Key Points: This study reports the first documented case of myofilament loss in gastrointestinal smooth muscle cells in MELAS-associated chronic intestinal pseudo-obstruction (CIPO). Electron microscopic analysis demonstrated marked reduction of myofilaments accompanied by abundant abnormal mitochondria throughout the digestive tract, revealing that mitochondrial dysfunction may directly impair the smooth muscle contractile apparatus independent of previously described enteric nervous system abnormalities. These findings suggest that apparent superior mesenteric artery syndrome in MELAS patients may represent underlying CIPO with inherent intestinal structural vulnerability, supporting early implementation of enteral nutrition strategies that bypass affected gastrointestinal segments. Future research should focus on quantitative assessment of contractile protein abnormalities and development of therapeutic interventions targeting smooth muscle function in mitochondrial disorders.

🆕🔥Loss of #Myofilaments in gastrointestinal smooth muscle represents a novel pathological mechanism in MELAS-associated chronic intestinal Pseudo-obstruction #CIPO‼️
🎯 #Mitochondrial dysfunction directly impairs smooth muscle contractile apparatus
👉 onlinelibrary.wiley.com/doi/10.1111/...
#ANMS #ESNM

A primer on the methods of skeletal and cardiac muscle mechanics using permeabilized preparations. New review from Anthony Hessel @hesselanthony.bsky.social, Christopher Rand @crand22.bsky.social, Khoi Nguyen and colleagues: rupress.org/jgp/article/...

#Myofilaments #SkeletalMuscle #CardiacMuscle

Review @jgp.org: @hesselanthony.bsky.social @crand22.bsky.social, Nguyen et al. provide useful tips and tricks for all those beginning their journey into permeabilized muscle fiber mechanics. rupress.org/jgp/article/...

#Myofilaments #SkeletalMuscle #CardiacMuscle

Review: @hesselanthony.bsky.social @crand22.bsky.social, Nguyen et al. provide useful tips and tricks for all those beginning their journey into permeabilized muscle fiber mechanics. rupress.org/jgp/article/...

#Myofilaments #SkeletalMuscle #CardiacMuscle

Myosin-binding protein H-like nonsense variants exhibit impaired sarcomere incorporation and alter contractility, say Alejandro Alvarez-Arce, David Barefield @barefieldlab.bsky.social and colleagues @loyolachicago.bsky.social: rupress.org/jgp/article/...

#Myofilaments #CardiacMuscle

New study from Alvarez-Arce et al. @barefieldlab.bsky.social shows that premature stop variants in myosin-binding protein H-like prevent sarcomere incorporation of the translated protein regardless of the location of the premature stop along the protein. rupress.org/jgp/article/...

#Myofilaments

Resolving zone-specific regulation of cardiac #myosin. Shane Nelson @uvmvermont.bsky.social provides commentary on work from Pilagov et al. (rupress.org/jgp/article/...) that explores role of MyBP-C in regulation of the myosin SRX state in cardiac muscle. rupress.org/jgp/article/...

#Myofilaments

GSK3β-driven phosphorylation of ABLIM1 regulates its interactions with titin cardiac muscle, say Bin Sun, Alec Loftus, Peter Kekenes-Huskey and colleagues @loyolachicago.bsky.social: rupress.org/jgp/article/...

#Myofilaments #Biophysics #ComputationalBiology #MolecularPhysiology

Latest in @jgp.org Research News: study from Woods, Swank, and Miller (rupress.org/jgp/article/...) suggests that stretch activation of fast-contracting skeletal muscle fibers might increase muscle endurance by boosting force production during fatigue. rupress.org/jgp/article/...

#Myofilaments

Latest in Research News: study from Woods, Swank, and Miller (rupress.org/jgp/article/...) suggests that stretch activation of fast-contracting skeletal muscle fibers might increase muscle endurance by boosting force production during fatigue. rupress.org/jgp/article/...

#Myofilaments

Stretch activation combats force loss from fatigue in fast-contracting mouse skeletal muscle fibers, say Philip Woods, Douglas Swank, and Mark Miller @umassamherst.bsky.social: rupress.org/jgp/article/...

#SkeletalMuscle #Myofilaments

Spatially resolving how cMyBP-C phosphorylation and haploinsufficiency in porcine and human myofibrils affects ß-cardiac myosin activity, say Matvey Pilagov, Sonette Steczina, Ateeqa Naim, Neil Kad and colleagues @kent.ac.uk: rupress.org/jgp/article/...

#Myofilaments #CardiacMuscle

Trouble in store for muscle fibers. Our latest Research news highlights a new study (doi.org/10.1085/jgp....) from @seongwonhan.bsky.social, Granzier and colleagues: rupress.org/jgp/article/...

#Myofilaments #Titin

Glycerol storage increases passive stiffness of muscle fibers through effects on titin extensibility, say Seong-Won Han (@seongwonhan.bsky.social), Henk Granzier and colleagues @uarizona.bsky.social: rupress.org/jgp/article/...

#Myofilaments #SkeletalMuscle

Myosin binding protein-C modulates loaded sarcomere shortening in rodent permeabilized cardiac myocytes, say Kerry McDonald and colleagues: rupress.org/jgp/article/...

#CardiacMuscle #Myofilaments #Contraction #CellMotility #Biophysics

Regulation of loaded sarcomere shortening: McDonald et al. @Mizzou show that cardiac myosin binding protein-C regulates sarcomere-loaded shortening, especially at high loads, seemingly, by modulating cross-bridge availability rupress.org/jgp/article/...

#CardiacMuscle #Myofilaments

Marfan-syndrome cardiomyocytes show excess of #titin isoform N2BA and extended sarcomeric M-band, say Dalma Kellermayer, Cristina Șulea, Miklós Kellermayer, Balázs Kiss and colleagues: rupress.org/jgp/article/...

#CardiacMuscle #Contraction #Myofilaments

New review: Structural and functional insights into α-actinin isoforms and their implications in cardiovascular disease. From Maya Noureddine, Fiyaz Mohammed and colleagues: https://buff.ly/4jKxZtj

#ComputationalBiology #ProteinStructure #CardiacMuscle #Myofilaments