TDP-43 differentially propagates to induce antero- and retrograde degeneration in the corticospinal circuits in mouse focal ALS models.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by TDP-43 inclusions in the cortical and spinal motor neurons. It remains unknown whether and how pathogenic TDP-43 spreads across neural connections to progress degenerative processes in the cortico-spinal motor circuitry. Here we established novel mouse ALS models that initially induced mutant TDP-43 inclusions in specific neuronal or cell types in the motor circuits, and investigated whether TDP-43 and relevant pathological processes spread across neuronal or cellular connections. We first developed ALS models that primarily induced TDP-43 inclusions in the corticospinal neurons, spinal motor neurons, or forelimb skeletal muscle, by using adeno-associated virus (AAV) expressing mutant TDP-43. We found that TDP-43 induced in the corticospinal neurons was transported along the axons anterogradely and transferred to the oligodendrocytes along the corticospinal tract (CST), coinciding with mild axon degeneration. In contrast, TDP-43 introduced in the spinal motor neurons did not spread retrogradely to the cortical or spinal neurons; however, it induced an extreme loss of spinal motor neurons and subsequent degeneration of neighboring spinal neurons, suggesting a degenerative propagation in a retrograde manner in the spinal cord. The intraspinal degeneration further led to severe muscle atrophy. Finally, TDP-43 induced in the skeletal muscle did not propagate pathological events to spinal neurons retrogradely. Our data revealed that mutant TDP-43 spread across neuro-glial connections anterogradely in the corticospinal pathway, whereas it exhibited different retrograde degenerative properties in the spinal circuits. This suggests that pathogenic TDP-43 may induce distinct antero- and retrograde mechanisms of degeneration in the motor system in ALS.

Maternal Dietary Vitamin D Intake during Pregnancy Is Associated with Allergic Disease Symptoms in Children at 3 Years Old: The Japan Environment and Children's Study.

INTRODUCTION: Vitamin D plays an important role in the immune system, and postnatal vitamin D insufficiency is one of the risk factors for the development of allergic disease. However, the effects of women's vitamin D intake during pregnancy on the prevalence of allergic disease in their children remain controversial. METHODS: From the Japan Environment and Children's Study, an ongoing nationwide birth cohort study, we obtained information on maternal dietary vitamin D intake determined using a food frequency questionnaire and parent-reported allergic disease symptoms based on the ISAAC questionnaire in children at 3 years of age. RESULTS: From the full dataset of 103,060 pregnancies, we analyzed complete data for 73,309 mother-child pairs. The prevalence of current wheeze, current rhinitis, current rhino-conjunctivitis, current eczema, ever asthma, ever pollinosis, and ever atopic dermatitis in the children was 17.2%, 29.7%, 3.8%, 15.2%, 9.6%, 3.7%, and 11.0%, respectively. The ORs for current rhinitis were significantly lower in the 3rd, 4th, and 5th quintiles than in the 1st quintile after adjustment for various covariates and showed a linear association. The ORs for ever pollinosis were significantly lower in the 2nd, 3rd, and 4th quintiles than in the 1st quintile, showing a U-shaped curve. There was no clear association between mothers' dietary vitamin D intake and symptoms of asthma or atopic dermatitis in their 3-year-old children. CONCLUSION: Maternal dietary vitamin D intake during pregnancy is associated with the ORs for nasal allergies in children at the age of 3 years. Further studies are warranted to evaluate the appropriate intake dose of vitamin D for pregnant women to prevent the development of nasal allergies in their children.

Oxygen-Glucose Deprived Peripheral Blood Mononuclear Cells Protect Against Ischemic Stroke.

Stroke is the leading cause of severe long-term disability. Cell therapy has recently emerged as an approach to facilitate functional recovery in stroke. Although administration of peripheral blood mononuclear cells preconditioned by oxygen-glucose deprivation (OGD-PBMCs) has been shown to be a therapeutic strategy for ischemic stroke, the recovery mechanisms remain largely unknown. We hypothesised that cell-cell communications within PBMCs and between PBMCs and resident cells are necessary for a polarising protective phenotype. Here, we investigated the therapeutic mechanisms underlying the effects of OGD-PBMCs through the secretome. We compared levels of transcriptomes, cytokines, and exosomal microRNA in human PBMCs by RNA sequences, Luminex assay, flow cytometric analysis, and western blotting under normoxic and OGD conditions. We also performed microscopic analyses to assess the identification of remodelling factor-positive cells and evaluate angiogenesis, axonal outgrowth, and functional recovery by blinded examination by administration of OGD-PBMCs after ischemic stroke in Sprague-Dawley rats. We found that the therapeutic potential of OGD-PBMCs was mediated by a polarised protective state through decreased levels of exosomal miR-155-5p, and upregulation of vascular endothelial growth factor and a pluripotent stem cell marker stage-specific embryonic antigen-3 through the hypoxia-inducible factor-1α axis. After administration of OGD-PBMCs, microenvironment changes in resident microglia by the secretome promoted angiogenesis and axonal outgrowth, resulting in functional recovery after cerebral ischemia. Our findings revealed the mechanisms underlying the refinement of the neurovascular unit by secretome-mediated cell-cell communications through reduction of miR-155-5p from OGD-PBMCs, highlighting the therapeutic potential carrier of this approach against ischemic stroke.

Phosphorylation of α-synuclein at T64 results in distinct oligomers and exerts toxicity in models of Parkinson's disease.

α-Synuclein accumulates in Lewy bodies, and this accumulation is a pathological hallmark of Parkinson's disease (PD). Previous studies have indicated a causal role of α-synuclein in the pathogenesis of PD. However, the molecular and cellular mechanisms of α-synuclein toxicity remain elusive. Here, we describe a novel phosphorylation site of α-synuclein at T64 and the detailed characteristics of this post-translational modification. T64 phosphorylation was enhanced in both PD models and human PD brains. T64D phosphomimetic mutation led to distinct oligomer formation, and the structure of the oligomer was similar to that of α-synuclein oligomer with A53T mutation. Such phosphomimetic mutation induced mitochondrial dysfunction, lysosomal disorder, and cell death in cells and neurodegeneration in vivo, indicating a pathogenic role of α-synuclein phosphorylation at T64 in PD.

Prevalence of Allergic Diseases across All Ages in Japan: A Nationwide Cross-Sectional Study Employing Designated Allergic Disease Medical Hospital Network.

Introduction: Allergic diseases affect both children and adults, but generation-specific prevalence rates are unclear. Methods: An online questionnaire was used from December 2021 to January 2022 to survey the prevalence of allergic diseases among staff and their families of designated allergic disease medical hospitals in Japan. In this study, bronchial asthma (BA), atopic dermatitis (AD), food allergies (FAs), allergic rhinitis (AR), allergic conjunctivitis (AC), metal allergies (MAs), and drug allergies (DAs) were the allergic diseases surveyed. Results: In total, 18,706 individuals were surveyed (median age, 36 years; quartile range, 18-50). Allergic disease was reported in 62.2% of respondents. Across all ages, prevalence rates were as follows: BA (14.7%), AD (15.6%), FAs (15.2%), AR (47.4%), AC (19.5%), MAs (1.9%), and DAs (4.6%). The prevalence of BA and AR was higher in male children, whereas that of FAs and AC was higher in adult females. The prevalence of MAs and DAs peaked during adulthood and predominated among females. Conclusions: Our results suggest that approximately two-thirds of the Japanese population may have an allergic disease, with AR being the most prevalent.

Association of soap use when bathing 18-month-old infants with the prevalence of allergic diseases at age 3 years: The Japan Environment and Children's Study.

BACKGROUND: Atopic march is defined as the progression from atopic dermatitis (AD) during early life to other allergic diseases in later childhood. In a nationwide birth cohort study, the Japan Environment and Children's Study, we investigated the association of bathing habits, which are known to affect skin conditions, for infants with their later development of allergic diseases. METHODS: Pregnant women who lived in 15 designated regional centers throughout Japan were recruited. We obtained information on bathing habits for their 18-month-old infants and the prevalence of allergic diseases when they were aged 3 years. RESULTS: Data for 74,349 children were analyzed. Most 18-month-old infants were bathed or showered almost every day. When they were divided into four groups according to the frequency of soap use during bathing (every time, most of the time, sometimes, and seldom), the risk of AD later at age 3 was shown to increase in association with a decreasing frequency of soap use [most of the time: adjusted odds ratio (aOR) 1.18, 95% confidence interval (CI) 1.05-1.34; sometimes: aOR 1.72, 95% CI 1.46-2.03; seldom: aOR 1.99, 95% CI 1.58-2.50], compared with soap use every time during bathing at 18 months of age. Similar results were obtained for food allergy but not for bronchial asthma. CONCLUSIONS: Frequent soap use when bathing 18-month-old infants was associated with a decreased risk of them developing allergic diseases at age 3. Further well-designed clinical studies are warranted to determine an effective bathing regimen for preventing the development of allergic diseases.

Association between Maternal Vitamin D Intake and Infant Allergies: The Japan Environment and Children's Study.

Maternal nutrition during pregnancy is one of the factors affecting the health of offspring. There are conflicting findings about the association between maternal vitamin D status and the development of allergic diseases in offspring. The purpose of this study is to evaluate the association between maternal vitamin D intake and the development of allergic diseases in offspring at 1 y of age. From an ongoing nationwide birth cohort study (the Japan Environment and Children's Study), we obtained information on maternal vitamin D intake, determined by a food frequency questionnaire, and parent-reported physician-diagnosed allergic diseases in offspring at 1 y of age. From the full dataset of 103,062 pregnancies, we analyzed complete data for 82,592 mother-offspring pairs. The prevalence of physician-diagnosed asthma, food allergy, and atopic dermatitis in the children was 2.5%, 6.6%, and 4.3%, respectively. The mean (± standard deviation) maternal vitamin D intake was 4.7±4.7 µg/d, which is much lower than the recommended amount in Japan (7 µg/d). After adjustment for various covariates, the odds ratios were significantly higher for asthma in the 2nd quintile and for food allergies in the 3rd and 4th quintiles compared with the 1st quintile. However, there were no clear associations between maternal vitamin D intake and the development of allergic diseases in offspring at 1 y of age, even in a large nation-wide cohort study. Protective effects of vitamin D supplementation remain unclear.

Endogenous human retrovirus-K is not increased in the affected tissues of Japanese ALS patients.

Activation of human endogenous retrovirus-K (HERV-K) is one of the proposed risk factors for amyotrophic lateral sclerosis (ALS). The HERV-K envelope protein has been reported to show neurotoxicity, and development of therapy with reverse transcriptase inhibitors is being investigated. On the other hand, some reports have failed to show HERV-K activation in ALS. In this study, we analyzed the expression of HERV-K mRNA in the motor cortex and spinal cord of 15 Japanese patients with sporadic ALS and 19 controls using reverse transcriptase droplet digital PCR. This revealed no significant increase of HERV-K expression in ALS-affected tissues, suggesting that the association between ALS and HERV-K remains questionable.

Candesartan prevents arteriopathy progression in cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy model.

Cerebral small vessel disease (CSVD) causes dementia and gait disturbance due to arteriopathy. Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a hereditary form of CSVD caused by loss of high-temperature requirement A1 (HTRA1) serine protease activity. In CARASIL, arteriopathy causes intimal thickening, smooth muscle cell (SMC) degeneration, elastic lamina splitting, and vasodilation. The molecular mechanisms were proposed to involve the accumulation of matrisome proteins as substrates or abnormalities in transforming growth factor ß (TGF-ß) signaling. Here, we show that HTRA1-/- mice exhibited features of CARASIL-associated arteriopathy: intimal thickening, abnormal elastic lamina, and vasodilation. In addition, the mice exhibited reduced distensibility of the cerebral arteries and blood flow in the cerebral cortex. In the thickened intima, matrisome proteins, including the hub protein fibronectin (FN) and latent TGF-ß binding protein 4 (LTBP-4), which are substrates of HTRA1, accumulated. Candesartan treatment alleviated matrisome protein accumulation and normalized the vascular distensibility and cerebral blood flow. Furthermore, candesartan reduced the mRNA expression of Fn1, Ltbp-4, and Adamtsl2, which are involved in forming the extracellular matrix network. Our results indicate that these accumulated matrisome proteins may be potential therapeutic targets for arteriopathy in CARASIL.

Corrigendum: HTRA1 Mutations Identified in Symptomatic Carriers Have the Property of Interfering the Trimer-Dependent Activation Cascade.

[This corrects the article DOI: 10.3389/fneur.2019.00693.].

HTRA1-Related Cerebral Small Vessel Disease: A Review of the Literature.

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is clinically characterized by early-onset dementia, stroke, spondylosis deformans, and alopecia. In CARASIL cases, brain magnetic resonance imaging reveals severe white matter hyperintensities (WMHs), lacunar infarctions, and microbleeds. CARASIL is caused by a homozygous mutation in high-temperature requirement A serine peptidase 1 (HTRA1). Recently, it was reported that several heterozygous mutations in HTRA1 also cause cerebral small vessel disease (CSVD). Although patients with heterozygous HTRA1-related CSVD (symptomatic carriers) are reported to have a milder form of CARASIL, little is known about the clinical and genetic differences between the two diseases. Given this gap in the literature, we collected clinical information on HTRA1-related CSVD from a review of the literature to help clarify the differences between symptomatic carriers and CARASIL and the features of both diseases. Forty-six symptomatic carriers and 28 patients with CARASIL were investigated. Twenty-eight mutations in symptomatic carriers and 22 mutations in CARASIL were identified. Missense mutations in symptomatic carriers are more frequently identified in the linker or loop 3 (L3)/loop D (LD) domains, which are critical sites in activating protease activity. The ages at onset of neurological symptoms/signs were significantly higher in symptomatic carriers than in CARASIL, and the frequency of characteristic extraneurological findings and confluent WMHs were significantly higher in CARASIL than in symptomatic carriers. As previously reported, heterozygous HTRA1-related CSVD has a milder clinical presentation of CARASIL. It seems that haploinsufficiency can cause CSVD among symptomatic carriers according to the several patients with heterozygous nonsense/frameshift mutations. However, the differing locations of mutations found in the two diseases indicate that distinct molecular mechanisms influence the development of CSVD in patients with HTRA1-related CSVD. These findings further support continued careful examination of the pathogenicity of mutations located outside the linker or LD/L3 domain in symptomatic carriers.

Excessive Production of Transforming Growth Factor ß1 Causes Mural Cell Depletion From Cerebral Small Vessels.

It is increasingly becoming apparent that cerebrovascular dysfunction contributes to the pathogenic processes involved in vascular dementia, Alzheimer's disease, and other neurodegenerative disorders. Under these pathologic conditions, the degeneration of cerebral blood vessels is frequently accompanied by a loss of mural cells from the vascular walls. Vascular mural cells play pivotal roles in cerebrovascular functions, such as regulation of cerebral blood flow and maintenance of the blood-brain barrier (BBB). Therefore, cerebrovascular mural cell impairment is involved in the pathophysiology of vascular-related encephalopathies, and protecting these cells is essential for maintaining brain health. However, our understanding of the molecular mechanism underlying mural cell abnormalities is incomplete. Several reports have indicated that dysregulated transforming growth factor ß (TGFß) signaling is involved in the development of cerebral arteriopathies. These studies have specifically suggested the involvement of TGFß overproduction. Although cerebrovascular toxicity via vascular fibrosis by extracellular matrix accumulation or amyloid deposition is known to occur with enhanced TGFß production, whether increased TGFß results in the degeneration of vascular mural cells in vivo remains unknown. Here, we demonstrated that chronic TGFß1 overproduction causes a dropout of mural cells and reduces their coverage on cerebral vessels in both smooth muscle cells and pericytes. Mural cell degeneration was also accompanied by vascular luminal dilation. TGFß1 overproduction in astrocytes significantly increased TGFß1 content in the cerebrospinal fluid (CSF) and increased TGFß signaling-regulated gene expression in both pial arteries and brain capillaries. These results indicate that TGFß is an important effector that mediates mural cell abnormalities under pathological conditions related to cerebral arteriopathies.

HTRA1 Mutations Identified in Symptomatic Carriers Have the Property of Interfering the Trimer-Dependent Activation Cascade.

Background: Mutations in the high-temperature requirement A serine peptidase 1 (HTRA1) cause cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). Most carriers for HTRA1 mutations are asymptomatic, but more than 10 mutations have been reported in symptomatic carriers. The molecular differences between the mutations identified in symptomatic carriers and mutations identified only in CARASIL patients are unclear. HTRA1 is a serine protease that forms homotrimers, with each HTRA1 subunit activating the adjacent HTRA1 via the sensor domain of loop 3 (L3) and the activation domain of loop D (LD). Previously, we analyzed four HTRA1 mutant proteins identified in symptomatic carriers and found that they were unable to form trimers or had mutations in the LD or L3 domain. The mutant HTRA1s with these properties are presumed to inhibit trimer-dependent activation cascade. Indeed, these mutant HTRA1s inhibited wild-type (WT) protease activity. In this study, we further analyzed 15 missense HTRA1s to clarify the molecular character of mutant HTRA1s identified in symptomatic carriers. Methods: We analyzed 12 missense HTRA1s identified in symptomatic carriers (hetero-HTRA1) and three missense HTRA1s found only in CARASIL (CARASIL-HTRA1). The protease activity of the purified recombinant mutant HTRA1s was measured using fluorescein isothiocyanate-labeled casein as substrate. Oligomeric structure was evaluated by size-exclusion chromatography. The protease activities of mixtures of WT with each mutant HTRA1 were also measured. Results: Five hetero-HTRA1s had normal protease activity and were excluded from further analysis. Four of the seven hetero-HTRA1s and one of the three CARASIL-HTRA1s were unable to form trimers. The other three hetero-HTRA1s had mutations in the LD domain. Together with our previous work, 10 of 11 hetero-HTRA1s and two of six CARASIL-HTRA1s were either defective in trimerization or had mutations in the LD or L3 domain (P = 0.006). By contrast, eight of 11 hetero-HTRA1s and two of six CARASIL-HTRA1 inhibited WT protease activity (P = 0.162). Conclusions: HTRA1 mutations identified in symptomatic carriers have the property of interfering the trimer-dependent activation cascade of HTRA1.

Non-genetically modified models exhibit TARDBP mRNA increase due to perturbed TDP-43 autoregulation.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by accumulation of fragmented insoluble TDP-43 and loss of TDP-43 from the nucleus. Increased expression of exogenous TARDBP (encoding TDP-43) induces TDP-43 pathology and cytotoxicity, suggesting the involvement of aberrant expression of TDP-43 in the pathogenesis of ALS. In normal conditions, however, the amount of TDP-43 is tightly regulated by the autoregulatory mechanism involving alternative splicing of TARDBP mRNA. To investigate the influence of autoregulation dysfunction, we inhibited the splicing of cryptic intron 6 using antisense oligonucleotides in vivo. This inhibition doubled the Tardbp mRNA expression, increased the fragmented insoluble TDP-43, and reduced the number of motor neurons in the mouse spinal cord. In human induced pluripotent stem cell-derived neurons, the splicing inhibition of intron 6 increased TARDBP mRNA and decreased nuclear TDP-43. These non-genetically modified models exhibiting rise in the TARDBP mRNA levels suggest that TDP-43 autoregulation turbulence might be linked to the pathogenesis of ALS.

Ectopic Expression Induces Abnormal Somatodendritic Distribution of Tau in the Mouse Brain.

Tau is a microtubule (MT)-associated protein that is localized to the axon. In Alzheimer's disease, the distribution of tau undergoes a remarkable alteration, leading to the formation of tau inclusions in the somatodendritic compartment. To investigate how this mislocalization occurs, we recently developed immunohistochemical tools that can separately detect endogenous mouse and exogenous human tau with high sensitivity, which allows us to visualize not only the pathological but also the pre-aggregated tau in mouse brain tissues of both sexes. Using these antibodies, we found that in tau-transgenic mouse brains, exogenous human tau was abundant in dendrites and somata even in the presymptomatic period, whereas the axonal localization of endogenous mouse tau was unaffected. In stark contrast, exogenous tau was properly localized to the axon in human tau knock-in mice. We tracked this difference to the temporal expression patterns of tau. Endogenous mouse tau and exogenous human tau in human tau knock-in mice exhibited high expression levels during the neonatal period and strong suppression into the adulthood. However, human tau in transgenic mice was expressed continuously and at high levels in adult animals. These results indicated the uncontrolled expression of exogenous tau beyond the developmental period as a cause of mislocalization in the transgenic mice. Superresolution microscopic and biochemical analyses also indicated that the interaction between MTs and exogenous tau was impaired only in the tau-transgenic mice, but not in knock-in mice. Thus, the ectopic expression of tau may be critical for its somatodendritic mislocalization, a key step of the tauopathy.SIGNIFICANCE STATEMENT Somatodendritic localization of tau may be an early step leading to the neuronal degeneration in tauopathies. However, the mechanisms of the normal axonal distribution of tau and the mislocalization of pathological tau remain obscure. Our immunohistochemical and biochemical analyses demonstrated that the endogenous mouse tau is transiently expressed in neonatal brains, that exogenous human tau expressed corresponding to such tau expression profile can distribute into the axon, and that the constitutive expression of tau into adulthood (e.g., human tau in transgenic mice) results in abnormal somatodendritic localization. Thus, the expression profile of tau is tightly associated with the localization of tau, and the ectopic expression of tau in matured neurons may be involved in the pathogenesis of tauopathy.