MiR-369-5p positively modulates plasticity-related proteins in hippocampal cultures and in a mouse model of Alzheimer's disease

Author(s):  
Yu Liu ◽  
Qingwei Xiang
Author(s):  
Christi Cho ◽  
Maxwell Zeigler ◽  
Stephanie Mizuno ◽  
Richard S. Morrison ◽  
Rheem Totah ◽  
...  

Epilepsy is a heterogenous neurological disorder characterized by recurrent unprovoked seizures, mitochondrial stress, and neurodegeneration. Hydrogen sulfide (H2S), a gasotransmitter, promotes mitochondrial function and biogenesis, elicits neuromodulation and neuroprotection, and may acutely suppress seizures. A major gap in knowledge remains in understanding the role of mitochondrial dysfunction and progressive changes in H2S levels following acute seizures and during epileptogenesis. We thus sought to quantify changes in H2S and its methylated metabolite (MeSH) via LC-MS/MS subsequent to acute maximal electroshock and 6 Hz 44 mA seizures in mice, as well as in the corneal kindled mouse model of chronic seizures. Plasma H2S was acutely reduced after a maximal electroshock seizure. H2S or MeSH levels in whole brain homogenate and expression of related genes in corneal kindled mice were not altered. However, plasma H2S and MeSH levels were significantly lower during kindling, but not after established kindling. Morever, we demonstrated a time-dependent increase in expression of mitochondrial membrane integrity-related proteins, Opa1, Mfn2, Drp1, and Mff during kindling, which did not correlate with gene expression. Taken together, short-term reductions in plasma H2S could be a novel biomarker for seizures. Future studies should further define the role of H2S and mitochondrial stress in epilepsy.


Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1353
Author(s):  
Ji Hyun Kim ◽  
Sanghyun Lee ◽  
Eun Ju Cho

Obesity increases risk of Alzheimer’s Disease (AD). A high fat diet (HFD) can lead to amyloidosis and amyloid beta (Aβ) accumulation, which are hallmarks of AD. In this study, protective effects of the ethyl acetate fraction of Acer okamotoanum (EAO) and isoquercitrin were evaluated on obesity and amyloidosis in the HFD- and Aβ-induced mouse model. To induce obesity and AD by HFD and Aβ, mice were provided with HFD for 10 weeks and were intracerebroventricularly injected with Aβ25–35. For four weeks, 100 and 10 mg/kg/day of EAO and isoquercitrin, respectively, were administered orally. Administration of EAO and isoquercitrin significantly decreased body weight in HFD and Aβ-injected mice. Additionally, EAO- and isoquercitrin-administered groups attenuated abnormal adipokines release via a decrease in leptin and an increase in adiponectin levels compared with the control group. Furthermore, HFD and Aβ-injected mice had damaged liver tissues, but EAO- and isoquercitrin-administered groups attenuated liver damage. Moreover, administration of EAO and isoquercitrin groups down-regulated amyloidosis-related proteins in the brain such as β-secretase, presenilin (PS)-1 and PS-2 compared with HFD and Aβ-injected mice. This study indicated that EAO and isoquercitrin attenuated HFD and Aβ-induced obesity and amyloidosis, suggesting that they could be effective in preventing and treating both obesity and AD.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1563-1563
Author(s):  
Andrew Guirguis ◽  
David J. Curtis ◽  
Christopher Slape ◽  
Jesslyn Saw ◽  
Andrew H Wei ◽  
...  

Abstract One of the key hallmarks of myelodysplastic syndromes (MDS) is that of ineffective haematopoiesis. The main factor contributing to this is increased apoptosis of bone marrow progenitors – a prominent feature particularly of early-stage MDS. Although apoptosis has been attributed to cell extrinsic triggers such as increased levels of Fas and TNF-α, there is increasing evidence implicating the cell intrinsic pathway – in which Bcl-2 and its related proteins play an important role and which is activated by p53. Consistent with this, we have recently shown that apoptosis in the Nup98-HoxD13 (NHD13) transgenic mouse model of MDS can be effectively blocked by enforced expression of Bcl-2. To further define the molecular mechanism of apoptosis upstream of Bcl-2, we mated NHD13 mice with mice deficient for p53. Consistent with a lineage specific role for p53, we observed p53-dependent apoptosis of the erythroid, but not the myeloid lineage. In NHD13 progenitors, gene expression analysis for members of the intrinsic pathway, showed elevated expression of Noxa but not Puma – both of which are BH3-only proteins and transcriptional targets of p53. We proceeded to mate NHD13 mice with mice deficient in Noxa and Puma. Unexpectedly, the expression levels were in fact misleading as genetic ablation studies showed that apoptosis of both erythroid and myeloid lineages was Puma dependent, with no role for Noxa. These studies have demonstrated that gene expression of Bcl-2 proteins cannot be used to predict functional relevance and in this case, Puma is the critical BH3-only protein mediating apoptosis in MDS. Disclosures: Guirguis: Leukaemia Foundation - Australia: Research Funding.


2021 ◽  
Vol 12 ◽  
Author(s):  
Md. Mahiuddin Ahmed ◽  
Andrew J. Carrel ◽  
Yasmin Cruz Del Angel ◽  
Jessica Carlsen ◽  
Ajay X. Thomas ◽  
...  

Epilepsy is characterized by recurrent, spontaneous seizures and is a major contributor to the global burden of neurological disease. Although epilepsy can result from a variety of brain insults, in many cases the cause is unknown and, in a significant proportion of cases, seizures cannot be controlled by available treatments. Understanding the molecular alterations that underlie or are triggered by epileptogenesis would help to identify therapeutics to prevent or control progression to epilepsy. To this end, the moderate throughput technique of Reverse Phase Protein Arrays (RPPA) was used to profile changes in protein expression in a pilocarpine mouse model of acquired epilepsy. Levels of 54 proteins, comprising phosphorylation-dependent and phosphorylation-independent components of major signaling pathways and cellular complexes, were measured in hippocampus, cortex and cerebellum of mice at six time points, spanning 15 min to 2 weeks after induction of status epilepticus. Results illustrate the time dependence of levels of the commonly studied MTOR pathway component, pS6, and show, for the first time, detailed responses during epileptogenesis of multiple components of the MTOR, MAPK, JAK/STAT and apoptosis pathways, NMDA receptors, and additional cellular complexes. Also noted are time- and brain region- specific changes in correlations among levels of functionally related proteins affecting both neurons and glia. While hippocampus and cortex are primary areas studied in pilocarpine-induced epilepsy, cerebellum also shows significant time-dependent molecular responses.


2021 ◽  
Author(s):  
shijie zhang ◽  
Hui-Han Ma ◽  
Can Wan ◽  
Lu-Ding Zhang ◽  
Rong-Rong Zhang ◽  
...  

Abstract Alzheimer’s disease (AD) is a most common neurodegenerative disease. Sodium Tanshinone IIA Sulfonate (STS) has been reported to ameliorate AD pathology. However, the underlying mechanism is still unclear. In this study, APP/PS1 mouse model was used to explore the potential mechanism of STS against AD. Morris water maze and Y-maze tests showed that administration of STS (10 or 20 mg/kg/day) improved learning and memory abilities of APP/PS1 mice. STS reduced the levels of ROS and MDA, while improved the activity of SOD in both hippocampus and cortex in APP/PS1 mice. STS inhibited the activity of AChE, while improved the activity of ChAT in APP/PS1 mice. In addition, STS elevated the protein expressions of neurotrophic factors (BDNF and NGF) and synapse-related proteins (PSD93, PSD95 and SYP) in both the hippocampus and cortex in APP/PS1 mice. At last, STS improved the protein expressions of GLUT1 and LRP1. These results indicated that the potential mechanism of STS on AD might be related to Aβ transportation function via GLUT1/LRP1 pathway.


2020 ◽  
Vol 11 (9) ◽  
Author(s):  
Meng-Lu Zhang ◽  
Guo-Li Zhao ◽  
Yu Hou ◽  
Shu-Min Zhong ◽  
Lin-Jie Xu ◽  
...  

Abstract Autophagy has a fundamental role in maintaining cell homeostasis. Although autophagy has been implicated in glaucomatous pathology, how it regulates retinal ganglion cell (RGC) injury is largely unknown. In the present work, we found that biphasic autophagy in RGCs occurred in a mouse model of chronic ocular hypertension (COH), accompanied by activation of Rac1, a member of the Rho family. Rac1 conditional knockout (Rac1 cKO) in RGCs attenuated RGC apoptosis, in addition to blocking the increase in the number of autophagosomes and the expression of autophagy-related proteins (Beclin1, LC3-II/I, and p62) in COH retinas. Electron micrograph and double immunostaining of LAMP1 and LC3B showed that Rac1 cKO accelerated autolysosome fusion in RGC axons of COH mice. Inhibiting the first autophagic peak with 3-methyladenine or Atg13 siRNA reduced RGC apoptosis, whereas inhibiting the second autophagic peak with 3-MA or blocking autophagic flux by chloroquine increased RGC apoptosis. Furthermore, Rac1 cKO reduced the number of autophagosomes and apoptotic RGCs induced by rapamycin injected intravitreally, which suggests that Rac1 negatively regulates mTOR activity. Moreover, Rac1 deletion decreased Bak expression and did not interfere with the interaction of Beclin1 and Bcl-2 or Bak in COH retinas. In conclusion, autophagy promotes RGC apoptosis in the early stages of glaucoma and results in autophagic cell death in later stages. Rac1 deletion alleviates RGC damage by regulating the cross talk between autophagy and apoptosis through mTOR/Beclin1-Bak. Interfering with the Rac1/mTOR signaling pathway may provide a new strategy for treating glaucoma.


2015 ◽  
Vol 16 (S1) ◽  
Author(s):  
Jantine AC Broek ◽  
Z Lin ◽  
H Van't Spijker ◽  
S Ozcan ◽  
HM De Gruiter ◽  
...  

Nephron ◽  
2021 ◽  
pp. 1-12
Author(s):  
Jing Wang ◽  
Shifeng Yang ◽  
Wendong Li ◽  
Ming Zhao ◽  
Kai Li

<b><i>Background:</i></b> Diabetic nephropathy (DN) is a severe microvascular complication of diabetes. Recently, many circular RNAs can exert crucial roles in DN progression. This study intended to explore the role and mechanism of circ_0000491 in DN. <b><i>Methods:</i></b> The DN mouse model was constructed by streptozotocin injection, and the DN cell model was established using high glucose (HG) treatment in mouse mesangial cells (SV40-MES13). The expression of circ_0000491 and microRNA-455-3p (miR-455-3p) was detected by quantitative real-time polymerase chain reaction. Cell apoptosis was evaluated by flow cytometry. The expression levels of high-mobility group box 1 (Hmgb1) protein, apoptosis-related proteins, and fibrosis-related proteins were examined by the Western blot assay. The release of inflammatory cytokines was assessed by enzyme-linked immunosorbent assay. The oxidative stress factors were analyzed by corresponding kits. The predicted interaction between miR-455-3p and circ_0000491 or Hmgb1 was verified by dual-luciferase reporter assay and RNA immunoprecipitation assay. <b><i>Results:</i></b> Circ_0000491 was overexpressed in the DN mouse model and HG-induced SV40-MES13 cells. Knockdown of circ_0000491 weakened HG-induced apoptosis, inflammation, oxidative stress, and fibrosis in SV40-MES13 cells. miR-455-3p was a direct target of circ_0000491, and miR-455-3p inhibition could reverse the role of circ_0000491 silencing in HG-induced SV40-MES13 cells. Moreover, Hmgb1 was a target gene of miR-455-3p, and miR-455-3p played a protective role against HG-induced cell injury by targeting Hmgb1. In addition, circ_0000491 regulated Hmgb1 expression by sponging miR-455-3p. <b><i>Conclusion:</i></b> Circ_0000491 knockdown inhibited HG-induced apoptosis, inflammation, oxidative stress, and fibrosis in SV40-MES13 cells by regulating miR-455-3p/Hmgb1 axis.


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