Conference Agenda

Mitochondrial function depends on direct interactions between respiratory proteins encoded by genes in two genomes, mitochondrial and nuclear, which evolve in very different ways. Serious incompatibilities between these genomes can have severe effects on development, fitness and viability. The effect of subtle mitonuclear mismatches has received less attention, especially when subject to mild physiological stress, such as high-protein diet, though these subtle mismatches are arguably more relevant to both evolutionary population dynamics and precision medicine. Here we show that subtle differences in mtDNA (1-9 SNPs) between Drosophila melanogaster lines that are isogenic in their nuclear background can cause substantial differences in lifespan, fertility and physical activity. These phenotypic differences were amplified by a high protein diet. Even though the genotypic differences between our fly lines affect respiratory-chain function alone, we only detected subtle variations in substrate use and complex I function using high-resolution O2k fluorespirometry in the thoraces and reproductive tissues of young and old flies of both sexes. These subtle variations underpinned marked differences at the level of metabolic flux and especially gene expression, with changes in core metabolism including Krebs cycle and glycolysis as well as purine and pyrimidine pathways. Differences in gene expression were especially marked in the reproductive tissues of both sexes, and in older flies. Surprisingly, the line with the most mitonuclear mismatches also had (slightly) the best complex I function in young adults, which corresponded to the longest lifespan, the greatest fertility and the most physical activity. This suggests that subtle differences in substrate preference can have concerted effects on metabolic plasticity, gene expression and epigenetic state. Better complex I function may enhance metabolic plasticity and life-history outcomes. These outcomes are not easily predicted on the basis of mitonuclear match alone, but a better understanding of respiratory flux will have important implications for both evolutionary biology and health.

In nature, photosynthetic organisms are exposed to a wide range of light intensities that fluctuate rapidly, while nutrient depletion and CO₂ limitation can limit photosynthesis and growth. Excessively absorbed solar flux can lead to photooxidative stress through reactive oxygen species (ROS). Regulatory mechanisms, such as alternative electron pathways, help to increase light-harvesting efficiency and prevent ROS production under suboptimal conditions. Although dynamic light conditions and contrasting CO₂ availability are ubiquitous in the environment, little is known about their effects on primary metabolism. Here, we show how the model unicellular alga Chlamydomonas reinhardtii responds photosynthetically and metabolically to high, low and fluctuating light intensity under unrestricted (2%) or restricted (0.04%) CO₂ availability. Unrestricted CO₂ availability increased growth rates under high and fluctuating light regimes. This was consistent not only with increased photosynthetic efficiency, but also with increased oxygen evolution in the light and respiratory rates, as revealed by high-resolution oxygen flux analysis. Furthermore, primary metabolite profiling revealed increased accumulation of metabolites associated with photosynthesis (e.g. sugars) and respiration (e.g. TCA cycle), as well as amino acids and other organic acids when CO₂ availability was unrestrictive. Our results highlight that photosynthesis and respiration are highly sensitive to CO₂ availability, affecting primary metabolism and growth, particularly under high and fluctuating light.

Activation of brown adipocytes in mammals is reliant on the enhanced activity of respiratory complexes and allows organismal adaptation to cold environments. Comparative biochemical and cryo-EM analyses of respiratory complexes CI:III₂ from thermoneutral (low metabolic activity) and cold-acclimated (high metabolic activity) brown adipose tissue from mice reveal a distinct CI:III₂ assembly in the cold-acclimated mice (termed as type 2) that is absent in the thermoneutral condition (termed as type 1). This cold-inducible type 2 non-canonical CI:CIII₂ supercomplex (SC) structure (type 2) [1] displays a 25° rotation of CIII₂ relative to CI compared to the canonical form type 1, creating a larger void for lipids to occupy the region between them.

Large scale classical MD simulations of a ~2.1 million atom model of CI:III₂ SC in realistic membrane-solvent environment were performed to reveal the molecular basis of the physiological differences between the two states (type 1 and 2). MD simulations of type 2 SC exhibit an increase in CIII stability compared to type 1 owing to the more rotated arrangement of CIII with respect to CI. We find the higher lipid occupancy in the region between the two respiratory complexes to be partly responsible for the enhanced stability of type 2 SCs. Moreover, we show how different lipid species interact with the CI:CIII₂ interface through the simulations of the two different states.

The simulation findings provide a dynamic view into the differences between type 1 and 2 interactions and how the enrichment of type 2 CIII₂ rotated conformation in cold-adapted brown fat tissues can enhance the activity of the respiratory complexes. We suggest a model wherein, under thermoneutral conditions, the energy barrier for transitioning from type 1 to type 2 is higher compared to colder environments.

[1] Y.-Ch. Shin, P. Latorre-Muro, A. Djurabekova, O. Zdorevskyi, Ch. F. Bennett, N. Burger, K. Song, Ch. Xu, V. Sharma, M. Liao, P. Puigserver. Structural basis of respiratory complexes adaptation to cold temperatures. bioRxiv (Pre-Print) (2024)

Molecular function of respiratory complex I (NADH:ubiquinone oxidoreductase) has remained one of the most controversial problems in bioenergetics. This large molecular machine (up to 1 MDa in some organisms) utilises the energy from NADH oxidation and quinone reduction for the pumping of four protons across the inner mitochondrial membrane. Being spatially separated by ca. 200 Å, it is not completely understood how these charge transfer processes are coupled together [1]. In our work, we address this question by employing microsecond-long classical molecular dynamics (MD) in combination with state-of-the-art hybrid quantum-mechanical/molecular-mechanical (QM/MM) free energy calculation methods.

Our simulations on the high-resolution structures of respiratory complex I from yeast [2], and mammalian species [3,4] reveal the mechanistic details of the long-range charge transfer processes in various catalytic regions of the enzyme. Particularly, we show that the protons can travel along the membrane-bound subunits parallel to the membrane [5], coupling the redox reaction to the proton pumping site(s). Also, we underline the importance of the partially reduced and partially protonated quinone species in the catalytic cycle of respiratory complex I, and how electron transfer between two quinone ligands can facilitate redox catalysis in certain physiological conditions [4].

Our findings challenge the current models of redox-coupled proton transfer by respiratory complex I and have far-reaching implications in understanding complex I-associated metabolic disorders on the atomistic scale.

[1] A.Djurabekova et al., Biochem J (2024) 481 (7): 499–514.

[2] K. Parey, J. Lasham et al., Sci. Adv. 7.46 (2021): eabj3221.

[3] J. Gu et al., Nat. Struct. Mol. Biol 29.2 (2022): 172-182.

[4] Y.-C. Shin, bioRxiv (2024)

[5] O.Zdorevskyi et al., Chem. Sci. 14.23 (2023): 6309-6318.

NADH:ubiquinone oxidoreductase, respiratory I, is a key enzyme in cellular energy metabolism. It couples electron transfer from NADH to ubiquinone in its peripheral arm with proton translocation across the membrane in its membrane arm. The coupling of these two processes remains, however, elusive [1]. Is is generally accepted that the quinone redox chemistry drives proton translocation by a yet unknown mechanism. Quinone is reduced in a unique cavity between the two arms [2]. It was proposed that a reduced quinone species is protonated by conserved amino acid residuesof the cavity. However, site-directed mutagenesis indicates that this is not the case. Furthermore, redox-difference UV/vis spectra from Escherichia coli complex I indicated the formation of a quinol anion during turn-over [3, 4]. Here, a mechanism for energy conversion including a quinol anion as catalytic intermediate is proposed.

[1] I. Chung, D. N. Grba, J. J. Wright, J. Hirst, Making the leap from structure to mechanism: are the open states of mammalian complex I identified by cryoEM resting states or catalytic intermediates?, Curr. Opin. Struct. Biol., 77 (2022) 102447.

[2] K. Fiedorczuk, J. A. Letts, G. Degliesposti, K. Kaszuba, M. Skehel, L. A. Sazanov, Atomic structure of the entire mammalian mitochondrial complex I, Nature, 538 (2016) 406-410.

[3] F. Nuber, L. Mérono, S. Oppermann, J. Schimpf, D. Wohlwend, T. Friedrich, A Quinol Anion as Catalytic Intermediate Coupling Proton Translocation with Electron Transfer in E. coli Respiratory Complex I, Front. Chem., 9 (2021) 672969.

[3] V. R. Kaila, Resolving Chemical Dynamics in Biological Energy Conversion: Long-range Proton-Coupled Electron transfer in Respiratory Complex I, Acc. Chem. Res., 54 (2021) 4462-4473.

The energy stored in the proton-motive force across the specific membrane of almost all eubacteria, thylakoids, or mitochondria is used by the F₁F_O-ATP-synthase to synthesize ATP (Mitchell, 1967; Boyer, 1997). The F₁F_O-ATP-synthase consists of two connected sectors, F₁ and F_O. Identification by MS/MS of the F₁F_O-ATP-synthase subunits in Ustilago maydis showed the whole set of subunits reported (Esparza-Perusquía, 2017); from these, e and g are the dimerizing subunits. The ATPase activity of the dimer was 9-times higher than the monomer indicating that interface monomer-monomer plays a role in the activity of the F₁F_O-ATP-synthase dimer. In the mitochondria, the ATPase activity of the F₁F_O-ATP-synthase is prevented by the regulatory subunit IF1. Previous studies show that IF1 doesn’t play an important role in the dimerization of F₁F_O-ATP-synthase (Nakamura, 2013). Although IF1 (Inh1) does not play a role in the dimerization of F₁F_O-ATP-synthase, no studies on ATPase dimer activity have been performed. In U. maydis the elimination of the gene codifying the Inh1 subunit didn’t affect the cell growth, glucose consumption, and biomass production in the mutant strain. Ultrastructure and fluorescence analysis show that the size, the shape of the ridges, the lattice, and the distribution of the mitochondria were like that of the wild-type strain. The ΔY_m, ATP synthesis, and oxygen consumption in wild-type and Inh1Δ strains had similar values. Kinetic analysis of ATPase activity of complex V in permeabilized mitochondria showed similar values of V_max and K_m for both strains, and no effect of pH was observed. Interestingly, the dimeric state of complex V occurs in the mutant strain, indicating that this subunit is not essential for dimerization. ATPase activity of the isolated monomeric and dimeric forms of complex V indicated V_max values 4-times higher for the Inh1Δ strain than for the WT strain, suggesting that the absence of Inh1 subunit increased ATPase activity, and supporting a regulatory role for this protein; however, no effect of pH was observed (Romero-Aguilar, 2021). The deletion of gen codifying subunit g in Saccharomyces cerevisiae induces a decrease in dimer amount and modifies the mitochondrial architecture (Paumard, 2002). In U. maydis elimination of g subunit does not prevent dimerization of complex V in the inner membrane. However, the ATPase activity of the dimer is low in contrast to the monomer, suggesting that the g subunit is not essential for dimerization, but it could have an important role in the activity of the enzyme (Esparza-Perusquía, 2023).

Multidrug Resistance-Associated Protein 2 (MRP2/ABCC2) plays a pivotal role in the cellular efflux of organic anions, including drugs and bilirubin glucuronides, with its dysfunction leading to jaundice and Dubin-Johnson syndrome. Moreover, MRP2 has been identified as the determinant in anticancer therapy resistance, mediating efflux of many anticancer drugs such as paclitaxel and cisplatin. We present novel insights into the structural and functional modulation of MRP2, using cryo-EM to capture the architecture of rat Mrp2 in its autoinhibited state or bound to the drug probenecid. The autoinhibited conformation reveals a unique regulatory domain arrangement within the transmembrane domain cavity, restricting transporter activity. Phosphorylation of Ser922 and Ser926 triggers a significant increase in transport activity, as evidenced by in vitro phosphorylation studies, mass spectrometry, and functional assays in proteoliposomes following the fluorescent substrate 5(6)-Carboxy-2′,7′-dichlorofluorescein. The probenecid-bound structure uncovers two distinct drug-binding sites, providing a structural basis for the drug's modulatory effects on MRP2 activity. Experimental data, including ATPase activity assays and substrate transport analysis, underscore the importance of phosphorylation in modulating MRP2's function and the intricate relationship between drug binding and transporter regulation. This proposed work sheds light on the molecular dynamics of MRP2, offering potential avenues for therapeutic intervention in drug resistance and transport-related disorders. The findings underscore the critical role of structural modifications and kinase-mediated phosphorylation in determining MRP2's activity, laying the basis for future research into targeted drug development and treatment strategies for related pathological conditions.

[1] Mazza, T., Roumeliotis, T.I., Garitta, E. et al. Structural basis for the modulation of MRP2 activity by phosphorylation and drugs. Nat Commun 15, 1983 (2024). https://doi.org/10.1038/s41467-024-46392-8

As mitochondrial Ca²⁺ is crucial for metabolism and life/cell decision, regulation of its homeostasis is an important factor. Mitochondrial Ca²⁺ homeostasis is controlled by uptake and release transporters: mitochondrial Ca²⁺ uniporter complex (MCUC), Na⁺/Li⁺/Ca²⁺ exchanger (NCLX), and the Na⁺-independent Ca²⁺/H⁺ exchanger (CHE), which we molecularly identified as Transmembrane BAX inhibitor-1 motif-containing protein 5 (TMBIM5/MICS1)[1]. In addition, the mitochondrial permeability transition pore is a critical Ca²⁺ determinant through transient opening.

TMBIM5/MICS1 belongs to the evolutionary conserved TMBIM family, with TMBIM5 as the only mitochondrial member and BsYetJ as the bacterial ancestor. The crystal structure of BsYetJ suggests a pH-sensitive regulation of Ca²⁺ transport, which is likely mediated by highly conserved amino acid residues. Having previously demonstrated that TMBIM5 mediates mitochondrial Ca²⁺ and H⁺ fluxes in intact and permeabilised cells and in in-vitro systems, and that TMBIM5 interacts with LETM1 the mitochondrial K⁺/H⁺ exchanger (KHE)[1], now we are showing a mutational analysis exploring whether, similarly to the ancestral bacterial homolog BsYetJ model, TMBIM5 regulates Ca²⁺ fluxes by a pH-sensitive switch between an open and a closed conformation, and if the mutations affect the interaction with LETM1 and eventually it’s function. The amino acid sequence alignment between BsYetJ and TMBIM5 points to highly conserved residues proposed to regulate the conformational changes. We analysed the effect of mutating these residues on the protein function (CHE) and on the interaction with LETM1. Using a Ca²⁺ fluorophore and permeabilised cells, in which knockout of TMBIM5 (TMBIM5KO) abolishes CHE, we functionally explore the CHE activity in TMBIM5KO that re-express TMBIM5WT or TMBIM5 mutants. We then investigated the effect of these mutations on the interaction with LETM1 and eventually its role in mitochondrial KHE in the function of KOAc-induced mitochondrial swelling.

[1] S. Austin, R. Mekis, S.E.M. Mohammed, M. Scalise, W.-A. Wang, M. Galluccio, C. Pfeiffer, T. Borovec, K. Parapatics, D. Vitko, N. Dinhopl, N. Demaurex, K.L. Bennett, C. Indiveri, K. Nowikovsky, TMBIM5 is the Ca2+/H+ antiporter of mammalian mitochondria, EMBO Rep 23 (2022) e54978. https://doi.org/10.15252/EMBR.202254978.

The mitochondrial pyruvate carrier (MPC) is a mitochondrial inner membrane transporter, which links cytosolic and mitochondrial metabolism by transporting pyruvate into the matrix [1-2]. The functional human carrier is a heterodimer, formed of two homologous protomers [2]. It is ubiquitously expressed as MPC1/MPC2 in humans, with an additional dimer of MPC1L/MPC2 expressed in the testis [3]. Although the carrier is a putative drug target for diseases, such as diabetes, metabolic dysfunction-associated steatotic liver disease (MASLD), and neurodegeneration, little is known about its structure and transport mechanism.

In this work, a model of the human mitochondrial pyruvate carrier heterodimer was generated, based on predicted structures of the individual MPC1L and MPC2 protomers and known structural homologs of the transporter. By mutagenesis in the dimerisation interface and thermostability shift assays with a range of canonical MPC inhibitors, we have validated our structural model and identified residues essential for inhibitor binding in the functional heterodimer. Using radiolabelled pyruvate transport assays in proteoliposomes, we have also identified residues required for pyruvate transport, as well as key chemical features of MPC inhibitors required for high affinity transport inhibition. This information will be crucial for future investigations and for identifying medically relevant inhibitors of MPC.

[1] S. Tavoulari, C. Thangaratnarajah, V. Mavridou, M.E. Harbour, J. Martinou, E.R. Kunji, The yeast mitochondrial pyruvate carrier is a hetero‐dimer in its functional state, The EMBO Journal. 38 (2019). doi:10.15252/embj.2018100785.

[2] S. Tavoulari, T.J.J. Schirris, V. Mavridou, C. Thangaratnarajah, M.S. King, D.T.D. Jones, et al., Key features of inhibitor binding to the human mitochondrial pyruvate carrier hetero-dimer, Molecular Metabolism. 60 (2022) 101469. doi:10.1016/j.molmet.2022.101469.

[3] B. Vanderperre, K. Cermakova, J. Escoffier, M. Kaba, T. Bender, S. Nef, et al., MPC1-like is a placental mammal-specific mitochondrial pyruvate carrier subunit expressed in postmeiotic male germ cells, Journal of Biological Chemistry. 291 (2016) 16448–16461. doi:10.1074/jbc.m116.733840.

Uncoupling protein 1 (UCP1), highly expressed in brown adipose tissue, plays a pivotal role in non-shivering thermogenesis by dissipating the mitochondrial proton motive force. When activated, UCP1 allows protons across the mitochondrial inner membrane bypassing ATP synthesis. Recent structures of UCP1 inhibited by purine nucleotides [1,2] reveal that these nucleotides block proton conductance by binding with high affinity to the central cavity of UCP1, preventing the necessary conformational changes [3]. This study investigates the nucleotide specificity of UCP1 inhibition. Using functional and structural analysis, we reveal how different nucleotide species have distinct affinities for UCP1. We also analysed the role of pH in the regulation of inhibition. Additionally, we explored how related mitochondrial carriers interact with nucleotides. UCP1 has evolved to bind nucleotides with high affinity, requiring only minimal changes to central cavity residues compared to related mitochondrial carriers. We also investigated which modifications in the central cavity have enabled the broad nucleotide specificity of UCP1. Our study suggests that UCP1 regulation may involve multiple nucleotides, contingent upon cellular conditions, highlighting the potential complexity of its regulatory mechanism. A complete understanding of the regulation of non-shivering thermogenesis is vital for harnessing the process to treat metabolic disease.

Adverse childhood experiences (ACEs) encompass a variety of stressors encountered by children and adolescents, including household dysfunctions and experiences of violence, abuse, and neglect. ACEs affect more than 20% of all children worldwide. ACEs often occur repeatedly and have profound effects not only on mental health, like Major Depression Disorder (MDD), but also on various physical illnesses. Individuals with a history of ACEs show an increased risk for severe health complications, while the biological mechanisms and the underlying pathophysiology remain hardly understood.

A growing body of evidence suggests that mitochondrial physiology could present a biological function underlying this risk. Mitochondria are sensitive to endogenous and exogenous stressors, exhibiting susceptibility to oxidative stress and resulting inflammatory states. Studies have shown increased mitochondrial activity in individuals with ACEs, suggesting a dose-response relationship with the severity and timing of childhood trauma. Therefore, it is important to better understand the impact of ACEs on the transition from (mental) health to disease, with mitochondrial bioenergetics in PBMC from individuals with and without depression.

In a collaboration with the University Hospital Zurich (project CCO-NIRS), participants with and without MDD completed the Childhood Trauma Questionnaire (CTQ). In addition, the severity of depressive symptoms was determined using the Beck Depression Inventory (BDI), together with the Hamilton Depression Rating Scale(HDRS). PBMC were isolated from whole blood, and cryopreserved cells were analyzed with O2K oxygraph technology. High-resolution respirometry was performed using a SUIT protocol for the assessment of oxygen consumption states and flux control ratios.

Data analysis investigated the relationships between ACEs, mitochondrial respiration in PBMC, and the clinical severity.

The 140 participants were divided into four groups (ACE^- MDD^-with N=61, ACE^- MDD⁺ with N=24, ACE⁺MDD^- with N= 19 and ACE⁺MDD⁺ with N= 37) and the group differences were examined. The statistical examination is currently being processed, and results will be presented at EBEC 2024.

Background

Normothermic machine perfusion (NMP) of the liver is a dynamic organ preservation method, which offers the ability to assess organ function ex situ but requires reliable biomarkers. Since bioenergetic competency is central for cellular maintenance and thus, organ functionality, we herein aimed to characterize mitochondrial function using high-resolution respirometry (HRR) during liver NMP.

Methods

Human livers (N=50) considered for transplantation were applied to clinical NMP for up to 24 hours. Serial perfusate and biopsy samples were collected at the end of cold storage and longitudinal during NMP. Conventional perfusate parameters and histopathology was performed. HRR was applied to assess LEAK respiration, OXPHOS capacity, efficiency of ATP production (P-L control efficiency) and integrity of the mitochondrial outer membrane (cytochrome c control efficiency). Livers declined for transplantation during NMP were considered for experimental long-term perfusion up to 7 days.

Results

A considerable variability of the individual liver grafts was observed at the end of cold storage, which remained stable after the start of NMP. For the 35 livers deemed suitable for transplantation the area under curve (AUC) during 6 hours of NMP was calculated. For those livers the AUC of LEAK respiration, cytochrome c control efficiency and P-L control efficiency correlated with the early clinical outcome (L-GrAFT score). Four of the declined livers could be preserved for 7 days by application of a novel perfusion protocol. The bioenergetic function in the liver biopsies was stable as indicated by adequate P-L control efficiency (0.780 ± 0.099) and outer mitochondrial membrane integrity (0.108 ± 0.047) and was in line with conventional assessment methods.

Conclusion

Evaluation of the bioenergetic function in livers undergoing NMP can be included in liver functionality assessment methods and predict the clinical outcome after transplantation. In addition, NMP can preserve bioenergetic competency of the liver during long-term preservation.

Protein kinases play an important role in numerous signaling pathways regulating cell proliferation, differentiation, cell death, and metabolism. Deregulation of kinase functions have been connected to various human diseases, such as cancer [1, 2]. In recent years, kinase inhibitors have gained recognition by aiming to block single or multiple oncogenic kinase pathways, which is underlined by 49 FDA-approved kinase inhibitor drugs. Besides kinases also mitochondrial metabolism has emerged as a central drug target. Mitochondria are dynamic cell organelles, orchestrating cellular energy production and cellular signalling. Blockade of kinase activities has been shown to converge on mitochondria [3].

In our study, we have applied defined pharmacological perturbations to manipulate kinase pathways involved in both, mitochondrial functions and oncogenesis. We set out to systematically profile the impact of broad and specific kinase drugs on mitochondrial respiration in several cancer cell models using High-resolution respirometry. We observed that the impact of kinase inhibitors depends on the mutational background of the tested cancer cell lines as well as on cell culture medium formulations [4]. First, we detected off-target effects of sunitinib, an FDA-approved multikinase blocker, only in a more physiological cell culture medium as compared with classical formulations. Second, mitochondrial profiling of the glycolytic kinase inhibitor PFK158 revealed off-target mitochondrial dysfunction. Third, we were able to show that inhibition of kinase signaling is connected to mitochondrial reactive oxygen species (ROS), which can be influenced by protein kinase modulators. In summary, examining drug-induced mitochondrial dysfunctions offers a deeper understanding of the apparent off-target effects of kinase inhibitors. Consequently, utilizing cell-based diagnostics to analyze mitochondrial bioenergetic profiles emerges as a promising approach for identifying on-target effects or predicting potential off-target effects of drugs that disrupt cell metabolism.

[1] Deribe, Y. L., Pawson, T. & Dikic, I (2010). Nat. Struct. Mol. Biol.

[2] Zhang R, Loughran TP, Jr (2011). Leukemia & Lymphoma.

[3] Torres-Quesada O, Strich S, Stefan E (2022).Bioenerg. Commun.

[4] Torres-Quesada, O, Doerrier, C, Strich, S, Gnaiger, E, Stefan, E (2022). Cancers.

Long-COVID is a clinical condition characterized by long-term consequences of severe respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which poses a persistent public health concern worldwide. It impacts multiple body functions, including immunological, respiratory, cardiovascular, gastrointestinal, neuropsychological, musculoskeletal, and other important systems. Affected individuals frequently describe symptoms such as “mental fog” and persistent fatigue, among other various symptoms. Despite intensified research, the biological mechanisms causing this multitude of symptoms are not fully understood, sparking a quest for innovative research directions, particularly in the combined area of bioenergetics and psychoneuroimmunology. This interdisciplinary field focusses on how (immune) cells generate energy, exploring possible bioenergetic disruptions in individuals with Long-COVID, especially focusing on the role of mitochondrial functioning in peripheral blood mononuclear cells (PBMC) isolated from whole blood.

This research adopts a comprehensive approach, starting with clinical evaluations to measure both mental and physical impairments in those impacted. Using a thorough methodology, it merges clinical assessments of psychological issues and the influence of body weight, with the gathering of blood samples for isolating PBMC. These cells are being analyzed applying O2K high-resolution respirometry to evaluate mitochondrial function, providing insights into cellular energy dynamics and potential malfunctions in Long-COVID.

Our findings indicates significant disruptions in the mitochondrial activity in intact PBMC collected from patients with Long-COVID compared to non-affected controls, indicating a major loss of cellular energy processes, at least in immune cells. Being under current investigation, these issues might also correlate with the clinical symptom severity of Long-COVID, such as severe fatigue and cognitive impairments. The final findings will be shared during the presentation.

We will highlight the essential importance of mitochondrial health in understanding and managing Long-COVID more broadly. Evidence for mitochondrial perturbations in PBMC points towards bioenergetic health as a key area for both tracking and addressing the wide range of Long-COVID symptoms. Expanding our grasp of the disease's biological basis not only deepens our understanding of Long-COVID, but also unveils new paths for developing specific interventions aimed at reducing the long-lasting impact of the ailment and asks for a holistic approach.