Casper Soendenbroe

Bispebjerg Hospital, Copenhagen University | bispebjerghospital · Institute for Sports Medicine

Exercise preserves neuromuscular function in aging through unknown mechanisms. Skeletal muscle fibroblasts (FIB) and stem cells (MuSC) are abundant in skeletal muscle and reside close to neuromuscular junctions, but their relative roles in motor neuron maintenance remain undescribed. Using direct cocultures of embryonic rat motor neurons with eithe...

Exercise preserves neuromuscular function in ageing through unknown mechanisms. Skeletal muscle fibroblasts (FIB) and stem cells (MuSC) are abundant in skeletal muscle and reside close to neuromuscular junctions, but their relative roles in motor neuron maintenance remain undescribed. Using direct co-cultures of embryonic rat motor neurons with eit...

Background Age‐related loss of strength is disproportionally greater than the loss of mass, suggesting maladaptations in the neuro‐myo‐tendinous system. Myofibers are often misshaped in aged and diseased muscle, but systematic analyses of large sample sets are lacking. Our aim was to investigate myofiber shape in relation to age, exercise, myofiber...

Immunohistochemistry, fluorescent microscopy, and image analysis are key tools for visualizing and analyzing specific proteins in a variety of tissues. Together these techniques are readily available in most laboratories and in an infinite number of variations. Herein, a working example is used relating to the aging human skeletal muscle being char...

Background Age-related loss of strength is disproportionally greater than the loss of mass, suggesting maladaptations in the neuro-myo-tendinous system. Myofibers are often misshaped in aged and diseased muscle, but systematic analyses of large sample sets are lacking. Our aim was to investigate myofiber shape in relation to age, exercise, myofiber...

It has recently been established that myosin, the molecular motor protein, is able to exist in two conformations in relaxed skeletal muscle. These conformations are known as the super-relaxed (SRX) and disordered-relaxed (DRX) states and are finely balanced to optimize ATP consumption and skeletal muscle metabolism. Indeed, SRX myosins are thought...

Skeletal muscle injury in aged rodents is characterized by an asynchronous infiltration of pro-and anti-inflammatory macrophage waves, leading to improper and incomplete regeneration. It is unclear whether this aberration also occurs in aged human muscle. In this study, we quantified the macrophage responses in a human model of muscle damage and re...

It has recently been established that myosin, the molecular motor protein, is able to exist in two conformations in relaxed skeletal muscle. These conformations are known as super-relaxed (SRX) and disordered-relaxed (DRX) states and are finely balanced to optimize skeletal muscle metabo-lism. Indeed, SRX myosins are thought to have a 10-fold reduc...

Genomic instability, telomere attrition, epigenetic alterations, mitochondrial dysfunction, loss of proteostasis, deregulated nutrient-sensing, cellular senescence, stem cell exhaustion, and altered intercellular communication were the original nine hallmarks of ageing proposed by López-Otín and colleagues in 2013. The proposal of these hallmarks o...

Muscle fiber denervation is a major contributor to the decline in muscle mass and function during aging. Heavy resistance exercise is an effective tool for increasing muscle mass and strength, but whether it can rescue denervated muscle fibers remains unclear. Therefore, the purpose of this study was to investigate the potential of heavy resistance...

Skeletal muscle possesses remarkable adaptability to mechanical loading and regenerative potential following muscle injury primarily due to satellite cell activity. Although the roles of several types of interstitial cells in skeletal muscle have been documented, the signaling interplay between the skeletal muscle and the adjacent tendon tissue has...

A human muscle biopsy that was obtained from an elderly individual, has been immunofluorescently stained with dystrophin (magenta) and NCAM/ CD56 (cyan). The extent of muscle fiber denervation can be quantified using this approach. See Soendenbroe et al. pp 1969–1989.

Muscle fibre denervation and declining numbers of muscle stem (satellite) cells are defining characteristics of ageing skeletal muscle. The aim of this study was to investigate the potential for lifelong recreational exercise to offset muscle fibre denervation and compromised satellite cell content and function, both at rest and under challenged co...

Insight into the bidirectional signaling between primary human myogenic cells and neurons is lacking. For this purpose, human myogenic cells were derived from the semitendinosus and gracilis muscles of five healthy individuals and co‐cultured with cerebellar granule neurons from two litters of 7‐day‐old Wistar rat pups, in muscle medium or neural m...

Muscle fiber denervation is a major contributor to the decline in physical function observed with aging. Denervation can occur through breakdown of the NMJ itself, affecting only that particular fiber, or through the death of a motoneuron, which can lead to a loss of all the muscle fibers in that motor unit. In this review we discuss the muscle-ner...

The decline in muscle mass and function with age is partly caused by a loss of muscle fibres through denervation. The purpose of this study was to investigate the potential of exercise to influence molecular targets involved in neuromuscular junction (NMJ) stability in healthy elderly individuals. Participants from two studies (one group of 12 youn...

Blunted muscle hypertrophy and impaired regeneration with aging have been partly attributed to satellite cell (SC) dysfunction. However, true muscle regeneration has not yet been studied in elderly individuals. To investigate this, muscle injury was induced by 200 electrically stimulated (ES) eccentric contractions of the vastus lateralis (VL) of o...

Long-term denervated muscle fibers stained positive for neural cell adhesion molecule (NCAM). For details, see Figure 2 in Soendenbroe et al: Molecular indicators of denervation in aging human skeletal muscle, pages 453–463.

Introduction: Muscle fiber denervation increases with age and yet studies at the tissue level are sparse, due to the challenging nature of establishing the relative role of regeneration and denervation. Methods: Muscle biopsies were obtained from the vastus lateralis of 70 healthy male participants (72±6 yrs, range: 65-94 yrs). mRNA levels of ac...

Age-Related expression of Neonatal and Embryonic Myosin in Human Skeletal Muscle Tissue