New insights into the effects of APP gene dose on synapse in Down syndrome

Synaptic dysfunction:Alzheimer’s disease(AD)is a prevalent form of dementia,affecting over 35 million people worldwide(Tzioras et al.,2023).A synapse serves as the connection point between neurons,facilitating the transmission of information from one neuron to another.Dynamic alterations in synapses,known as synaptic plasticity,play a pivotal role in cognitive processes such as learning and memory.Synaptic loss has been identified as a key contributor to cognitive decline in AD patients.Studies have shown that the soluble forms of amyloid-beta(Aβ)and tau proteins are toxic to synapses,leading to cognitive impairment in animal models(Spires-Jones and Hyman,2014).Additionally,the formation of oligomers of tau and Aβcan spread pathology through synaptic connections in the brain,emphasizing the vital role of synapses in disease progression.

ATP6AP2,a regulator of LRP6/β-catenin protein trafficking,promotes Wnt/β-catenin signaling and bone formation in a cell type dependent manner

Wnt/β-catenin signaling is critical for various cellular processes in multiple cell types,including osteoblast(OB)differentiation and function.Exactly how Wnt/β-catenin signaling is regulated in OBs remain elusive.ATP6AP2,an accessory subunit of V-ATPase,plays important roles in multiple cell types/organs and multiple signaling pathways.However,little is known whether and how ATP6AP2 in OBs regulates Wnt/β-catenin signaling and bone formation.Here we provide evidence for ATP6AP2 in the OB-lineage cells to promote OB-mediated bone formation and bone homeostasis selectively in the trabecular bone regions.Conditionally knocking out(CKO)ATP6AP2 in the OB-lineage cells(Atp6ap2^(Ocn-Cre))reduced trabecular,but not cortical,bone formation and bone mass.Proteomic and cellular biochemical studies revealed that LRP6 and N-cadherin were reduced in ATP6AP2-KO BMSCs and OBs,but not osteocytes.Additional in vitro and in vivo studies revealed impairedβ-catenin signaling in ATP6AP2-KO BMSCs and OBs,but not osteocytes,under both basal and Wnt stimulated conditions,although LRP5 was decreased in ATP6AP2-KO osteocytes,but not BMSCs.Further cell biological studies uncovered that osteoblastic ATP6AP2 is not required for Wnt3a suppression ofβ-catenin phosphorylation,but necessary for LRP6/β-catenin and N-cadherin/β-catenin protein complex distribution at the cell membrane,thus preventing their degradation.Expression of activeβ-catenin diminished the OB differentiation deficit in ATP6AP2-KO BMSCs.Taken together,these results support the view for ATP6AP2 as a critical regulator of both LRP6 and N-cadherin protein trafficking and stability,and thus regulatingβ-catenin levels,demonstrating an un-recognized function of osteoblastic ATP6AP2 in promoting Wnt/LRP6/β-catenin signaling and trabecular bone formation.

Decline and fall of aging astrocytes:the human perspective

“Last scene of all that ends this strange,eventful history,is second childishness and mere oblivion.I am sans teeth,sans eyes,sans taste,sans everything.”William Shakespeare‘As You Like It'Act 2,Sc.7,l.139Aging of the human brain is characterized by a progressive decline of its functional capacity;this decline however varies widely,and cognitive longevity differs substantially between individuals.

The interplay mechanism between IDH mutation, MGMT-promoter methylation, and PRMT5 activity in the progression of grade 4 astrocytoma: unraveling the complex triad theory

Background:The dysregulation of Isocitrate dehydrogenase(IDH)and the subsequent production of 2-Hydroxyglutrate(2HG)may alter the expression of epigenetic proteins in Grade 4 astrocytoma.The interplay mechanism between IDH,O-6-methylguanine-DNA methyltransferase(MGMT)-promoter methylation,and protein methyltransferase proteins-5(PRMT5)activity,with tumor progression has never been described.Methods:A retrospective cohort of 34 patients with G4 astrocytoma is classified into IDH-mutant and IDH-wildtype tumors.Both groups were tested for MGMT-promoter methylation and PRMT5 through methylation-specific and gene expression PCR analysis.Inter-cohort statistical significance was evaluated.Results:Both IDH-mutant WHO grade 4 astrocytomas(n=22,64.7%)and IDH-wildtype glioblastomas(n=12,35.3%)had upregulated PRMT5 gene expression except in one case.Out of the 22 IDH-mutant tumors,10(45.5%)tumors showed MGMT-promoter methylation and 12(54.5%)tumors had unmethylated MGMT.All IDH-wildtype tumors had unmethylated MGMT.There was a statistically significant relationship between MGMT-promoter methylation and IDH in G4 astrocytoma(p-value=0.006).Statistically significant differences in progression-free survival(PFS)were also observed among all G4 astrocytomas that expressed PRMT5 and received either temozolomide(TMZ)or TMZ plus other chemotherapies,regardless of their IDH or MGMT-methylation status(p-value=0.0014).Specifically,IDH-mutant tumors that had upregulated PRMT5 activity and MGMT-promoter methylation,who received only TMZ,have exhibited longer PFS.Conclusions:The relationship between PRMT5,MGMT-promoter,and IDH is not tridirectional.However,accumulation of D2-hydroxyglutarate(2-HG),which partially activates 2-OG-dependent deoxygenase,may not affect their activities.In IDH-wildtype glioblastomas,the 2HG-2OG pathway is typically inactive,leading to PRMT5 upregulation.TMZ alone,compared to TMZ-plus,can increase PFS in upregulated PRMT5 tumors.Thus,using a PRMT5 inhibitor in G4 astrocytomas may help in tumor regression.

PCDH17 restricts dendritic spine morphogenesis by regulating ROCK2-dependent control of the actin cytoskeleton,modulating emotional behavior

Proper regulation of synapse formation and elimination is critical for establishing mature neuronal circuits and maintaining brain function.Synaptic abnormalities,such as defects in the density and morphology of postsynaptic dendritic spines,underlie the pathology of various neuropsychiatric disorders.Protocadherin 17(PCDH17)is associated with major mood disorders,including bipolar disorder and depression.However,the molecular mechanisms by which PCDH17 regulates spine number,morphology,and behavior remain elusive.In this study,we found that PCDH17 functions at postsynaptic sites,restricting the number and size of dendritic spines in excitatory neurons.Selective overexpression of PCDH17 in the ventral hippocampal CA1 results in spine loss and anxiety-and depression-like behaviors in mice.Mechanistically,PCDH17 interacts with actin-relevant proteins and regulates actin filament(F-actin)organization.Specifically,PCDH17 binds to ROCK2,increasing its expression and subsequently enhancing the activity of downstream targets such as LIMK1 and the phosphorylation of cofilin serine-3(Ser3).Inhibition of ROCK2 activity with belumosudil(KD025)ameliorates the defective F-actin organization and spine structure induced by PCDH17 overexpression,suggesting that ROCK2 mediates the effects of PCDH17 on F-actin content and spine development.Hence,these findings reveal a novel mechanism by which PCDH17 regulates synapse development and behavior,providing pathological insights into the neurobiological basis of mood disorders.

Reconsidering the role of depression and common psychiatric disorders as partners in the type 2 diabetes epidemic

Common psychiatric disorders(CPDs)and depression contribute significantly to the global epidemic of type 2 diabetes(T2D).We postulated a possible pathophysiological mechanism that through Bridge-Symptoms present in depression and CPDs,promotes the establishment of emotional eating,activation of the reward system,onset of overweight and obesity and,ultimately the increased risk of developing T2D.The plausibility of the proposed pathophysiological mechanism is supported by the mechanism of action of drugs such as naltrexonebupropion currently approved for the treatment of both obesity/overweight with T2D and as separate active pharmaceutical ingredients in drug addiction,but also from initial evidence that is emerging regarding glucagon-like peptide 1 receptor agonists that appear to be effective in the treatment of drug addiction.We hope that our hypothesis may be useful in interpreting the higher prevalence of CPDs and depression in patients with T2D compared with the general population and may help refine the integrated psychiatric-diabetic therapy approach to improve the treatment and or remission of T2D.

Gut microbiota in women:The secret of psychological and physical well-being

The gut microbiota works in unison with the host,promoting its health.In particular,it has been shown to exert protective,metabolic and structural functions.Recent evidence has revealed the influence of the gut microbiota on other organs such as the central nervous system,cardiovascular and the endocrine-metabolic systems and the digestive system.The study of the gut microbiota is outlining new and broader frontiers every day and holds enormous innovation potential for the medical and pharmaceutical fields.Prevention and treatment of specific women’s diseases involves the need to deepen the function of the gut as a junction organ where certain positive bacteria can be very beneficial to health.The gut microbiota is unique and dynamic at the same time,subject to external factors that can change it,and is capable of modulating itself at different stages of a woman’s life,playing an important role that arises from the intertwining of biological mechanisms between the microbiota and the female genital system.The gut microbiota could play a key role in personalized medicine.

The landscape of cognitive impairment in superoxide dismutase 1-amyotrophic lateral sclerosis

Although mutations in the superoxide dismutase 1 gene account for only a minority of total amyotrophic lateral sclerosis cases,the discovery of this gene has been crucial for amyotrophic lateral sclerosis research.Since the identification of superoxide dismutase 1 in 1993,the field of amyotrophic lateral sclerosis genetics has considerably widened,improving our understanding of the diverse pathogenic basis of amyotrophic lateral sclerosis.In this review,we focus on cognitive impairment in superoxide dismutase 1-amyotrophic lateral sclerosis patients.Literature has mostly reported that cognition remains intact in superoxide dismutase 1-amyotrophic lateral sclerosis patients,but recent reports highlight frontal lobe function frailty in patients carrying different superoxide dismutase 1-amyotrophic lateral sclerosis mutations.We thoroughly reviewed all the various mutations reported in the literature to contribute to a comprehensive database of superoxide dismutase 1-amyotrophic lateral sclerosis genotype-phenotype correlation.Such a resource could ultimately improve our mechanistic understanding of amyotrophic lateral sclerosis,enabling a more robust assessment of how the amyotrophic lateral sclerosis phenotype responds to different variants across genes,which is important for the therapeutic strategy targeting genetic mutations.Cognition in superoxide dismutase 1-amyotrophic lateral sclerosis deserves further longitudinal research since this peculiar frailty in patients with similar mutations can be conditioned by external factors,including environment and other unidentified agents including modifier genes.

A novel model of drug cue-induced behaviours in rhesus macaque subjected to chronic ketamine exposure

To the Editor,Non-human primate(NHP)models are advantageous for mimicking human addiction with high behavioural validity.1 However,current NHP drug addiction models(eg,self-administration)often require a comprehensive behavioural training paradigm,relatively expensive apparatus and invasive surgical procedures.

Profiling neuroprotective potential of trehalose in animal models of neurodegenerative diseases:a systematic review

Trehalose,a unique nonreducing crystalline disaccharide,is a potential disease-modifying treatment for neurodegenerative diseases associated with protein misfolding and aggregation due to aging,intrinsic mutations,or autophagy dysregulation.This systematic review summarizes the effects of trehalose on its underlying mechanisms in animal models of selected neurodegenerative disorders(tau pathology,synucleinopathy,polyglutamine tract,and motor neuron diseases).All animal studies on neurodegenerative diseases treated with trehalose published in Medline(accessed via EBSCOhost)and Scopus were considered.Of the 2259 studies screened,29 met the eligibility criteria.According to the SYstematic Review Center for Laboratory Animal Experiment(SYRCLE)risk of bias tool,we reported 22 out of 29 studies with a high risk of bias.The present findings support the purported role of trehalose in autophagic flux and protein refolding.This review identified several other lesser-known pathways,including modifying amyloid precursor protein processing,inhibition of reactive gliosis,the integrity of the blood-brain barrier,activation of growth factors,upregulation of the downstream antioxidant signaling pathway,and protection against mitochondrial defects.The absence of adverse events and improvements in the outcome parameters were observed in some studies,which supports the transition to human clinical trials.It is possible to conclude that trehalose exerts its neuroprotective effects through both direct and indirect pathways.However,heterogeneous methodologies and outcome measures across the studies rendered it impossible to derive a definitive conclusion.Translational studies on trehalose would need to clarify three important questions:1)bioavailability with oral administration,2)optimal time window to confer neuroprotective benefits,and 3)optimal dosage to confer neuroprotection.

A broad overview of genotype imputation:Standard guidelines,approaches,and future investigations in genomic association studies

The advent of genomic big data and the statistical need for reaching significant results have led genome-wide association studies to be ravenous of a huge number of genetic markers scattered along the whole genome.Since its very beginning,the so-called genotype imputation served this purpose;this statistical and inferential procedure based on a known reference panel opened the theoretical possibility to extend association analyses to a greater number of polymorphic sites which have not been previously assayed by the used technology.In this review,we present a broad overview of the genotype imputation process,showing the most known methods and presenting the main areas of interest,with a closer look to the most up-to-date approaches and a deeper understanding of its usage in the presentday genomic landscape,shedding a light on its future developments and investigation areas.

(Phospho)creatine:the reserve and merry-go-round of brain energetics

Creatine transporter(CrT)-deficiency,the most common form of the cerebral creatine deficiency syndromes,causes cognition impairments and severe reduction of the brain creatine(Cr)and phosphocreatine(PCr)levels,and responds poorly to oral Cr supplement as a treatment option.The ca uses of cognitive impairments in CrT-deficient children remain unclear.We recently use gene-targeting to create a mouse model of CrT-deficiency to assess the impacts of Cr/PCr deficiency on brain energetics and stress-adaptation responses(Chen et al.,2021).

A systematic review of robot-assisted partial nephrectomy outcomes for advanced indications:Large tumors(cT2-T3),solitary kidney,completely endophytic,hilar,recurrent,and multiple renal tumors

Objective:Robot-assisted partial nephrectomy(RAPN)has become widely used for treatment of renal cell carcinoma and it is expanding in the field of complex renal masses.The aim of this systematic review was to analyze outcomes of RAPN for completely endophytic renal masses,large tumors(cT2-T3),renal cell carcinoma in solitary kidney,recurrent tumors,completely endophytic and hilar masses,and simultaneous and multiple tumors.Methods:A comprehensive search in the PubMed,Scopus,Web of Science,and Cochrane Central Register of Controlled Trials databases was performed in December 2022 for English language papers.The primary endpoint was to evaluate the role of RAPN in the setting of each category of complex renal masses considered.The secondary endpoint was to evaluate the surgical and functional outcomes.Results:After screening 1250 records,43 full-text manuscripts were selected,comprising over 8500 patients.Twelve and thirteen studies reported data for endophytic and hilar renal masses,respectively.Five and three studies reported outcomes for cT2-T3 and solitary kidney patients,respectively.Four studies focused on redo-RAPN for recurrent tumors.Two studies investigated simultaneous bilateral renal masses and five reports focused on multiple tumor excision in ipsilateral kidney.Conclusion:Over the past decade,evidence supporting the use of RAPN for the most challenging nephron-sparing surgery indications has continuously grown.Although limitations remain including study design and lack of detailed long-term functional and oncological outcomes,the adoption of RAPN for the included advanced indications is associated with favorable surgical outcomes with good preservation of renal function without compromising the oncological result.Certainly,a higher likelihood of complication might be expected when facing extremely challenging cases.However,none of these indications should be considered per se an exclusion criterion for performing RAPN.Ultimately,a risk-adapted approach should be employed.

Multifaceted superoxide dismutase 1 expression in amyotrophic lateral sclerosis patients:a rare occurrence?

Amyotrophic lateral sclerosis(ALS)is a neuromuscular condition resulting from the progressive degeneration of motor neurons in the cortex,brainstem,and spinal cord.While the typical clinical phenotype of ALS involves both upper and lower motor neurons,human and animal studies over the years have highlighted the potential spread to other motor and non-motor regions,expanding the phenotype of ALS.Although superoxide dismutase 1(SOD1)mutations represent a minority of ALS cases,the SOD1 gene remains a milestone in ALS research as it represents the first genetic target for personalized therapies.Despite numerous single case reports or case series exhibiting extramotor symptoms in patients with ALS mutations in SOD1(SOD1-ALS),no studies have comprehensively explored the full spectrum of extramotor neurological manifestations in this subpopulation.In this narrative review,we analyze and discuss the available literature on extrapyramidal and non-motor features during SOD1-ALS.The multifaceted expression of SOD1 could deepen our understanding of the pathogenic mechanisms,pointing towards a multidisciplinary approach for affected patients in light of new therapeutic strategies for SOD1-ALS.

Combining neural progenitor cell transplant and rehabilitation for enhanced recovery after cervical spinal cord injury

Efforts to promote recovery of function after human spinal cord injury(SCI) will likely require interventions to rgeting the corticospinal tract(CST) motor system:the most important pathway for voluntary motor control in humans.This system has historically been the most refractory to regenerative efforts after SCI.The "nonregeneration" of the CST changed when robust regeneration of the CST into spared tissue was demonstrated by the inactivation of phosphatase and tensin homolog and delivery of inosine.

Corneal collagen cross-linking in patients with keratoconus from the Dresden protocol to customized solutions:theoretical basis

Keratoconus is an ectatic condition characterized by gradual corneal thinning,corneal protrusion,progressive irregular astigmatism,corneal fibrosis,and visual impairment.The therapeutic options regarding improvement of visual function include glasses or soft contact lenses correction for initial stages,gas-permeable rigid contact lenses,scleral lenses,implantation of intrastromal corneal ring or corneal transplants for most advanced stages.In keratoconus cases showing disease progression corneal collagen crosslinking(CXL)has been proven to be an effective,minimally invasive and safe procedure.CXL consists of a photochemical reaction of corneal collagen by riboflavin stimulation with ultraviolet A radiation,resulting in stromal crosslinks formation.The aim of this review is to carry out an examination of CXL methods based on theoretical basis and mathematical models,from the original Dresden protocol to the most recent developments in the technique,reporting the changes proposed in the last 15y and examining the advantages and disadvantages of the various treatment protocols.Finally,the limits of non-standardized methods and the perspectives offered by a customization of the treatment are highlighted.

Multiple sclerosis is at a checkpoint: advancing the program

Multiple sclerosis(MS) is a chronic inflammatory and demyelinating disease of the central nervous system(CNS). Patients with MS experience sensory and motor function loss due to myelin and/or axon damage perpetuated by infiltrating immune cells(Hauser and Cree, 2020).

Small molecular decoys in Alzheimer's disease

Recent progress in the treatment of Alzheimer’s disease(AD)using antibodies against amyloid sustains amyloid generation as a key process in AD.Amyloid formation starts with two amyloidbeta(Aβ)molecules interacting(dimer formation)followed by an accelerating build-up of socalled protofibrils,which turn into fibrils,which accumulate in the characteristic plaques.

Astrocyte syncytium:from neonatal genesis to aging degeneration

Modern neuroscience began from all reaching and fierce conflict between“neuronismo and reticulismo”——between neuronal and reticular theories of the organization of the nervous system;the conflict culminated in December of 1906 in Stockholm where Santiago Ramon y Cajal(the proponent of the neuronal doctrine)and Camillo Golgi(who advocated the syncytial reticular organization of neural networks)delivered their Noble prize lectures(Verkhratsky,2009).

Apolipoprotein A-I binding protein-mediated neuroprotection in glaucomatous neuroinflammation and neurodegeneration

Glaucoma is a multifactorial eye disorder that can cause vision loss and irreversible blindness,affecting individ uals aged 40 to 80 yea rs worldwide.Due to the aging population,it is expected that the number of people affected by glaucoma will surpass 111 million by 2040 as the disease becomes more prevalent.Glaucoma primarily contributes to optic nerve axon loss and the progressive degeneration of retinal ganglion cells (RGCs),subsequently leading to vision impairment.