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1.
J Biol Chem ; : 107619, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39098530

RESUMO

Alzheimer's disease (AD) poses an immense challenge in healthcare, lacking effective therapies. This study investigates the potential of AAD23, a selective M2 receptor antagonist, in proactively preventing cognitive impairments and cholinergic neuronal degeneration in GRK5-deficient Swedish APP (GAP) mice. GAP mice manifest cognitive deficits by 7 months and develop senile plaques (SPs) by 9 months. A six-month AAD23 treatment was initiated at 5 months and stopped at 11 months before behavioral assessments without the treatment. AAD23-treated mice exhibited preserved cognitive abilities and improved cholinergic axonal health in the nucleus basalis of Meynert (NBM) akin to wild-type mice. Conversely, vehicle-treated GAP mice displayed memory deficits and pronounced cholinergic axonal swellings in the NBM. Notably, AAD23 treatment did not alter SPs and microgliosis. These findings highlight AAD23's efficacy in forestalling AD-related cognitive decline in GRK5-deficient subjects, attributing its success to restoring cholinergic neuronal integrity and resilience, enhancing resistance against diverse degenerative insults.

2.
Front Neurol ; 15: 1382365, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39081338

RESUMO

Background: Brain inflammation plays a key role in ischemia/reperfusion (I/R) injury and is the main cause of "ineffective or futile recanalization" after successful mechanical thrombectomy (MT) in acute ischemic stroke (AIS). One of the primary sources of inflammatory cells after AIS are derived from the spleen. As an innovative and potential neuroprotective strategy after stroke, Remote Administration of Hypothermia (RAH) temporarily suppresses immune activities in the spleen, reduces the release of inflammatory cells and cytokines into blood, and thus reversibly diminishes inflammatory injury in the brain. Methods: This single-center, prospective, randomized controlled study (RCT) is proposed for AIS patients with anterior circulation large vessel occlusion (LVO). Subjects will be randomly assigned to either the control or intervention groups in a 1:1 ratio (n = 40). Participants allocated to the intervention group will receive RAH on the abdomen above the spleen prior to recanalization until 6 h after thrombectomy. All enrolled patients will receive standard stroke Guideline care. The main adverse events associated with RAH are focal cold intolerance and abdominal pain. The primary outcome will assess safety as it pertains to RAH application. The secondary outcomes include the efficacy of RAH on spleen, determined by spleen volumes, blood inflammatory factor (cells and cytokines), and on brain injury, determined by infarction volumes and poststroke functional outcomes. Discussion: This study aims to examine the safety and preliminary effectiveness of RAH over the spleen during endovascular therapy in AIS patients. The results of this study are expected to facilitate larger randomized clinical trials and hopefully prove RAH administration confers adjuvant neuroprotective properties in AIS treated with MT. Clinical trial registration: https://www.chictr.org.cn/. Identifier ChiCTR 2300077052.

3.
FASEB J ; 38(13): e23790, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38982638

RESUMO

Integrase strand transfer inhibitors (INSTIs) based antiretroviral therapy (ART) is currently used as first-line regimen to treat HIV infection. Despite its high efficacy and barrier to resistance, ART-associated neuropsychiatric adverse effects remain a major concern. Recent studies have identified a potential interaction between the INSTI, dolutegravir (DTG), and folate transport pathways at the placental barrier. We hypothesized that such interactions could also occur at the two major blood-brain interfaces: blood-cerebrospinal fluid barrier (BCSFB) and blood-brain barrier (BBB). To address this question, we evaluated the effect of two INSTIs, DTG and bictegravir (BTG), on folate transporters and receptor expression at the mouse BCSFB and the BBB in vitro, ex vivo and in vivo. We demonstrated that DTG but not BTG significantly downregulated the mRNA and/or protein expression of folate transporters (RFC/SLC19A1, PCFT/SLC46A1) in human and mouse BBB models in vitro, and mouse brain capillaries ex vivo. Our in vivo study further revealed a significant downregulation in Slc19a1 and Slc46a1 mRNA expression at the BCSFB and the BBB following a 14-day DTG oral treatment in C57BL/6 mice. However, despite the observed downregulatory effect of DTG in folate transporters/receptor at both brain barriers, a 14-day oral treatment of DTG-based ART did not significantly alter the brain folate level in animals. Interestingly, DTG treatment robustly elevated the mRNA and/or protein expression of pro-inflammatory cytokines and chemokines (Cxcl1, Cxcl2, Cxcl3, Il6, Il23, Il12) in primary cultures of mouse brain microvascular endothelial cells (BBB). DTG oral treatment also significantly upregulated proinflammatory cytokines and chemokine (Il6, Il1ß, Tnfα, Ccl2) at the BCSFB in mice. We additionally observed a downregulated mRNA expression of drug efflux transporters (Abcc1, Abcc4, and Abcb1a) and tight junction protein (Cldn3) at the CP isolated from mice treated with DTG. Despite the structural similarities, BTG only elicited minor effects on the markers of interest at both the BBB and BCSFB. In summary, our current data demonstrates that DTG but not BTG strongly induced inflammatory responses in a rodent BBB and BCSFB model. Together, these data provide valuable insights into the mechanism of DTG-induced brain toxicity, which may contribute to the pathogenesis of DTG-associated neuropsychiatric adverse effect.


Assuntos
Barreira Hematoencefálica , Compostos Heterocíclicos com 3 Anéis , Oxazinas , Piperazinas , Piridonas , Animais , Camundongos , Piperazinas/farmacologia , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Oxazinas/farmacologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , Camundongos Endogâmicos C57BL , Feminino , Inibidores de Integrase de HIV/farmacologia , Inibidores de Integrase de HIV/efeitos adversos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/metabolismo , Masculino , Antirretrovirais/efeitos adversos , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos
5.
Odontology ; 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630323

RESUMO

Peri-implantitis (PI) is a chronic, inflammatory, and infectious disease which affects dental implants and has certain similarities to periodontitis (PD). Evidence has shown that PD may be related to several types of systemic disorders, such as diabetes and insulin resistance, cardiovascular diseases, respiratory tract infections, adverse pregnancy outcomes, and neurological disorders. Furthermore, some types of bacteria in PD can also be found in PI, leading to certain similarities in the immunoinflammatory responses in the host. This review aims to discuss the possible connection between PI and neuroinflammation, using information based on studies about periodontal disorders, a topic whose connection with systemic alterations has been gaining the interest of the scientific community. Literature concerning PI, PD, and systemic disorders, such as neuroinflammation, brain inflammation, and neurological disorder, was searched in the PubMed database using different keyword combinations. All studies found were included in this narrative review. No filters were used. Eligible studies were analyzed and reviewed carefully. This study found similarities between PI and PD development, maintenance, and in the bacterial agents located around the teeth (periodontitis) or dental implants (peri-implantitis). Through the cardiovascular system, these pathologies may also affect blood-brain barrier permeability. Furthermore, scientific evidence has suggested that microorganisms from PI (as in PD) can be recognized by trigeminal fiber endings and start inflammatory responses into the trigeminal ganglion. In addition, bacteria can traverse from the mouth to the brain through the lymphatic system. Consequently, the immune system increases inflammatory mediators in the brain, affecting the homeostasis of the nervous tissue and vice-versa. Based on the interrelation of microbiological, inflammatory, and immunological findings between PD and PI, it is possible to infer that immunoinflammatory changes observed in PD can imply systemic changes in PI. This, as discussed, could lead to the development or intensification of neuroinflammatory changes, contributing to neurodegenerative diseases.

6.
Brain Behav Immun ; 119: 713-723, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38642615

RESUMO

The COVID-19 pandemic caused by SARS-CoV-2 has triggered a consequential public health crisis of post-acute sequelae of COVID-19 (PASC), sometimes referred to as long COVID. The mechanisms of the heterogeneous persistent symptoms and signs that comprise PASC are under investigation, and several studies have pointed to the central nervous and vascular systems as being potential sites of dysfunction. In the current study, we recruited individuals with PASC with diverse symptoms, and examined the relationship between neuroinflammation and circulating markers of vascular dysfunction. We used [11C]PBR28 PET neuroimaging, a marker of neuroinflammation, to compare 12 PASC individuals versus 43 normative healthy controls. We found significantly increased neuroinflammation in PASC versus controls across a wide swath of brain regions including midcingulate and anterior cingulate cortex, corpus callosum, thalamus, basal ganglia, and at the boundaries of ventricles. We also collected and analyzed peripheral blood plasma from the PASC individuals and found significant positive correlations between neuroinflammation and several circulating analytes related to vascular dysfunction. These results suggest that an interaction between neuroinflammation and vascular health may contribute to common symptoms of PASC.


Assuntos
Encéfalo , COVID-19 , Doenças Neuroinflamatórias , Tomografia por Emissão de Pósitrons , SARS-CoV-2 , Humanos , COVID-19/diagnóstico por imagem , COVID-19/complicações , Masculino , Tomografia por Emissão de Pósitrons/métodos , Feminino , Pessoa de Meia-Idade , Adulto , Doenças Neuroinflamatórias/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Síndrome de COVID-19 Pós-Aguda , Doenças Vasculares/diagnóstico por imagem , Idoso , Piridinas , Pirimidinas
7.
Neuroimmunomodulation ; 31(1): 78-88, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38527434

RESUMO

BACKGROUND: The brain and the immune systems represent the two primary adaptive systems within the body. Both are involved in a dynamic process of communication, vital for the preservation of mammalian homeostasis. This interplay involves two major pathways: the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system. SUMMARY: The establishment of infection can affect immunoneuroendocrine interactions, with functional consequences for immune organs, particularly the thymus. Interestingly, the physiology of this primary organ is not only under the control of the central nervous system (CNS) but also exhibits autocrine/paracrine regulatory circuitries mediated by hormones and neuropeptides that can be altered in situations of infectious stress or chronic inflammation. In particular, Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), impacts upon immunoneuroendocrine circuits disrupting thymus physiology. Here, we discuss the most relevant findings reported in relation to brain-thymic connections during T. cruzi infection, as well as their possible implications for the immunopathology of human Chagas disease. KEY MESSAGES: During T. cruzi infection, the CNS influences thymus physiology through an intricate network involving hormones, neuropeptides, and pro-inflammatory cytokines. Despite some uncertainties in the mechanisms and the fact that the link between these abnormalities and chronic Chagasic cardiomyopathy is still unknown, it is evident that the precise control exerted by the brain over the thymus is markedly disrupted throughout the course of T. cruzi infection.


Assuntos
Encéfalo , Doença de Chagas , Timo , Humanos , Doença de Chagas/imunologia , Doença de Chagas/fisiopatologia , Animais , Encéfalo/imunologia , Timo/imunologia , Timo/fisiologia , Trypanosoma cruzi/fisiologia , Trypanosoma cruzi/imunologia , Sistema Hipotálamo-Hipofisário/imunologia , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipotálamo-Hipofisário/fisiopatologia , Neuroimunomodulação/fisiologia , Neuroimunomodulação/imunologia , Sistema Hipófise-Suprarrenal/imunologia , Sistema Hipófise-Suprarrenal/fisiopatologia , Sistema Hipófise-Suprarrenal/metabolismo
9.
bioRxiv ; 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37905031

RESUMO

The COVID-19 pandemic caused by SARS-CoV-2 has triggered a consequential public health crisis of post-acute sequelae of COVID-19 (PASC), sometimes referred to as long COVID. The mechanisms of the heterogeneous persistent symptoms and signs that comprise PASC are under investigation, and several studies have pointed to the central nervous and vascular systems as being potential sites of dysfunction. In the current study, we recruited individuals with PASC with diverse symptoms, and examined the relationship between neuroinflammation and circulating markers of vascular dysfunction. We used [11C]PBR28 PET neuroimaging, a marker of neuroinflammation, to compare 12 PASC individuals versus 43 normative healthy controls. We found significantly increased neuroinflammation in PASC versus controls across a wide swath of brain regions including midcingulate and anterior cingulate cortex, corpus callosum, thalamus, basal ganglia, and at the boundaries of ventricles. We also collected and analyzed peripheral blood plasma from the PASC individuals and found significant positive correlations between neuroinflammation and several circulating analytes related to vascular dysfunction. These results suggest that an interaction between neuroinflammation and vascular health may contribute to common symptoms of PASC.

10.
Front Neurosci ; 17: 1119943, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37700750

RESUMO

Living in a globalized world, viral infections such as CHIKV, SARS-COV-2, and ZIKV have become inevitable to also infect the most vulnerable groups in our society. That poses a danger to these populations including pregnant women since the developing brain is sensitive to maternal stressors including viral infections. Upon maternal infection, the viruses can gain access to the fetus via the maternofetal barrier and even to the fetal brain during which factors such as viral receptor expression, time of infection, and the balance between antiviral immune responses and pro-viral mechanisms contribute to mother-to-fetus transmission and fetal infection. Both the direct pro-viral mechanisms and the resulting dysregulated immune response can cause multi-level impairment in the maternofetal and brain barriers and the developing brain itself leading to dysfunction or even loss of several cell populations. Thus, maternal viral infections can disturb brain development and even predispose to neurodevelopmental disorders. In this review, we discuss the potential contribution of maternal viral infections of three relevant relative recent players in the field: Zika, Chikungunya, and Severe Acute Respiratory Syndrome Coronavirus-2, to the impairment of brain development throughout the entire route.

11.
J Neuroinflammation ; 20(1): 209, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37705084

RESUMO

BACKGROUND: In the demyelinating disease multiple sclerosis (MS), chronic-active brain inflammation, remyelination failure and neurodegeneration remain major issues despite immunotherapy. While B cell depletion and blockade/sequestration of T and B cells potently reduces episodic relapses, they act peripherally to allow persistence of chronic-active brain inflammation and progressive neurological dysfunction. N-acetyglucosamine (GlcNAc) is a triple modulator of inflammation, myelination and neurodegeneration. GlcNAc promotes biosynthesis of Asn (N)-linked-glycans, which interact with galectins to co-regulate the clustering/signaling/endocytosis of multiple glycoproteins simultaneously. In mice, GlcNAc crosses the blood brain barrier to raise N-glycan branching, suppress inflammatory demyelination by T and B cells and trigger stem/progenitor cell mediated myelin repair. MS clinical severity, demyelination lesion size and neurodegeneration inversely associate with a marker of endogenous GlcNAc, while in healthy humans, age-associated increases in endogenous GlcNAc promote T cell senescence. OBJECTIVES AND METHODS: An open label dose-escalation mechanistic trial of oral GlcNAc at 6 g (n = 18) and 12 g (n = 16) for 4 weeks was performed in MS patients on glatiramer acetate and not in relapse from March 2016 to December 2019 to assess changes in serum GlcNAc, lymphocyte N-glycosylation and inflammatory markers. Post-hoc analysis examined changes in serum neurofilament light chain (sNfL) as well as neurological disability via the Expanded Disability Status Scale (EDSS). RESULTS: Prior to GlcNAc therapy, high serum levels of the inflammatory cytokines IFNγ, IL-17 and IL-6 associated with reduced baseline levels of a marker of endogenous serum GlcNAc. Oral GlcNAc therapy was safe, raised serum levels and modulated N-glycan branching in lymphocytes. Glatiramer acetate reduces TH1, TH17 and B cell activity as well as sNfL, yet the addition of oral GlcNAc dose-dependently lowered serum IFNγ, IL-17, IL-6 and NfL. Oral GlcANc also dose-dependently reduced serum levels of the anti-inflammatory cytokine IL-10, which is increased in the brain of MS patients. 30% of treated patients displayed confirmed improvement in neurological disability, with an average EDSS score decrease of 0.52 points. CONCLUSIONS: Oral GlcNAc inhibits inflammation and neurodegeneration markers in MS patients despite concurrent immunomodulation by glatiramer acetate. Blinded studies are required to investigate GlcNAc's potential to control residual brain inflammation, myelin repair and neurodegeneration in MS.


Assuntos
Encefalite , Esclerose Múltipla , Humanos , Animais , Camundongos , Acetilglucosamina/uso terapêutico , Interleucina-17 , Acetato de Glatiramer , Interleucina-6 , Esclerose Múltipla/tratamento farmacológico , Inflamação/tratamento farmacológico , Citocinas
12.
Encephalitis ; 3(1): 15-23, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37469716

RESUMO

Purpose: Purpose Regulatory T cells (Tregs) have been implicated in the pathogenesis of several autoimmune disorders and used in adoptive cell transfer therapies. Neither have been explored in patients with autoimmune encephalitis where treated patient outcomes remain suboptimal with frequent relapses. Here, to identify new treatment strategies for autoimmune encephalitis, we sought to evaluate the proportion of circulating Tregs and Treg subpopulations in peripheral blood of patients with N-methyl-ᴅ-aspartate receptor-antibody encephalitis (NMDAR-Ab-E) and compared this with healthy controls. Methods: We compared the phenotype of peripheral blood Tregs in four adult NMDAR-Ab-E patients and four age- and sex-matched healthy controls using an 11-color flow cytometry assay panel for characterization of Tregs (CD4+ CD25+ FoxP3+) cells into naïve (chemokine receptor [CCR] 7+ CD45RA+), central memory (CCR7+ CD45RA-), and effector memory (CCR7- CD45RA-) cells. We also examined and compared the expression of the CCR6 by circulating Tregs and the respective Treg subpopulations between the study groups. Results: The proportion of circulating Tregs was similar between patients with NMDAR-Ab-E and healthy controls but the proportion of naïve Tregs was lower in NMDAR-Ab-E patients (p = 0.0026). Additionally, the frequency of circulating effector memory Tregs was higher, and the proportion of circulating effector memory Tregs expressing CCR6 was lower, in NMDAR-Ab-E patients compared with healthy controls (p = 0.0026). Conclusion: Altered Treg homeostasis may be a feature of patients with NMDAR-Ab-E. Future studies with larger samples are warranted to validate these findings.

14.
J Neurol ; 270(10): 5034-5047, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37400659

RESUMO

BACKGROUND: Encephalitis is an uncommon but severe disorder due to an inflammation of the brain parenchyma, usually diagnosed on clinical, laboratory, electroencephalographic, and neuroradiological features. New causes of encephalitis have been reported in recent years, so diagnostic criteria have changed over time. We report on a single-center experience of a pediatric Hospital, the hub of its region, over 12 years (2008-2021), with the evaluation of all children managed for acute encephalitis. METHODS: We retrospectively reviewed clinical, laboratory, neuroradiological, and EEG data from the acute phase and outcome of all immunocompetent patients diagnosed with acute encephalitis. According to the newly proposed criteria for pediatric autoimmune encephalitis, we divided patients into infectious, definite autoimmune, probable autoimmune, and possible autoimmune, and performed a comparison between the different groups. RESULTS: 48 patients (26 females, mean age 4.4 years), 19 with infections, and 29 with autoimmune encephalitis, were included. Herpes simplex virus 1 encephalitis was the most frequently identified etiology followed by anti-NMDA receptor encephalitis. Movement disorders at onset and a longer hospital stay were observed more frequently in autoimmune compared to infectious encephalitis (p p < 0.001 and p = 0.001, respectively). Among the autoimmune group, children who started immunomodulatory treatment earlier (within 7 days from onset) had more frequent complete functional recovery (p = 0.002). CONCLUSIONS: Herpes virus and anti-NMDAR encephalitis are the most frequent etiologies within our cohort. Clinical onset and course are extremely variable. Since early immunomodulatory treatment was associated with a better functional outcome, our data confirm that a timely diagnostic classification in definite, probable, or possible autoimmune encephalitis can help the clinician in a successful therapeutic approach.


Assuntos
Encefalite Antirreceptor de N-Metil-D-Aspartato , Doença de Hashimoto , Feminino , Humanos , Criança , Pré-Escolar , Estudos Retrospectivos , Encefalite Antirreceptor de N-Metil-D-Aspartato/diagnóstico , Encéfalo/diagnóstico por imagem
15.
Alerta (San Salvador) ; 6(2): 119-124, jul. 19, 2023. ilus, tab.
Artigo em Espanhol | BISSAL, LILACS | ID: biblio-1442659

RESUMO

Presentación del caso. Se trata de una mujer de 44 años de edad, con historia de cefalea occipital, lenguaje incoherente y pensamiento confuso. Inicialmente presentaba diez puntos en la escala de Glasgow y una hemiparesia izquierda. La tomografía computarizada de cráneo, reportó edema cerebral con lesión hipodensa talámica derecha y deterioro neurológico progresivo.El electroencefalograma evidenció desaceleración unilateral hemisférica derecha. El estudio del líquido cefalorraquídeo describió hiperproteinorraquia y un recuento a predominio linfocitario de 450 células con glucorraquia conservada, sin presencia de bacterias. Intervención terapéutica. se manejó con soporte ventilatorio invasivo y con tratamiento antibiótico y antiviral a dosis meníngeas, además de anticonvulsivantes. Los hallazgos tomográficos de control reportaron una hidrocefalia; se colocó una derivación ventricular tipo Becker. La serología IgM resultó positiva para virus de Epstein Barr y se identificó el genoma viral en el líquido cefalorraquídeo, a través de la prueba de reacción en cadena de polimerasa. La tomografía cerebral de control, evidenció la persistencia de la ventriculomegalia y de edema cerebral, lo que generó el diagnóstico de una encefalitis de etiología viral complicada con epilepsia secundaria por una lesión estructural desmielinizante del hemisferio cerebral derecho. Evolución clínica. La intervención terapéutica con inmunoglobulina intravenosa generó una mejoría del estado general. Fue posible retirar la derivación ventricular y la ventilación pulmonar diez y 19 días después del ingreso, respectivamente. La paciente se encuentra actualmente en fisioterapia con persistencia de hemiparesia izquierda, alteraciones de la marcha, disartria y episodios convulsivos controlados durante los últimos seis meses


Case presentation. This case is about a 44 years old woman with a history of occipital headache, incoherent speech and confused thinking. She initially presented ten points on the Glasgow scale and left hemiparesis. Cranial CT scan reported cerebral edema with right thalamic hypodense lesion and progressive neurological deterioration. The electroencephalogram showed unilateral right hemispheric deceleration. The cerebrospinal fluid study showed hyperproteinuria and a predominantly lymphocyte count of 450 cells with preserved glycorrhachia, without the presence of bacteria. Treatment.was managed with invasive ventilatory support and antibiotic and antiviral treatment at meningeal doses, in addition to anticonvulsants. Control tomographic findings showed hydrocephalus; a Becker type ventricular shunt was placed. IgM serology was positive for Epstein Barr virus and the viral genome was identified in the cerebrospinal fluid by polymerase chain reaction test. The control brain tomography showed persistent ventriculomegaly and cerebral edema, which led to the diagnosis of encephalitis of viral etiology complicated by epilepsy secondary to a demyelinating structural lesion of the right cerebral hemisphere. Outcome. Therapeutic intervention with intravenous immunoglobulin was performed with improvement of the general condition, it was possible to remove the ventricular shunt and pulmonary ventilation ten and 19 days after admission, respectively. The patient is currently in physical therapy with persistence of left hemiparesis, gait disturbances, dysarthria, and controlled convulsive episodes during the last six months.


Assuntos
Humanos , Feminino , Herpesvirus Humano 4 , El Salvador
16.
Clin Nutr Res ; 12(2): 154-167, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37214781

RESUMO

Hepatic encephalopathy (HE) associated with liver failure is accompanied by hyperammonemia, severe inflammation, depression, anxiety, and memory deficits as well as liver injury. Recent studies have focused on the liver-brain-inflammation axis to identify a therapeutic solution for patients with HE. Lipocalin-2 is an inflammation-related glycoprotein that is secreted by various organs and is involved in cellular mechanisms including iron homeostasis, glucose metabolism, cell death, neurite outgrowth, and neurogenesis. In this study, we investigated that the roles of lipocalin-2 both in the brain cortex of mice with HE and in Neuro-2a (N2A) cells. We detected elevated levels of lipocalin-2 both in the plasma and liver in a bile duct ligation mouse model of HE. We confirmed changes in cytokine expression, such as interleukin-1ß, cyclooxygenase 2 expression, and iron metabolism related to gene expression through AKT-mediated signaling both in the brain cortex of mice with HE and N2A cells. Our data showed negative effects of hepatic lipocalin-2 on cell survival, iron homeostasis, and neurite outgrowth in N2A cells. Thus, we suggest that regulation of lipocalin-2 in the brain in HE may be a critical therapeutic approach to alleviate neuropathological problems focused on the liver-brain axis.

17.
Int J Mol Sci ; 24(7)2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-37047062

RESUMO

Cerebellar ataxia is a neurodegenerative disorder with no definitive treatment. Although previous study demonstrated the neuroprotective effects of Hericium erinaceus (H.E.), the mechanisms of H.E. treatment on the neuroinflammatory response, neurotransmission, and related metabolites remain largely unknown. We demonstrated that 3-AP rats treated with 25 mg/kg H.E. extracts had improved motor coordination and balance in the accelerated rotarod and rod tests. We showed that the H.E. treatment upregulated the expression of Tgfb1, Tgfb2, and Smad3 genes to levels comparable to those in the non-3-AP control group. Interestingly, we also observed a significant correlation between Tgfb2 gene expression and rod test performance in the 3-AP saline group, but not in the non-3-AP control or H.E.+3-AP groups, indicating a relationship between Tgfb2 gene expression and motor balance in the 3-AP rat model. Additionally, we also found that the H.E. treatment increased mitochondrial COX-IV protein expression and normalized dopamine-serotonin neurotransmission and metabolite levels in the cerebellum of the H.E.+3-AP group compared to the 3-AP saline group. In conclusion, our findings suggest that the H.E. treatment improved motor function in the 3-AP rat model, which was potentially mediated through neuroprotective mechanisms involving TGFB2-Smad3 signaling via normalization of neurotransmission and metabolic pathways.


Assuntos
Ataxia Cerebelar , Ratos , Animais , Ataxia Cerebelar/tratamento farmacológico , Ataxia Cerebelar/genética , Ataxia Cerebelar/metabolismo , Hericium , Modelos Animais de Doenças , Anti-Inflamatórios/uso terapêutico
18.
Mater Today Bio ; 18: 100525, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36619201

RESUMO

Several human pathogens can cause long-lasting neurological damage. Despite the increasing clinical knowledge about these conditions, most still lack efficient therapeutic interventions. Gene therapy (GT) approaches comprise strategies to modify or adjust the expression or function of a gene, thus providing therapy for human diseases. Since recombinant nucleic acids used in GT have physicochemical limitations and can fail to reach the desired tissue, viral and non-viral vectors are applied to mediate gene delivery. Although viral vectors are associated to high levels of transfection, non-viral vectors are safer and have been further explored. Different types of nanosystems consisting of lipids, polymeric and inorganic materials are applied as non-viral vectors. In this review, we discuss potential targets for GT intervention in order to prevent neurological damage associated to infectious diseases as well as the role of nanosized non-viral vectors as agents to help the selective delivery of these gene-modifying molecules. Application of non-viral vectors for delivery of GT effectors comprise a promising alternative to treat brain inflammation induced by viral infections.

19.
Metab Brain Dis ; 38(5): 1707-1716, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36326976

RESUMO

Hepatic encephalopathy (HE) is a frequent complication of chronic liver disease (CLD) and has a complex pathogenesis. Several preclinical and clinical studies have reported the presence of both peripheral and brain inflammation in CLD and their potential impact in the development of HE. Altered brain vascular density and tone, as well as compromised cerebral and systemic blood flow contributing to the development of brain hypoxia, have also been reported in animal models of HE, while a decrease in cerebral metabolic rate of oxygen and cerebral blood flow has consistently been observed in patients with HE. Whilst significant strides in our understanding have been made over the years, evaluating all these mechanistic elements in vivo and showing causal association with development of HE, have been limited through the practical constraints of experimentation. Nonetheless, improvements in non-invasive assessments of different neurophysiological parameters, coupled with techniques to assess changes in inflammatory and metabolic pathways, will help provide more granular insights on these mechanisms. In this special issue we discuss some of the emerging evidence supporting the hypothesis that brain inflammation and abnormal oxygen homeostasis occur interdependently during CLD and comprise important contributors to the development of HE. This review aims at furnishing evidence for further research in brain inflammation and oxygen homeostasis as additional therapeutic targets and potentially diagnostic markers for HE.


Assuntos
Encefalite , Encefalopatia Hepática , Hepatopatias , Animais , Encefalopatia Hepática/metabolismo , Oxigênio/metabolismo , Encéfalo/metabolismo , Hepatopatias/metabolismo , Encefalite/metabolismo , Homeostase
20.
J Hepatol ; 78(1): 180-190, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35995127

RESUMO

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) has been associated with mild cerebral dysfunction and cognitive decline, although the exact pathophysiological mechanism remains ambiguous. Using a diet-induced model of NAFLD and monocarboxylate transporter-1 (Mct1+/-) haploinsufficient mice, which resist high-fat diet-induced hepatic steatosis, we investigated the hypothesis that NAFLD leads to an encephalopathy by altering cognition, behaviour, and cerebral physiology. We also proposed that global MCT1 downregulation offers cerebral protection. METHODS: Behavioural tests were performed in mice following 16 weeks of control diet (normal chow) or high-fat diet with high fructose/glucose in water. Tissue oxygenation, cerebrovascular reactivity, and cerebral blood volume were monitored under anaesthesia by multispectral optoacoustic tomography and optical fluorescence. Cortical mitochondrial oxygen consumption and respiratory capacities were measured using ex vivo high-resolution respirometry. Microglial and astrocytic changes were evaluated by immunofluorescence and 3D reconstructions. Body composition was assessed using EchoMRI, and liver steatosis was confirmed by histology. RESULTS: NAFLD concomitant with obesity is associated with anxiety- and depression-related behaviour. Low-grade brain tissue hypoxia was observed, likely attributed to the low-grade brain inflammation and decreased cerebral blood volume. It is also accompanied by microglial and astrocytic morphological and metabolic alterations (higher oxygen consumption), suggesting the early stages of an obesogenic diet-induced encephalopathy. Mct1 haploinsufficient mice, despite fat accumulation in adipose tissue, were protected from NAFLD and associated cerebral alterations. CONCLUSIONS: This study provides evidence of compromised brain health in obesity and NAFLD, emphasising the importance of the liver-brain axis. The protective effect of Mct1 haploinsufficiency points to this protein as a novel therapeutic target for preventing and/or treating NAFLD and the associated brain dysfunction. IMPACT AND IMPLICATIONS: This study is focused on unravelling the pathophysiological mechanism by which cerebral dysfunction and cognitive decline occurs during NAFLD and exploring the potential of monocarboxylate transporter-1 (MCT1) as a novel preventive or therapeutic target. Our findings point to NAFLD as a serious health risk and its adverse impact on the brain as a potential global health system and economic burden. These results highlight the utility of Mct1 transgenic mice as a model for NAFLD and associated brain dysfunction and call for systematic screening by physicians for early signs of psychological symptoms, and an awareness by individuals at risk of these potential neurological effects. This study is expected to bring attention to the need for early diagnosis and treatment of NAFLD, while having a direct impact on policies worldwide regarding the health risk associated with NAFLD, and its prevention and treatment.


Assuntos
Encefalopatias , Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Hepatopatia Gordurosa não Alcoólica/metabolismo , Dieta Hiperlipídica/efeitos adversos , Fígado/patologia , Obesidade/metabolismo , Camundongos Transgênicos , Encefalopatias/metabolismo , Encefalopatias/patologia , Encéfalo/metabolismo , Camundongos Endogâmicos C57BL
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