scholarly journals Neuroprotective and Neurorestorative Effects of Holothuria scabra Extract in the MPTP/MPP+-Induced Mouse and Cellular Models of Parkinson’s Disease

2020 ◽  
Vol 14 ◽  
Author(s):  
Kunwadee Noonong ◽  
Prasert Sobhon ◽  
Morakot Sroyraya ◽  
Kulathida Chaithirayanon

Extracts from Holothuria scabra (HS) have been shown to possess anti-inflammation, anti-oxidant and anti-cancer activities. More recently, it was shown to have neuroprotective potential in Caenorhabditis elegans PD model. Here, we assessed whether HS has neuroprotective and neurorestorative effects on dopaminergic neurons in both mouse and cellular models of PD. We found that both pre-treatment and post-treatment with HS improved motor deficits in PD mouse model induced with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) as determined by grid walk test. This was likely mediated by HS protective and restorative effects on maintaining the numbers of dopaminergic neurons and fibers in both substantia nigra pars compacta (SNpc) and striatum. In a cellular model of PD, HS significantly attenuated 1-methyl-4-phenylpyridinium (MPP+)-induced apoptosis of DAergic-like neurons differentiated from SH-SY5Y cells by enhancing the expression of Bcl-2, suppressing the expression of cleaved Caspase 3 and preventing depolarization of mitochondrial membrane. In addition, HS could stimulate the expression of tyrosine hydroxylase (TH) and suppressed the formation of α-synuclein protein. Taken together, our in vivo and in vitro findings suggested that HS is an attractive candidate for the neuroprotection rather than neurorestoration in PD.

2020 ◽  
Vol 21 (21) ◽  
pp. 8376
Author(s):  
Peng Chen ◽  
Youcui Wang ◽  
Leilei Chen ◽  
Ning Song ◽  
Junxia Xie

Parkinson’s disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Several brain–gut peptides are able to exert neuroprotective effects on the nigrostriatal dopaminergic system. Apelin-13 is a neuropeptide, conveying potential neuroprotective activities. However, whether, and how, apelin-13 could antagonize rotenone-induced neurotoxicity has not yet been elucidated. In the present study, rotenone-treated SH-SY5Y cells and rats were used to clarify whether apelin-13 has protective effects on dopaminergic neurons, both in vivo and in vitro. The results showed that apelin-13 could protect SH-SY5Y cells from rotenone-induced injury and apoptosis. Apelin-13 was able to activate autophagy, and restore rotenone induced autophagy impairment in SH-SY5Y cells, which could be blocked by the autophagy inhibitor 3-Methyladenine. Apelin-13 activated AMPK/mTOR/ULK-1 signaling, AMPKα inhibitor compound C, as well as apelin receptor blockage via siRNA, which could block apelin-13-induced signaling activation, autophagy activation, and protective effects, in rotenone-treated SH-SY5Y cells. These results indicated that apelin-13 exerted neuroprotective properties against rotenone by stimulating AMPK/mTOR/ULK-1 signaling-mediated autophagy via the apelin receptor. We also observed that intracerebroventricular injection of apelin-13 could alleviate nigrostriatal dopaminergic neuron degeneration in rotenone-treated rats. Our findings provide new insights into the mechanism by which apelin-13 might attenuate neurotoxicity in PD.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Theodora Mourtzi ◽  
Dimitrios Dimitrakopoulos ◽  
Dimitrios Kakogiannis ◽  
Charalampos Salodimitris ◽  
Konstantinos Botsakis ◽  
...  

Abstract Background Loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) underlines much of the pathology of Parkinson’s disease (PD), but the existence of an endogenous neurogenic system that could be targeted as a therapeutic strategy has been controversial. BNN-20 is a synthetic, BDNF-mimicking, microneurotrophin that we previously showed to exhibit a pleiotropic neuroprotective effect on the dopaminergic neurons of the SNpc in the “weaver” mouse model of PD. Here, we assessed its potential effects on neurogenesis. Methods We quantified total numbers of dopaminergic neurons in the SNpc of wild-type and “weaver” mice, with or without administration of BNN-20, and we employed BrdU labelling and intracerebroventricular injections of DiI to evaluate the existence of dopaminergic neurogenesis in the SNpc and to assess the origin of newborn dopaminergic neurons. The in vivo experiments were complemented by in vitro proliferation/differentiation assays of adult neural stem cells (NSCs) isolated from the substantia nigra and the subependymal zone (SEZ) stem cell niche to further characterize the effects of BNN-20. Results Our analysis revealed the existence of a low-rate turnover of dopaminergic neurons in the normal SNpc and showed, using three independent lines of experiments (stereologic cell counts, BrdU and DiI tracing), that the administration of BNN-20 leads to increased neurogenesis in the SNpc and to partial reversal of dopaminergic cell loss. The newly born dopaminergic neurons, that are partially originated from the SEZ, follow the typical nigral maturation pathway, expressing the transcription factor FoxA2. Importantly, the pro-cytogenic effects of BNN-20 were very strong in the SNpc, but were absent in other brain areas such as the cortex or the stem cell niche of the hippocampus. Moreover, although the in vitro assays showed that BNN-20 enhances the differentiation of NSCs towards glia and neurons, its in vivo administration stimulated only neurogenesis. Conclusions Our results demonstrate the existence of a neurogenic system in the SNpc that can be manipulated in order to regenerate the depleted dopaminergic cell population in the “weaver” PD mouse model. Microneurotrophin BNN-20 emerges as an excellent candidate for future PD cell replacement therapies, due to its area-specific, pro-neurogenic effects.


2021 ◽  
Author(s):  
Jingyi Li ◽  
Longmin Chen ◽  
Qixiong Qin ◽  
Danlei Wang ◽  
Jingwei Zhao ◽  
...  

Abstract Background: Parkinson’s disease (PD) is characterized by impaired mitochondrial function and decreased ATP levels. Glycolysis is upregulated and lactate production is enhanced in PD. Since lactate promotes apoptosis and α-synuclein accumulation in neurons, we hypothesized that the increased lactate resulted from upregulated glycolysis is involved in the apoptosis of dopaminergic neurons in PD.Methods: We examined the expression of hexokinase 2 (HK2) and lactate dehydrogenase (LDH), the key enzymes in glycolysis, and lactate levels in the substantia nigra pars compacta (SNpc) of MPTP-induced mouse model of PD and in MPP+-treated SH-SY5Y cells. We investigated the role of HK2, lactate and AMPK pathway in the apoptosis of dopaminergic neurons by intervened with 3-Brpa, the HK2 inhibitor, in in vivo and in vitro systems.Results: We found that the expression of HK2 and LDHA, and lactate levels were markedly increased in brain SNpc of MPTP-treated mouse and in MPP+-treated SH-SY5Y cells. Meanwhile, the apoptosis of dopaminergic neurons in the mouse model and the apoptosis of the SH-SY5Y in vitro system were increased. Intriguingly, using HK2 inhibitor or siRNA can decrease the lactate levels and suppressed the apoptosis of dopaminergic neurons both in vivo and in vitro. Mechanistically, lactate increased the activity of adenosine monophosphate activated protein kinase (AMPK), and suppressed the phosphorylation of serine/threonine kinase 1 (Akt) and mammalian target of rapamycin (mTOR). Conclusion:Inhibition of HK2 ameliorate the apoptosis of dopaminergic neurons through downregulating the lactate production and AMPK/ Akt/ mTOR pathway activation in PD.


2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Zixuan Lin ◽  
Chen Chen ◽  
Dongqin Yang ◽  
Jianqing Ding ◽  
Guanghui Wang ◽  
...  

AbstractParkinson’s disease (PD), one of the most common neurodegenerative disorders, is characterized by progressive neurodegeneration of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). DJ-1 acts essential roles in neuronal protection and anti-neuroinflammatory response, and its loss of function is tightly associated with a familial recessive form of PD. However, the molecular mechanism of DJ-1 involved in neuroinflammation is largely unclear. Here, we found that wild-type DJ-1, rather than the pathogenic L166P mutant DJ-1, directly binds to the subunit p65 of nuclear factor-κB (NF-κB) in the cytoplasm, and loss of DJ-1 promotes p65 nuclear translocation by facilitating the dissociation between p65 and NF-κB inhibitor α (IκBα). DJ-1 knockout (DJ-1−/−) mice exhibit more microglial activation compared with wild-type littermate controls, especially in response to lipopolysaccharide (LPS) treatment. In cellular models, knockdown of DJ-1 significantly upregulates the gene expression and increases the release of LPS-treated inflammatory cytokines in primary microglia and BV2 cells. Furthermore, DJ-1 deficiency in microglia significantly enhances the neuronal toxicity in response to LPS stimulus. In addition, pharmacological blockage of NF-κB nuclear translocation by SN-50 prevents microglial activation and alleviates the damage of DA neurons induced by microglial DJ-1 deficiency in vivo and in vitro. Thus, our data illustrate a novel mechanism by which DJ-1 facilitates the interaction between IκBα and p65 by binding to p65 in microglia, and thus repressing microglial activation and exhibiting the protection of DA neurons from neuroinflammation-mediated injury in PD.


Author(s):  
Verónica Company ◽  
Abraham Andreu-Cervera ◽  
M. Pilar Madrigal ◽  
Belén Andrés ◽  
Francisca Almagro-García ◽  
...  

The fasciculus retroflexus is an important fascicle that mediates reward-related behaviors and is associated with different psychiatric diseases. It is the main habenular efference and constitutes a link between forebrain regions, the midbrain, and the rostral hindbrain. The proper functional organization of habenular circuitry requires complex molecular programs to control the wiring of the habenula during development. However, the mechanisms guiding the habenular axons toward their targets remain mostly unknown. Here, we demonstrate the role of the mesodiencephalic dopaminergic neurons (substantia nigra pars compacta and ventral tegmental area) as an intermediate target for the correct medial habenular axons navigation along the anteroposterior axis. These neuronal populations are distributed along the anteroposterior trajectory of these axons in the mesodiencephalic basal plate. Using in vitro and in vivo experiments, we determined that this navigation is the result of netrin 1 attraction generated by the mesodiencephalic dopaminergic neurons. This attraction is mediated by the receptor deleted in colorectal cancer (DCC), which is strongly expressed in the medial habenular axons. The increment in our knowledge on the fasciculus retroflexus trajectory guidance mechanisms opens the possibility of analyzing if its alteration in mental health patients could account for some of their symptoms.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3821-3821
Author(s):  
Melissa Rodriguez ◽  
Warren Fiskus ◽  
Sunil Sharma ◽  
Jun Qi ◽  
John A Valenta ◽  
...  

Abstract Mutations in FLT3 are detected in approximately 30% of AML and are associated with poor overall survival. Although first (PKC412, sorafenib and CEP701) and second generation (AC220) FLT3 tyrosine kinase inhibitors (TKI) induce remissions, resistance-causing gatekeeper (F691I/L), activation loop (AL) mutations (D835V/Y/F) or compound FLT3-ITD/F691I AL mutations are known to impair the in vitro and in vivo activity of the FLT3-TKIs. The BET (bromodomain and extraterminal) protein family members including BRD4 bind to acetylated lysines on the histone proteins, help assemble transcriptional regulators at the target gene promoters and enhancers, and regulate the expression of important oncogenes, e.g., MYC and BCL-2. BRD4 antagonists JQ1 and I-BET151 disrupt the binding of the bromodomain of BRD4 to acetylated lysines on histone proteins, thereby inhibiting expressions of c-MYC and BCL-2 and inducing apoptosis of AML cells. Based on this, we evaluated the in vitro and in vivo activity of JQ1 and FLT3 antagonists AC220 and ponatinib against cultured mouse lymphoid (Ba/F3/FLT3-ITD), as well as human cultured (MOLM13 and MV4-11) and primary AML blast progenitor cells (BPCs) expressing FLT3-ITD. JQ1, but not its inactive enantiomer R-JQ1, potently induced apoptosis of not only Ba/F3/FLT3-ITD but also of Ba/F3/FLT3-ITD expressing the highly FLT3 TKI-resistant mutations F691L and D835V (IC50 values for JQ1 were 697, 1588 and 909 nM, in the three cell lines, respectively). This was associated with attenuation of c-MYC, but the induction of BIM levels. Both JQ1 and I-BET151 dose-dependently induced apoptosis of MOLM13 and MV4-11 cells, as well as of primary AML BPCs expressing FLT3-ITD. Concomitantly, JQ1 treatment attenuated c-MYC, BCL2 and CDK6, while inducing p21, p27, BIM and cleaved PARP levels. JQ1 and I-BET151 did not induce apoptosis of CD34+ normal bone marrow progenitor cells. Following engraftment of NOD/SCID mice with MOLM13 cell xenograft, treatment with JQ1 (50 mg/kg, formulated in 10% 2-hydroxypropyl-β-cyclodextrin, daily x 5 days per week x 3 weeks), versus treatment with vehicle control, significantly improved survival of the mice (p< 0.05), without causing any toxicity. This was associated with the in vivo attenuation of c-MYC and BCL-2 levels in the harvested AML cells from the mice. Co-treatment with JQ1 or I-BET151 and FLT3 antagonist AC220 or ponatinib synergistically induced apoptosis of MOLM13 and MV4-11 cells. This was associated with greater reduction in the levels of MYC, BCL2 and CDK6, but more induction of BIM, p27 and cleaved PARP levels. Knockdown of BRD4 by treatment with specific shRNA phenocopied the effects of JQ1 and sensitized MOLM13 cells to ponatinib and AC220. As compared to each agent alone, treatment with JQ1 and ponatinib or AC220 also induced more apoptosis of primary AML BPCs expressing FLT3-ITD, associated again with greater reduction of the levels of MYC, BCL2 and CDK6, but more induction of BIM, p27 and cleaved PARP levels. We also determined the effects of JQ1 against MOLM13/TKIR cells that were generated under the continuous selection pressure of FLT3 TKI, and exhibited > 10 fold resistance to ponatinib but > 50 fold resistance to AC220. Importantly, as compared to the parental MOLM13, the MOLM13/TKIR cells were markedly more sensitive to JQ1-induced apoptosis (p< 0.001). Additionally, co-treatment with JQ1 and ponatinib but not AC220 synergistically induced apoptosis of MOLM13/TKIR cells. Supporting our previous findings (Blood. 2005;105:1768) that FLT3-ITD is a heat shock protein (hsp) 90 client-oncoprotein, the non-geldanamycin hsp90 inhibitor AUY922 was equally effective in inducing apoptosis of MOLM13 versus MOLM13/TKIR cells. Collectively, these findings demonstrate that BRD4 antagonist exhibits potent activity against cultured and primary AML cells expressing FLT-3-ITD, as well as against cellular models of FLT3 with gate-keeper and activation loop mutations. These findings also highlight the novel and synergistic activity of the combination of BRD4 antagonist and AC220 or ponatinib against AML BPCs expressing FLT3-ITD, and support the rationale for testing ponatinib and BRD4 antagonist against TKI-refractory AML expressing FLT3-ITD. Disclosures: No relevant conflicts of interest to declare.


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Ria de Haas ◽  
Lisa C M W Heltzel ◽  
Denise Tax ◽  
Petra van den Broek ◽  
Hilbert Steenbreker ◽  
...  

Abstract The PTEN-induced putative kinase 1 knockout rat (Pink1−/−) is marketed as an established model for Parkinson’s disease, characterized by development of motor deficits and progressive degeneration of half the dopaminergic neurons in the substantia nigra pars compacta by 8 months of age. In this study, we address our concerns about the reproducibility of the Pink1−/− rat model. We evaluated behavioural function, number of substantia nigra dopaminergic neurons and extracellular striatal dopamine concentrations by in vivo microdialysis. Strikingly, we and others failed to observe any loss of dopaminergic neurons in 8-month-old male Pink1−/− rats. To understand this variability, we compared key experimental parameters from the different studies and provide explanations for contradictory findings. Although Pink1−/− rats developed behavioural deficits, these could not be attributed to nigrostriatal degeneration as there was no loss of dopaminergic neurons in the substantia nigra and no changes in neurotransmitter levels in the striatum. To maximize the benefit of Parkinson’s disease research and limit the unnecessary use of laboratory animals, it is essential that the research community is aware of the limits of this animal model. Additional research is needed to identify reasons for inconsistency between Pink1−/− rat colonies and why degeneration in the substantia nigra is not consistent.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
M Adam ◽  
K K Singh ◽  
K A Connelly

Abstract Introduction Doxorubicin is amongst the most widely prescribed chemotherapy drugs due to its effectiveness in cancer treatment. However, progressive treatment using doxorubicin severely increases the risk of congestive heart failure. Mechanistically, researchers have shown that doxorubicin (i) intercalates into DNA and disrupts topoisomerase-II-mediated DNA repair and (ii) generates free radicals which then causes damage to cellular membranes, DNA, and proteins. Ultimately these cellular insults induce cardiomyocyte (CM) death mediated by the tumour suppressor, p53. Currently, there are no clinically applicable preventative treatments for doxorubicin-induced cardiotoxicity and so, extensive research is being done in discovering a potential therapy. One such candidate is curcumin – a natural polyphenol compound non-toxic to humans. We have previously demonstrated that curcumin inhibits lysine acetyltransferase activity of p300, therefore reducing both histone and non-histone protein acetylation. To induce CM death, p53 requires acetylation by p300. Therefore, we hypothesize that curcumin protects against doxorubicin-induced CM death and cardiotoxicity via p300-mediated inactivation of p53. Methods Rat H9c2 cardiomyoblast cells were cultured and treated with a 2.5 μM dose of doxorubicin for 16 hours. One group of cells were pre-treated with curcumin (15μM) 4 hours prior to doxorubicin treatment, and controls were cultured with only diluent added. Following treatment, the cells were harvested for total protein. At end point, we performed immunoblotting to measure protein expression of key proteins involved in DNA damage (y-H2A.X, p53), and apoptosis (cleaved-Caspase 3). Results Our findings show that following doxorubicin treatment, p53 expression was significantly increased (p<0.001), confirming its role in doxorubicin-associated cardiotoxicity. Furthermore, doxorubicin was associated with increased DNA-damage as evidenced by increased expression and activation of DNA double-stranded breaks (DSBs) marker, y-H2A.X (p<0.001). Elevated levels of DNA-damage were further associated with significantly increased doxorubicin-induced apoptosis as measured by immunoblotting for cleaved-Caspase 3 (p<0.001). However, DNA-damage and apoptosis were attenuated by pre-treatment of cells with curcumin. Curcumin treatment led to a significant decrease in both y-H2A.X (p<0.01) and cleaved-Caspase 3 (p<0.01) expression compared to cells treated with only doxorubicin. Conclusions Our data provides the first evidence that curcumin protects against doxorubicin-induced apoptosis in rat cardiomyoblast cells in vitro. Further studies are warranted in vivo to confirm the potential of curcumin as a cardio-protective drug. Curcumin is a natural compound with little to no side-effects in humans, therefore our finding may provide a novel therapeutic target and treatment approach for doxorubicin-associated cardiotoxicity. Acknowledgement/Funding Heart & Stroke Foundation of Canada


2018 ◽  
Vol 19 (8) ◽  
pp. 2242 ◽  
Author(s):  
Dewei He ◽  
Bingxu Huang ◽  
Shoupeng Fu ◽  
Yuhang Li ◽  
Xin Ran ◽  
...  

Parkinson’s disease (PD), a frequent degenerative disease in the elderly, is characterized by dopaminergic neurodegeneration in the substantia nigra pars compacta (SNpc). Neuroinflammation caused by over-activated microglia plays a crucial role in the pathogenesis of PD. Tubeimoside I (TBMS1) has a broad anti-inflammatory effect in peripheral tissues, but the effect on neuroinflammation has not been reported. Therefore, we explored whether TBMS1 could protect dopaminergic neurons by inhibiting the activation of microglia in lipopolysaccharide (LPS)-induced PD rat model. In addition, then, the effect and mechanism of TBMS1 on neuroinflammation were assessed in LPS-exposed murine microglial BV-2 cells. The results in vivo showed that TBMS1 suppressed microglial activation and dopaminergic neurons’ reduction in LPS-injected PD rat model. In vitro study found that TBMS1 could inhibit LPS-induced inflammatory responses in BV-2 cells, and this effect was mediated by suppressing the phosphorylation of protein kinase B (AKT), nuclear factor-kappa B (NF-κB p65), p38 and extracellular regulated protein kinases (ERK1/2). Taken together, these results demonstrated for the first time that TBMS1 played a role in protecting dopaminergic neurons by inhibiting neuroinflammation mediated by microglia.


2018 ◽  
Vol 47 (3) ◽  
pp. 1287-1298 ◽  
Author(s):  
Wenya Ma ◽  
Fang He ◽  
Fengzhi Ding ◽  
Lai Zhang ◽  
Qi Huang ◽  
...  

Background/Aims: Melatonin possesses many biological activities such as antioxidant and anti-aging. Cardiac progenitor cells (CPCs) have emerged as a promising therapeutic strategy for myocardial infarction (MI). However, the low survival of transplanted CPCs in infarcted myocardium limits the successful use in treating MI. In the present study, we aimed to investigate if melatonin protects against oxidative stress-induced CPCs damage and enhances its therapeutic efficacy for MI. Methods: TUNEL assay and EdU assay were used to detect the effects of melatonin and miR-98 on H2O2-induced apoptosis and proliferation. MI model was used to evaluate the potential cardioprotective effects of melatonin and miR-98. Results: Melatonin attenuated H2O2-induced the proliferation reduction and apoptosis of c-kit+ CPCs in vitro, and CPCs which pretreated with melatonin significantly improved the functions of post-infarct hearts compared with CPCs alone in vivo. Melatonin was capable to inhibit the increase of miR-98 level by H2O2 in CPCs. The proliferation reduction and apoptosis of CPCs induced by H2O2 was aggravated by miR-98. In vivo, transplantation of CPCs with miR-98 silencing caused the more significant improvement of cardiac functions in MI than CPCs. MiR-98 targets at the signal transducer and activator of the transcription 3 (STAT3), and thus aggravated H2O2-induced the reduction of Bcl-2 protein. Conclusions: Pre-treatment with melatonin protects c-kit+ CPCs against oxidative stress-induced damage via downregulation of miR-98 and thereby increasing STAT3, representing a potentially new strategy to improve CPC-based therapy for MI.


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