The Role of the Vascular System in Degenerative Diseases: Mechanisms and Implications.

Degenerative diseases, encompassing a wide range of conditions affecting various organ systems, pose significant challenges to global healthcare systems. This comprehensive review explores the intricate interplay between the vascular system and degenerative diseases, shedding light on the underlying mechanisms and profound implications for disease progression and management. The pivotal role of the vascular system in maintaining tissue homeostasis is highlighted, as it serves as the conduit for oxygen, nutrients, and immune cells to vital organs and tissues. Due to the vital role of the vascular system in maintaining homeostasis, its dysfunction, characterized by impaired blood flow, endothelial dysfunction, and vascular inflammation, emerges as a common denominator of degenerative diseases across multiple systems. In the nervous system, we explored the influence of vascular factors on neurodegenerative diseases such as Alzheimer's and Parkinson's, emphasizing the critical role of cerebral blood flow regulation and the blood-brain barrier. Within the kidney system, the intricate relationship between vascular health and chronic kidney disease is scrutinized, unraveling the mechanisms by which hypertension and other vascular factors contribute to renal dysfunction. Throughout this review, we emphasize the clinical significance of understanding vascular involvement in degenerative diseases and potential therapeutic interventions targeting vascular health, highlighting emerging treatments and prevention strategies. In conclusion, a profound appreciation of the role of the vascular system in degenerative diseases is essential for advancing our understanding of degenerative disease pathogenesis and developing innovative approaches for prevention and treatment. This review provides a comprehensive foundation for researchers, clinicians, and policymakers seeking to address the intricate relationship between vascular health and degenerative diseases in pursuit of improved patient outcomes and enhanced public health.

Alzheimer's Amyloid ß Peptide Induces Angiogenesis in an Alzheimer's Disease Model Mouse through Placental Growth Factor and Angiopoietin 2 Expressions.

Increased angiogenesis, especially the pathological type, has been documented in Alzheimer's disease (AD) brains, and it is considered to be activated due to a vascular dysfunction-mediated hypoxic condition. To understand the role of the amyloid ß (Aß) peptide in angiogenesis, we analyzed its effects on the brains of young APP transgenic AD model mice. Immunostaining results revealed that Aß was mainly localized intracellularly, with very few immunopositive vessels, and there was no extracellular deposition at this age. Solanum tuberosum lectin staining demonstrated that compared to their wild-type littermates, the vessel number was only increased in the cortex of J20 mice. CD105 staining also showed an increased number of new vessels in the cortex, some of which were partially positive for collagen4. Real-time PCR results demonstrated that placental growth factor (PlGF) and angiopoietin 2 (AngII) mRNA were increased in both the cortex and hippocampus of J20 mice compared to their wild-type littermates. However, vascular endothelial growth factor (VEGF) mRNA did not change. Immunofluorescence staining confirmed the increased expression of PlGF and AngII in the cortex of the J20 mice. Neuronal cells were positive for PlGF and AngII. Treatment of a neural stem cell line (NMW7) with synthetic Aß1-42 directly increased the expression of PlGF and AngII, at mRNA levels, and AngII at protein levels. Thus, these pilot data indicate that pathological angiogenesis exists in AD brains due to the direct effects of early Aß accumulation, suggesting that the Aß peptide regulates angiogenesis through PlGF and AngII expression.

iTRAQ-Based Proteomic Analysis of APP Transgenic Mouse Urine Exosomes.

Alzheimer's disease (AD) is a common dementia disease in the elderly. To get a better understanding of the pathophysiology, we performed a proteomic analysis of the urine exosomes (U-exo) in AD model mice (J20). The polymer precipitation method was used to isolate U-exo from the urine of 3-month-old J20 and wild-type (WT) mice. Neuron-derived exosome (N-exo) was isolated from U-exo by immunoprecipitation. iTRAQ-based MALDI TOF MS/MS was used for proteomic analysis. The results showed that compared to WT, the levels of 61 and 92 proteins were increased in the J20 U-exo and N-exo, respectively. Gene ontology enrichment analysis demonstrated that the sphingolipid catabolic process, ceramide catabolic process, membrane lipid catabolic process, Aß clearance, and Aß metabolic process were highly enriched in U-exo and N-exo. Among these, Asah1 was shown to be the key protein in lipid metabolism, and clusterin, ApoE, neprilysin, and ACE were related to Aß metabolism and clearance. Furthermore, protein-protein interaction analysis identified four protein complexes where clusterin and ApoE participated as partner proteins. Thus, J20 U-exo and N-exo contain proteins related to lipid- and Aß-metabolism in the early stages of AD, providing a new insight into the underlying pathological mechanism of early AD.

Aggregation of Cystatin C Changes Its Inhibitory Functions on Protease Activities and Amyloid ß Fibril Formation.

Cystatin C (CST3) is an endogenous cysteine protease inhibitor, which is implicated in cerebral amyloid angiopathy (CAA). In CAA, CST3 is found to be aggregated. The purpose of this study is to investigate whether this aggregation could alter the activity of the protein relevant to the molecular pathology of CAA. A system of CST3 protein aggregation was established, and the aggregated protein was characterized. The results showed that CST3 aggregated both at 80 °C without agitation, and at 37 °C with agitation in a time-dependent manner. However, the levels of aggregation were high and appeared earlier at 80 °C. Dot-blot immunoassay for oligomers revealed that CST3 could make oligomeric aggregates at the 37 °C condition. Electron microscopy showed that CST3 could make short fibrillary aggregates at 37 °C. Cathepsin B activity assay demonstrated that aggregated CST3 inhibited the enzyme activity less efficiently at pH 5.5. At 7.4 pH, it lost the inhibitory properties almost completely. In addition, aggregated CST3 did not inhibit Aß1-40 fibril formation, rather, it slightly increased it. CST3 immunocytochemistry showed that the protein was positive both in monomeric and aggregated CST3-treated neuronal culture. However, His6 immunocytochemistry revealed that the internalization of exogenous recombinant CST3 by an astrocytoma cell culture was higher when the protein was aggregated compared to its monomeric form. Finally, MTT cell viability assay showed that the aggregated form of CST3 was more toxic than the monomeric form. Thus, our results suggest that aggregation may result in a loss-of-function phenotype of CST3, which is toxic and responsible for cellular degeneration.

Evaluation of autonomic functions of patients with multiple system atrophy and Parkinson's disease by head-up tilt test.

The aim of this study was to evaluate the autonomic neural function in Parkinson's disease (PD) and multiple system atrophy (MSA) with head-up tilt test and spectral analysis of cardiovascular parameters. This study included 15 patients with MSA, 15 patients with PD, and 29 healthy control (HC) subjects. High frequency power of the RR interval (RR-HF), the ratio of low frequency power of RR interval to RR-HF (RR-LF/HF) and LF power of systolic BP were used to evaluate parasympathetic, cardiac sympathetic and vasomotor sympathetic functions, respectively. Both patients with PD and MSA showed orthostatic hypotension and lower parasympathetic function (RR-HF) at tilt position as compared to HC subjects. Cardiac sympathetic function (RR-LF/HF) was significantly high in patients with PD than MSA at supine position. RR-LF/HF tended to increase in MSA and HC, but decreased in PD by tilting. Consequently, the change of the ratio due to tilting (ΔRR-LF/HF) was significantly lower in patients with PD than in HC subjects. Further analysis showed that compared to mild stage of PD, RR-LF/HF at the supine position was significantly higher in advanced stage. By tilting, it was increased in mild stage and decreased in the advanced stage of PD, causing ΔRR-LF/HF to decrease significantly in the advanced stage. Thus, we demonstrated that spectral analysis of cardiovascular parameters is useful to identify sympathetic and parasympathetic disorders in MSA and PD. High cardiac sympathetic function at the supine position, and its reduction by tilting might be a characteristic feature of PD, especially in the advanced stage.

Correction: Shibly et al. Analysis of Cerebral Small Vessel Changes in AD Model Mice. Biomedicines 2023, 11, 50.

In the original publication [...].

Effect of high-fat diet on cerebral pathological changes of cerebral small vessel disease in SHR/SP rats.

Cerebral small vessel diseases (CSVD) are neurological disorders associated with microvessels, manifested pathologically as white matter (WM) changes and cortical microbleeds, with hypertension as a risk factor. Additionally, a high-fat diet (HFD) can affect peripheral vessel health. Our study explored how HFD affects cerebral small vessels in normotensive WKY, hypertensive SHR, and SHR/SP rats. The MRI results revealed that HFD specifically increased WM hyperintensity in SHR/SP rats. Pathologically, it increased WM pallor and vacuolation in SHR and SHR/SP rats. Levels of blood-brain barrier (BBB) protein claudin 5 were decreased in SHR and SHR/SP compared to WKY, with HFD having minimal impact on these levels. Conversely, collagen IV levels remained consistent among the rat strains, which were increased by HFD. Consequently, HFD caused vessel leakage in all rat strains, particularly within the corpus callosum of SHR/SP rats. To understand the underlying mechanisms, we assessed the levels of hypoxia-inducible factor-1α (HIF-1α), Gp91-phox, and neuroinflammatory markers astrocytes, and microglia were increased in SHR and SHR/SP compared to WKY and were further elevated by HFD in all rat strains. Gp91-phox was also increased in SHR and SHR/SP compared to WKY, with HFD causing an increase in WKY but little effect in SHR and SHR/SP. In conclusion, our study demonstrates that HFD, in combined with hypertension, intensifies cerebral pathological alterations in CSVD rats. This exacerbation involves increased oxidative stress and HIF-1α in cerebral vessels, triggering neuroinflammation, vascular basement membrane remodeling, IgG leakage, and ultimately WM damage.

Human mesenchymal stem cell transplantation changes proinflammatory gene expression through a nuclear factor-κB-dependent pathway in a rat focal cerebral ischemic model.

Previous studies have demonstrated the immunomodulatory functions of mesenchymal stem cells (MSCs) in cerebral ischemic rats. However, the underlying mechanisms are unclear. The purpose of this study is to investigate the effects of MSC transplantation on transcriptional regulations of proinflammatory genes in cerebral ischemia. Transient ischemia was induced by middle cerebral artery occlusion (MCAO) in adult male Sprague-Dawley rats. After 24 hr, vehicle (PBS) or a human MSC line (B10) was transplanted intravenously. The neurological deficits, infarct volume, cellular accumulations, and gene expression changes were monitored by means of behavior tests, MRI, immunohistochemistry, Western blotting, laser capture microdissection, and real-time PCR. In the core area of the B10 transplantation group, the number of ED1-positive macrophage/microglia was decreased compared with the PBS group. In the core, nuclear factor-κB (NF-κB) was decreased, although CCAAT/enhancer-binding protein ß was not changed; both were expressed mainly in ED1-positive macrophage/microglia. Likewise, mRNAs of NF-κB-dependent genes including interleukin-1ß, MCP-1, and inducible nitric oxide synthase were decreased in ED1-positive and Iba-1-positive macrophage/microglia in the B10 transplantation group. Moreover, upstream receptors of the NF-κB pathway, including CD40 and Toll-like receptor 2 (TLR2), were decreased. Immunofluorescence results showed that, in the B10 transplantation group, the percentages of NF-κB-positive, CD40-positive, and TLR2-positive cells were decreased in ED1-positive macrophage/microglia. Furthermore, NF-κB-positive cells in the CD40- or TLR2-expressing cell population were decreased in the B10 transplantation group. This study demonstrates that B10 transplantation inhibits NF-κB activation, possibly through inhibition of CD40 and TLR2, which might be responsible for the inhibition of proinflammatory gene expression in macrophage/microglia in the infarct lesion.

Neither Trimethylamine-N-Oxide nor Trimethyllysine Is Associated with Atherosclerosis: A Cross-Sectional Study in Older Japanese Adults.

Recent evidence suggests that trimethylamine-N-oxide (TMAO), a metabolite of L-carnitine and choline, is linked to atherosclerosis and cardiovascular diseases. As TMAO content is very high in fish, we raised the following question: why do Japanese people, who consume lots of fish, show a low risk of atherosclerosis? To address this question, we investigated the effects of TMAO and other L-carnitine-related metabolites on carotid intima-media thickness (IMT). Participants were recruited from a small island and a mountainous region. Plasma L-carnitine, γ-butyrobetaine (γBB), TMAO, trimethyllysine (TML), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) levels were measured using liquid or gas chromatography-mass spectrometry. Plasma L-carnitine concentration was higher in men than in women. TMAO and TML were significantly higher in the residents of the island than in the mountainous people. In multiple linear regression analyses in all participants, TML showed a significant inverse association with max-IMT and plaque score (PS), whereas TMAO did not show any associations. In women, L-carnitine was positively associated with max-IMT and PS. TMAO was correlated with both EPA and DHA levels, implying that fish is a major dietary source of TMAO in Japanese people. Our study found that plasma TMAO was not an apparent risk factor for atherosclerosis in elderly Japanese people, whereas a low level of TML might be a potential risk. L-carnitine may be a marker for atherosclerosis in women.

Rho-Kinase inhibition decreases focal cerebral ischemia-induced glial activation in rats.

Background: Rho-kinase inhibition in a rat middle cerebral artery occlusion (MCAO) model is reported to improve neurological functions and decrease infarction size. Objective: The objective of this study is to investigate the underlying mechanisms of such improvement by evaluating the effects of Rho-kinase inhibition on astrocytes and microglial accumulation and activation in this condition. Methods: Adult male Sprague-Dawley (SD) rats were used to generate the MCAO model, which received an I.P injection of a chemical Rho-kinase inhibitor (Fasudil- 5 mg/kg/day) or vehicle (PBS) for 2 and 4 days. Results: Fasudil treatment significantly decreased the stroke volumes and water content in the lesion areas, as revealed by MRI. Immunostaining and Western blotting results demonstrated that Fasudil significantly decreased the levels of Aquaporin-4, a water channel protein. The number of GFAP+ astrocytes and Iba-1+ macrophage/microglia was decreased in the lesion areas. Proinflammatory transcription factor NF-κB protein levels were decreased in the Fasudil group 2 days after MCAO. Also, proinflammatory mediators including TNF-α, IL-1ß, and iNOS levels were decreased. In vitro migration study using a human microglial cell line (HMO6) confirmed the inhibitory effects of Fasudil on the process. Fasudil also decreased combined IL-1ß and IFNγ-induced NF-κB nuclear translocation in HMO6. Moreover, Fasudil transiently decreased combined IL-1ß and IFNγ-induced iNOS, TNFα, and IL-1ß mRNA levels in HMO6. Conclusion: Our study demonstrates the inhibitory effects of Rho-kinase on NF-κB-mediated glial activation and cerebral edema, which might be a promising therapeutic target in acute cerebral ischemia conditions.

Analysis of Cerebral Small Vessel Changes in AD Model Mice.

Amyloid ß (Aß) peptide is deposited in the brains of sporadic Alzheimer's disease (AD) due to impaired vessel-dependent clearance. To understand the mechanisms, we investigated time-dependent cerebrovascular changes in AD model mice. Cerebrovascular and other pathological changes were analyzed in AD model mice (J20 strain) aging from 2 to 9 months by immunostaining. At 2 months, Aß was only intraneuronal, whereas vessels were positive from 3 months in J20 mice. Compared to wild-type (WT), vessel density was increased at 2 months but decreased at 9 months in J20 mice, claudin-5 levels were decreased, and vascular endothelial growth factor (VEGF) levels were increased in the cortex and hippocampus of J20 mice brain at all time points. Albumin extravasation was evident from 3 months in J20 brains. Collagen 4 was increased at 2 and 3 months. Aquaporin 4 was spread beyond the vessels starting from 3 months in J20, which was restricted around the vessel in wild-type mice. In conclusion, the study showed that an early decrease in claudin-5 was associated with VEGF expression, indicating dysfunction of the blood-brain barrier. Decreased claudin-5 might cause the leakage of blood constituents into the parenchyma that alters astrocyte polarity and its functions.

Mesenchymal stem cell transplantation modulates neuroinflammation in focal cerebral ischemia: contribution of fractalkine and IL-5.

Mesenchymal stem cells (MSCs) are reported to possess immunomodulatory properties. Previous reports have demonstrated the beneficial effects of MSC-transplantation in focal cerebral ischemia animal models. In this study, we have investigated the neuroimmunomodulatory functions of human MSCs, transplanted in a rat focal ischemia model of transient middle cerebral artery occlusion (MCAO). Our results revealed that in a human mesenchymal stem cell line, B10 cell transplantation decreased the accumulation of Iba-1(+) microglia and GFAP(+) astrocytes, and inhibited proinflammatory gene expression in the core and ischemic border zone (IBZ). Among the proinflammatory genes iNOS, which was expressed in microglia/macrophage, was persistently inhibited up to 7days after MCAO. In vivo laser capture microdissection and double immunofluorescence staining, and in vitro B10 cell culture experiments showed that, in inflammatory conditions, B10 cells expressed cytokines and growth factors including IL-5, fractalkine, IGF-1, GDNF and VEGF. Fractalkine and IL-5 inhibited cytokine-induced proinflammatory gene expression including iNOS in a human microglia cell line. Thus, our results demonstrate that MSC transplantation suppresses MCAO focal ischemia-induced inflammation, possibly through expression of fractalkine and IL-5.

Proteomic analysis of extracellular vesicles enriched serum associated with future ischemic stroke.

Identifying new biomarkers beyond the established risk factors that make it possible to predict and prevent ischemic stroke has great significance. Extracellular vesicles are powerful cell‒cell messengers, containing disease-specific biomolecules, which makes them powerful diagnostic candidates. Therefore, this study aimed to identify proteins derived from extracellular vesicles enriched serum related to future ischemic stroke events, using a proteomic method. Of Japanese subjects who voluntarily participated in health checkups at our institute a number of times, 10 subjects (6 males and 4 females, age: 64.2 ± 3.9 years) who developed symptomatic ischemic stroke (7.3 ± 4.4 years' follow-up) and 10 age‒sex matched controls without brain lesions (6.7 ± 2.8 years' follow-up) were investigated. Extracellular vesicles enriched fractions were derived from serum collected at the baseline visit. Differentially expressed proteins were evaluated using isobaric tagging for relative and absolute protein quantification (iTRAQ)-based proteomic analysis. Of the 29 proteins identified, alpha-2-macroglobulin, complement C1q subcomponent subunit B, complement C1r subcomponent, and histidine-rich glycoprotein were significantly upregulated (2.21-, 2.15-, 2.24-, and 2.16-fold, respectively) in subjects with future ischemic stroke, as compared with controls. Our study supports the concept of serum-derived extracellular vesicles enriched fractions as biomarkers for new-onset stroke. These proteins may be useful for prediction or for targeted therapy.

Alteration of Neural Stem Cell Functions in Ataxia and Male Sterility Mice: A Possible Role of ß-Tubulin Glutamylation in Neurodegeneration.

Ataxia and Male Sterility (AMS) is a mutant mouse strain that contains a missense mutation in the coding region of Nna1, a gene that encodes a deglutamylase. AMS mice exhibit early cerebellar Purkinje cell degeneration and an ataxic phenotype in an autosomal recessive manner. To understand the underlying mechanism, we generated neuronal stem cell (NSC) lines from wild-type (NMW7), Nna1 mutation heterozygous (NME), and Nna1 mutation homozygous (NMO1) mouse brains. The NNA1 levels were decreased, and the glutamylated tubulin levels were increased in NMO1 cultures as well as in the cerebellum of AMS mice at both 15 and 30 days of age. However, total ß-tubulin protein levels were not altered in the AMS cerebellum. In NMO1 neurosphere cultures, ß-tubulin protein levels were increased without changes at the transcriptional level. NMO1 grew faster than other NSC lines, and some of the neurospheres were attached to the plate after 3 days. Immunostaining revealed that SOX2 and nestin levels were decreased in NMO1 neurospheres and that the neuronal differentiation potentials were reduced in NMO1 cells compared to NME or NMW7 cells. These results demonstrate that the AMS mutation decreased the NNA1 levels and increased glutamylation in the cerebellum of AMS mice. The observed changes in glutamylation might alter NSC properties and the neuron maturation process, leading to Purkinje cell death in AMS mice.

Time-Dependent Analysis of Plasmalogens in the Hippocampus of an Alzheimer's Disease Mouse Model: A Role of Ethanolamine Plasmalogen.

Plasmalogens are alkenyl-acyl glycerophospholipids and decreased in post-mortem Alzheimer's disease (AD) brains. The aim of this study is to investigate the time-dependent changes of plasmalogens in the hippocampus of an AD model mouse (J20). Plasmalogen levels at 3, 6, 9, 12 and 15 months were analyzed by liquid-chromatography-targeted-multiplexed-selected-reaction-monitoring-tandem-mass-spectrometry (LC-SRM/MS). Reactive oxygen species (ROS) levels were evaluated using dichlorofluorescein diacetate (DCF-DA). Plasmalogen synthesizing enzyme glycerone-phosphate O-acyltransferase (GNPAT) and late endosome marker Rab7 levels were quantified by Western blotting. GNPAT localization, changes of neuronal and glial cell numbers were evaluated by immunostaining. Compared to wild-type mice (WT), total plasmalogen-ethanolamine, but not plasmalogen-choline levels, were increased at 9 months and subsequently decreased at 15 months in J20 mice. A principal component analysis of plasmalogen-ethanolamine species could separate WT and J20 mice both at 9 and 15 months. Both GNPAT and Rab7 protein were increased in J20 mice at 9 months, whereas GNPAT was decreased at 15 months. ROS levels were increased in J20 mice except for 9 months. Our results suggest that increased plasmalogen-ethanolamine could counteract ROS levels and contribute to the phagocytosis process in J20 mice at 9 months. Such results might indicate a transient protective response of plasmalogen-ethanolamine in AD conditions.

Transplantation of human mesenchymal stem cells promotes functional improvement and increased expression of neurotrophic factors in a rat focal cerebral ischemia model.

Previous studies have suggested that intravenous transplantation of mesenchymal stem cells (MSCs) in rat ischemia models reduces ischemia-induced brain damage. Here, we analyzed the expression of neurotrophic factors in transplanted human MSCs and host brain tissue in rat middle cerebral artery occlusion (MCAO) ischemia model. At 1 day after transient MCAO, 3 x 10(6) immortalized human MSC line (B10) cells or PBS was intravenously transplanted. Behavioral tests, infarction volume, and B10 cell migration were investigated at 1, 3, 7, and 14 days after MCAO. The expression of endogenous (rat origin) and exogenous (human origin) neurotrophic factors and cytokines was evaluated by quantitative real-time RT-PCR and Western blot analysis. Compared with PBS controls, rats receiving MSC transplantation showed improved functional recovery and reduced brain infarction volume at 7 and 14 days after MCAO. In MSC-transplanted brain, among many neurotrophic factors, only human insulin-like growth factor 1 (IGF-1) was detected in the core and ischemic border zone at 3 days after MCAO, whereas host cells expressed markedly higher neurotrophic factors (rat origin) than control rats, especially vascular endothelial growth factor (VEGF) at 3 days and epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) at 7 days after MCAO. Intravenously transplanted human MSCs induced functional improvement, reduced infarct volume, and neuroprotection in ischemic rats, possibly by providing IGF-1 and inducing VEGF, EGF, and bFGF neurotrophic factors in host brain.

A Cationic Gallium Phthalocyanine Inhibits Amyloid ß Peptide Fibril Formation.

BACKGROUND: Amyloid ß (Aß) peptide deposition is considered as the main cause of Alzheimer's disease (AD). Previously, we have shown that a Zn containing neutral phthalocyanine (Zn-Pc) inhibits Aß fibril formation. OBJECTIVE: The objective of this study is to investigate the effects of a cationic gallium containing Pc (GaCl-Pc) on Aß fibril formation process. METHODS AND RESULT: Aß fibril formation was induced by incubating synthetic Aß peptides in a fibril forming buffer, and the amount of fibril was evaluated by ThT fluorescence assay. GaCl-Pc dosedependently inhibited both Aß1-40 and Aß1-42 fibril formation. It mainly inhibited the elongation phase of Aß1-42 fibril formation kinetics, but not the lag phase. Western blotting results showed that it did not inhibit its oligomerization process, rather increased it. Additionally, GaCl-Pc destabilized preformed Aß1- 42 fibrils dose-dependently in vitro condition, and decreased Aß levels in the brain slice culture of APP transgenic AD model mice (J20 strain). Near-infrared scanning results showed that GaCl-Pc had the ability to bind to Aß1-42. MTT assay demonstrated that GaCl-Pc did not have toxicity towards a neuronal cell line (A1) in culture rather, showed protective effects on Aß-induced toxicity. Moreover, it dosedependently decreased Aß-induced reactive oxygen species levels in A1 culture. CONCLUSION: Thus, our result demonstrated that GaCl-Pc decreased Aß aggregation and destabilized the preformed fibrils. Since cationic molecules show a better ability to cross the blood-brain barrier, cationic GaCl-Pc could be important for the therapy of AD.

Association between cystatin C gene polymorphism and the prevalence of white matter lesion in elderly healthy subjects.

Cystatin C (CST3) is a cysteine protease inhibitor abundant in the central nervous system, and demonstrated to have roles in several pathophysiological processes including vascular remodeling and inflammation. Previously, we showed a relation of CST3 gene polymorphisms with deep and subcortical white matter hyperintensity (DSWMH) in a small case-control study. In this study, we aimed to investigate the relation in a larger cross-sectional study. Participants of a brain health examination program were recruited (n = 1795) in the study, who underwent routine blood tests and cognitive function tests. Cerebral white matter changes were analyzed by MRI. Additionally, 7 single nucleotide polymorphisms (SNPs) (-82G/C, -78T/G, -5G/A, +4A/C, +87C/T, +148G/A and +213G/A) in the promoter and coding regions of CST3 gene were examined. Among them, carriers of the minor allele haplotype -82C/+4C/+148A were significantly associated with decreased CST3 concentration in the plasma. Unadjusted analysis did not show significant relation between carriers of the minor allele haplotype and periventricular hyperintensity (PVH), but DSWMH was marginally (p < 0.054) increased in this group. After adjusting the effects of other variables like age and kidney function, logistic regression analysis revealed that carriers of the minor allele haplotype were at a significantly increased risk of developing both PVH and DSWMH. Thus, our results suggest that carriers of the minor allele haplotype -82C/+4C/+148A of CST3 gene could be at an increased risk to develop cerebral white matter disturbance.

Lysophosphatidylcholine induces glial cell activation: role of rho kinase.

Lysophosphatidylcholine (LPC), a major phospholipid component of atherogenic oxidized LDL, is implicated in atherosclerosis and, recently, in neurodegenerative diseases. We investigated the immunomodulatory functions of LPC in the central nervous system (CNS) using both an in vivo rat model, and in vitro culture systems of human primary astrocytes and a microglia cell line, HMO6. Compared with PBS injection, 20 nmol LPC-injection into the rat striatum increased astrocyte and microglial accumulation and elevated iNOS expression; concomitantly a time-dependent decrease in number of neurons was exhibited. In vitro studies on astrocytes and HMO6 cells showed that LPC increased the gene expression of proinflammatory factors IL-1beta, COX-2, and GM-CSF. LPC also induced chemotactic responses in HMO6 cells. Inhibition of rho kinase by fasudil, Y27632, or expressing a dominant negative form of rho kinase inhibited the LPC-induced IL-1beta mRNA expression in both astrocytes and HMO6. Moreover, intraperitoneal fasudil injection inhibited the LPC-induced microglial accumulation and iNOS expression and also was effective in protecting against neuronal loss. Silencing G2A, a specific receptor for LPC, inhibited proinflammatory gene expression and HMO6 migration. Overall, our results indicate that LPC induced considerable neuroinflammatory reactivity in glia mediated by rho kinase-dependent pathways with inhibition of these pathways conferring significant extents of neuroprotection.

An Improved Assay for Quantitation of Cerebrospinal Fluid Cystatin C Using Liquid Chromatography Tandem Mass Spectrometry.

Cystatin C (CST3) is expressed ubiquitously and implicated in several neurological diseases. It can be posttranscriptionally modified. CST3 is usually quantified in a biological sample using antibody-based methods. Posttranscriptional modification can hamper antibody-based detection systems by altering antibody-binding epitope(s). To circumvent this problem, enzymatic digestion and liquid chromatography tandem mass spectrometry (LC-MS/MS) technique can be employed to identify and measure peptides of a target protein in a complex biological mixture. This chapter describes an LC-MS/MS-based method for accurate measurement of CST3 in cerebrospinal fluid (CSF). Here, CSF was directly subjected to trypsin digestion and digested peptides were extracted using a solid-phase extraction column. Extracted peptide samples were directly used for LC-MS/MS-based identification and quantification of CST3 peptides. Comparing the concentration in a set of samples measured by LC-MS/MS with that of immunoassay shows that it was significantly higher when measured by LC-MS/MS method, suggesting it a better quantification method. This approach is particularly well suited when posttranscriptional modification of CST3 is suspected and sample volume of CSF is small.