficiency also affected oligodendrocyte differentiation as indicated by the strong reduction of myelin basic protein. Two sequential 2-hydroxypropyl-β-cyclodextrin administrations at PN4 and PN7 counteract these defects, partially preventing functional impairment of BG and fully restoring the normal patterns of glutamatergic/GABAergic stimulation to PCs. These findings indicate that in Npc1 nmf164 homozygous mice the derangement of synaptic connectivity and dysmyelination during cerebellar morphogenesis largely anticipate motor deficits that are typically observed during adulthood.

Taurine (2-aminoethanesulphonic acid) is an endogenous amino acid that has a number of protective roles in most mammalian cells, including modulation of cytoplasmic calcium levels, antioxidant effects and protection against mitochondrial dysfunction and endoplasmic reticulum stress associated with neurological disorders. Thiotaurine (2-aminoethane thiosulfonate), a molecule structurally related to hypotaurine and taurine, counteracts the damaging effect of oxidants and prevents apoptosis of human neutrophils.