Measuring Mitochondrial Shape with ImageJ

Merrill, Ronald A.; Flippo, Kyle H.; Strack, Stefan

doi:10.1007/978-1-4939-6890-9_2

Cited by 53 publications

(59 citation statements)

References 15 publications

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“…Mitochondrial shape parameters were quantified using the open-source software package ImageJ and as previously described [ 22 ]. Briefly, images were background-subtracted (rolling ball radius = 50 pixels) and uneven labeling of mitochondria was improved through local contrast enhancement using contrast-limited adaptive histogram equalization (“CLAHE”).…”

Section: Methodsmentioning

confidence: 99%

Clock-Controlled Mitochondrial Dynamics Correlates with Cyclic Pregnenolone Synthesis

Witzig

Grimm

Schmitt

et al. 2020

Cells

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Neurosteroids are steroids synthetized in the nervous system, with the first step of steroidogenesis taking place within mitochondria with the synthesis of pregnenolone. They exert important brain-specific functions by playing a role in neurotransmission, learning and memory processes, and neuroprotection. Here, we show for the first time that mitochondrial neurosteroidogenesis follows a circadian rhythm and correlates with the rhythmic changes in mitochondrial morphology. We used synchronized human A172 glioma cells, which are steroidogenic cells with a functional core molecular clock, to show that pregnenolone levels and translocator protein (TSPO) are controlled by the clock, probably via circadian regulation of mitochondrial fusion/fission. Key findings were recapitulated in mouse brains. We also showed that genetic or pharmacological abrogation of fusion/fission activity, as well as disturbing the core molecular clock, abolished circadian rhythms of pregnenolone and TSPO. Our findings provide new insights into the crosstalk between mitochondrial function (here, neurosteroidogenesis) and circadian cycles.

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Section: Methodsmentioning

confidence: 99%

Clock-Controlled Mitochondrial Dynamics Correlates with Cyclic Pregnenolone Synthesis

Witzig

Grimm

Schmitt

et al. 2020

Cells

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“…Images were analyzed from each 250 M SFA treatment condition and the corresponding 0.25% vehicle control at a 1,024 × 1,024 resolution using the NIS-Elements Software (Nikon Instruments). Mitochondrial morphology analysis was performed using a mitochondrial morphology macro in Fiji to determine mitochondrial circularity and area as described previously (43,44). To determine mitochondrial size distribution, the mitochondria were binned into different size categories with each bin increasing by 2 m 2 (45) using a frequency distribution and Kolmogorov-Smirnov test to show SFA-induced statistically significant changes in mitochondrial size (46).…”

Section: Mitochondrial Morphology Analysismentioning

confidence: 99%

Chain length of saturated fatty acids regulates mitochondrial trafficking and function in sensory neurons

Rumora

Lograsso

Haidar

et al. 2019

Journal of Lipid Research

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This article is available online at http://www.jlr.org experience a loss of sensation that occurs in a stockingand-glove distribution and has a severe impact on the individual's quality of life and societal productivity (3-7). The progressive loss of sensory function results from distal-toproximal peripheral nerve damage and dysfunction of sensory neurons. Although the pathogenesis of DPN is not fully understood, recent studies indicate that DPN pathogenesis is directly linked to a continuum of metabolic factors associated with dyslipidemia (8-10).Plasma concentrations of free saturated FAs (SFAs) are commonly elevated in T2D (11). In general, SFAs are classified as inducers of lipotoxicity (12, 13), mitochondrial dysfunction (14-17), and apoptosis (17); however, recent evidence indicates that hydrocarbon chain length of SFAs defines the level of intracellular lipotoxicity (18,19). Moreover, the Western diet, characterized by increased intake of foods with high levels of long-chain SFAs (LCSFAs), including myristate (C14:0), palmitate (C16:0), and stearate (C18:0), and low levels of beneficial medium-chain SFAs (MCSFAs), such as laurate (C12:0) (20-22), is a driving factor in the onset of dyslipidemia and T2D (23). MCSFAs are reported to prevent lipotoxicity and increase mitochondrial energy production (18,24,25). Likewise, equimolar caloric intake of MCSFAs and LCSFAs increases mitochondrial energy expenditure and leads to oxidative metabolic pathways as opposed to the metabolic dysfunction triggered by LCSFAs (24,26). SFAs are also directed to mitochondrial oxidative pathways through hydrocarbon chain length-dependent mechanisms; LCSFAs are targeted into the mitochondrial matrix for -oxidation through a transport system consisting of palmitoyltransferases (18,24,27), whereas MCSFAs are transported independently into the mitochondria, allowing for more efficient modulation of mitochondrial energy production (18,24). Hence, chain length of SFAs plays a critical role in regulating mitochondrial Abstract Dyslipidemia associated with T2D leads to diabetic neuropathy, a complication characterized by sensory neuronal dysfunction and peripheral nerve damage. Sensory dorsal root ganglion (DRG) neurons are dependent on axonal mitochondrial energy production facilitated by mitochondrial transport mechanisms that distribute mitochondria throughout the axon. Because long-chain saturated FAs (SFAs) damage DRG neurons and medium-chain SFAs are reported to improve neuronal function, we evaluated . Chain length of saturated fatty acids regulates mitochondrial trafficking and function in sensory neurons. J. Lipid Res. 2019. 60: 58-70. Supplementary key words diabetes • dyslipidemias • apoptosis • palmitate • stearate • laurate • myristate • mitochondrial depolarizationDiabetic peripheral neuropathy (DPN) is a common complication that affects up to 30% of patients with prediabetes and 50% of T2D patients (1, 2). Patients with DPN

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“…Prior to imaging, cells were stained with a mounting medium with DAPI and analyzed by confocal microscopy using 60x oil immersion objective. Background subtraction, noise reduction, local contrast enhancement, unsharp mask, and bandpass filtering were applied on raw images for better image quality and proper image evaluation [124]. Processed images were analyzed by ImageJ software.…”

Section: Assessment Of Mitochondrial Morphology and Autophagy By Confmentioning

confidence: 99%

PARP1 Inhibition Augments UVB-Mediated Mitochondrial Changes—Implications for UV-Induced DNA Repair and Photocarcinogenesis

Hegedűs

Boros

Fidrus

et al. 2019

Cancers

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Keratinocytes provide the first line of defense of the human body against carcinogenic ultraviolet (UV) radiation. Acute and chronic UVB-mediated cellular responses were widely studied. However, little is known about the role of mitochondrial regulation in UVB-induced DNA damage. Here, we show that poly (ADP-ribose) polymerase 1 (PARP1) and ataxia-telangiectasia-mutated (ATM) kinase, two tumor suppressors, are important regulators in mitochondrial alterations induced by UVB. Our study demonstrates that PARP inhibition by ABT-888 upon UVB treatment exacerbated cyclobutane pyrimidine dimers (CPD) accumulation, cell cycle block and cell death and reduced cell proliferation in premalignant skin keratinocytes. Furthermore, in human keratinocytes UVB enhanced oxidative phosphorylation (OXPHOS) and autophagy which were further induced upon PARP inhibition. Immunoblot analysis showed that these cellular responses to PARP inhibition upon UVB irradiation strongly alter the phosphorylation level of ATM, adenosine monophosphate-activated kinase (AMPK), p53, protein kinase B (AKT), and mammalian target of rapamycin (mTOR) proteins. Furthermore, chemical inhibition of ATM led to significant reduction in AMPK, p53, AKT, and mTOR activation suggesting the central role of ATM in the UVB-mediated mitochondrial changes. Our results suggest a possible link between UVB-induced DNA damage and metabolic adaptations of mitochondria and reveal the OXPHOS-regulating role of autophagy which is dependent on key metabolic and DNA damage regulators downstream of PARP1 and ATM. IntroductionMitochondria regulate their shape, number, distribution, mass, content of mitochondrial DNA (mtDNA), and metabolic capacity in a process called mitochondrial biogenesis, which requires the orchestration of complex transcriptional control of both nuclear and mitochondrial genes [1,2]. The function of mitochondrial biogenesis is to provide quality control of mitochondria by regulating mitochondrial fission, fusion, and mitophagy [3,4] to maximize the energy utilization of mitochondria [5] to meet cellular and environmental demands. Imbalances or perturbations in these processes can lead to mitochondrial dysfunction [3,6].Accumulating evidence suggests that mitochondria also play a central role in skin physiology. Although, involvement of other organ systems predominates in classical mitochondrial disorders, several cutaneous diseases can be linked to mitochondrial dysfunctions [7]. Interestingly, mitochondria lack functional nucleotide excision repair (NER) pathway [8,9] which is responsible for the removal of ultraviolet (UV)-induced DNA lesions including cyclobutane pyrimidine dimers (CPD). Accumulation of these DNA photoproducts in mtDNA leads to mutations and deletions resulting in mitochondrial alterations which have been associated with photoaging [10,11] and are present in melanoma [12], as well as in non-melanoma skin cancers [13,14]. The other types of mitochondrial alterations such as upregulated oxidative phosphorylation (OXPHOS), mitochondrial memb...

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Measuring Mitochondrial Shape with ImageJ

Cited by 53 publications

References 15 publications

Clock-Controlled Mitochondrial Dynamics Correlates with Cyclic Pregnenolone Synthesis

Clock-Controlled Mitochondrial Dynamics Correlates with Cyclic Pregnenolone Synthesis

Chain length of saturated fatty acids regulates mitochondrial trafficking and function in sensory neurons

PARP1 Inhibition Augments UVB-Mediated Mitochondrial Changes—Implications for UV-Induced DNA Repair and Photocarcinogenesis

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