LncRNA MEG3 regulates ferroptosis of lens epithelial cells via PTBP1/GPX4 axis to participate in age-related cataract.

Age-related cataract (ARC) is regarded as the principal cause of vision impairment among the aged. The regulatory role of long noncoding RNAs (LncRNAs) in ARC remains unclear. The lncRNA maternally expressed gene 3 (MEG3) has been reported to promote ARC progression, and the underlying mechanism was further investigated in this study. Lens epithelium samples were collected to verify the expression of MEG3. Lens epithelial cells (LECs) were treated with H2O2 to mimic microenvironment of ARC in vitro. Cell viability, reactive oxygen species, and ferroptosis were evaluated during the in viro experiments. In the present work, lncRNA MEG3 was highly expressed in ARC group, compared with normal group. MEG3 was induced, cell viability and glutathione peroxidase 4 (GPX4) level were inhibited, and ferroptosis was promoted in H2O2 treated LECs. LncRNA MEG3 silence reversed the effects of H2O2 on viability and ferroptosis in LECs. Thereafter, lncRNA MEG3 was found to bind to PTBP1 for GPX4 degradation. Silencing of GPX4 reversed the regulation of lncRNA MEG3 inhibition in H2O2-treated LECs. To sum up, lncRNA MEG3 exhibited high expression in ARC. In H2O2-induced LECs, inhibition of lncRNA MEG3 accelerated cell viability and repressed ferroptosis by interaction with PTBP1 for GPX4 messenger RNA decay. Targeting lncRNA MEG3 may be a novel treatment of ARC.

Down-regulation of NR2B receptors contributes to the analgesic and antianxiety effects of enriched environment mediated by endocannabinoid system in the inflammatory pain mice.

Chronic pain states are highly prevalent and yet poorly controlled by currently available analgesics. It has been reported that enriched environment (EE), as a new way of endogenous pharmacotherapy, is effective in attenuating chronic inflammatory pain. However, the underlying molecular mechanisms are still not fully understood. NMDA NR2B receptor plays a critical role in pain transmission and modulation. Thus, in this study, we aimed at the effect of EE on the NR2B receptors expression in the prefrontal cortex, hippocampus and thalamus in the inflammatory pain mice. The results showed a significant increase of NR2B receptors in the thalamus of mice at 7 d following injection of CFA in the subcutaneous of the bottom of the left hind paw. EE significantly reduced the duration of mechanical hypersensitivity and anxiety-related behavior and the expression of NR2B receptors as compared to the standard condition. Furthermore, EE significantly increased 2-arachidonoylglycero (2-AG) levels at 7 d in the inflammatory pain mice as compared to the standard condition, and the effect of EE on the behavior and the expression of NR2B receptors was abolished by intraperitoneal injection of AM281 (a selective antagonist of CB1 receptor). Elevated 2-AG levels by intraperitoneal injection of JZL184 (a selective inhibitor of MAGL, the enzyme responsible for 2-AG hydrolysis) produced the same effect as EE. Results from this study provide the evidence that EE mimics endocannabinoids to take analgesic and anti-anxiety activities by decreasing the expression of the NR2B receptors via the CB1 receptor in the thalamus, pending further studies.

[Comparison of Pattern-pulse and Pattern-reversal Multifocal Visual Evoked Potentials in Normal Individuals].

OBJECTIVE: To compare pattern-pulse multifocal visual evoked potential (PPmfVEP) with pattern-reversal multifocal visual evoked potential (PRmfVEP), and to investigate the symmetry of mfVEP between both eyes in normal individuals. METHODS: The multifocal Vision Monitor was used to observe the mfVEP. T-test and ANOVA were used to analyze P1 wave, amplitude and signal noise ratios (SNR) of two mfVEPs. RESULTS: The SNR and the P1 amplitude reached the maximum at the central visual field and decreased with the increase of eccentricity, and then decreased slowly. The amplitude of the PPmfVEP was significantly smaller than the PRmfVEP in the central retina, while in the peripheral retina the result was exactly the opposite. SNR and amplitude of the PRmfVEP showed no statistical difference in both eyes (P > 0.05). The variance of the amplitude at the same side of visual field was larger than that at the symmetrical visual quadrant. CONCLUSION: mfVEP can reflect the visual function in different parts of retina objectively and exactly. PPmfVEP reflect the vision function of the central retina better than PRmfVEP. The stability of PPmfVEP is better than PRmfVEP in the central retina, while the result is opposite in the peripheral retina. The mfVEP is symmetrical in both eyes of the same individual.

[The evaluation of SCI by TMS-MEP and its forensic significance].

OBJECTIVE: To find an objective and accurate examination for evaluation of spinal cord injury (SCI) in forensic clinical medicine. METHODS: The onset latency of cortex, peak latency of N1, central motor conduction time (CMCT) and wave width of the abductor pollicis brevis and the anterior tibialis were calculated by transcranial magnetic stimulation-motor evoked potential (TMS-MEP). The data of 68 patients suffered from SCI including 23 cervical levels and 45 thoracolumbar levels were collected and compared with that of 30 normal controls. RESULTS: In experimental group, when the muscle strength of the abductor pollicis brevis or the anterior tibialis decreased or disappeared, the onset latency of cortex, the peak latency of N1, and CMCT prolonged and the wave width broadened. And these indexes of grade 2 and 3 muscle strength in experimental group were higher than that in the control group (P < 0.05). CONCLUSION: The TMS-MEP can determine directly and objectively the motor functional status of pyramidal tract of spinal cord in order to provide more accurate and objective evidences in forensic medicine.

[Analysis of forensic identification of traumatic macular hole in 16 cases].

OBJECTIVE: To analyze and summarize the characteristics of traumatic macular hole and to discuss the key points and matters need attention in forensic identification. METHODS: Sixteen cases of traumatic macular hole were collected from Forensic Science Identification Center of China Medical University from 2004 to 2009 and analyzed. RESULTS: All of the 16 cases resulted from closed ocular contusion. Traumatic macular hole was more common in young men and may occur immediately after injury or after a certain interval. Six months after injury, there was a spontaneous closure of macular hole in 2 cases and the vision of the injured in 12 cases improved to different degrees. According to the degree of vision dysfunction, 12 cases were identified as slight injury, 4 cases were identified as severe injury. CONCLUSION: Traumatic macular hole has its characteristics. Its injury degree is all slight or severe injury. The time of identification should be within 3-6 months.

[Analysis of 158 forensic identification cases involved with peripheral nerve injury].

OBJECTIVE: To study the characteristics of forensic identification cases involved with peripheral nerve injury, and to discuss how to apply the clinical information, forensic examination and neurophysiological testing. METHODS: One hundred and fifty-eight cases which were diagnosed peripheral nerve injury in clinic, were collected. Then the individual characteristics, injuries, identification results, exaggeration or camouflage were analysed. RESULTS: The male, the unemployed, and the young and middle-aged were common in our cases. The main reasons of "peripheral nerve injury" were traffic accidents and sharp injuries. Most wounded parts were in limbs. Also the exaggeration and camouflage accounted for a considerable proportion in our cases. CONCLUSION: The forensic identification of "peripheral nerve injury" cases should be evaluated with clinical information, forensic examination and electrophysiological testing comprehensively.

[Application of spiral CT reconstruction in the forensic identification of atlantoaxial injuries].

OBJECTIVE: To evaluate diagnostic value of spiral CT reconstruction in atlantoaxial injuries. METHODS: The images of 25 cases of spiral CT reconstruction were analyzed and compared with images of CT scan and X-ray. RESULTS: In 7 cases of odontoid process fracture, X-ray demonstrated 4 cases and CT demonstrated 5 cases, whereas the spiral CT reconstruction diagnosed 7 cases, which could display the displacement of fracture clearly. The X-ray and CT showed asymmetric space between left and right gaps of atlantoaxial joint in 6 cases, while spiral CT reconstruction showed normal and excluded the possibility of atlantoaxial dislocation. There was one case of lateral atlantoaxial joint dislocation, which was demonstrated by the spiral CT reconstruction clearly but not by the X-ray and CT scan. There were 3 cases of atlantoaxial congenital deformity (1 case of absence of both posterior arch of atlas and odontoid process and 2 cases of maldevelopment of the odontoid process), which were displayed clearly by spiral CT reconstruction, but misdiagnosed as odontoid process fracture and atlantoaxial subluxation by X-ray and CT scan. CONCLUSION: Spiral CT reconstruction can provide the most accurate and integrity imaging information and is very useful in the diagnosis of atlantoaxial injuries and deformity.

[The retrospective analysis of 23 cases of post-traumatic abortion].

OBJECTIVE: To analyze the clinical characteristics of post-traumatic abortion and the relationship between trauma and abortion. METHODS: We collected and analyzed 23 cases of post-traumatic abortion encountered in the department of clinical forensic medicine, faculty of forensic medicine, China Medical University in recent years. RESULTS: All 23 post-traumatic abort inns were early abortions. Their traumata were mild and external only. Vagina bleeding and abortion occurred shortly after trauma. Most patients were older, from countryside, or unemployed. CONCLUSION: The causes of abortion are complex. Post-traumatic abortion can only be diagnosed after excluding non-traumatic factors. For those cases abortion occur shortly after injuries and non-traumatic factors can not be excluded, trauma should be assessed for its role in abortions as primary, secondary or induction factors correlated with clinical symptoms and pre-

[The diagnostic value of SEP in LDH and its forensic significance].

OBJECTIVE: To evaluate the diagnostic value of somatosensory evoked potential(SEP) in lumbosacral disc herniation(LDH). METHODS: Posterior tibial nerve somatosensory evoked potential(PTNSEP) and dermatomal somatosensory evoked potential (DSEP) were recorded from 60 patients with radiculopathy caused by LDH and 30 healthy subjects. RESULTS: DSEP was abnormal in 56 cases (93.3%) and PTNSEP was abnormal in 26 cases (43.3%). The significant difference was observed (P<0.001). The abnormality of DSEP from L4 dermatome was detected mainly in patients with L3-4 LDH, the abnormality of DSEP from L5 dermatome was detected mainly in patients with L4-5 LDH, the abnormality of DSEP from L5S1 dermatome was detected mainly in patients with S1 LDH. DSEP can reflect the compressed extent of nerve root. CONCLUSIONS: There was a good correlation of DSEP with lumbosacral nerve root injury,which supplement the information that can not be provided by imaging examingation. DSEP is a sensitive electrophysic method that not only is used to evaluate single nerve root function, but also is helpful in the location of the lesion.