Evolutionary Singularities and the Eukaryotic Dawn
The mitochondrion represents a biological singularity, a discrete evolutionary event that fundamentally partitioned life on Earth into two distinct energetic stratums: the prokaryotic and the eukaryotic. While colloquially reduced to the moniker of "cellular powerhouse," the mitochondrion is, in functional reality, a highly integrated endosymbiont that serves as the master regulator of eukaryotic physiology. It is the nexus of cellular respiration, the arbiter of programmed cell death, a buffer for intracellular calcium, and a hub for biosynthetic pathways ranging from heme synthesis to steroidogenesis. To comprehend the complexity of multicellular life, one must first dissect the intricate molecular sociology of this organelle.
The origin of the mitochondrion is the subject of intense phylogenomic reconstruction. The prevailing consensus, the endosymbiotic theory, posits that the mitochondrion descends from a free-living bacterial ancestor—specifically a lineage within the Alphaproteobacteria—that entered into a symbiotic relationship with a host archaeal cell approximately 1.5 to 2 billion years ago. This was not a trivial acquisition but a transformative merger. The energetic capacity afforded by the internalization of a bioenergetic specialist allowed the host cell to escape the surface-area-to-volume constraints that limit prokaryotic genome size, facilitating the expansion of the nuclear genome and the development of complex intracellular compartmentalization.
Mitochondria Is the Cell's Central Processing Unit
Recent metagenomic advances have provided granular resolution to this narrative. The discovery of the Asgard superphylum of Archaea, and specifically the Lokiarchaeota, has revolutionized our understanding of the host lineage. These archaea possess "Eukaryotic Signature Proteins" (ESPs) involved in cytoskeleton formation and membrane trafficking, suggesting that the host was already primed with a degree of cellular complexity prior to mitochondrial acquisition. The integration of the endosymbiont involved massive Endosymbiotic Gene Transfer (EGT), where the vast majority of the bacterial symbiont’s genes were transferred to the host nucleus. Today, the mitochondrion retains a vestigial genome (mtDNA) encoding only a fraction of its proteome, necessitating a sophisticated bidirectional communication network—anterograde and retrograde signaling—between the nucleus and the organelle to coordinate biogenesis with metabolic demand.
This evolutionary history has profound immunological implications. The mitochondrion retains molecular motifs distinct to bacteria—circular DNA with unmethylated CpG islands, N-formyl peptides, and cardiolipin-rich membranes. Consequently, the eukaryotic cell effectively hosts a "domesticated alien." If mitochondrial integrity is compromised and these components leak into the cytosol, they are recognized as Damage-Associated Molecular Patterns (DAMPs) by the innate immune system, triggering sterile inflammation mimicking a bacterial infection. Thus, the mitochondrion is a double-edged sword: the engine of life and a potential detonator of inflammation and cell death.
Architectural Dynamics: Membrane Systems and Compartmentalization
The structural organization of the mitochondrion is not a static anatomy but a dynamic, plastic landscape that remodels in response to bioenergetic status. The organelle is defined by two disparate membranes—the Outer Mitochondrial Membrane (OMM) and the Inner Mitochondrial Membrane (IMM)—which delineate two soluble compartments: the Intermembrane Space (IMS) and the Matrix.
The Outer Mitochondrial Membrane (OMM): The Cellular Interface
The OMM serves as the boundary between the mitochondrial network and the cytosolic environment. It is functionally distinct from the IMM, possessing a high permeability to ions and small metabolites (up to ~5 kDa) due to the abundance of Voltage-Dependent Anion Channels (VDAC), also known as mitochondrial porins. VDACs are not merely passive sieves; they are regulatory gates that control the flux of anionic metabolites like ADP, ATP, and succinate, and they serve as docking sites for cytosolic kinases such as Hexokinase II, linking glycolysis directly to mitochondrial ATP export.
For larger macromolecules, the OMM is a selective barrier. The translocation of nuclear-encoded precursor proteins is mediated by the Translocase of the Outer Membrane (TOM) complex. This machinery recognizes specific N-terminal targeting sequences on nascent polypeptides, threading them through the membrane in an unfolded state. The OMM is also the site of extensive inter-organellar contact. Mitochondria-Associated Membranes (MAMs) are specialized subdomains where the OMM forms tethered contacts with the Endoplasmic Reticulum (ER). These junctions are critical for lipid trafficking—specifically the import of phosphatidylserine for decarboxylation to phosphatidylethanolamine—and for the direct transfer of calcium ions from ER stores to the mitochondrial matrix, a signal essential for stimulating oxidative metabolism.
The Inner Mitochondrial Membrane (IMM) and Cristae Architecture
The IMM is the functional epicenter of oxidative phosphorylation. In stark contrast to the OMM, the IMM is virtually impermeable to ions and polar molecules, a property strictly maintained to support the electrochemical proton gradient. Transport across this barrier is mediated by a diverse family of specific carrier proteins, such as the Adenine Nucleotide Translocase (ANT) and the Phosphate Carrier (PiC), which function as obligate exchangers.
Structurally, the IMM is differentiated into two domains: the Inner Boundary Membrane (IBM), which closely parallels the OMM, and the Cristae Membrane (CM), which invaginates deep into the matrix to maximize the surface area for respiratory complexes. Historically depicted as simple baffles, super-resolution microscopy and cryo-electron tomography have revealed that cristae are complex, pleomorphic compartments connected to the IBM by narrow tubular openings known as Cristae Junctions (CJs).
The MICOS Complex: Organizing the Inner Architecture
The stability and localized curvature of cristae are governed by the Mitochondrial Contact Site and Cristae Organizing System (MICOS), a large oligomeric complex embedded in the IMM. MICOS acts as the molecular skeleton of the cristae junctions. It is composed of two distinct subcomplexes that assemble independently:
- The Mic60 Subcomplex (Mic60/Mic19): Mic60 (formerly Mitofilin) is the core architect, possessing a large IMS domain that physically bridges the IMM to the OMM via interactions with the SAM complex (Sorting and Assembly Machinery). Mic60 self-assembles to mark the sites of nascent cristae junctions and is sufficient for their formation.
- The Mic10 Subcomplex (Mic10/Mic12/Mic26/Mic27): This module is responsible for the induction of membrane curvature. Mic10 oligomerizes to form a curvature-inducing scaffold that stabilizes the tubular shape of the cristae junction. It regulates the formation of lamellar (sheet-like) cristae; its absence leads to the formation of unconnected, stacked membrane vesicles.
The physiological importance of MICOS is paramount. By stabilizing CJs, MICOS creates a diffusion barrier that segregates the fluid contents of the cristae from the rest of the IMS. This compartmentalization traps soluble electron carriers like cytochrome c within the cristae, enhancing the efficiency of electron transport. Furthermore, upon apoptotic signaling, the remodeling of MICOS and the widening of CJs are prerequisites for the rapid release of cytochrome c into the cytosol.
Lipid Specificity: The Role of Cardiolipin
The structural integrity of the IMM is intimately tied to its unique lipid composition, particularly the presence of Cardiolipin (CL). Synthesized exclusively within the mitochondria, CL is a dimeric phospholipid consisting of two phosphatidyl moieties linked by a glycerol backbone, resulting in four acyl chains. This structure grants CL a conical geometry, which relieves the lateral stress of high-curvature membranes found at cristae tips and junctions.
CL acts as a "molecular glue" for the respiratory chain. It is essential for the stabilization of supercomplexes (respirasomes) and the proper dimerization of ATP synthase. It seals the protein-lipid interface of respiratory complexes, preventing proton leakage and maintaining the efficiency of the proton motive force. Pathological remodeling of CL—such as the failure to remodel acyl chains from saturated to unsaturated forms (tafazzin deficiency in Barth syndrome) or oxidative damage—disrupts supercomplex assembly, destabilizes the membrane potential, and triggers the externalization of CL to the OMM, where it serves as a signal for mitophagy or apoptosis.
The Bioenergetics Engine: Chemiosmosis and the Respirasome
The canonical function of the mitochondrion is the transduction of chemical energy from metabolic fuels into the phosphate bond energy of ATP. This is achieved through the Electron Transport Chain (ETC) and Oxidative Phosphorylation (OXPHOS), a system of macromolecular complexes that couple electron transfer to proton translocation.
Detailed Mechanisms of Electron Transport
The ETC consists of four major membrane-embedded complexes that sequentially transfer electrons from reduced cofactors (NADH, FADH2) to molecular oxygen.
- Complex I (NADH:Ubiquinone Oxidoreductase): This L-shaped giant is the entry point for electrons from NADH. The hydrophilic arm protrudes into the matrix and facilitates electron transfer through a series of iron-sulfur (Fe-S) clusters to the membrane-embedded quinone reduction site. The reduction of ubiquinone (Q) to ubiquinol (QH2) induces a long-range conformational change in the membrane arm—analogous to a steam piston—that drives the active transport of four protons from the matrix to the IMS. Complex I is a major site of Reactive Oxygen Species (ROS) production, specifically superoxide, particularly when the Flavin Mononucleotide (FMN) site is highly reduced (reverse electron transport).
- Complex II (Succinate Dehydrogenase): Uniquely shared with the Krebs cycle, Complex II oxidizes succinate to fumarate, transferring electrons via FAD and Fe-S clusters to ubiquinone. Unlike Complex I, it does not span the entire membrane and does not pump protons; it contributes to the energetic pool solely by feeding electrons into the Q-pool.
- Complex III (Cytochrome bc1 Complex): This complex transfers electrons from ubiquinol to cytochrome c. It employs the sophisticated "Q-cycle" mechanism to maximize proton translocation. The Q-cycle involves two distinct quinone binding sites (Qo and Qi). For every two electrons entering from ubiquinol, one is passed to the Rieske Fe-S protein and then to cytochrome c (linear path), while the second is recycled back through the low-potential hemes (bL and bH) to reduce a quinone at the Qi site. This bifurcation forces the release of four protons into the IMS for every pair of electrons transferred to cytochrome c, doubling the proton-pumping efficiency compared to a direct transfer.
- Complex IV (Cytochrome c Oxidase): The terminal oxidase accepts electrons from soluble cytochrome c and uses them to reduce molecular oxygen to water. This reaction is thermodynamically favorable and drives the pumping of two additional protons across the membrane. The regulation of Complex IV is highly nuanced, with tissue-specific isoforms of its nuclear-encoded subunits allowing for the fine-tuning of respiration rates in response to metabolic demand (e.g., regulation by ATP/ADP ratios).
Supercomplexes: The Respirasome Architecture
While textbook models often depict these complexes as independent entities floating in a fluid mosaic, substantial evidence now confirms that they organize into supramolecular assemblies known as Supercomplexes (SCs) or "Respirasomes." The most abundant configuration in mammalian mitochondria is the SC I+III2+IV (one Complex I, a dimer of Complex III, and one or more copies of Complex IV).
Composition and Stoichiometry of Major Mitochondrial Supercomplexes
- Respirasome
- Composition: I + III₂ + IV
- Primary Physiological Function: Complete transfer of electrons from NADH to O₂. Stabilizes Complex I.
- Abundance (Mammalian): High (dominant form)
- Pre-Respirasome
- Composition: I + III₂
- Primary Physiological Function: Intermediate assembly state; functional NADH oxidation but lacks terminal oxidase.
- Abundance (Mammalian): Moderate
- Complex III/IV
- Composition: III₂ + IV₁₋₂
- Primary Physiological Function: Efficient transfer from QH₂ to O₂; independent of Complex I (succinate pathway).
- Abundance (Mammalian): Moderate
- Complex V Dimer
- Composition: V₂
- Primary Physiological Function: Localization to cristae ridges; induces membrane curvature essential for morphology.
- Abundance (Mammalian): High (in cristae)
The functional significance of respirasomes is debated but centers on two hypotheses:
1. Stability: Physical association is required for the stability of Complex I. In patients with defects in Complex III or IV assembly, Complex I is often secondarily degraded, indicating a scaffold requirement.
2. Substrate Channeling: The arrangement creates a micro-environment that traps the mobile electron carriers (ubiquinone and cytochrome c) between the enzymatic centers. This channeling potentially enhances catalytic efficiency and minimizes the escape of single electrons to oxygen, thereby reducing oxidative stress.
Recent structural data from 2023-2024 supports a "plasticity model" where supercomplexes and free complexes coexist, allowing the electron transport chain to adapt dynamically to different substrates (e.g., switching between glucose-driven NADH oxidation and fatty acid-driven FADH2 oxidation).
ATP Synthase (Complex V): The Nanomotor
The proton motive force generated by the respirasomes is harvested by the F1Fo-ATP synthase. This enzyme functions as a rotary nanomotor. Protons flow from the IMS back into the matrix through the membrane-embedded Fo subcomplex, driving the rotation of the c-ring.
The efficiency of this motor is dictated by the stoichiometry of the c-ring, which varies across species. The c-ring is composed of a variable number of identical hairpin helices (c-subunits).
- Mechanics: One complete 360-degree rotation of the c-ring generates exactly 3 ATP molecules at the catalytic F1 head.
- Stoichiometry: If a species has a c-ring with 8 subunits (e.g., bovine mitochondria), it requires 8 protons to complete a revolution, yielding a cost of 2.7 protons per ATP. If a species has 10 subunits (e.g., yeast), the cost is 3.33 protons per ATP.
- Adaptation: This variability represents an evolutionary adaptation to specific bioenergetic niches. A smaller ring (fewer subunits) is more efficient (cheaper ATP) but generates less torque, requiring a higher proton motive force to initiate rotation. A larger ring generates more torque and can operate at lower membrane potentials but consumes more protons per ATP.
High-resolution measurements have revealed that the rotation occurs in discrete steps (e.g., 11-degree substeps) coupled to the protonation of conserved glutamate residues on the c-subunits.
Uncoupling: Thermogenesis and Proton Leaks
Energy transduction is not perfectly coupled. A significant fraction of the proton gradient can be dissipated as heat, a process known as proton leak. In Brown Adipose Tissue (BAT), this is a regulated physiological function mediated by Uncoupling Protein 1 (UCP1).
UCP1 acts as a gated proton channel. It is activated by Long-Chain Fatty Acids (LCFAs), which act as cycling cofactors to shuttle protons, and it is inhibited by purine nucleotides (ATP, GDP) which bind to the pore and block conductance. A breakthrough study in 2025 expanded this regulatory landscape, demonstrating that pyrimidine nucleotides (e.g., UTP, CTP, dTTP) also bind and inhibit UCP1 in a pH-dependent manner, revealing that the inhibitor binding site lacks strict nucleobase specificity and is instead dominated by electrostatic interactions with the phosphate groups.
Beyond UCP1, recent research has validated UCP1-independent thermogenic pathways, specifically "creatine cycling" and "calcium cycling" in skeletal muscle and beige fat. These futile cycles consume ATP to transport ions, thereby driving respiration and heat production in tissues previously thought to be non-thermogenic.
The Mitochondrial Genome: Inheritance, Maintenance, and Expression
Mitochondria possess their own genetic material (mtDNA), a circular double-stranded molecule of approximately 16.5 kb in humans. It encodes 13 essential polypeptides of the OXPHOS system, along with 22 tRNAs and 2 rRNAs required for their translation.
Nucleoid Organization and Segregation
Unlike the nuclear genome, mtDNA is not organized into chromatin by histones. Instead, it is packaged into discrete protein-DNA complexes called nucleoids. The primary packaging protein is Mitochondrial Transcription Factor A (TFAM). TFAM binds mtDNA non-specifically, imposing a sharp U-turn (approx. 180 degrees) on the DNA backbone, effectively compacting the genome into a functional unit.
Nucleoids are not free-floating; they are often tethered to the IMM, positioning them near the translational machinery. The regulation of nucleoid structure is dynamic; "loosening" of the structure facilitates transcription, while compaction segregates the genome for replication or transmission. Current models suggest that nucleoids behave as phase-separated liquid droplets, a property that may facilitate the rapid segregation of mtDNA during mitochondrial fission.
Heteroplasmy and the Threshold Effect
A single cell contains hundreds to thousands of mtDNA copies. In healthy tissues, all copies are typically identical (homoplasmy). However, due to the high mutation rate of mtDNA—estimated at 10-20 times that of nuclear DNA—cells can accumulate a mixture of wild-type and mutant genomes, a state known as heteroplasmy.
The clinical manifestation of pathogenic mtDNA mutations is governed by the threshold effect. A specific mutation must accumulate to a critical level (typically 60-90%, depending on the mutation and tissue energy demand) before the bioenergetic output fails and symptoms appear. This explains the extreme phenotypic variability seen in mitochondrial diseases, where even siblings with the same mutation can display vastly different severities depending on the random segregation of mutant mtDNA during embryogenesis.
The Mutation Rate Controversy: ROS vs. Replication
For decades, the high mutation rate of mtDNA was attributed to the "Mitochondrial Theory of Aging," which argued that the proximity of mtDNA to the ROS-generating ETC led to oxidative DNA damage (e.g., 8-oxo-guanine). However, this dogma is being overturned. Recent high-fidelity sequencing and mutagenesis studies (e.g., using Pol gamma mutator mice) suggest that the majority of mtDNA mutations are transition mutations (A>G or T>C) caused by replication errors by the mitochondrial DNA polymerase (Pol γ), rather than transversion mutations typical of oxidative damage. This shifts the focus of aging research from antioxidants to maintaining the fidelity of the replication machinery.
Proteostatic and Organellar Quality Control
The health of the mitochondrial network is maintained by a rigorous quality control system involving dynamic fission and fusion events, and the selective removal of damaged units via autophagy (mitophagy).
Fission and Fusion Dynamics
Mitochondria exist as a reticulum that continuously fuses and divides.
- Fusion: Facilitated by Mitofusins (Mfn1/Mfn2) on the OMM and OPA1 on the IMM. Fusion allows for "complementation," where a mitochondrion with damaged DNA or proteins can fuse with a healthy one, sharing functional components to maintain respiration.
- Fission: Mediated by the cytosolic GTPase Drp1 (Dynamin-Related Protein 1), which is recruited to the OMM by receptors (MFF, MiD49/51). Drp1 oligomerizes into spirals that constrict and sever the organelle.
Recent Breakthroughs (2024-2025): The mechanics of fission have been further elucidated. A 2025 study identified a two-stage fission process regulated by the protein MTFP1 (Mitochondrial Fission Process 1). While Drp1 provides the mechanical force, MTFP1 serves as a metabolic checkpoint, integrating cellular energy status to permit or inhibit the division. Additionally, the protein CLUH (Clustered Mitochondria Homolog) was identified as a key regulator that recruits Drp1 to the mitochondrial surface, linking the transport of nuclear-encoded mRNAs to the site of division.
Furthermore, a 2024 study challenged the dogma that high rates of dynamics are intrinsically necessary. It demonstrated that balanced rates of fission and fusion—even if significantly reduced—are sufficient to maintain mtDNA integrity. It is the imbalance (e.g., excessive fission leading to fragmentation) that is pathogenic.
Mitophagy and Paternal Elimination
When a mitochondrion is damaged beyond repair (loss of membrane potential), it is targeted for degradation. The canonical pathway involves PINK1 (a kinase) and Parkin (a ubiquitin ligase). PINK1 accumulates on the OMM of depolarized mitochondria, phosphorylating ubiquitin chains to recruit Parkin. Parkin then hyper-ubiquitinates OMM proteins, tagging the organelle for engulfment by autophagosomes.
This machinery is also repurposed for the elimination of paternal mitochondria after fertilization. In most animals, mitochondrial inheritance is strictly maternal. Sperm mitochondria are actively destroyed to prevent the transmission of "selfish" or damaged paternal mtDNA. This elimination utilizes both ubiquitin-dependent pathways (involving Parkin and the ligase MUL1) and ubiquitin-independent pathways (involving the autophagy receptor FNDC-1). Failure of this system can lead to heteroplasmy and potential incompatibility between nuclear and mitochondrial genomes.
The Signaling Hub: Calcium, Death, and Communication
Beyond energy, mitochondria are central processors of cellular signals.
The Calcium Uniporter (MCU) Complex
Mitochondrial calcium uptake coordinates energy production with cellular activity. The channel responsible, the Mitochondrial Calcium Uniporter (MCU), is a highly regulated macromolecular complex.
- The Pore: Formed by tetramers of the MCU protein.
- The Gatekeepers: MICU1 and MICU2 sense calcium levels in the IMS. At low resting calcium, they physically block the pore to prevent futile cycling. When calcium rises, they undergo a conformational change that unblocks the pore, allowing rapid influx.
- The Stabilizers: EMRE (Essential MCU Regulator) bridges the pore and the gatekeepers. Cardiolipin is essential for the structural integrity of this complex, embedding the tetramer in the membrane.
Apoptosis and the BAX/BAK Pore
Mitochondria control the intrinsic apoptotic pathway. Cellular stress triggers the activation of BAX and BAK, which oligomerize in the OMM to cause Mitochondrial Outer Membrane Permeabilization (MOMP). Recent biophysical studies support a proteolipidic toroidal pore model for BAX/BAK. Rather than a rigid protein channel, BAX/BAK helices line the edge of a lipid pore, stabilizing the high curvature of the membrane edge. This "tunable" pore can expand to allow the release of massive pro-apoptotic factors like cytochrome c and Smac/DIABLO.
The Permeability Transition Pore (mPTP)
Distinct from the specific BAX pore is the mPTP, a catastrophic non-selective channel that opens under conditions of calcium overload and oxidative stress (e.g., ischemia-reperfusion). The molecular identity of the mPTP remains a major controversy. While dimers of F-ATP synthase were strongly proposed as the pore-forming unit, a pivotal 2023 study demonstrated that deletion of ATP synthase subunits actually sensitized cells to pore opening, suggesting ATP synthase may regulate the pore but is not the pore itself. The search for the definitive pore component continues, with Cyclophilin D remaining the only confirmed regulatory target.
Pathological Landscapes: From Rare Diseases to Aging
Leber's Hereditary Optic Neuropathy (LHON)
LHON serves as a paradigm for mitochondrial disease. It is caused by point mutations in Complex I subunits (most commonly m.11778G>A in MT-ND4). The pathology is highly specific: the selective death of Retinal Ganglion Cells (RGCs). RGCs are uniquely vulnerable due to the high energy requirements of their unmyelinated intra-retinal axons. The mutation lowers the threshold for apoptosis in these cells, leading to sudden, profound central vision loss.
MELAS Syndrome
MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes) is primarily caused by the m.3243A>G mutation in the mitochondrial tRNA-Leu gene. Mechanistically, this mutation prevents the "taurinomethyluridine" modification at the wobble position of the tRNA. This defect causes stalling of mitochondrial translation, particularly of Complex I subunits, leading to a severe energy deficit that manifests as stroke-like episodes in the metabolically demanding brain tissue.
Therapeutic Horizons: Engineering the Future
The distinct biology of mitochondria requires novel therapeutic modalities.
Mitochondrial Replacement Therapy (MRT)
MRT (Three-Parent Babies) involves transferring the nuclear DNA from a mother with mtDNA disease into a donor egg with healthy mitochondria. While promising, the phenomenon of reversion remains a critical challenge. In some cases, trace amounts of maternal mutant mtDNA carried over during the procedure can paradoxically outcompete the donor mtDNA and repopulate the embryo. This may be due to haplotype-specific replicative advantages (e.g., specific D-loop sequences that recruit Pol gamma more efficiently).
Mitochondrial Transplantation
A more direct intervention is the transplantation of exogenous mitochondria into damaged tissues. This approach is currently in clinical trials for acute ischemic stroke (NCT04998357). Autologous mitochondria are isolated from the patient's muscle and infused into the cerebral arteries. The mechanism relies on the natural ability of cells to internalize mitochondria via macropinocytosis. A 2025 breakthrough in stem cell culture has enabled the mass production of human mitochondria (854-fold yield increase), utilizing a "mito-condition" media that shifts cellular metabolism toward biogenesis, potentially solving the supply chain issue for this therapy.
Small Molecule Therapies
Substrate enhancement therapies are gaining regulatory traction. Doxecitine and Doxribtimine are under FDA review (as of 2025) for TK2 deficiency. These compounds bypass the enzymatic defect to restore the dNTP pools required for mtDNA replication, offering the first targeted pharmaceutical cure for a primary mitochondrial DNA depletion syndrome.
My Final Thought
The mitochondrion has transcended its role as a mere power plant to become recognized as the central processing unit of the eukaryotic cell. It is a structurally dynamic, genetically independent, and functionally integrated organelle that governs the decisions of life and death. From the physics of its fission machinery to the atomic details of its proton pumps, our understanding of the mitochondrion is becoming increasingly granular.
As we move into 2025, the field is shifting from observation to engineering. We are no longer just cataloging mutations; we are replacing genomes, transplanting organelles, and tuning the physics of membrane dynamics. The challenges of heteroplasmy and reversion remind us of the complexity of this ancient endosymbiont, but the rapid progress in therapeutics suggests that we are entering a new era of mitochondrial medicine, where the power of the cell can be restored, replaced, or reprogrammed.
Research Links Scientific Frontline:
Mitochondrial activation in transplanted cells promotes regenerative therapy for heart healing
New type of DNA damage found in our cells’ powerhouses
How heart failure disrupts the cell’s powerhouse
Study untangles mitochondria to reap rewards of exercise
Reference Number: wi112225_01
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