ABSTRACT
The function of many organs, including skeletal muscle, depends on their three-dimensional structure. Muscle regeneration therefore requires not only reestablishment of myofibers but also restoration of tissue architecture. Resident muscle stem cells (SCs) are essential for regeneration, but how SCs regenerate muscle architecture is largely unknown. We address this problem using genetic labeling of mouse SCs and whole-mount imaging to reconstruct, in three dimensions, muscle regeneration. Unexpectedly, we found that myofibers form via two distinct phases of fusion and the residual basement membrane of necrotic myofibers is critical for promoting fusion and orienting regenerated myofibers. Furthermore, the centralized myonuclei characteristic of regenerated myofibers are associated with myofibrillogenesis and endure months post injury. Finally, we elucidate two cellular mechanisms for the formation of branched myofibers, a pathology characteristic of diseased muscle. We provide a synthesis of the cellular events of regeneration and show that these differ from those used during development.
Subject(s)
Imaging, Three-Dimensional , Muscle, Skeletal , Regeneration , Animals , Regeneration/physiology , Mice , Muscle, Skeletal/physiology , Imaging, Three-Dimensional/methods , Muscle Fibers, Skeletal/metabolism , Muscle Fibers, Skeletal/cytology , Muscle Development/physiology , Stem Cells/cytology , Stem Cells/metabolism , Basement Membrane/metabolismABSTRACT
INTRODUCTION: Laparoscopic Roux-en-Y gastric bypass (LRYGB) is known to increase risk for calcium oxalate nephrolithiasis due to hyperoxaluria; however, nephrolithiasis rates after laparoscopic sleeve gastrectomy (LSG) are not well described. Our objective was to determine the rate of nephrolithiasis after LRYGB versus LSG. METHODS: The electronic medical records of patients who underwent LRYGB or LSG between 2001 and 2017 were retrospectively reviewed. RESULTS: 1,802 patients were included. Postoperative nephrolithiasis was observed in 133 (7.4%) patients, overall, and 8.12% of LRYGB (122/1503) vs. 3.68% of LSG (11/299) patients (Pâ¯<â¯0.001). Mean time to stone formation was 2.97⯱â¯2.96 years. Patients with a history of UTI (ORâ¯=â¯2.12, 95%CI 1.41-3.18; Pâ¯<â¯0.001) or nephrolithiasis (ORâ¯=â¯8.81, 95%CI 4.93-15.72; Pâ¯<â¯0.001) were more likely to have postoperative nephrolithiasis. CONCLUSION: The overall incidence of symptomatic nephrolithiasis after bariatric surgery was 7.4%. Patients who underwent LRYGB had a higher incidence of nephrolithiasis versus LSG. Patients with a history of stones had the highest risk of postoperative nephrolithiasis.
