Vangl2 participates in the primary ciliary assembly under low fluid shear stress in hUVECs.

The pattern of blood fluid shear stress (FSS) is considered the main factor that affects ciliogenesis in human umbilical vein endothelial cells (hUVECs), the underlying mechanism is unclear. Microfluidic chamber experiments were carried out to load hUVECs with low fluid shear stress (LSS, 0.1 dynes/cm2) or high fluid shear stress (HSS, 15 dynes/cm2). Van Gogh2 (Vangl2), a core protein in the planar cell polarity (PCP) pathway, was silenced and overexpressed in hUVECs. Immunofluorescence analysis showed that primary cilia assemble under LSS while disassembling under HSS. Vangl2 expression was consistent with cilia assembly, and its localization showed a polar distribution under LSS. Furthermore, the average number of ciliated cells and primary cilia length were increased in the Vangl2 overexpressing cell lines (the OE group) but decreased in the Vangl2 silenced cell lines (the SH group). When these cells were loaded with different FSS, more ciliated cells with longest primary cilia were observed in the LSS loaded OE group compared with those in the other groups. Immunoprecipitation showed that the interaction between Bardet-Biedl syndrome 8 (BBS8) and Vangl2 was enhanced following LSS loading compared to that under HSS. However, the interactions between phosphorylated dishevelled segment polarity protein 2 (pDvl2), kinesin family member 2a (Kif2a), and polo-like kinase 1 (Plk1) and Vangl2 were restrained following LSS loading. Overall, the results indicated that Vangl2 played a significant role during LSS-induced primary cilia assembly by recruiting BBS to promote the apical docking of basal bodies and by restraining Dvl2 phosphorylation from reducing primary cilia disassembly.

Hip Adductor Intramuscular Nerve Distribution Pattern of Children: A Guide for BTX-A Treatment to Muscle Spasticity in Cerebral Palsy.

To investigate the intramuscular nerve distribution pattern in the hip adductors of children and to precisely locate the injection site for botulinum toxin type A (BTX-A) as a treatment for hip adductor spasticity in children with cerebral palsy. Modified Sihler's whole mount nerve staining technique was employed to observe the distribution of intramuscular nerves in hip adductors of children and to further locate zones where terminal nerves are concentrated. The terminal nerves of the adductor longus appeared in a longitudinal distribution band parallel to the line between the upper 1/3 point of the lateral boundary and the center of the medial boundary. In adductor brevis, the terminal nerves showed a sheet-like distribution with a nerve dense area located in the middle of the muscle belly that extends from the upper-inner region to the lower-outer region. Gracilis showed a dense area of terminal nerves in the middle of the muscle belly, closer to the posterior boundary. In adductor magnus, the dense area of terminal nerves showed a sheet-like distribution in the middle and lower region of the muscle belly. The dense area of terminal nerves in the pectineus was located in the middle of the muscle belly. This study is the first to systematically investigate the intramuscular nerve distribution pattern in the hip adductors. The results indicated that the best targets for BTX-A injection, when treating spasticity, are the dense regions of terminal nerves described above.

Intramuscular nerve distribution patterns of anterior forearm muscles in children: a guide for botulinum toxin injection.

Botulinum toxin (BoNT) can relieve muscle spasticity by blocking axon terminals acetylcholine release at the motor endplate (MEP) and is the safest and most effective agent for the treatment of muscle spasticity in children with cerebral palsy. In order to achieve maximum effect with minimum effective dose of BoNT, one needs to choose an injection site as near to the MEP zone as possible. This requires a detailed understanding about the nerve terminal distributions within the muscles targeted for BoNT injection. This study focuses on BoNT treatment in children with muscle spasms caused by cerebral palsy. Considering the differences between children and adults in anatomy, we used child cadavers and measured both the nerve entry points and nerve terminal sense zones in three deep muscles of the anterior forearm: flexor digitorum profundus (FDP), flexor pollicis longus (FPL), and pronator quadratus (PQ). We measured the nerve entry points by using the forearm midline as a reference and demonstrated intramuscular nerve terminal dense zones by using a modified Sihler's nerve staining technique. The locations of the nerve entry points and that of the nerve terminal dense zones in the muscles were compared. We found that all nerve entry points are away from the corresponding intramuscular nerve terminal dense zones. Simply selecting nerve entry points as the sites for BoNT injection may not be an optimal choice for best effects in blocking muscle spasm. We propose that the location of the nerve terminal dense zones in each individual muscle should be used as the optimal target sites for BoNT injection when treating muscle spasms in children with cerebral palsy.