[Different concentrations of adapalene induce differentiation and apoptosis of SH-SY5Y cells]

OBJECTIVES

To investigate the effects of different concentrations of adapalene on the morphology and functions of neuroblastoma cell line SH-SY5Y, as well as its role in inducing cell differentiation and apoptosis.

METHODS

SH-SY5Y cells were divided into control group, low concentration (0.1 μM and 1 μM) adapalene groups, and high concentration (10 μM) adapalene group. Time-lapse microscopy was used to observe the morphological changes of SH-SY5Y cells. Immunofluorescence staining was performed to detect the expression of neuronal specific marker βIII-tubulin and mature neuronal marker neurofilament heavy polypeptide (NFH). Multi-electrode array was used to record the electrophysiological features of SH-SY5Y cells. Cell apoptosis was evaluated using a cell apoptosis detection kit.

RESULTS

Low concentrations of adapalene promoted the formation of neurite outgrowth in SH-SY5Y cells, with the neurites interconnected to form a network. Spontaneous discharge activity was observed in SH-SY5Y cells treated with low concentrations of adapalene. Compared to the control group, the expression of βIII-tubulin and NFH increased in the 1 μM adapalene group, while the level of cell apoptosis increased in the high concentration adapalene group (P<0.05).

CONCLUSIONS

Low concentrations of adapalene can induce differentiation of SH-SY5Y cells into mature functional neurons, while high concentrations of adapalene can induce apoptosis in SH-SY5Y cells.

[Clinical, pathological and genetic characteristics of 8 patients with distal hereditary motor neuropathy]

OBJECTIVE

Distal hereditary motor neuropathy (dHMN) comprises a heterogeneous group of inherited disorders associated with neurodegeneration of motor nerves and neurons, mainly charac-terized by progressive atrophy and weakness of distal muscle without clinical or electrophysiological sensory abnormalities. To improve the recognition and diagnosis of the disease, we summarized the clinical manifestations, electrophysiological, pathological, and genetic characteristics in eight patients with dHMN.

METHODS

Eight probands from different families diagnosed with dHMN were recruited in this study between June 2018 and April 2019 at Peking University People's Hospital. Eight patients underwent complete neurological examination and standard electrophysiological examinations. The clinical criteria were consistent with the patients presenting with a pure motor neuropathy with no sensory changes on electrophysiology. The detailed clinical symptoms, neurophysiological examinations, pathological features and gene mutations were analyzed retrospectively. Genetic testing was performed on the eight patients using targeted next-generation sequencing panel for inherited neuromuscular disorder and was combined with segregation analysis.

RESULTS

The age of onset ranged between 11 and 64 years (median 39.5 years) in our dHMN patients. All the cases showed a slowly progressive disease course, mainly characterized by distal limb muscle weakness and atrophy. The motor nerve conduction revealed decreased compound muscle action potential amplitude and velocity, while the sensory nerve conduction velocities and action potentials were not affected. Needle electromyography indicated neurogenic chronic denervation in all patients. Muscle biopsy performed in two patients demonstrated neurogenic skeletal muscle damage. Sural nerve biopsy was performed in one patient, Semithin sections shows relatively normal density and structure of large myelinated fibers, except very few fibers with thin myelin sheaths, which suggested very mild sensory nerve involvement. Eight different genes known to be associated with dHMN were identified in the patients by next-generation sequencing, pathogenic dHMN mutations were identified in three genes, and the detection rate of confirmed genetic diagnosis of dHMN was 37.5% (3/8). Whereas five variants of uncertain significance (VUS) were identified, among which two novel variants co-segregated the phenotype.

CONCLUSION

dHMN is a group of inherited peripheral neuropathies with great clinical and genetic heterogeneity. Next-generation sequencing is widely used to discover pathogenic genes in patients with dHMN, but more than half of the patients still remain genetically unknown.

[Comparison and correlation analysis of sleep parameters between watch-type sleep monitor (Actiwatch) and polysomnography]

OBJECTIVE

With the rapid development of sleep medicine, there are various methods for detecting sleep diseases. This study compared the correlation between the lightweight watch-type sleep monitor (Actiwatch) and the "gold standard" polysomnography (PSG) in the Chinese population, in order to provide a basis for clinical application.

METHODS

From August 2018 to December 2019, 121 subjects who simultaneously performed sleep breathing monitoring (PSG) and wearing a watch-type sleep monitor (Actiwatch) in the Sleep Center of Peking University People's Hospital were enrolled. All subjects received PSG and Actiwatch at the same time, and filled out the sleep diary next morning. Monitoring indicators were collected for linear correlation analysis and paired t test to compare the differences.

RESULTS

Under low sensitivity conditions, the correlation coefficient of total sleep time (TST) between PSG and Actiwatch was 0.53 (P < 0.05). Paired t test analysis showed that there was no significant difference between the TSTs of Actiwatch and PSG (t=-0.890, P=0.36). According to age stratification, the smaller the age, the stronger the correlation between the TSTs of Actiwatch and PSG, and the coefficient could be up to 0.92 (P < 0.05). Paired t test showed that there was no significant difference between them (t=-1.057, P=0.35). According to the stratification by diagnosis, the correlation coefficient between the TSTs of Actiwatch and PSG in normal PSG group could be as high as 0.79 (P < 0.05), the results of paired t test showed that there was no significant difference between the TSTs of Actiwatch and PSG in normal PSG group (t=-0.784, P=0.44).

CONCLUSION

As a wearable home recorder, when the analysis parameters of Actiwatch were set as low sensitivity, PSG and Actiwatch had the highest TST correlation. The younger the age, the stronger correlation between the TSTs of Actiwatch and PSG. The PSG and Actiwatch subjects with normal PSG presentation had a higher TST correlation.