Title:The Enigmas of Lymphatic Muscle Cells: Where Do They Come From,
How Are They Maintained, and Can They Regenerate?
Volume: 19
Issue: 3
Author(s): H. Mark Kenney, Yue Peng, Karen L. de Mesy Bentley, Lianping Xing, Christopher T. Ritchlin and Edward M. Schwarz*
Affiliation:
- Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Ave, Box 665, Rochester, NY, 14642, USA
- Department of Pathology & Laboratory Medicine, University of Rochester Medical Center, Rochester,
NY, USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY, USA
- Department
of Medicine, Division of Allergy, Immunology, Rheumatology, University of Rochester Medical Center, Rochester, NY,
USA
Keywords:
Lymphatic muscle cell, smooth muscle, striated muscle, contractility, development, cell recruitment, regeneration, lymphangiogenesis.
Abstract: Lymphatic muscle cell (LMC) contractility and coverage of collecting lymphatic vessels
(CLVs) are integral to effective lymphatic drainage and tissue homeostasis. In fact, defects in lymphatic
contractility have been identified in various conditions, including rheumatoid arthritis, inflammatory
bowel disease, and obesity. However, the fundamental role of LMCs in these pathologic
processes is limited, primarily due to the difficulty in directly investigating the enigmatic nature
of this poorly characterized cell type. LMCs are a unique cell type that exhibit dual tonic and phasic
contractility with hybrid structural features of both vascular smooth muscle cells (VSMCs) and cardiac
myocytes. While advances have been made in recent years to better understand the biochemistry
and function of LMCs, central questions regarding their origins, investiture into CLVs, and homeostasis
remain unanswered. To summarize these discoveries, unexplained experimental results,
and critical future directions, here we provide a focused review of current knowledge and open
questions related to LMC progenitor cells, recruitment, maintenance, and regeneration. We also
highlight the high-priority research goal of identifying LMC-specific genes towards genetic conditional-
inducible in vivo gain and loss of function studies. While our interest in LMCs has been focused
on understanding lymphatic dysfunction in an arthritic flare, these concepts are integral to the
broader field of lymphatic biology, and have important potential for clinical translation through targeted
therapeutics to control lymphatic contractility and drainage.
