scholarly journals Bax-inhibitor-1 loss of function phenotypes are suppressed by Buffy in Drosophila

2016 ◽  
Author(s):  
P Githure M'Angale ◽  
Brian E Staveley
Keyword(s):  
Er Stress ◽  
Dopaminergic Neurons ◽  
Compound Eye ◽  
Transmembrane Protein ◽  
Loss Of Function ◽  
Diverse Range ◽  
Biometric Analysis ◽  
Climbing Ability ◽  
Induced Apoptosis ◽  
Locomotor Ability

Background. Bax Inhibitor-1 (BI-1), an integral transmembrane protein, acts as a suppressor of Bax-induced apoptosis through regulation of endoplasmic reticulum (ER) stress-induced cell death. The gene is highly conserved being found in a diverse range of organisms that include yeast, Arabidopsis, Drosophila, mouse and humans. BI-1 is implicated in the regulation of calcium levels, reactive oxygen species, apoptosis, autophagy and ER stress signalling pathways. We inhibited the cytoprotective BI-1 in the dopa decarboxylase (Ddc) expressing neurons and in the developing eye of Drosophila melanogaster to investigate its neuroprotective functions. Methods. We assessed the longevity and locomotor ability of flies in response to altered BI-1 expression in the Ddc-Gal4-expressing neurons where we exploited two RNAi transgenic fly lines. A control that expressed the benign lacZ responding transgene was used to compare against the RNAi transgenic flies. In addition, we compared the effect of the loss of BI-1 expression in the developing eye, through biometric analysis of the number of ommatidia and extent of disruption of the ommatidial arrays. Finally, Buffy and α-synuclein were co-expressed to evaluate the potential for interactions. Results. The inhibition of BI-1 in these neurons resulted in a shortened lifespan and precocious loss of locomotor ability. The co-expression of Buffy, the sole anti-apoptotic Bcl-2 homologue in Drosophila, with BI-1-RNAi resulted in suppression of the reduced lifespan and impaired climbing ability. Expression of human α-synuclein in Drosophila dopaminergic neurons results in age-dependent loss in climbing ability. We exploited this neurotoxic system to investigate possible BI-1 neuroprotective function. The co-expression of α-synuclein with BI-1-RNAi results in decreased survival coupled with an impaired climbing ability. In supportive experiments, we employed the neuron-rich Drosophila compound eye to investigate subtle phenotypes that result from altered gene expression. The inhibition of BI-1 in the Drosophila developing eye under the direction of the GMR-Gal4 transgene results in reduced ommatidia number and increased disruption of the ommatidial array. Similarly, the co-expression of BI-1-RNAi with Buffy results in the suppression of the eye phenotypes. The expression of α-synuclein along with the inhibition of BI-1 results in reduction of ommatidia number and increased disruption of the ommatidial array. Conclusions. Inhibition of BI-1 in the dopaminergic neurons of Drosophila results in a shortened lifespan and premature loss in climbing ability, phenotypes that appear to be strongly associated with models of Parkinson disease in Drosophila. These are suppressed upon overexpression of Buffy and worsened by co-expression with α-synuclein. This suggests that BI-1 acts in neuroprotection and that its inhibition can be counteracted by the overexpression of the pro-survival Bcl-2 homologue, Buffy.

scholarly journals Bax-inhibitor-1 loss of function phenotypes are suppressed by Buffy in Drosophila

2016 ◽  
Author(s):  
P Githure M'Angale ◽  
Brian E Staveley
Keyword(s):  
Er Stress ◽  
Dopaminergic Neurons ◽  
Compound Eye ◽  
Transmembrane Protein ◽  
Loss Of Function ◽  
Diverse Range ◽  
Biometric Analysis ◽  
Climbing Ability ◽  
Induced Apoptosis ◽  
Locomotor Ability

Background. Bax Inhibitor-1 (BI-1), an integral transmembrane protein, acts as a suppressor of Bax-induced apoptosis through regulation of endoplasmic reticulum (ER) stress-induced cell death. The gene is highly conserved being found in a diverse range of organisms that include yeast, Arabidopsis, Drosophila, mouse and humans. BI-1 is implicated in the regulation of calcium levels, reactive oxygen species, apoptosis, autophagy and ER stress signalling pathways. We inhibited the cytoprotective BI-1 in the dopa decarboxylase (Ddc) expressing neurons and in the developing eye of Drosophila melanogaster to investigate its neuroprotective functions. Methods. We assessed the longevity and locomotor ability of flies in response to altered BI-1 expression in the Ddc-Gal4-expressing neurons where we exploited two RNAi transgenic fly lines. A control that expressed the benign lacZ responding transgene was used to compare against the RNAi transgenic flies. In addition, we compared the effect of the loss of BI-1 expression in the developing eye, through biometric analysis of the number of ommatidia and extent of disruption of the ommatidial arrays. Finally, Buffy and α-synuclein were co-expressed to evaluate the potential for interactions. Results. The inhibition of BI-1 in these neurons resulted in a shortened lifespan and precocious loss of locomotor ability. The co-expression of Buffy, the sole anti-apoptotic Bcl-2 homologue in Drosophila, with BI-1-RNAi resulted in suppression of the reduced lifespan and impaired climbing ability. Expression of human α-synuclein in Drosophila dopaminergic neurons results in age-dependent loss in climbing ability. We exploited this neurotoxic system to investigate possible BI-1 neuroprotective function. The co-expression of α-synuclein with BI-1-RNAi results in decreased survival coupled with an impaired climbing ability. In supportive experiments, we employed the neuron-rich Drosophila compound eye to investigate subtle phenotypes that result from altered gene expression. The inhibition of BI-1 in the Drosophila developing eye under the direction of the GMR-Gal4 transgene results in reduced ommatidia number and increased disruption of the ommatidial array. Similarly, the co-expression of BI-1-RNAi with Buffy results in the suppression of the eye phenotypes. The expression of α-synuclein along with the inhibition of BI-1 results in reduction of ommatidia number and increased disruption of the ommatidial array. Conclusions. Inhibition of BI-1 in the dopaminergic neurons of Drosophila results in a shortened lifespan and premature loss in climbing ability, phenotypes that appear to be strongly associated with models of Parkinson disease in Drosophila. These are suppressed upon overexpression of Buffy and worsened by co-expression with α-synuclein. This suggests that BI-1 acts in neuroprotection and that its inhibition can be counteracted by the overexpression of the pro-survival Bcl-2 homologue, Buffy.

scholarly journals Bax-inhibitor-1knockdown phenotypes are suppressed byBuffyand exacerbate degeneration in aDrosophilamodel of Parkinson disease

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2974 ◽  
Author(s):  
P. Githure M’Angale ◽  
Brian E. Staveley
Keyword(s):  
Parkinson Disease ◽  
Dopaminergic Neurons ◽  
Compound Eye ◽  
Neuronal Degeneration ◽  
Transmembrane Protein ◽  
Control Line ◽  
Altered Expression ◽  
Biometric Analysis ◽  
Climbing Ability ◽  
Locomotor Ability

BackgroundBax inhibitor-1 (BI-1) is an evolutionarily conserved cytoprotective transmembrane protein that acts as a suppressor ofBax-induced apoptosis by regulation of endoplasmic reticulum stress-induced cell death. We knocked downBI-1in the sensitivedopa decarboxylase(Ddc) expressing neurons ofDrosophila melanogasterto investigate its neuroprotective functions. We additionally sought to rescue theBI-1-induced phenotypes by co-expression with the pro-survivalBuffyand determined the effect ofBI-1knockdown on the neurodegenerative α-synuclein-induced Parkinson disease (PD) model.MethodsWe used organismal assays to assess longevity of the flies to determine the effect of the altered expression ofBI-1in theDdc-Gal4-expressing neurons by employing two RNAi transgenic fly lines. We measured the locomotor ability of these RNAi lines by computing the climbing indices of the climbing ability and compared them to a control line that expresses thelacZtransgene. Finally, we performed biometric analysis of the developing eye, where we counted the number of ommatidia and calculated the area of ommatidial disruption.ResultsThe knockdown ofBI-1in these neurons was achieved under the direction of theDdc-Gal4transgene and resulted in shortened lifespan and precocious loss of locomotor ability. The co-expression ofBuffy, the Drosophila anti-apoptotic Bcl-2 homologue, withBI-1-RNAiresulted in suppression of the reduced lifespan and impaired climbing ability. Expression of human α-synucleinin Drosophila dopaminergic neurons results in neuronal degeneration, accompanied by the age-dependent loss in climbing ability. We exploited this neurotoxic system to investigate possible BI-1 neuroprotective function. The co-expression of α-synucleinwithBI-1-RNAiresults in a slight decrease in lifespan coupled with an impairment in climbing ability. In supportive experiments, we employed the neuron-rich Drosophila compound eye to investigate subtle phenotypes that result from altered gene expression. The knockdown ofBI-1in the Drosophila developing eye under the direction of theGMR-Gal4transgene results in reduced ommatidia number and increased disruption of the ommatidial array. Similarly, the co-expression ofBI-1-RNAiwithBuffyresults in the suppression of the eye phenotypes. The expression of α-synucleinalong with the knockdown ofBI-1resulted in reduction of ommatidia number and more disruption of the ommatidial array.ConclusionKnockdown ofBI-1in the dopaminergic neurons of Drosophila results in a shortened lifespan and premature loss in climbing ability, phenotypes that appear to be strongly associated with models of PD in Drosophila, and which are suppressed upon overexpression ofBuffyand worsened by co-expression with α-synuclein. This suggests thatBI-1is neuroprotective and its knockdown can be counteracted by the overexpression of the pro-survivalBcl-2homologue.

scholarly journals ­Bcl-2 homologue debcl enhances α-synuclein-induced phenotypes in Drosophila

2016 ◽  
Author(s):  
Peter G M'Angale ◽  
Brian E Staveley
Keyword(s):  
Parkinson Disease ◽  
Dopaminergic Neurons ◽  
Neuronal Degeneration ◽  
Altered Expression ◽  
Drosophila Model ◽  
Age Dependent ◽  
Climbing Ability ◽  
The Common ◽  
Locomotor Ability

Background Parkinson disease (PD) is a debilitating movement disorder that afflicts 1 to 2% of the population over 50 years of age. The common hallmark for both sporadic and familial forms of PD is mitochondrial dysfunction. Mammals have at least twenty proapoptotic and antiapoptotic Bcl-2 family members, in contrast, only two Bcl-2 family genes have been identified in Drosophila melanogaster, the proapoptotic mitochondrial localized debcl and the antiapoptotic Buffy. The expression of α-synuclein, the first gene identified to contribute to inherited forms of PD, in the dopaminergic neurons (DA) of flies has provided a robust and well-studied Drosophila model of PD complete with the loss of neurons and accompanying motor defects. The altered expression of debcl in the DA neurons and neuron-rich eye and along with the expression of α-synuclein offers an opportunity to highlight the role of debcl in mitochondrial-dependent neuronal degeneration and death. Results The directed overexpression of debcl using the Ddc-Gal4 transgene in the dopaminergic neurons of Drosophila resulted in flies with severely decreased survival and a premature age-dependent loss in climbing ability. The inhibition of debcl resulted in enhanced survival and improved climbing ability whereas the overexpression of debcl in the α-synuclein-induced Drosophila model of PD resulted in more severe phenotypes. In addition, the co-expression of debcl along with Buffy partially counteracts the debcl-induced phenotypes, to improve the lifespan and the associated loss of locomotor ability observed. In complementary experiments, the overexpression of debcl along with the expression of α-synuclein in the eye, enhanced the eye ablation that results from the overexpression of debcl. The co-expression of Buffy along with debcl overexpression results in the rescue of the moderate developmental eye defects. The co-expression of Buffy along with inhibition of debcl partially restores the eye to a roughened eye phenotype. Discussion The overexpression of debcl in DA neurons produces flies with shortened lifespan and impaired locomotor ability, phenotypes that are strongly associated with models of PD in Drosophila. The co-expression of debcl along with α-synuclein enhanced the Parkinson disease-like phenotypes. The co-expression of debcl along with Buffy suppresses these phenotypes. Complementary experiments in the Drosophila eye show similar trends during development. Taken all together these results suggest a role for debcl in neurodegenerative disorders.

scholarly journals CHOP and AP-1 cooperatively mediate PUMA expression during lipoapoptosis

2010 ◽  
Vol 299 (1) ◽  
pp. G236-G243 ◽  
Author(s):  
Sophie C. Cazanave ◽  
Nafisa A. Elmi ◽  
Yuko Akazawa ◽  
Steven F. Bronk ◽  
Justin L. Mott ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Er Stress ◽  
Promoter Sequence ◽  
Loss Of Function ◽  
Protein Levels ◽  
Homologous Protein ◽  
Relative Contribution ◽  
Complex Protein ◽  
Puma Expression ◽  
Induced Apoptosis

Endoplasmic reticulum (ER) stress-mediated apoptosis is a key feature of hepatocyte cytotoxicity by saturated free fatty acids (FFA). This lipoapoptosis is dependent, in part, on the transcriptional upregulation of the BH3-only protein PUMA (p53 upregulated modulator of apoptosis). Although the activator protein (AP)-1 complex facilitates PUMA expression by saturated FFA, the transcription factor CAAT/enhancer binding homologous protein (CHOP) is also induced by ER stress and promotes apoptosis. To integrate the role of these two transcription factors in ER stress-induced apoptosis, we examined the relative contribution of CHOP and AP-1 in mediating PUMA induction by saturated FFA. Our results demonstrate that short-hairpin RNA-targeted knockdown of CHOP attenuates palmitate-induced apoptosis in Huh-7 cells. Loss of CHOP induction also reduced the increase in PUMA mRNA and protein levels as well as Bax activation by palmitate. No functional CHOP binding sites were identified in the PUMA promoter sequence. Rather, we observed that CHOP physically interacts with the AP-1 complex protein c-Jun upon palmitate treatment, and a CHOP:phosphorylated c-Jun heteromeric complex binds to the AP-1 consensus binding sequence within the PUMA promoter region. Finally, loss of function studies suggest that both transcription factors are necessary for maximal PUMA induction. Collectively, these data suggest that CHOP and AP-1 cooperatively mediate PUMA induction during hepatocyte lipoapoptosis.

scholarly journals Bcl-2homologueDebclenhancesα-synuclein-induced phenotypes inDrosophila

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2461 ◽  
Author(s):  
P. Githure M’Angale ◽  
Brian E. Staveley
Keyword(s):  
Neurodegenerative Disorders ◽  
Dopaminergic Neurons ◽  
Neuronal Degeneration ◽  
Altered Expression ◽  
Drosophila Model ◽  
Age Dependent ◽  
Climbing Ability ◽  
The Common ◽  
Locomotor Ability

BackgroundParkinson disease (PD) is a debilitating movement disorder that afflicts 1–2% of the population over 50 years of age. The common hallmark for both sporadic and familial forms of PD is mitochondrial dysfunction. Mammals have at least twenty proapoptotic and antiapoptoticBcl-2family members, in contrast, only twoBcl-2family genes have been identified inDrosophila melanogaster, the proapoptotic mitochondrial localizedDebcland the antiapoptoticBuffy. The expression of the human transgeneα-synuclein, a gene that is strongly associated with inherited forms of PD, in dopaminergic neurons (DA) of Drosophila, results in loss of neurons and locomotor dysfunction to model PD in flies. The altered expression ofDebclin the DA neurons and neuron-rich eye and along with the expression ofα-synucleinoffers an opportunity to highlight the role ofDebclin mitochondrial-dependent neuronal degeneration and death.ResultsThe directed overexpression ofDebclusing theDdc-Gal4transgene in the DA of Drosophila resulted in flies with severely decreased survival and a premature age-dependent loss in climbing ability. The inhibition ofDebclresulted in enhanced survival and improved climbing ability whereas the overexpression ofDebclin theα-synuclein-induced Drosophila model of PD resulted in more severe phenotypes. In addition, the co-expression ofDebclalong withBuffypartially counteracts theDebcl-induced phenotypes, to improve the lifespan and the associated loss of locomotor ability observed. In complementary experiments, the overexpression ofDebclalong with the expression ofα-synucleinin the eye, enhanced the eye ablation that results from the overexpression ofDebcl. The co-expression ofBuffyalong withDebcloverexpression results in the rescue of the moderate developmental eye defects. The co-expression ofBuffyalong with inhibition ofDebclpartially restores the eye to a roughened eye phenotype.DiscussionThe overexpression ofDebclin DA neurons produces flies with shortened lifespan and impaired locomotor ability, phenotypes that are strongly associated with models of PD in Drosophila. The co-expression ofDebclalong withα-synucleinenhanced the PD-like phenotypes. The co-expression ofDebclalong withBuffysuppresses these phenotypes. Complementary experiments in the Drosophila eye show similar trends during development. Taken all together these results suggest a role forDebclin neurodegenerative disorders.

scholarly journals ­Bcl-2 homologue debcl enhances α-synuclein-induced phenotypes in Drosophila

2016 ◽  
Author(s):  
Peter G M'Angale ◽  
Brian E Staveley
Keyword(s):  
Parkinson Disease ◽  
Dopaminergic Neurons ◽  
Neuronal Degeneration ◽  
Altered Expression ◽  
Drosophila Model ◽  
Age Dependent ◽  
Climbing Ability ◽  
The Common ◽  
Locomotor Ability

Background Parkinson disease (PD) is a debilitating movement disorder that afflicts 1 to 2% of the population over 50 years of age. The common hallmark for both sporadic and familial forms of PD is mitochondrial dysfunction. Mammals have at least twenty proapoptotic and antiapoptotic Bcl-2 family members, in contrast, only two Bcl-2 family genes have been identified in Drosophila melanogaster, the proapoptotic mitochondrial localized debcl and the antiapoptotic Buffy. The expression of α-synuclein, the first gene identified to contribute to inherited forms of PD, in the dopaminergic neurons (DA) of flies has provided a robust and well-studied Drosophila model of PD complete with the loss of neurons and accompanying motor defects. The altered expression of debcl in the DA neurons and neuron-rich eye and along with the expression of α-synuclein offers an opportunity to highlight the role of debcl in mitochondrial-dependent neuronal degeneration and death. Results The directed overexpression of debcl using the Ddc-Gal4 transgene in the dopaminergic neurons of Drosophila resulted in flies with severely decreased survival and a premature age-dependent loss in climbing ability. The inhibition of debcl resulted in enhanced survival and improved climbing ability whereas the overexpression of debcl in the α-synuclein-induced Drosophila model of PD resulted in more severe phenotypes. In addition, the co-expression of debcl along with Buffy partially counteracts the debcl-induced phenotypes, to improve the lifespan and the associated loss of locomotor ability observed. In complementary experiments, the overexpression of debcl along with the expression of α-synuclein in the eye, enhanced the eye ablation that results from the overexpression of debcl. The co-expression of Buffy along with debcl overexpression results in the rescue of the moderate developmental eye defects. The co-expression of Buffy along with inhibition of debcl partially restores the eye to a roughened eye phenotype. Discussion The overexpression of debcl in DA neurons produces flies with shortened lifespan and impaired locomotor ability, phenotypes that are strongly associated with models of PD in Drosophila. The co-expression of debcl along with α-synuclein enhanced the Parkinson disease-like phenotypes. The co-expression of debcl along with Buffy suppresses these phenotypes. Complementary experiments in the Drosophila eye show similar trends during development. Taken all together these results suggest a role for debcl in neurodegenerative disorders.

scholarly journals Role of ERO1-α–mediated stimulation of inositol 1,4,5-triphosphate receptor activity in endoplasmic reticulum stress–induced apoptosis

2009 ◽  
Vol 186 (6) ◽  
pp. 783-792 ◽  
Author(s):  
Gang Li ◽  
Marco Mongillo ◽  
King-Tung Chin ◽  
Heather Harding ◽  
David Ron ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Calcium Release ◽  
Loss Of Function ◽  
Ip3 Receptor ◽  
Calcium Dependent ◽  
Insulin Resistant ◽  
Stressed Cells ◽  
Induced Apoptosis

Endoplasmic reticulum (ER) stress–induced apoptosis is involved in many diseases, but the mechanisms linking ER stress to apoptosis are incompletely understood. Based on roles for C/EPB homologous protein (CHOP) and ER calcium release in apoptosis, we hypothesized that apoptosis involves the activation of inositol 1,4,5-triphosphate (IP3) receptor (IP3R) via CHOP-induced ERO1-α (ER oxidase 1 α). In ER-stressed cells, ERO1-α is induced by CHOP, and small interfering RNA (siRNA) knockdown of ERO1-α suppresses apoptosis. IP3-induced calcium release (IICR) is increased during ER stress, and this response is blocked by siRNA-mediated silencing of ERO1-α or IP3R1 and by loss-of-function mutations in Ero1a or Chop. Reconstitution of ERO1-α in Chop−/− macrophages restores ER stress–induced IICR and apoptosis. In vivo, macrophages from wild-type mice but not Chop−/− mice have elevated IICR when the animals are challenged with the ER stressor tunicamycin. Macrophages from insulin-resistant ob/ob mice, another model of ER stress, also have elevated IICR. These data shed new light on how the CHOP pathway of apoptosis triggers calcium-dependent apoptosis through an ERO1-α–IP3R pathway.

The HtrA2 Drosophila model of Parkinson’s disease is suppressed by the pro-survival Bcl-2 Buffy

Genome ◽  
2017 ◽  
Vol 60 (1) ◽  
pp. 1-7 ◽  
Author(s):  
P. Githure M’Angale ◽  
Brian E. Staveley
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Drosophila Melanogaster ◽  
High Temperature ◽  
Dopaminergic Neurons ◽  
Inhibitors Of Apoptosis ◽  
Drosophila Model ◽  
Age Dependent ◽  
Climbing Ability ◽  
Locomotor Ability

Mutations in High temperature requirement A2 (HtrA2), also designated PARK13, which lead to the loss of its protease activity, have been associated with Parkinson’s disease (PD). HtrA2 is a mitochondrial protease that translocates to the cytosol upon the initiation of apoptosis where it participates in the abrogation of inhibitors of apoptosis (IAP) inhibition of caspases. Here, we demonstrate that the loss of the HtrA2 function in the dopaminergic neurons of Drosophila melanogaster results in PD-like phenotypes, and we attempt to restore the age-dependent loss in locomotor ability by co-expressing the sole pro-survival Bcl-2 homologue Buffy. The inhibition of HtrA2 in the dopaminergic neurons of Drosophila resulted in shortened lifespan and impaired climbing ability, and the overexpression of Buffy rescued the reduction in lifespan and the age-dependent loss of locomotor ability. In supportive experiments, the inhibition of HtrA2 in the Drosophila eye results in eye defects, marked by reduction in ommatidia number and increased disruption of the ommatidial array; phenotypes that are suppressed by the overexpression of Buffy.

scholarly journals 5-ALA Attenuates the Palmitic Acid-Induced ER Stress and Apoptosis in Bovine Mammary Epithelial Cells

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1183
Author(s):  
Mst Mamuna Sharmin ◽  
Md Aminul Islam ◽  
Itsuki Yamamoto ◽  
Shin Taniguchi ◽  
Shinichi Yonekura
Keyword(s):  
T Cells ◽  
Epithelial Cells ◽  
Palmitic Acid ◽  
Er Stress ◽  
Aminolevulinic Acid ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Protective Effects ◽  
Bovine Mammary Epithelial Cells ◽  
Induced Apoptosis

The conservation of mammary gland physiology by maintaining the maximum number of mammary epithelial cells (MECs) is of the utmost importance for the optimum amount of milk production. In a state of negative energy balance, palmitic acid (PA) reduces the number of bovine MECs. However, there is no effective strategy against PA-induced apoptosis of MECs. In the present study, 5-aminolevulinic acid (5-ALA) was established as a remedial agent against PA-induced apoptosis of MAC-T cells (an established line of bovine MECs). In PA-treated cells, the apoptosis-related genes BCL2 and BAX were down- and upregulated, respectively. The elevated expression of major genes of the unfolded protein response (UPR), such as CHOP, a proapoptotic marker (C/EBP homologous protein), reduced the viability of PA-treated MAC-T cells. In contrast, 5-ALA pretreatment increased and decreased BCL2 and BAX expression, respectively. Moreover, cleaved caspase-3 protein expression was significantly reduced in the 5-ALA-pretreated group in comparison with the PA group. The downregulation of major UPR-related genes, including CHOP, extended the viability of MAC-T cells pretreated with 5-ALA and also reduced the enhanced intensity of the PA-induced expression of phospho-protein kinase R-like ER kinase. Moreover, the enhanced expression of HO-1 (antioxidant gene heme oxygenase) by 5-ALA reduced PA-induced oxidative stress (OxS). HO-1 is not only protective against OxS but also effective against ER stress. Collectively, these findings offer new insights into the protective effects of 5-ALA against PA-induced apoptosis of bovine MECs.

scholarly journals Multiple Pathways of LRRK2-G2019S/Rab10 Interaction in Dopaminergic Neurons

2021 ◽  
pp. 1-16
Author(s):  
Alison Fellgett ◽  
C. Adam Middleton ◽  
Jack Munns ◽  
Chris Ugbode ◽  
David Jaciuch ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Genetic Interaction ◽  
In Vitro Assays ◽  
Rab Proteins ◽  
Circadian Activity ◽  
Loss Of Function ◽  
Lrrk2 G2019s

Background: Inherited mutations in the LRRK2 protein are the common causes of Parkinson’s disease, but the mechanisms by which increased kinase activity of mutant LRRK2 leads to pathological events remain to be determined. In vitro assays (heterologous cell culture, phospho-protein mass spectrometry) suggest that several Rab proteins might be directly phosphorylated by LRRK2-G2019S. An in vivo screen of Rab expression in dopaminergic neurons in young adult Drosophila demonstrated a strong genetic interaction between LRRK2-G2019S and Rab10. Objective: To determine if Rab10 is necessary for LRRK2-induced pathophysiological responses in the neurons that control movement, vision, circadian activity, and memory. These four systems were chosen because they are modulated by dopaminergic neurons in both humans and flies. Methods: LRRK2-G2019S was expressed in Drosophila dopaminergic neurons and the effects of Rab10 depletion on Proboscis Extension, retinal neurophysiology, circadian activity pattern (‘sleep’), and courtship memory determined in aged flies. Results: Rab10 loss-of-function rescued LRRK2-G2019S induced bradykinesia and retinal signaling deficits. Rab10 knock-down, however, did not rescue the marked sleep phenotype which results from dopaminergic LRRK2-G2019S. Courtship memory is not affected by LRRK2, but is markedly improved by Rab10 depletion. Anatomically, both LRRK2-G2019S and Rab10 are seen in the cytoplasm and at the synaptic endings of dopaminergic neurons. Conclusion: We conclude that, in Drosophila dopaminergic neurons, Rab10 is involved in some, but not all, LRRK2-induced behavioral deficits. Therefore, variations in Rab expression may contribute to susceptibility of different dopaminergic nuclei to neurodegeneration seen in people with Parkinson’s disease.

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