[Expression changes of RNA m6A regulators in mouse cerebellum affected by hypobaric hypoxia stimulation]

Objective: To investigate the role of RNA m6A methylation in mediating cerebellar dysplasia through analyzing the phenotypes of the mouse cerebella and the expression of several key m6A regulators upon hypobaric hypoxia treatment. Methods: Five-day old C57/BL6 mice were exposed to hypobaric hypoxia for 9 days. The status of mouse cerebellar development was analyzed by comparing the body weights, brain weights and histological features. Immunostaining of cell-type-specific markers was performed to analyze the cerebellar morphology. Real-time PCR, Western blot and immunohistochemical staining were performed to detect the expression of key m6A regulators in the mouse cerebella. Results: Compared with the control, the body weights, brain weights and cerebellar volumes of hypobaric hypoxic mice were significantly reduced (P<0.01). The expression of specific markers in different cells, including NeuN (mature neuron), Calbindin-D28K (Purkinje cell) and GFAP (astrocyte), was decreased in hypobaric hypoxic mouse cerebella (P<0.01), accompanied with disorganized cellular structure. The expression of methyltransferase METTL3 was significantly down-regulated in the cerebella of hypobaric hypoxic mice (P<0.05). Conclusions: Hypobaric hypoxia stimulation causes mouse cerebellar dysplasia, with structural abnormalities in mature granular neurons, Purkinje cells and astrocytes. Expression of METTL3 is decreased in hypobaric hypoxic mice cerebellum compared with that of normobaric normoxic mice, suggesting that its mediated RNA m6A methylation may play an important role in hypobaric hypoxia-induced mouse cerebellar dysplasia.

MARS1 mutations linked to familial trigeminal neuralgia via the integrated stress response

BACKGROUND

While new genetic analysis methods are widely used in the clinic, few researchers have focused on trigeminal neuralgia (TN) with familial clustering (≥ 2 TN patients in one kindred family). Previous literature suggests that familial trigeminal neuralgia (FTN) may be associated with inherited genetic factors. To date, few next-generation sequencing studies have been reported for FTN. This study investigated the pathogenic mechanism of FTN by using whole-exome sequencing (WES) technology, which may enhance our understanding of human TN pathophysiology.  METHOD: We performed WES for 7 probands from families of FTN. Sanger sequencing was performed for two control groups (FTN family members group and nonfamilial TN subject group) to potentially identify new FTN-related gene mutations. In families where FTN probands carried potentially pathogenic gene mutations, the ribonucleic acid (RNA) of FTN probands and related family members, as well as nonfamilial TN patients were analysed by RNA sequencing (RNA-seq) to confirm differential gene expression.

RESULTS

Seven probands were derived from 3 Chinese families. WES and Sanger sequencing identified MARS1 mutation c.2398C > A p.(Pro800Thr) in Family 1. MARS1 mutation was confirmed in 14/26 [53.8%] members of Family 1 in FTN family member group, while none of nonfamilial TN subjects had this MARS1 mutation. RNA-seq showed that 3 probands in Family 1 had higher expression of Fosl1 (Fos-like antigen 1) and NFE2 (Nuclear factor, erythroid 2) than 3 subjects in the nonfamilial TN subject group. Fosl1 and NFE2 are genes related to integrated stress response (ISR).

CONCLUSION

MARS1 mutations may cause chronic activation of ISR, contribute to ISR pathophysiological changes in FTN, and cause/accelerate peripheral nerve degeneration. The findings of this study can enrich our knowledge of the role of molecular genetics in TN in humans.

Incontinentia pigmenti with intracranial arachnoid cyst: A case report

BACKGROUND

Incontinentia pigmenti (IP) is a rare X-linked dominant genetic disorder that can be fatal in male infants. It is a disease that affects many systems of the human body. In addition to characteristic skin changes, patients may also have pathological features of the eyes, teeth, and central nervous system. Therefore, the lesions in these systems may be the first symptoms for which patients seek treatment. To date, no cases of IP complicated by intracranial arachnoid cyst (IAC) have been reported. This paper aims to report a case of IP with IAC in order to share the diagnosis and treatment experience of this rare case with other clinicians.

CASE SUMMARY

An 11-year-old female patient suffered intermittent limb convulsions for five months and was sent to hospital. In the initial stage, the patient was considered to have primary epilepsy. Further investigation of the patient's medical history, physical examination and imaging examination led to the diagnosis of IP combined with intracranial space-occupying lesions, and secondary epilepsy. The patient was treated with craniotomy, and postoperative pathology revealed an IAC. The patient recovered well after craniotomy and had no obvious surgery-related complications. During the follow-up period, the patient did not have recurrent epilepsy symptoms.

CONCLUSION

IP is a multi-system disease that presents with typical skin lesions at birth, but the long-term prognosis of this disease depends on the involvement of systems other than the skin, especially nervous system and ocular lesions.

Primary intracranial synovial sarcoma with hemorrhage: A case report

BACKGROUND

Synovial sarcoma (SS) is a highly malignant tumor of unknown histological origin. This tumor can occur in various parts of the body, including those without synovial structures, but mainly in and around the joints, mostly in the lower extremities. Primary intracranial SSs are remarkably rare. This paper aims to report a case of primary intracranial SS with hemorrhage.

CASE SUMMARY

A 35-year-old male patient suffered a headache and slurred speech during manual labor and was sent to the emergency department. Through imaging examination, the patient was considered to have high-grade glioma complicated with hemorrhage and was treated with craniotomy. Postoperative pathology revealed SS. positron emission tomography/computed tomography was performed, which ruled out the possibility of metastasis to the intracranial from other parts of the body. Postoperative radiotherapy was given to the patient, during which radiation necrosis occurred. Sixteen months after craniotomy, cranial magnetic resonance imaging revealed recurrence of the tumor.

CONCLUSION

Primary intracranial SS is a rare malignant tumor. Primary intracranial SS with hemorrhage and radiation necrosis should be carefully monitored during postoperative radiotherapy. Surgical resection of the tumor combined with postoperative radiotherapy and chemotherapy is currently used, but the prognosis is poor.

Elevated Serum FGG Levels Prognosticate and Promote the Disease Progression in Prostate Cancer

Castration-resistant prostate cancer (CRPC) threatens the health of men in general and no effective therapeutics currently exists for the treatment of CRPC. It is therefore of great importance to find a novel molecule that can be a biomarker and a therapeutic target for CRPC. First, we found that the serum fibrinogen gamma (FGG) levels in patients with CRPC were significantly higher than those with localized prostate cancer (PCa) through iTRAQ proteomics and ELISA experiments. Immunohistochemistry, quantitative real-time polymerase chain reaction and western blot also showed an increase of FGG expression in CRPC tissues and cells. Then we proved the proliferation, invasion and migration ability of CRPC cells were significantly reduced after FGG knockdown. The number of apoptotic cells increased at least sixfold after FGG silencing, and was observed in conjunction with an upregulation of p53, caspase 3, clea-caspase 3, and Bax, and a downregulation of Bcl2 and survivin. FGG knockdown in DU145 cells resulted in smaller xenografts than control cells in a mouse model. and we established that FGG is modulated by IL-6 which was increased in CRPC patients via phosphorylation of STAT3. The data suggests that FGG may be a potential therapeutic target and prognostic marker for CRPC.

[Intra-nucleus accumbens shell injection of baclofen blocks the reconsolidation of conditioned place preference in morphine-addicted mice]

Preclinical studies suggest that the GABA_B receptor is a potential target for treatment of substance use disorders. Baclofen (BLF), a prototypical GABA_B receptor agonist, is the only specific GABA_B receptor agonist available for application in clinical addiction treatment. The nucleus accumbens shell (AcbSh) is a key node in the circuit that controls reward-directed behavior. However, the relationship between GABA_B receptors in the AcbSh and memory reconsolidation was unclear. The aim of this study was to investigate the effect of intra-AcbSh injection of BLF on the reconsolidation of morphine reward memory. Male C57BL/6J mice were used to establish morphine conditioned place preference (CPP) model and carry out morphine reward memory retrieval and activation experiment. The effects of intra-AcbSh injection of BLF on morphine-induced CPP, reinstatement of CPP and locomotor activity were observed after environmental cues activating morphine reward memory. The results showed that intra-AcbSh injection of BLF (0.06 nmol/0.2 μL/side or 0.12 nmol/0.2 μL/side), rather than vehicle or BLF (0.01 nmol/0.2 μL/side), following morphine reward memory retrieval abolished morphine-induced CPP by disrupting its reconsolidation in mice. Moreover, this effect persisted for more than 14 days, which was not reversed by a morphine priming injection. Furthermore, intra-AcbSh injection of BLF without morphine reward memory retrieval had no effect on morphine-associated reward memory. Interestingly, administration of BLF into the AcbSh had no effect on the locomotor activity of mice during testing phase. Based on these results, we concluded that intra-AcbSh injection of BLF following morphine reward memory could erase morphine-induced CPP by disrupting its reconsolidation. Activating GABA_B receptor in AcbSh during drug memory reconsolidation may be a potential approach to prevent drug relapse.

Soft tissue chondroma of the parapharyngeal space: a case report

Benign chondroma affecting the soft tissues is uncommon. This tumour is particularly rare in the neck. We present the first case of soft tissue chondroma arising in the parapharyngeal space of a 20-year-old man with a two-year history of a gradual sensation of a swelling in the pharynx with increasing snoring. The CT and pathological features of this lesion will be discussed. We suggest that a peroral approach should be considered for benign parapharyngeal tumour which has been demonstrated on imaging to be in the anterior parapharyngeal space, especially for tumours that are medial to the pterygoid muscles even though the tumour is a large one.