NLRP3 Inflammasome and Physical Therapy in ICU-Acquired Weakness

Official title

Effect of Physical Therapy on NLRP3 Inflammasome Activation and Muscle Atrophy in Critical Illness Myopathy (PT-NLRP3-CIM).

Overview

The goal of this clinical trial is to study whether physical therapy can reduce NLRP3 inflammasome activation and muscle atrophy in patients with critical illness myopathy (CIM). It will also explore the role of NLRP3 inflammasome in the pathophysiology of CIM. The main questions this study aims to answer are: Is NLRP3 inflammasome activation associated with muscle atrophy through the upregulation of atrogenes? Does physical therapy attenuate NLRP3 inflammasome activation in skeletal muscle, thereby contributing to the prevention or reduction of muscle atrophy in CIM? Researchers will compare enhanced physical therapy using servo-assisted bed cycling (Motomed Letto®) in critically ill patients at risk of developing CIM during the early phase of ICU stay to conventional physical therapy (standard physiotherapy), to assess whether physical therapy reduces NLRP3 inflammasome activation and muscle degradation. Participants will: Be randomized to receive either conventional physical therapy or enhanced physical therapy (Motomed Letto®) for 7 consecutive days. A control group of patients without CIM will also be included. Undergo assessments of NLRP3 activity, muscle atrophy markers, and transcriptomic profiles from serum and vastus lateralis muscle biopsies. Be clinically evaluated using the SOFA scale and muscle ultrasound for CIM diagnosis. Be followed up for changes in muscle strength and physical functionality. Provide sociodemographic and clinical information to be recorded throughout the study.

Detailed description

Critical illness myopathy (CIM) is a frequent complication in patients admitted to intensive care units (ICUs), characterized by symmetric proximal muscle weakness and respiratory muscle involvement. It has been linked to increased mortality, prolonged hospital stays, and long-term physical disability. CIM may also contribute to post-intensive care syndrome (PICS), which includes persistent cognitive, psychological, and physical impairments. In Chile, approximately 40% of patients with critical illness due to COVID-19 developed this syndrome.

Although several molecular mechanisms have been proposed, the precise etiopathogenesis of CIM remains unclear. Muscle atrophy and contractile dysfunction are hallmark features of CIM. The ubiquitin-proteasome system (UPS) and the upregulation of atrogenes such as MuRF1 and Atrogin-1 have been implicated in its development. In murine models of denervation and sepsis, the NLRP3 inflammasome-a multiprotein complex involved in innate immunity and IL-1β/IL-18 secretion-has been shown to promote muscle atrophy via activation of atrophy-related genes.

Evidence suggests that physical therapy can modulate inflammation at the skeletal muscle level, including downregulation of NLRP3 inflammasome components and IL-1β expression. Mechanical silencing, a major modifiable risk factor in CIM, can be mitigated by early mobilization strategies. However, it remains unknown whether physical therapy directly reduces NLRP3 inflammasome activation and associated muscle atrophy in patients with CIM.

This clinical trial is designed to test the hypothesis that physical therapy decreases NLRP3 inflammasome activity and reduces skeletal muscle atrophy in critically ill patients with CIM. In the early stage of ICU admission, sixteen patients at risk of CIM will be randomized to receive either conventional physical therapy or an enhanced protocol that includes servo-assisted motorized movement therapy (Motomed Letto®), twice daily for 60 minutes. In addition, eight patients without CIM will serve as non-CIM controls.

Muscle biopsy samples from the vastus lateralis will be analyzed to assess histological evidence of muscle atrophy, structural alterations in cellular organelles, and expression of atrophy-related genes. Quantitative real-time PCR (RT-qPCR) will be used to measure mRNA levels of atrogenes, and Western blot will assess protein expression of key mediators of NLRP3 inflammasome signaling. Transcriptomic analysis will be conducted using microarray profiling.

This study will address the following specific aims:

To evaluate the effect of physical therapy on NLRP3 inflammasome activation in skeletal muscle and compare it with non-CIM controls.

To assess the impact of physical therapy on muscle atrophy and explore its relationship with inflammasome activation.

To characterize the gene expression profile of signaling pathways involved in muscle degradation in CIM patients.

To analyze the association between molecular alterations in skeletal muscle and the clinical/ultrasound diagnosis of CIM.

It is expected that enhanced physical therapy will reduce NLRP3 inflammasome activity, attenuate muscle atrophy, and modify gene expression profiles involved in the progression of CIM. These molecular findings are anticipated to correlate with clinical assessments of muscle strength and ultrasound-based diagnosis, supporting the role of early mobilization as a non-pharmacological intervention in the management and prevention of CIM.

Interventions

• Device Motomed Letto® servo-assisted cycling + standard physiotherapy
  Servo-assisted cycling using the Motomed Letto® device with a cadence target of 30 revolutions per minute (rpm), performed for 60 minutes twice daily for 7 days. This intervention is administered in addition to standard ICU physiotherapy to critically ill patients at risk of critical illness myopathy (CIM).
• Behavioral Standard physiotherapy
  Standard physiotherapy including mobilization and passive/active range-of-motion exercises, delivered during routine ICU care for 7 days.

Primary outcome measures

• Relative mRNA expression of NLRP3, IL-1β, and IL-18 in muscle tissue (RT-qPCR) [Time frame: Baseline and Day 7 (on the final day of intervention)]
• Protein expression of phospho-p65S536 and total p65 (Western blot) [Time frame: Baseline and Day 7 (on the final day of intervention)]
• Ratio of cleaved/uncleaved caspase-1, IL-1β, and GSDMD-NT (Western blot) [Time frame: Baseline and Day 7 (on the final day of intervention)]
• Plasma concentrations of IL-1β and IL-18 (ELISA) [Time frame: Baseline and Day 7 (on the final day of intervention)]
• Expression of oxidative stress markers and cathepsin B (Western blot) [Time frame: Baseline and Day 7 (on the final day of intervention)]
• Expression of cathepsin B (RT-qPCR) [Time frame: Baseline and Day 7 (on the final day of intervention)]
• Ultrastructural mitochondrial damage and lysosomal vacuolization (TEM) [Time frame: Baseline and Day 7 (on the final day of intervention)]
• Muscle fiber diameter (immunofluorescence) [Time frame: Baseline and Day 7 (on the final day of intervention)]
• mRNA expression of atrogenes: MuRF1, Atrogin-1, MUSA1, TRIM62, TRIM32 [Time frame: Baseline and Day 7 (on the final day of intervention)]
• Myosin/actin ratio (Western blot) [Time frame: Baseline and Day 7 (on the final day of intervention)]

Secondary outcome measures (2)

• Differential expression of genes related to atrophy and inflammasome activation (microarray or nanopore-based RNA sequencing ) [Time frame: Baseline (prior to intervention) and Day 7 of intervention]
• Correlation between molecular findings and CIM clinical diagnosis [Time frame: From recovery of consciousness (in ICU or follow-up) through 90-day follow-up]

Eligibility criteria

Inclusion criteria

• Medical diagnosis of sepsis upon ICU admission.
• Receiving invasive mechanical ventilation with a projected requirement ≥7 days.
• SOFA score ≥8 for three consecutive days within the first five days of ICU admission.

Exclusion criteria

• Neurocritical illness.
• Prior malnutrition or cachexia.
• Pre-existing neuromuscular disease.
• Coagulopathy (severe liver disease or continuous dialysis).
• Thrombocytopenia <20,000 platelets/μL.
• Prior Clinical Frailty Scale ≥4.
• Lower limb amputation or fractures.
• Ongoing chemotherapy.
• Pregnancy.
• BMI >35.
• Uncontrolled epilepsy.
• Allergy to ultrasound gel.
• Prior prolonged corticosteroid therapy.
• Expected ICU stay <7 days.
• Imminent death.
• Legal guardian refusal to provide informed consent.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Basic science

Study locations

Chile · 3 centers

• Clínica INDISA — Santiago
• Hospital de Urgencia Asistencia Pública (HUAP) — Santiago
• University of Chile — Santiago

Publications

• Americo-Da-Silva L, Aguilera J, Quinteros-Waltemath O, Sanchez-Aguilera P, Russell J, Cadagan C, Meneses-Valdes R, Sanchez G, Estrada M, Jorquera G, Barrientos G, Llanos P. Activation of the NLRP3 Inflammasome Increases the IL-1beta Level and Decreases GLUT4 Translocation in Skeletal Muscle during Insulin Resistance. Int J Mol Sci. 2021 Sep 23;22(19):10212. doi: 10.3390/ijms221910212. PMID 34638553
• Neves M Jr, Barreto G, Boobis L, Harris R, Roschel H, Tricoli V, Ugrinowitsch C, Negrao C, Gualano B. Incidence of adverse events associated with percutaneous muscular biopsy among healthy and diseased subjects. Scand J Med Sci Sports. 2012 Apr;22(2):175-8. doi: 10.1111/j.1600-0838.2010.01264.x. Epub 2011 Mar 10. PMID 21392121
• Raithatha A, Ashraghi MR, Lord C, Limback-Stanic C, Viegas S, Amiras D. Ultrasound-guided muscle biopsy: a practical alternative for investigation of myopathy. Skeletal Radiol. 2020 Nov;49(11):1855-1859. doi: 10.1007/s00256-020-03484-y. Epub 2020 Jun 9. PMID 32519182
• Kho ME, Molloy AJ, Clarke F, Herridge MS, Koo KK, Rudkowski J, Seely AJ, Pellizzari JR, Tarride JE, Mourtzakis M, Karachi T, Cook DJ; Canadian Critical Care Trials Group. CYCLE pilot: a protocol for a pilot randomised study of early cycle ergometry versus routine physiotherapy in mechanically ventilated patients. BMJ Open. 2016 Apr 8;6(4):e011659. doi: 10.1136/bmjopen-2016-011659. PMID 27059469
• Moisi L, Mino JC, Guidet B, Vallet H. Frailty assessment in critically ill older adults: a narrative review. Ann Intensive Care. 2024 Jun 18;14(1):93. doi: 10.1186/s13613-024-01315-0. PMID 38888743
• Mahoney DJ, Carey K, Fu MH, Snow R, Cameron-Smith D, Parise G, Tarnopolsky MA. Real-time RT-PCR analysis of housekeeping genes in human skeletal muscle following acute exercise. Physiol Genomics. 2004 Jul 8;18(2):226-31. doi: 10.1152/physiolgenomics.00067.2004. PMID 15161965
• Gonzalez-Seguel F, Camus-Molina A, Carcamo M, Hiser S, Needham DM, Leppe J. Inter-observer reliability of trained physiotherapists on the Functional Status Score for the Intensive Care Unit Chilean-Spanish version. Physiother Theory Pract. 2022 Feb;38(2):365-371. doi: 10.1080/09593985.2020.1753272. Epub 2020 Apr 22. PMID 32316800
• Pardo E, El Behi H, Boizeau P, Verdonk F, Alberti C, Lescot T. Reliability of ultrasound measurements of quadriceps muscle thickness in critically ill patients. BMC Anesthesiol. 2018 Dec 27;18(1):205. doi: 10.1186/s12871-018-0647-9. PMID 30591032

Identifiers

NCT: NCT07017517 · 001-2025

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗