scholarly journals A selective p38α/β MAPKs inhibitor alleviates neuropathology and cognitive impairment by modulating microglia function in 5XFAD mouse

2020 ◽  
Author(s):  
Min Sung Gee ◽  
Seung Hwan Son ◽  
Seung Ho Jeon ◽  
Jimin Do ◽  
Namkwon Kim ◽  
...  

Abstract Background: Chronic neuroinflammation, aggressive amyloid beta (Aβ) deposition, neuronal cell loss and cognitive impairment are pathological symptoms of Alzheimer’s disease (AD). Regarding these symptoms, resolution of neuroinflammation and inhibition of Aβ-driven pathology might be one of the important strategies for AD therapy. Previous efforts to prevent AD progression have identified that p38 mitogen-activated protein kinase (MAPK) is a promising target for AD therapy. Especially, recent studies showed that pharmacological p38α MAPK inhibition improved memory impairment in AD mouse models. Methods: In this study, we explored the therapeutic potential of NJK14047, a selective p38α/β MAPKs inhibitor, using an Alzheimer’s disease mouse model, 5XFAD. The mice were injected 2.5 mg/kg NJK14047 or vehicle every other day for 3 months. Morris water maze task and histological imaging analysis were performed. Protein and mRNA expression levels were measured using immunoblotting and qRT-PCR respectively. In in vitro studies, the cytotoxicity of microglial conditioned medium and astrocyte conditioned medium on primary neurons were measured using MTT assay and TUNEL assay. Results: NJK14047 treatment downregulated phospho-p38 MAPK levels, decreased the amount of Aβ deposits, and prevented spatial learning memory loss in 9-month-old 5XFAD mice. Interestingly, we found the decreased pro-inflammatory conditions and increased expression of alternatively activated microglial markers and microglial phagocytic receptors. Furthermore, NJK14047 treatment reduced the number of Fluoro-jade B positive cells, a class of degenerating neurons, in the brains of 5XFAD mice. The neuroprotective effect of NJK14047 was further confirmed by in vitro studies. Conclusion: Taken together, a selective p38α/β MAPKs inhibitor NJK14047 successfully showed therapeutic effects in 5XFAD mice. Our data support that p38 MAPKs inhibition is a potential strategy for AD therapy and NJK14047 might be one of the promising candidates for AD therapeutics targeting p38 MAPKs.

2020 ◽  
Author(s):  
Min Sung Gee ◽  
Seung Hwan Son ◽  
Seung Ho Jeon ◽  
Jimin Do ◽  
Namkwon Kim ◽  
...  

Abstract Background: Chronic neuroinflammation, aggressive amyloid beta (Aβ) deposition, neuronal cell loss, and cognitive impairment are pathological presentations of Alzheimer’s disease (AD). Therefore, resolution of neuroinflammation and inhibition of Aβ-driven pathology have been suggested to be important strategies for AD therapy. Previous efforts to prevent AD progression have identified p38 mitogen-activated protein kinases (MAPKs) as a promising target for AD therapy. Recent studies showed pharmacological inhibition of p38α MAPK improved memory impairment in AD mouse models. Methods: In this study, we used an AD mouse model, 5XFAD, to explore the therapeutic potential of NJK14047 which is a novel, selective p38α/β MAPKs inhibitor. The mice were injected with 2.5 mg/kg NJK14047 or vehicle every other day for 3 months. Morris water maze task and histological imaging analysis were performed. Protein and mRNA expression levels were measured using immunoblotting and qRT-PCR, respectively. In vitro studies were conducted to measure the cytotoxicity of microglia- and astrocyte-conditioned medium on primary neurons using the MTT assay and TUNEL assay. Results: NJK14047 treatment downregulated phospho-p38 MAPK levels, decreased the amount of Aβ deposits, and reduced spatial learning memory loss in 9-month-old 5XFAD mice. While the pro-inflammatory conditions were decreased, the expression of alternatively activated microglial markers and microglial phagocytic receptors was increased. Furthermore, NJK14047 treatment reduced the number of degenerating neurons labeled with Fluoro-jade B in the brains of 5XFAD mice. The neuroprotective effect of NJK14047 was further confirmed by in vitro studies. Conclusion: Taken together, a selective p38α/β MAPKs inhibitor NJK14047 successfully showed therapeutic effects for AD in 5XFAD mice. Based on our data, p38 MAPKs inhibition is a potential strategy for AD therapy, suggesting NJK14047 as one of the promising candidates for AD therapeutics targeting p38 MAPKs. Keywords : Alzheimer’s disease, Amyloid-β, P38 mitogen-activated protein kinase, Kinase inhibitor, Microglia


2020 ◽  
Author(s):  
Min Sung Gee ◽  
Seung Hwan Son ◽  
Seung Ho Jeon ◽  
Jimin Do ◽  
Namkwon Kim ◽  
...  

Abstract Background: Chronic neuroinflammation, aggressive amyloid beta (Aβ) deposition, neuronal cell loss and cognitive impairment are pathological symptoms of Alzheimer’s disease (AD). Regarding these symptoms, resolution of neuroinflammation and inhibition of Aβ-driven pathology might be a novel strategy for AD therapy. Efforts to prevent AD progression have identified that p38 mitogen-activated protein kinase (MAPK) is a promising target for AD therapy. However, the actual therapeutic effect of selective p38 MAPK inhibition in AD has not been ascertained yet. Methods: In this study, we explored the therapeutic potential of NJK14047, a selective p38 MAPK inhibitor, using an Alzheimer’s disease mouse model, 5XFAD. The mice were injected 2.5 mg/kg NJK14047 or vehicle every other day for 3 months. Morris water maze task and histological imaging analysis were performed. Protein and mRNA expression levels were measured using immunoblotting and qRT-PCR. In in vitro studies, the cytotoxicity of microglial conditioned medium and astrocyte conditioned medium on primary neurons were measured using MTT assay and TUNEL assay. Results: NJK14047 treatment downregulated phospho-p38 MAPK levels, decreased the amount of Aβ deposits, and improved spatial learning memory in 5XFAD mice. Interestingly, these effects were associated with the decrease of inflammatory responses and the elevation of alternatively activated M2 markers. Furthermore, NJK14047 treatment reduced the number of Fluoro-jade B positive cells, a class of degenerating neurons, in the brains of 5XFAD mice. The neuroprotective effect of NJK14047, achieved via the restoration of microglia function, was further confirmed by in vitro studies. Conclusion: Taken together, our results reveal that inhibition of p38 MAPK in the brain alleviates AD pathology and represents a potential strategy for AD therapy. It also suggests that NJK14047 is a promising candidate for AD treatment. Keywords : Alzheimer’s disease, Amyloid-β, P38 mitogen-activated protein kinase, Kinase inhibitor, Microglia


2021 ◽  
pp. 1-16
Author(s):  
Esteban Leyton ◽  
Diego Matus ◽  
Sandra Espinoza ◽  
José Matías Benitez ◽  
Bastián I. Cortes ◽  
...  

Background: Disturbances in the autophagy/endolysosomal systems are proposed as early signatures of Alzheimer’s disease (AD). However, few studies are available concerning autophagy gene expression in AD patients. Objective: To explore the differential expression of classical genes involved in the autophagy pathway, among them a less characterized one, DEF8 (Differentially expressed in FDCP 8), initially considered a Rubicon family member, in peripheral blood mononuclear cells (PBMCs) from individuals with mild cognitive impairment (MCI) and probable AD (pAD) and correlate the results with the expression of DEF8 in the brain of 5xFAD mice. Method: By real-time PCR and flow cytometry, we evaluated autophagy genes levels in PBMCs from MCI and pAD patients. We evaluated DEF8 levels and its localization in brain samples of the 5xFAD mice by real-time PCR, western blot, and immunofluorescence. Results: Transcriptional levels of DEF8 were significantly reduced in PBMCs of MCI and pAD patients compared with healthy donors, correlating with the MoCA and MoCA-MIS cognitive tests scores. DEF8 protein levels were increased in lymphocytes from MCI but not pAD, compared to controls. In the case of brain samples from 5xFAD mice, we observed a reduced mRNA expression and augmented protein levels in 5xFAD compared to age-matched wild-type mice. DEF8 presented a neuronal localization. Conclusion: DEF8, a protein proposed to act at the final step of the autophagy/endolysosomal pathway, is differentially expressed in PBMCs of MCI and pAD and neurons of 5xFAD mice. These results suggest a potential role for DEF8 in the pathophysiology of AD.


2021 ◽  
Vol 13 ◽  
Author(s):  
Domenica Donatella Li Puma ◽  
Roberto Piacentini ◽  
Claudio Grassi

Adult hippocampal neurogenesis is a physiological mechanism contributing to hippocampal memory formation. Several studies associated altered hippocampal neurogenesis with aging and Alzheimer's disease (AD). However, whether amyloid-β protein (Aβ)/tau accumulation impairs adult hippocampal neurogenesis and, consequently, the hippocampal circuitry, involved in memory formation, or altered neurogenesis is an epiphenomenon of AD neuropathology contributing negligibly to the AD phenotype, is, especially in humans, still debated. The detrimental effects of Aβ/tau on synaptic function and neuronal viability have been clearly addressed both in in vitro and in vivo experimental models. Until some years ago, studies carried out on in vitro models investigating the action of Aβ/tau on proliferation and differentiation of hippocampal neural stem cells led to contrasting results, mainly due to discrepancies arising from different experimental conditions (e.g., different cellular/animal models, different Aβ and/or tau isoforms, concentrations, and/or aggregation profiles). To date, studies investigating in situ adult hippocampal neurogenesis indicate severe impairment in most of transgenic AD mice; this impairment precedes by several months cognitive dysfunction. Using experimental tools, which only became available in the last few years, research in humans indicated that hippocampal neurogenesis is altered in cognitive declined individuals affected by either mild cognitive impairment or AD as well as in normal cognitive elderly with a significant inverse relationship between the number of newly formed neurons and cognitive impairment. However, despite that such information is available, the question whether impaired neurogenesis contributes to AD pathogenesis or is a mere consequence of Aβ/pTau accumulation is not definitively answered. Herein, we attempted to shed light on this complex and very intriguing topic by reviewing relevant literature on impairment of adult neurogenesis in mouse models of AD and in AD patients analyzing the temporal relationship between the occurrence of altered neurogenesis and the appearance of AD hallmarks and cognitive dysfunctions.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1626
Author(s):  
Line Séguy ◽  
Léna Guyon ◽  
Manon Maurel ◽  
Pascal Verdié ◽  
Audrey Davis ◽  
...  

Background and Purpose: The activation of 5-HT4 receptors with agonists has emerged as a valuable therapeutic strategy to treat Alzheimer’s disease (AD) by enhancing the nonamyloidogenic pathway. Here, the potential therapeutic effects of tegaserod, an effective agent for irritable bowel syndrome, were assessed for AD treatment. To envisage its efficient repurposing, tegaserod-loaded nanoemulsions were developed and functionalized by a blood–brain barrier shuttle peptide. Results: The butyrylcholinesterase inhibitory activity of tegaserod and its neuroprotective cellular effects were highlighted, confirming the interest of this pleiotropic drug for AD treatment. In regard to its drugability profile, and in order to limit its peripheral distribution after IV administration, its encapsulation into monodisperse lipid nanoemulsions (Tg-NEs) of about 50 nm, and with neutral zeta potential characteristics, was performed. The stability of the formulation in stock conditions at 4 °C and in blood biomimetic medium was established. The adsorption on Tg-NEs of peptide-22 was realized. The functionalized NEs were characterized by chromatographic methods (SEC and C18/HPLC) and isothermal titration calorimetry, attesting the efficiency of the adsorption. From in vitro assays, these nanocarriers appeared suitable for enabling tegaserod controlled release without hemolytic properties. Conclusion: The developed peptide-22 functionalized Tg-NEs appear as a valuable tool to allow exploration of the repurposed tegaserod in AD treatment in further preclinical studies.


2010 ◽  
Vol 39 (6) ◽  
pp. 1604-1615 ◽  
Author(s):  
David E. Green ◽  
Meryn L. Bowen ◽  
Lauren E. Scott ◽  
Tim Storr ◽  
Michael Merkel ◽  
...  

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Leticia Pérez-Sisqués ◽  
Anna Sancho-Balsells ◽  
Júlia Solana-Balaguer ◽  
Genís Campoy-Campos ◽  
Marcel Vives-Isern ◽  
...  

AbstractRTP801/REDD1 is a stress-regulated protein whose upregulation is necessary and sufficient to trigger neuronal death. Its downregulation in Parkinson’s and Huntington’s disease models ameliorates the pathological phenotypes. In the context of Alzheimer’s disease (AD), the coding gene for RTP801, DDIT4, is responsive to Aβ and modulates its cytotoxicity in vitro. Also, RTP801 mRNA levels are increased in AD patients’ lymphocytes. However, the involvement of RTP801 in the pathophysiology of AD has not been yet tested. Here, we demonstrate that RTP801 levels are increased in postmortem hippocampal samples from AD patients. Interestingly, RTP801 protein levels correlated with both Braak and Thal stages of the disease and with GFAP expression. RTP801 levels are also upregulated in hippocampal synaptosomal fractions obtained from murine 5xFAD and rTg4510 mice models of the disease. A local RTP801 knockdown in the 5xFAD hippocampal neurons with shRNA-containing AAV particles ameliorates cognitive deficits in 7-month-old animals. Upon RTP801 silencing in the 5xFAD mice, no major changes were detected in hippocampal synaptic markers or spine density. Importantly, we found an unanticipated recovery of several gliosis hallmarks and inflammasome key proteins upon neuronal RTP801 downregulation in the 5xFAD mice. Altogether our results suggest that RTP801 could be a potential future target for theranostic studies since it could be a biomarker of neuroinflammation and neurotoxicity severity of the disease and, at the same time, a promising therapeutic target in the treatment of AD.


2011 ◽  
Vol 131 (5) ◽  
pp. 775-782 ◽  
Author(s):  
Keiko ZAKO ◽  
Maki SAKAGUCHI ◽  
Yuji KOMIZU ◽  
Hideaki ICHIHARA ◽  
Koichi GOTO ◽  
...  

2019 ◽  
Vol 8 (3) ◽  
pp. 194-204
Author(s):  
Zahra Memariani ◽  
Atena Rahimi ◽  
Mohammad Hosein Farzaei ◽  
Niloofar Zakaria Nejad

Nepeta menthoides Boiss & Buhse is one of the endemic species in Iran. Named Ostokhodus, it is almost used as substitute of the Lavandula stoechas –the original Ostokhodus- in traditional Persian medicine (TPM) over the time and widely used for the management of some ailments such as anxiety, depression, dementia and chronic pain. The aim of this study is to review the pharmacological and phytochemical evidence on Nepeta menthoides for the assessment of the recommended traditional indications of this herb. In this review, all the relevant articles that met our inclusion criteria [English or Persian articles, having full text, evaluating therapeutic effects of N. menthoides and dated mainly from the year 1980 to 2018] were included by searching studies in PubMed, Scopus, Google Scholar, Web of Science, and SID. The search terms were "Nepeta menthoides, "Ostokhodus". Triterpenes and monoterpenes were the most chemicals reported from essential oil of N. menthoides. Several pharmacological properties via in vitro, in vivo and clinical studies have been reported including antioxidant, anti-inflammatory, anti-nociceptive, antidepressant and anxiolytic, anticholinesterase, neuroprotective, memory enhancing, anti-Alzheimer’s disease, anticancer and effect on opioid dependence. Some proposed traditional indications of this herb in TPM books are in accordance with pharmacological evidence like anti-nociceptive, anti-seizure, anti-Alzheimer’s disease, memory enhancing, neuroprotective, antidepressant, anxiolytic activity and anti-infective properties. Although some properties in TPM, such as anti-tussive and gastrotonic effects are not supported by scientific evidence, they need more investigations.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Mehdi Jorfi ◽  
Carla D’Avanzo ◽  
Rudolph E. Tanzi ◽  
Doo Yeon Kim ◽  
Daniel Irimia

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