-
Neural Regeneration Research Jun 2024PrPSc, a misfolded, aggregation-prone isoform of the cellular prion protein (PrPC), is the infectious prion agent responsible for fatal neurodegenerative diseases of...
PrPSc, a misfolded, aggregation-prone isoform of the cellular prion protein (PrPC), is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals. PrPSc can adopt different pathogenic conformations (prion strains), which can be resistant to potential drugs, or acquire drug resistance, posing challenges for the development of effective therapies. Since PrPC is the obligate precursor of any prion strain and serves as the mediator of prion neurotoxicity, it represents an attractive therapeutic target for prion diseases. In this minireview, we briefly outline the approaches to target PrPC and discuss our recent identification of Zn(II)-BnPyP, a PrPC-targeting porphyrin with an unprecedented bimodal mechanism of action. We argue that in-depth understanding of the molecular mechanism by which Zn(II)-BnPyP targets PrPC may lead toward the development of a new class of dual mechanism anti-prion compounds.
PubMed: 38845221
DOI: 10.4103/NRR.NRR-D-24-00181 -
Bulletin of Mathematical Biology Jun 2024Many neurodegenerative diseases (NDs) are characterized by the slow spatial spread of toxic protein species in the brain. The toxic proteins can induce neuronal stress,...
Many neurodegenerative diseases (NDs) are characterized by the slow spatial spread of toxic protein species in the brain. The toxic proteins can induce neuronal stress, triggering the Unfolded Protein Response (UPR), which slows or stops protein translation and can indirectly reduce the toxic load. However, the UPR may also trigger processes leading to apoptotic cell death and the UPR is implicated in the progression of several NDs. In this paper, we develop a novel mathematical model to describe the spatiotemporal dynamics of the UPR mechanism for prion diseases. Our model is centered around a single neuron, with representative proteins P (healthy) and S (toxic) interacting with heterodimer dynamics (S interacts with P to form two S's). The model takes the form of a coupled system of nonlinear reaction-diffusion equations with a delayed, nonlinear flux for P (delay from the UPR). Through the delay, we find parameter regimes that exhibit oscillations in the P- and S-protein levels. We find that oscillations are more pronounced when the S-clearance rate and S-diffusivity are small in comparison to the P-clearance rate and P-diffusivity, respectively. The oscillations become more pronounced as delays in initiating the UPR increase. We also consider quasi-realistic clinical parameters to understand how possible drug therapies can alter the course of a prion disease. We find that decreasing the production of P, decreasing the recruitment rate, increasing the diffusivity of S, increasing the UPR S-threshold, and increasing the S clearance rate appear to be the most powerful modifications to reduce the mean UPR intensity and potentially moderate the disease progression.
Topics: Unfolded Protein Response; Prion Diseases; Mathematical Concepts; Neurons; Humans; Models, Neurological; Animals; Nonlinear Dynamics; Computer Simulation; Prions; Spatio-Temporal Analysis; Apoptosis
PubMed: 38837083
DOI: 10.1007/s11538-024-01307-y -
Intractable & Rare Diseases Research May 2024The Japanese Research Group for Neuro-infectious Diseases was founded in August 1996, and by 2004 it had evolved into the Japanese Society for Neuro-infectious Diseases....
The Japanese Research Group for Neuro-infectious Diseases was founded in August 1996, and by 2004 it had evolved into the Japanese Society for Neuro-infectious Diseases. The Society focuses on neuroinfectious conditions (., encephalitis/encephalopathy, myelitis, and meningitis), providing a venue for academic presentations and exchanges. Clinical guidelines for major neurological infectious diseases are also published by the Society, in order to meet the social demands of each era. Although the threat of herpes simplex encephalitis has declined due to acyclovir's introduction, the frequency of encephalitis or peripheral neuropathy caused by varicella-zoster virus is increasing. In Japan, prion disease, human T-cell leukemia virus-1 (HTLV-1)-associated myelopathy (HAM), subacute sclerosing panencephalitis (SSPE), and progressive multifocal leukoencephalopathy (PML) are designated as intractable diseases. The incidence of prion disease is 1.8/1,000,000 individuals, with the sporadic type accounting for 80%. Prion disease is fatal, and effective medications are awaited. HAM's prevalence is ~3/100,000 individuals, with a male-to-female ratio of 1:2-3. HAM is common in western Japan, including Kyushu and Okinawa. The prevalence of PML is rising with the spread of both immunosuppressive therapy for transplantation and treatment for multiple sclerosis. From late 2019 through 2020, the world faced a global outbreak of coronavirus disease 2019 (COVID-19) due to virus mutations, and the threat of new mutations persists. Close attention should be paid to the emergence of new neurological infections that could arise from abnormal weather patterns and/or a decline in immune function due to aging.
PubMed: 38836177
DOI: 10.5582/irdr.2024.01008 -
Neuro-oncology Jun 2024Brain metastases (BM) constitute an increasing challenge in oncology due to their impact on neurological function, limited treatment options, and poor prognosis. BM...
Brain metastases (BM) constitute an increasing challenge in oncology due to their impact on neurological function, limited treatment options, and poor prognosis. BM occur through extravasation of circulating tumor cells across the blood-brain barrier. However, the extravasation processes are still poorly understood. We here propose a brain colonization process which mimics infarction-like microenvironmental reactions, that is dependent on Angiopoietin (Ang-2) and vascular endothelial growth factor (VEGF). In this study, intracardiac BM models were used, and cerebral blood microcirculation was monitored by 2-photon microscopy through a cranial window. BM formation was observed using cranial magnetic resonance, bioluminescent imaging, and post-mortem autopsy. Ang-2/VEGF targeting strategies and Ang-2 gain-of-function (GOF) mice were employed to interfere with BM formation. In addition, vascular and stromal factors as well as clinical outcome were analyzed in BM patients. Blood vessel occlusions by cancer cells were detected, accompanied by significant disturbances of cerebral blood microcirculation, and focal stroke-like histological signs. Cerebral endothelial cells showed an elevated Ang-2 expression both in mouse and human BM. Ang-2 GOF resulted in an increased BM burden. Combined anti-Ang-2/anti-VEGF therapy led to a decrease in brain metastasis size and number. Ang-2 expression in tumor vessels of established human brain metastases negatively correlated with survival. Our observations revealed a relationship between disturbance of cerebral blood microcirculation and brain metastasis formation. This suggests that vessel occlusion by tumor cells facilitates brain metastatic extravasation and seeding, while combined inhibition of microenvironmental effects of Ang-2 and VEGF prevent the outgrowth of macrometastases.
PubMed: 38831719
DOI: 10.1093/neuonc/noae094 -
Heliyon Jun 2024The Forkhead box P2 (FOXP2) is an evolutionary conserved transcription factor involved in the maintenance of neuronal networks, implicated in language disorders. Some...
The Forkhead box P2 (FOXP2) is an evolutionary conserved transcription factor involved in the maintenance of neuronal networks, implicated in language disorders. Some evidence suggests a possible link between genetic variability and frontotemporal dementia (FTD) pathology and related endophenotypes. To shed light on this issue, we analysed the association between single-nucleotide polymorphisms (SNPs) in and FTD in 113 patients and 223 healthy controls. In addition, we investigated SNPs in two putative targets of FOXP2, , Contactin-associated protein-like 2 and , prion protein genes. Overall, 27 SNPs were selected by a tagging approach. -rs17213159-C/T resulted associated with disease risk (OR = 2.16, P = 0.0004), as well as with age at onset and severity of dementia. Other markers were associated with semantic and phonological fluency scores, cognitive levels (MMSE) and neuropsychological tests. Associations with language, cognitive and brain atrophy measures were found with and genetic variability. Overall, although preliminary, results here presented suggest an influence of regulatory pathways centred on FOXP2 as a molecular background of FTD affecting neurological function of multiple brain areas.
PubMed: 38828303
DOI: 10.1016/j.heliyon.2024.e31624 -
BioRxiv : the Preprint Server For... May 2024H5 influenza is considered a potential pandemic threat. Recently, H5 viruses belonging to clade 2.3.4.4b have caused large outbreaks in avian and multiple non-human...
H5 influenza is considered a potential pandemic threat. Recently, H5 viruses belonging to clade 2.3.4.4b have caused large outbreaks in avian and multiple non-human mammalian species. Previous studies have identified molecular phenotypes of the viral hemagglutinin (HA) protein that contribute to pandemic potential in humans, including cell entry, receptor preference, HA stability, and reduced neutralization by polyclonal sera. However, prior experimental work has only measured how these phenotypes are affected by a handful of the >10,000 different possible amino-acid mutations to HA. Here we use pseudovirus deep mutational scanning to measure how all mutations to a 2.3.4.4b H5 HA affect each phenotype. We identify mutations that allow HA to better bind α2-6-linked sialic acids, and show that some viruses already carry mutations that stabilize HA. We also measure how all HA mutations affect neutralization by sera from mice and ferrets vaccinated against or infected with 2.3.4.4b H5 viruses. These antigenic maps enable rapid assessment of when new viral strains have acquired mutations that may create mismatches with candidate vaccine strains. Overall, the systematic nature of deep mutational scanning combined with the safety of pseudoviruses enables comprehensive measurements of the phenotypic effects of mutations that can inform real-time interpretation of viral variation observed during surveillance of H5 influenza.
PubMed: 38826368
DOI: 10.1101/2024.05.23.595634 -
Veterinary Immunology and... Jul 2024Influenza A virus (IAV) is a major pathogen in the swine industry. Whole-inactivated virus (WIV) vaccines in swine are highly effective against homologous viruses but...
Influenza A virus (IAV) is a major pathogen in the swine industry. Whole-inactivated virus (WIV) vaccines in swine are highly effective against homologous viruses but provide limited protection to antigenically divergent viruses and may lead to vaccine-associated enhanced respiratory disease (VAERD) after heterologous infection. Although VAERD is reproducible in laboratory studies, clinical diagnosis is challenging, as it would require both knowledge of prior vaccine history and evidence of severe disease by assessment of pathologic lesions at necropsy following infection with a heterologous virus. The objective of this study was to identify potential biomarkers for VAERD for antemortem clinical diagnosis. Naïve pigs were split into two groups, and one group was vaccinated with IAV WIV vaccine. All pigs were then challenged with a heterologous virus to induce VAERD in the vaccinated group and necropsied at 5 days post infection (dpi). Blood was collected on 0, 1, 3, and 5 dpi, and assessed by hematology, plasma chemistry, acute phase proteins, and citrullinated H3 histone (CitH3) assays. Additionally, cytokine and CitH3 levels were assessed in bronchoalveolar lavage fluid (BALF) collected at necropsy. Compared to nonvaccinated challenged pigs, blood collected from vaccinated and challenged (V/C) pigs with VAERD had elevated white blood cells and neutrophils, elevated C-reactive protein and haptoglobin acute phase proteins, and elevated CitH3. In BALF, the proinflammatory cytokine IL-8 and CitH3 were elevated in V/C pigs. In conclusion, a profile of elevated white blood cells and neutrophils, elevated C-reactive protein and haptoglobin, and elevated CitH3 may be relevant for a clinical antemortem IAV VAERD diagnosis.
Topics: Animals; Swine; Orthomyxoviridae Infections; Swine Diseases; Influenza Vaccines; Biomarkers; Influenza A virus; Bronchoalveolar Lavage Fluid; Cytokines; Vaccines, Inactivated
PubMed: 38815504
DOI: 10.1016/j.vetimm.2024.110787 -
The Primary Care Companion For CNS... May 2024
Topics: Humans; Creutzfeldt-Jakob Syndrome
PubMed: 38815266
DOI: 10.4088/PCC.23cr03637 -
Biochemical Society Transactions Jun 2024The dysfunction of many RNA-binding proteins (RBPs) that are heavily disordered, including TDP-43 and FUS, are implicated in amyotrophic lateral sclerosis and... (Review)
Review
The dysfunction of many RNA-binding proteins (RBPs) that are heavily disordered, including TDP-43 and FUS, are implicated in amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). These proteins serve many important roles in the cell, and their capacity to form biomolecular condensates (BMCs) is key to their function, but also a vulnerability that can lead to misregulation and disease. Matrin-3 (MATR3) is an intrinsically disordered RBP implicated both genetically and pathologically in ALS/FTD, though it is relatively understudied as compared with TDP-43 and FUS. In addition to binding RNA, MATR3 also binds DNA and is implicated in many cellular processes including the DNA damage response, transcription, splicing, and cell differentiation. It is unclear if MATR3 localizes to BMCs under physiological conditions, which is brought further into question due to its lack of a prion-like domain. Here, we review recent studies regarding MATR3 and its roles in numerous physiological processes, as well as its implication in a range of diseases.
Topics: Humans; RNA-Binding Proteins; Amyotrophic Lateral Sclerosis; Nuclear Matrix-Associated Proteins; Frontotemporal Dementia; DNA-Binding Proteins; Animals; DNA Damage; RNA-Binding Protein FUS
PubMed: 38813817
DOI: 10.1042/BST20220585 -
Frontiers in Veterinary Science 2024Prion diseases in mammals are caused by the structural conversion of the natural prion protein (PrP) to a pathogenic isoform, the "scrapie form of prion protein (PrP)."...
BACKGROUND
Prion diseases in mammals are caused by the structural conversion of the natural prion protein (PrP) to a pathogenic isoform, the "scrapie form of prion protein (PrP)." Several studies reported that the shadow of prion protein (Sho), encoded by the shadow of prion protein gene (), is involved in prion disease development by accelerating the conformational conversion of PrP to PrP. Until now, genetic polymorphisms of the gene and the protein structure of Sho related to fragility to prion disease have not been investigated in pheasants, which are a species of poultry.
METHODS
Here, we identified the gene sequence by polymerase chain reaction (PCR) and compared the gene and Sho protein sequences among various prion disease-susceptible and -resistant species to identify the distinctive genetic features of pheasant Sho using Clustal Omega. In addition, we investigated genetic polymorphisms of the gene in pheasants and analyzed genotype, allele, and haplotype frequencies, as well as linkage disequilibrium among the genetic polymorphisms. Furthermore, we used programs, namely Mutpred2, MUpro and AMYCO, to investigate the effect of non-synonymous single nucleotide polymorphisms (SNPs). Finally, the predicted secondary and tertiary structures of Sho proteins from various species were analyzed by Alphafold2.
RESULTS
In the present study, we reported pheasant gene sequences for the first time and identified a total of 14 novel SNPs, including 7 non-synonymous and 4 synonymous SNPs. In addition, the pheasant Sho protein sequence showed 100% identity with the chicken Sho protein sequence. Furthermore, amino acid substitutions were predicted to affect the hydrogen bond distribution in the 3D structure of the pheasant Sho protein.
CONCLUSION
To the best of our knowledge, this is the first report of the genetic and structural features of the pheasant gene.
PubMed: 38812560
DOI: 10.3389/fvets.2024.1399548