LS-1-P-2273 Human myometrial telocytes: in vitro low-level laser stimulation

Background. Telocytes (TCs) are a brand-new cell type frequently observed in the interstitial space of many organs (see www.telocytes.com). TCs are defined by very long (tens of μm) and thin prolongations named telopodes. Dilations, called podoms (~300 nm) alternate with podomers (80-100 nm). The mechanisms of telopodes’ elongation and ramification is not known.
Methods. TCs were identified in a myometrial interstitial cell culture based on morphological criteria and by CD34 and PDGFRα immunopositivity. We report here the low-level laser stimulation (LLLS) using a 1064 nm Nd:YAG laser, with an output power of 60 mW, of the telopode growth in cell culture. The laser beam was focused through the 100x/1.3 Oil objective.
Results. LLLS of TCs determines a higher growth rate of telopodes in pregnant myometrium primary cultures (10.3 ± 1.0 μm/min) compared to non-pregnant ones (6.6 ± 0.9 μm/min). Acute exposure (30 min) of TCs from pregnant myometrium to 1 μM mibefradil, a selective inhibitor of T-type calcium channels, determines a significant reduction in the LLLS growth rate (5.7 ± 0.8 μm/min) compared to LLLS per se in same type of samples. Meanwhile chronic exposure (24 h) completely abolishes the LLLS telopodes growth in both non-pregnant and pregnant myometrium. The initial direction of telopode growth was modified by LLLS, the angle of deviation being more accentuated in TCs from human pregnant myometrium than in TCs from non-pregnant myometrium.
Conclusion. TCs from pregnant myometrium are more susceptible of reacting to LLLS than those from non-pregnant myometrium. Therefore, some implications are emerging for low level laser therapy in uterine regenerative medicine.