MOTS-c in Sepsis-Induced Cardiomyopathy: Evidence Review (August 2026)
Answer first: the August 23, 2026 European Journal of Pharmacology review concludes that MOTS-c is biologically plausible but insufficiently validated for sepsis-induced cardiomyopathy (SICM).[1] It is a review, not a clinical trial. The direct disease-specific evidence comes from LPS-based mouse and cell experiments, and there is no human treatment evidence for MOTS-c in SICM.[1][2][3]
The review is useful because it does not treat every reported MOTS-c effect as direct SICM evidence. It separates two disease-relevant preclinical programs from mechanisms inferred mainly from other cardiovascular, metabolic, inflammatory, or stress models.[1] That distinction should govern how the literature is read: a pathway can be plausible without being validated as a drug target, biomarker, or treatment in septic patients.
The review is indexed as PMID 42633878 and DOI 10.1016/j.ejphar.2026.179261.[1]
What the 2026 review actually concluded
The authors describe SICM as involving inflammatory dysregulation, mitochondrial dysfunction, disturbed metabolism, and changes in the myocardial microenvironment.[1] MOTS-c intersects with several of those processes through AMPK-linked energy regulation, antioxidant responses, inflammatory restraint, endothelial protection, and mitochondrial quality control.[1]
Their conclusion is deliberately qualified. Direct SICM-specific evidence is limited, while proposed mechanisms such as stress-responsive nuclear signaling were established mainly outside SICM.[1] The paper identifies biomarker specificity, efficacy when treatment begins after disease onset, target-cell mechanisms, and septic-state pharmacokinetics or biodistribution as unresolved translation questions.[1]
That makes the review a map of hypotheses and evidence gaps—not confirmation that MOTS-c prevents or reverses human cardiac dysfunction during sepsis.
SICM background in one minute
Sepsis-induced cardiomyopathy is acute cardiac dysfunction arising in the setting of sepsis. The phenotype is heterogeneous: myocardial depression can coexist with altered loading conditions, vasoplegia, microvascular injury, inflammation, mitochondrial stress, and injury-marker changes. This complexity makes model choice important. An LPS challenge reproduces selected endotoxin-driven inflammatory and metabolic features, but it is not the same as a living polymicrobial infection, evolving organ failure, source control, fluids, vasopressors, antimicrobials, and other clinical exposures.
The direct MOTS-c literature examines two connected but different compartments:
- cardiomyocytes and whole-heart function, emphasizing AMPK-linked metabolism, oxidative stress, inflammation, and apoptosis[2]
- cardiac microvascular endothelial cells, emphasizing mitochondrial DNA injury, cytoskeletal barrier integrity, and microvascular homeostasis[3]
Neither program enrolled people, modeled the full clinical syndrome, or established treatment after SICM was already present.[2][3]
Direct SICM evidence: two preclinical programs
| Study | Model and timing | Main endpoints | What it supports | Key limitations |
|---|---|---|---|---|
| 2023 cardiomyocyte/mouse program, PMID 36786072[2] | Wild-type mice received LPS; MOTS-c was given 6 hours before LPS, with assessment 12 hours after LPS. H9c2 rat cardiomyoblasts were exposed to LPS for 24 hours with experimental MOTS-c treatment.[2] | Echocardiography; serum TnT, CK-MB, and TNF-alpha; cardiac cytokine transcripts; histology; mitochondrial membrane potential; ATP, ROS, apoptosis; AMPK, AKT, ERK, JNK, and STAT3 signaling.[2] | MOTS-c-associated protection across cardiac-function, injury, inflammatory, mitochondrial, oxidative, and apoptotic readouts; compound C weakened selected cell effects, supporting AMPK involvement.[2] | Prophylactic mouse design; acute LPS rather than polymicrobial sepsis; H9c2 cells are not adult human cardiomyocytes; no exposure-response, PK, biodistribution, blinded clinical-style treatment allocation, or post-onset rescue test reported.[2] |
| 2024 endothelial/microvascular program, PMID 38389837[3] | Endotoxemia in endothelial DNA-PKcs knockout and control mice, assessed 72 hours after LPS. Exogenous MOTS-c was given daily for 7 days before LPS. Human coronary artery endothelial cells received MOTS-c 24 hours before LPS.[3] | Microvascular erythrocyte aggregation and fibrin; neutrophil recruitment; serum TnT, CK-MB, LDH, and BNP; echocardiography and survival time; permeability and transendothelial resistance; mitochondrial fission and mtDNA breaks; JNK, profilin-S173, F-actin, and lamellipodia.[3] | A mechanistic chain connecting endothelial DNA-PKcs activity to mitochondrial fission, lower MOTS-c, JNK/profilin signaling, actin disruption, and barrier injury; genetic and pharmacological perturbations strengthen causality within the models.[3] | Pretreatment-heavy design; LPS endotoxemia; mixed genetic, inhibitor, supplementation, and cell-line evidence; no established-infection treatment test, human SICM cohort, cell-specific human exposure measurement, or clinical efficacy evidence.[3] |
These are not two replications of one experiment. The 2023 study focuses more directly on cardiomyocyte injury and ventricular function, while the 2024 study expands the disease model toward the endothelial microenvironment.[2][3]
AMPK-linked metabolic, oxidative, and apoptotic pathway
The 2023 program reported that MOTS-c exposure accompanied higher AMPK activation and improved multiple stress readouts after LPS.[2] In H9c2 cells, the AMPK inhibitor compound C abolished selected favorable effects on inflammatory transcripts and ROS, which is stronger than a simple correlation.[2]
The proposed sequence is:
The diagram summarizes the experimental interpretation, not a proven human pathway. Compound C can support AMPK dependence in a cell model, but it does not prove that AMPK is the only target, that adult human cardiomyocytes respond identically, or that systemic exposure can engage the pathway during clinical sepsis.[2]
For broader pathway context, see the AMPK pathway guide and mitochondrial biogenesis overview. Those pages explain the biology but are not additional SICM efficacy evidence.
DNA-PKcs, mitochondrial fission, MOTS-c, JNK, profilin, and the endothelial barrier
The 2024 program proposes a more specific endothelial chain. LPS increased DNA-PKcs activity in cardiac microvascular endothelial cells.[3] Genetic deletion or pharmacological inhibition of endothelial DNA-PKcs reduced microvascular injury in the reported models.[3]
Mechanistically, DNA-PKcs promoted pathological mitochondrial fission and mitochondrial DNA breaks, which the authors connected to suppressed MOTS-c transcription.[3] Lower MOTS-c removed restraint on JNK; JNK then phosphorylated profilin at serine 173, with F-actin depolymerization, lamellipodial degradation, and impaired endothelial-barrier function downstream.[3]
The perturbation package is the study’s strength. Inhibiting MOTS-c weakened the protection associated with DNA-PKcs deletion, while exogenous MOTS-c, JNK inhibition, and a phosphorylation-defective profilin mutant each tested links in the chain.[3] The result is mechanistically richer than an association between peptide concentration and cardiac injury.
Its translational weakness is timing. Exogenous MOTS-c preceded LPS by seven days in mice and 24 hours in endothelial cells.[3] The data therefore show prevention under controlled exposure, not restoration of a failing microvasculature after sepsis is established.
Direct versus extrapolated mechanisms
| Mechanism or claim | Evidence classification for SICM | Why |
|---|---|---|
| AMPK-linked changes in inflammation, ROS, mitochondrial function, apoptosis, and cardiac readouts | Direct preclinical SICM evidence | Tested in an LPS mouse/H9c2 program, including compound C perturbation.[2] |
| Endothelial DNA-PKcs to mitochondrial fission and mtDNA breaks to lower MOTS-c | Direct preclinical endotoxemia/microvascular evidence | Tested with endothelial genetic deletion, pharmacological inhibition, and mitochondrial assays.[3] |
| MOTS-c to JNK restraint to profilin/F-actin/lamellipodia and barrier integrity | Direct preclinical endothelial evidence | Tested in LPS-exposed endothelial systems with pathway and mutant perturbations.[3] |
| Stress-responsive nuclear translocation and transcriptional regulation | Extrapolated to SICM | The 2026 review notes that this mechanism is established primarily in non-SICM settings.[1] |
| General metabolic, antioxidant, anti-inflammatory, or mitochondrial-quality-control effects | Biologically supportive, mostly extrapolated | These processes fit SICM biology, but disease-specific target and timing validation remains limited.[1] |
| Human diagnostic biomarker or treatment response | Not established | No validated SICM assay or human intervention evidence exists.[1] |
This table prevents a common category error: evidence that MOTS-c can influence a stress pathway somewhere is not automatically direct evidence that the same pathway controls human SICM.
Biomarker limits: association would not equal specificity
The review discusses MOTS-c as an exploratory stress-related adjunctive biomarker, not a validated diagnostic marker.[1] Current evidence does not establish:
- an assay-specific reference range or SICM threshold
- molecular specificity for intact MOTS-c versus related or degraded material
- sensitivity, specificity, calibration, or prospective diagnostic accuracy
- independence from age, metabolic state, exercise, renal function, sepsis severity, medication, or other mitochondrial stress
- whether blood values represent cardiomyocyte, endothelial, immune-cell, or other tissue biology
- whether serial change predicts recovery, treatment response, or a patient outcome
A useful clinical biomarker study would need prespecified SICM criteria, matched septic controls without cardiac dysfunction, non-septic cardiac controls, serial sampling, orthogonal assay validation, and blinded outcome analysis. The LC-MS peptide quantification guide explains why molecular identity, recovery, matrix effects, and lower limits of quantification matter before a peptide signal is interpreted biologically.
Translation blockers that remain
- Prevention dominates the direct evidence. Six-hour, seven-day, and 24-hour pretreatment designs do not establish efficacy after hemodynamic or myocardial dysfunction begins.[2][3]
- LPS is not polymicrobial sepsis. Endotoxemia is experimentally controlled but cannot reproduce pathogen burden, source control, evolving immune phases, or the clinical treatment environment.
- Post-onset efficacy is unknown. No direct program has randomized only after a prespecified SICM phenotype appeared.[1][2][3]
- PK and biodistribution are unresolved. Intact-peptide exposure in plasma, heart, cardiac microvasculature, cardiomyocytes, kidney, and liver during septic physiology has not been mapped.[1]
- Target-cell specificity is uncertain. Cardiomyocyte, endothelial, immune, and systemic metabolic effects may require different exposures and may not move together.[1][2][3]
- Assay specificity needs work. Endogenous MOTS-c measurements need orthogonal confirmation, standards, recovery data, and controls for mitochondrial sequence or peptide cross-reactivity.
- Human dosing, safety, and efficacy for SICM do not exist. A current ClinicalTrials.gov check found one recruiting interventional study that directly administers MOTS-c, NCT07505745, but it is a Phase 2 study in adults with prediabetes and overweight or obesity—not sepsis or cardiomyopathy.[4] It should not be presented as a SICM clinical program.
The peptide pharmacokinetics and bioavailability guide provides the relevant framework for separating an experimental concentration from intact target-tissue exposure.
The next experiments that would materially change confidence
1. Test treatment after a defined SICM phenotype
Use a polymicrobial model such as cecal ligation and puncture alongside LPS, then randomize only after prespecified echocardiographic, hemodynamic, or injury criteria are met. Include standard sepsis care, blinded outcome assessment, both sexes, survival, organ injury, pathogen burden, and safety endpoints.
2. Build an exposure-to-target map
Measure intact MOTS-c and degradation products with a validated LC-MS method in plasma and relevant tissues over time. Pair exposure with AMPK engagement in cardiomyocytes and DNA-PKcs/JNK/profilin engagement in endothelial cells rather than assuming one systemic concentration proves both mechanisms.
3. Separate the cellular compartments
Use adult primary cardiomyocytes, cardiac microvascular endothelial cells, immune cells, and cell-specific genetic perturbations. Test whether protection in one compartment persists when signaling is disabled in another.
4. Replicate the two direct pathways independently
Confirm the 2023 AMPK dependency with orthogonal genetic approaches rather than only compound C.[2] Reproduce the 2024 DNA-PKcs–mitochondrial-fission–MOTS-c–JNK–profilin sequence with independent laboratories, biological replicates, prespecified analyses, and direct peptide quantification.[3]
5. Design the biomarker study before choosing a cutoff
Prospectively enroll septic patients with and without rigorously adjudicated cardiac dysfunction. Lock the assay, sampling schedule, confounder plan, and diagnostic-performance analysis before examining thresholds.
6. Require a full translational package before human SICM testing
A credible program would need septic-state PK, biodistribution, toxicology, immunogenicity, formulation stability, exposure margins, interaction assessment with standard care, and a rationale for starting time and target engagement. None can be inferred from protective pretreatment in mice.
Bottom line
The August 2026 review identifies MOTS-c as a coherent SICM research hypothesis, not a validated therapy or biomarker.[1] Two direct preclinical programs support complementary mechanisms: an AMPK-linked cardiomyocyte/whole-heart pathway and a DNA-PKcs–mitochondrial-fission–MOTS-c–JNK–profilin endothelial-barrier pathway.[2][3]
The same studies also define the central weakness: both relied heavily on pretreatment and LPS-based models.[2][3] There is no demonstrated post-onset rescue, no septic-state PK or biodistribution package, no validated SICM biomarker, and no human dosing, safety, or efficacy evidence.[1][4]
The correct August 2026 conclusion is therefore biologically plausible, directly supported at selected preclinical steps, and still insufficiently validated for clinical translation.[1]
This guide is for scientific education only. It does not provide medical advice, treatment, dosing, or sourcing guidance.
Sources
[1] https://doi.org/10.1016/j.ejphar.2026.179261 — MOTS-c in sepsis-induced cardiomyopathy: Mechanisms and translational potential (PMID 42633878)
“Overall, MOTS-c represents a plausible but insufficiently validated molecule in SICM research, and its translational relevance will depend on disease-specific mechanistic and pharmacological validation.”
[2] https://pmc.ncbi.nlm.nih.gov/articles/PMC10157545/ — The protective effect of the mitochondrial-derived peptide MOTS-c on LPS-induced septic cardiomyopathy (PMID 36786072; DOI 10.3724/abbs.2023006)
“For the MOTS-c group, mice were intraperitoneally injected with 15 mg/kg of MOTS-c 6 h before LPS injection.”
“However, treatment with the AMPK pathway inhibitor compound C (CC) abolishes the positive effect of MOTS-c on LPS stress.”
[3] https://pmc.ncbi.nlm.nih.gov/articles/PMC10879869/ — DNA-PKcs, MOTS-c/JNK, profilin, and endotoxemia-induced myocardial microvascular injury (PMID 38389837; DOI 10.7150/thno.92650)
“MOTS-c (15 mg/kg) was administered daily via intraperitoneal injection for seven days before the mice were subjected to lipopolysaccharide-induced endotoxemia.”
“MOTS-c downregulation disinhibited c-Jun N-terminal kinase (JNK), allowing JNK to phosphorylate profilin-S173.”
[4] https://clinicaltrials.gov/study/NCT07505745 — MOTS-c for improving insulin sensitivity in adults with prediabetes and overweight/obesity
“MOTS-c for Improving Insulin Sensitivity in Adults With Prediabetes and Overweight/Obesity”
Related Research
- MOTS-c Research Guide - compound-level biology, proposed mechanisms, and research status
- MOTS-c Animal vs Human Evidence - evidence hierarchy across preclinical and human observations
- MOTS-c as a Host Defense Peptide - separate 2026 antibacterial and macrophage research; complementary to this SICM review
- AMPK Pathway - energy-sensing pathway context for the cardiomyocyte program
- Mitochondrial Biogenesis - mitochondrial stress and adaptation context
- LC-MS Peptide Quantification - analytical identity, recovery, matrix effects, and exposure measurement
- Peptide Pharmacokinetics and Bioavailability - why assay concentration and target-tissue exposure differ