scholarly journals Rooibos Flavonoids, Aspalathin, Isoorientin, and Orientin Ameliorate Antimycin A-Induced Mitochondrial Dysfunction by Improving Mitochondrial Bioenergetics in Cultured Skeletal Muscle Cells

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6289
Author(s):  
Sinenhlanhla X. H. Mthembu ◽  
Christo J. F. Muller ◽  
Phiwayinkosi V. Dludla ◽  
Evelyn Madoroba ◽  
Abidemi P. Kappo ◽  
...  

The current study investigated the physiological effects of flavonoids found in daily consumed rooibos tea, aspalathin, isoorientin, and orientin on improving processes involved in mitochondrial function in C2C12 myotubes. To achieve this, C2C12 myotubes were exposed to a mitochondrial channel blocker, antimycin A (6.25 µM), for 12 h to induce mitochondrial dysfunction. Thereafter, cells were treated with aspalathin, isoorientin, and orientin (10 µM) for 4 h, while metformin (1 µM) and insulin (1 µM) were used as comparators. Relevant bioassays and real-time PCR were conducted to assess the impact of treatment compounds on some markers of mitochondrial function. Our results showed that antimycin A induced alterations in the mitochondrial respiration process and mRNA levels of genes involved in energy production. In fact, aspalathin, isoorientin, and orientin reversed such effects leading to the reduced production of intracellular reactive oxygen species. These flavonoids further enhanced the expression of genes involved in mitochondrial function, such as Ucp 2, Complex 1/3, Sirt 1, Nrf 1, and Tfam. Overall, the current study showed that dietary flavonoids, aspalathin, isoorientin, and orientin, have the potential to be as effective as established pharmacological drugs such as metformin and insulin in protecting against mitochondrial dysfunction in a preclinical setting; however, such information should be confirmed in well-established in vivo disease models.

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3113
Author(s):  
Sanjay Awasthi ◽  
Ashly Hindle ◽  
Neha A. Sawant ◽  
Mathew George ◽  
Murali Vijayan ◽  
...  

The purpose of our study is to understand the role of the RALBP1 gene in oxidative stress (OS), mitochondrial dysfunction and cognition in Alzheimer’s disease (AD) pathogenesis. The RALPB1 gene encodes the 76 kDa protein RLIP76 (Rlip). Rlip functions as a stress-responsive/protective transporter of glutathione conjugates (GS-E) and xenobiotic toxins. We hypothesized that Rlip may play an important role in maintaining cognitive function. The aim of this study is to determine whether Rlip deficiency in mice is associated with AD-like cognitive and mitochondrial dysfunction. Brain tissue obtained from cohorts of wildtype (WT) and Rlip+/− mice were analyzed for OS markers, expression of genes that regulate mitochondrial fission/fusion, and synaptic integrity. We also examined mitochondrial ultrastructure in brains obtained from these mice and further analyzed the impact of Rlip deficiency on gene networks of AD, aging, stress response, mitochondrial function, and CREB signaling. Our studies revealed a significant increase in the levels of OS markers and alterations in the expression of genes and proteins involved in mitochondrial biogenesis, dynamics and synapses in brain tissues from these mice. Furthermore, we compared the cognitive function of WT and Rlip+/− mice. Behavioral, basic motor and sensory function tests in Rlip+/− mice revealed cognitive decline, similar to AD. Gene network analysis indicated dysregulation of stress-activated gene expression, mitochondrial function and CREB signaling genes in the Rlip+/− mouse brain. Our results suggest that Rlip deficiency-associated increases in OS and mitochondrial dysfunction could contribute to the development or progression of OS-related AD processes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tao Liang ◽  
Weijian Hang ◽  
Jiehui Chen ◽  
Yue Wu ◽  
Bin Wen ◽  
...  

Abstract Background Apolipoprotein E4 (apoE4) is a major genetic risk factor of Alzheimer’s disease. Its C-terminal-truncated apoE4 (Δ272–299) has neurotoxicity by affecting mitochondrial respiratory function. However, the molecular mechanism(s) underlying the action of apoE4 (Δ272–299) in mitochondrial function remain poorly understood. Methods The impact of neuronal apoE4 (Δ272–299) expression on ER stress, mitochondrial-associated membrane (MAM) formation, GRP75, calcium transport and mitochondrial impairment was determined in vivo and in vitro. Furthermore, the importance of ER stress or GRP75 activity in the apoE4 (Δ272–299)-promoted mitochondrial dysfunction in neuron was investigated. Results Neuronal apoE4 (Δ272–299) expression induced mitochondrial impairment by inducing ER stress and mitochondrial-associated membrane (MAM) formation in vivo and in vitro. Furthermore, apoE4 (Δ272–299) expression promoted GRP75 expression, mitochondrial dysfunction and calcium transport into the mitochondria in neuron, which were significantly mitigated by treatment with PBA (an inhibitor of ER stress), MKT077 (a specific GRP75 inhibitor) or GRP75 silencing. Conclusions ApoE4 (Δ272–299) significantly impaired neuron mitochondrial function by triggering ER stress, up-regulating GRP75 expression to increase MAM formation, and mitochondrial calcium overload. Our findings may provide new insights into the neurotoxicity of apoE4 (Δ272–299) against mitochondrial function and uncover new therapeutic targets for the intervention of Alzheimer’s disease.


2017 ◽  
Vol 49 (8) ◽  
pp. 416-429 ◽  
Author(s):  
Ivana Mižíková ◽  
Francesco Palumbo ◽  
Tamás Tábi ◽  
Susanne Herold ◽  
István Vadász ◽  
...  

Lysyl oxidases are credited with pathogenic roles in lung diseases, including cancer, fibrosis, pulmonary hypertension, congenital diaphragmatic hernia, and bronchopulmonary dysplasia (BPD). Lysyl oxidases facilitate the covalent intra- and intermolecular cross-linking of collagen and elastin fibers, thereby imparting tensile strength to the extracellular matrix (ECM). Alternative ECM-independent roles have recently been proposed for lysyl oxidases, including regulation of growth factor signaling, chromatin remodeling, and transcriptional regulation, all of which impact cell phenotype. We demonstrate here that three of the five lysyl oxidase family members, Lox, Loxl1, and Loxl2, are highly expressed in primary mouse lung fibroblasts compared with other constituent cell types of the lung. Microarray analyses revealed that small interfering RNA knockdown of Lox, Loxl1, and Loxl2 was associated with apparent changes in the expression of 134, 3,761, and 3,554 genes, respectively, in primary mouse lung fibroblasts. The impact of lysyl oxidase expression on steady-state Mmp3, Mmp9, Eln, Rarres1, Gdf10, Ifnb1, Csf2, and Cxcl9 mRNA levels was validated, which is interesting, since the corresponding gene products are relevant to lung development and BPD, where lysyl oxidases play a functional role. In vivo, the expression of these genes broadly correlated with Lox, Loxl1, and Loxl2 expression in a mouse model of BPD. Furthermore, β-aminopropionitrile (BAPN), a selective lysyl oxidase inhibitor, did not affect the steady-state mRNA levels of lysyl oxidase target genes, in vitro in lung fibroblasts or in vivo in BAPN-treated mice. This study is the first to report that lysyl oxidases broadly influence the cell transcriptome.


2019 ◽  
Vol 3 (s1) ◽  
pp. 24-24
Author(s):  
Rubens Sautchuk ◽  
Brianna H. Shares ◽  
Roman A. Eliseev

OBJECTIVES/SPECIFIC AIMS: The study aims to further investigate how cyclophilin D (CypD), the key mPTP opening regulator, affects BMSCs fate and to determine potential regulatory mechanisms involved in CypD regulation during osteogenesis. METHODS/STUDY POPULATION: We evaluated CypD mRNA expression in mouse BMSCs and in osteogenic-like (OL) cells during the course of OB differentiation. CypD protein level was also probed. Moreover, BMSCs had their mPTP activity recorded during osteoinduction. We further analyzed the effect of CypD genetic deletion on osteogenesis in vitro and in vivo. For our in vivo model, we performed the ectopic bone formation assay to asses differences in ossicle formation when CypD KO BMSCs were transplanted compared to wild type littermate BMSCs. In our in vitro model, we transfected OL cells with either CypD gain of function or CypD loss of function vector and measured their osteogenic differentiation potential. Additionally, we treated BMSCs with CypD inhibitor and compare to non-treated BMSCs for mineralization level. To determine potential regulatory mechanisms involved in CypD regulation, we analyzed the CypD gene (Ppif) promoter for potential transcription factor (TF) binding sites and found multiple Smad-binding elements within this promoter. Smads (Smad1, 5, 8) are TFs downstream from Bone Morphogenic Protein (BMP) signaling pathway that transmit cell differentiation signaling, and exert either activating or inhibitory effects on a variety of genes. We also transfect OL cells with Smad1 vector and analyzed for CypD mRNA levels. RESULTS/ANTICIPATED RESULTS: - Our data showed that CypD mRNA levels decreased in both primary cells and OL cells at day 7 and day 14 in osteogenic media. - Osteogenic induction also decreased mPTP activity. - In vivo ectopic bone formation assay showed increased ossicle fo DISCUSSION/SIGNIFICANCE OF IMPACT: Our data suggest that downregulation of CypD increases OB differentiation due to improved OxPhos activity led by mPTP closure. Our results corroborate reports of CypD downregulation and mPTP closure during neuronal differentiation in developing rat brains as well as in cardiomyocyte differentiation in developing mouse hearts. Our studies also suggest a yet unknown mechanism linking differentiation signaling with mitochondrial function – BMP/Smad mediated downregulation of CypD transcription. As initially mentioned, in a previous study, our lab showed that CypD KO mice present higher mitochondrial function and osteogenicity in aged BMSCs and less osteoporosis burden. Taken together, these results suggest that CypD can be a potential target to prevent bone loss in aging.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Nora E. Gray ◽  
Jonathan A. Zweig ◽  
Donald G. Matthews ◽  
Maya Caruso ◽  
Joseph F. Quinn ◽  
...  

Centella asiatica has been used for centuries to enhance memory. We have previously shown that a water extract of Centella asiatica (CAW) protects against the deleterious effects of amyloid-β (Aβ) in neuroblastoma cells and attenuates Aβ-induced cognitive deficits in mice. Yet, the neuroprotective mechanism of CAW has yet to be thoroughly explored in neurons from these animals. This study investigates the effects of CAW on neuronal metabolism and oxidative stress in isolated Aβ-expressing neurons. Hippocampal neurons from amyloid precursor protein overexpressing Tg2576 mice and wild-type (WT) littermates were treated with CAW. In both genotypes, CAW increased the expression of antioxidant response genes which attenuated the Aβ-induced elevations in reactive oxygen species (ROS) and lipid peroxidation in Tg2576 neurons. CAW also improved mitochondrial function in both genotypes and increased the expression of electron transport chain enzymes and mitochondrial labeling, suggesting an increase in mitochondrial content. These data show that CAW protects against mitochondrial dysfunction and oxidative stress in Aβ-exposed hippocampal neurons which could contribute to the beneficial effects of the extract observed in vivo. Since CAW also improved mitochondrial function in the absence of Aβ, these results suggest a broader utility for other conditions where neuronal mitochondrial dysfunction occurs.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lyess Allas ◽  
Sybille Brochard ◽  
Quitterie Rochoux ◽  
Jules Ribet ◽  
Cleo Dujarrier ◽  
...  

Abstract Histone methyltransferase EZH2 is upregulated during osteoarthritis (OA), which is the most widespread rheumatic disease worldwide, and a leading cause of disability. This study aimed to assess the impact of EZH2 inhibition on cartilage degradation, inflammation and functional disability. In vitro, gain and loss of EZH2 function were performed in human articular OA chondrocytes stimulated with IL-1β. In vivo, the effects of EZH2 inhibition were investigated on medial meniscectomy (MMX) OA mouse model. The tissue alterations were assayed by histology and the functional disabilities of the mice by actimetry and running wheel. In vitro, EZH2 overexpression exacerbated the action of IL-1β in chondrocytes increasing the expression of genes involved in inflammation, pain (NO, PGE2, IL6, NGF) and catabolism (MMPs), whereas EZH2 inhibition by a pharmacological inhibitor, EPZ-6438, reduced IL-1β effects. Ex vivo, EZH2 inhibition decreased IL-1β-induced degradation of cartilage. In vivo, intra-articular injections of the EZH2 inhibitor reduced cartilage degradation and improved motor functions of OA mice. This study demonstrates that the pharmacological inhibition of the histone methyl-transferase EZH2 slows the progression of osteoarthritis and improves motor functions in an experimental OA model, suggesting that EZH2 could be an effective target for the treatment of OA by reducing catabolism, inflammation and pain.


Author(s):  
Amy L. Ball ◽  
Katarzyna M. Bloch ◽  
Lucille Rainbow ◽  
Xuan Liu ◽  
John Kenny ◽  
...  

AbstractMitochondrial DNA (mtDNA) is highly polymorphic and encodes 13 proteins which are critical to the production of ATP via oxidative phosphorylation. As mtDNA is maternally inherited and undergoes negligible recombination, acquired mutations have subdivided the human population into several discrete haplogroups. Mitochondrial haplogroup has been found to significantly alter mitochondrial function and impact susceptibility to adverse drug reactions. Despite these findings, there are currently limited models to assess the effect of mtDNA variation upon susceptibility to adverse drug reactions. Platelets offer a potential personalised model of this variation, as their anucleate nature offers a source of mtDNA without interference from the nuclear genome. This study, therefore, aimed to determine the effect of mtDNA variation upon mitochondrial function and drug-induced mitochondrial dysfunction in a platelet model. The mtDNA haplogroup of 383 healthy volunteers was determined using next-generation mtDNA sequencing (Illumina MiSeq). Subsequently, 30 of these volunteers from mitochondrial haplogroups H, J, T and U were recalled to donate fresh, whole blood from which platelets were isolated. Platelet mitochondrial function was tested at basal state and upon treatment with compounds associated with both mitochondrial dysfunction and adverse drug reactions, flutamide, 2-hydroxyflutamide and tolcapone (10–250 μM) using extracellular flux analysis. This study has demonstrated that freshly-isolated platelets are a practical, primary cell model, which is amenable to the study of drug-induced mitochondrial dysfunction. Specifically, platelets from donors of haplogroup J have been found to have increased susceptibility to the inhibition of complex I-driven respiration by 2-hydroxyflutamide. At a time when individual susceptibility to adverse drug reactions is not fully understood, this study provides evidence that inter-individual variation in mitochondrial genotype could be a factor in determining sensitivity to mitochondrial toxicants associated with costly adverse drug reactions.


2013 ◽  
Vol 304 (4) ◽  
pp. F367-F375 ◽  
Author(s):  
Wenzheng Zhang ◽  
Zhiyuan Yu ◽  
Hongyu Wu ◽  
Lihe Chen ◽  
Qun Kong ◽  
...  

The epithelial Na+ channel subunit-α ( αENaC) of the distal nephron is essential for salt balance. We previously demonstrated that the histone methyltransferase Dot1a and its protein partner Af9 basally repress αENaC transcription in mouse inner medullary collecting duct type 3 (mIMCD3) cells and link aldosterone-elicited chromatin modifications to αENaC transcriptional activation. Af9 DNA-binding activity has never been demonstrated, and whether and where Af9 binds to the αENaC promoter to target Dot1a are unknown. The present study sought to identify functional Af9 cis-element(s) in the −57/+439 “R3” subregion of αENaC, the principal site for Dot1a-Af9 interaction, in mIMCD3 cells. We also exploited connecting tubule/collecting duct-specific Dot1l-deficient mice ( Dot1l AC) to determine the impact of Dot1l inactivation on renal αENaC expression in vivo. mIMCD3 cell lines expressing αENaC promoter-reporter constructs harboring deletion of +74/+107 demonstrated greatly reduced association of Af9 and Dot1a by ChIP/qPCR. Aldosterone treatment resulted in further decrements in Af9 and Dot1a association with the αENaC promoter. Gel shift and antibody competition assays using wild-type and mutant oligomers revealed Af9-containing +78/+92 αENaC DNA-protein complexes in nuclear extracts of mIMCD3 cells. Mutation of the +78/+92 element resulted in higher basal αENaC promoter activity and impaired Dot1a-mediated inhibition in trans-repression assays. In agreement, mice with connecting tubule/collecting duct-specific knockout of Dot1l exhibited greater αENaC mRNA levels in kidney compared with control. Thus, we conclude that +78/+92 of αENaC represents the primary Af9 binding site involved in recruiting Dot1a to repress basal and aldosterone-sensitive αENaC transcription and that Dot1l inactivation promotes αENaC mRNA expression by eliminating Dot1a-mediated repression.


2010 ◽  
Vol 298 (3) ◽  
pp. F807-F817 ◽  
Author(s):  
Renfang Song ◽  
Melissa Spera ◽  
Colleen Garrett ◽  
Samir S. El-Dahr ◽  
Ihor V. Yosypiv

ANG II AT2 receptor (AT2R)-deficient mice exhibit abnormal ureteric bud (UB) budding, increased incidence of double ureters, and vesicoureteral reflux. However, the role of the AT2R during UB morphogenesis and the mechanisms by which aberrant AT2R signaling disrupts renal collecting system development have not been fully defined. In this study, we mapped the expression of the AT2R during mouse metanephric development, examined the impact of disrupted AT2R signaling on UB branching, cell proliferation, and survival, and investigated the cross talk of the AT2R with the glial-derived neurotrophic factor ( GDNF)/ c-Ret/Wnt11 signaling pathway. Embryonic mouse kidneys express AT2R in the branching UB and the mesenchyme. Treatment of embryonic day 12.5 ( E12.5) metanephroi with the AT2R antagonist PD123319 or genetic inactivation of the AT2R in mice inhibits UB branching, decreasing the number of UB tips compared with control (34 ± 1.0 vs. 43 ± 0.6, P < 0.01; 36 ± 1.8 vs. 48 ± 1.3, P < 0.01, respectively). In contrast, treatment of metanephroi with the AT2R agonist CGP42112 increases the number of UB tips compared with control (48 ± 1.8 vs. 39 ± 12.3, P < 0.05). Using real-time quantitative RT-PCR and whole mount in situ hybridization, we demonstrate that PD123319 downregulates the expression of GDNF, c-Ret, Wnt11, and Spry1 mRNA levels in E12.5 metanephroi grown ex vivo. AT2R blockade or genetic inactivation of AT2R stimulates apoptosis and inhibits proliferation of the UB cells in vivo. We conclude that AT2R performs essential functions during UB branching morphogenesis via control of the GDNF/c-Ret/Wnt11 signaling pathway, UB cell proliferation, and survival.


2017 ◽  
Vol 29 (6) ◽  
pp. 1169 ◽  
Author(s):  
Nicola A. Pascarelli ◽  
Antonella Fioravanti ◽  
Elena Moretti ◽  
Giacomo M. Guidelli ◽  
Lucia Mazzi ◽  
...  

Tumour necrosis factor (TNF)-α is primarily involved in the regulation of cell proliferation and apoptosis; in addition it possesses pro-inflammatory properties. Anti-TNF-α strategies involve either administration of anti-TNF-α antibody or soluble TNF receptor to mop up circulating TNF-α. Etanercept, a recombinant human TNF-α receptor, was found to be effective in the treatment of rheumatoid arthritis. The impact of TNF-α inhibitors on human fertility is of notable interest. This in vitro study investigated the effect of different concentrations of TNF-α and etanercept used alone or in combination on sperm viability, motility, mitochondrial function, percentage of apoptosis and chromatin integrity in swim-up selected human spermatozoa. A negative effect of TNF-α (300 and 500 ng mL–1) and etanercept (from 800 µg mL–1 to 2000 µg mL–1) individually on sperm viability, motility, mitochondrial function, percentage of apoptotic spermatozoa and sperm DNA integrity was demonstrated. However, at concentrations of 100 and 200 µg mL–1, etanercept can block, in a significant way, the toxic effects of TNF-α (500 ng mL–1) on studied sperm characteristics. Our results confirm that TNF-α has a detrimental effect on sperm function and suggest, for the first time, that etanercept may counteract the in vitro toxic action of TNF-α. This data appears to be quite promising, although further studies, both in vivo and in vitro, are needed to understand the exact mechanism of action of TNF-α and TNF-α antagonists on sperm function.


Sign in / Sign up

Export Citation Format

Share Document