Vitamin D is a fat‐soluble vitamin and plays an important role in calcium absorption and bone development, whose lack can cause a variety of diseases, including cancer. Human epidemiological studies suggested that vitamin D3 deficiency might increase glioma incidence, but molecular mechanism is less understood. In this study, we show that 1,25‐dihydroxyvitamin D3 (the active form of vitamin D3) induces senescence of glioma cells and increases the expression of senescence markers, INK4A and cyclin‐dependent kinase inhibitor 1A (CDKN1A). 1,25‐Dihydroxyvitamin D3 also upregulates the expression of histone demethylase, KDM6B. Knockdown of KDM6B attenuates 1,25‐dihydroxyvitamin D3‐induced senescence and upregulation of INK4A and CDKN1A. KDM6B promotes the transcription of INK4A by eliminating the trimethylation of repressive marker H3K27me3 near its promoter. This study reveals a new regulatory mechanism involved in vitamin D3 inhibition on gliomas, which is beneficial to prevention and adjuvant therapy of glioma.
Background Cranioplasty is a common procedure in neurosurgery. It is usually performed following decompressive craniectomy (DC). However, complications may occur after the operation, such as massive brain swelling. Up to now, far too little attention has been given to this severe complication. We report one case of fatal cerebral swelling after cranioplasty and analyze the possible mechanism of this complication.
Case Description The patient was a 40-year-old man who had a severe right basal ganglia cerebral hemorrhage and underwent DC ∼ 2 months before. One day before scheduled cranioplasty, a lumbar cerebrospinal fluid drainage was placed. The cranioplasty itself was uneventful. However, he gradually fell into a coma, and his right pupil was moderately dilated 20 hours after the surgery. A brain computed tomography (CT) scan indicated massive right cerebral edema with compressed right midbrain. The patient did not regain consciousness, and he remained quadriplegic.
Conclusion It is necessary to increase awareness of complications of cranioplasty in high-risk patients. The lessons learned from this case include avoiding excessive drainage of cerebrospinal fluid. Patients with low-density lesions in the brain need to be treated with caution. Once the CT scan shows massive cerebral swelling, the patient has a poor prognosis.
Purpose To investigate the role of ICA II in subarachnoid hemorrhage (SAH)- related chronic hydrocephalus. Methods A two hemorrhage injection model of SAH was created in Sprague Dawley rats (6-8 weeks). A total of 125 rats were randomly assigned into five groups: Sham group, SAH group, SAH+ ICA II (1 mg/kg) group, SAH + ICA II (5 mg/kg) group, and SAH + ICA II (10 mg/kg) group. TGF-β1, phospho-Smad2/3, connective tissue growth factor (CTGF), and procollagen type I carboxy-terminal propeptide (PICP) were assessed via real-time PCR, Western blotting, and enzyme-linked immunosorbent assay. Lateral ventricular index, Masson staining, and Morris water maze tests were employed to evaluate subarachnoid fibrosis, hydrocephalus, and long term neurological function following SAH. Results ICA II (1, 5, 10 mg/kg) inhibited subarachnoid fibrosis, attenuated ventriculomegaly, and effectively suppressed SAH related chronic hydrocephalus. In addition, parallel reduced expression of members of the TGF-β1/Smad/CTGF signaling pathway were observed. Importantly, ICA II may improve long term neurocognitive deficits after SAH. Conclusion ICA II might suppress fibrosis via inhibition of TGF-β1/Smad/CTGF pathway, prevent the development of SAH related chronic hydrocephalus, and improve long term neurocognitive defects following SAH.
Pyroptosis has been reported to contribute to the traumatic brain injury (TBI) process. Ac-FLTD-CMK is a newly synthesized pyroptosis inhibitor. However, whether Ac-FLTD-CMK inhibits pyroptosis and plays a neuroprotective role after TBI is unknown. The present study aimed to determine the effects of Ac-FLTD-CMK on TBI in a mouse model. Male C57BL/6 mice were randomly divided into sham, TBI + vehicle, and TBI + Ac-FLTD-CMK groups. TBI was induced using a weight-drop apparatus. Intraventricular injection of Ac-FLTD-CMK was performed 30 min after TBI. Caspase-1, caspase-11, gasdermin-D (GSDMD), and caspase-3 expression in the peri-contusional cortex were assessed by western blotting. Interleukin-1β (IL-1β) and interleukin-18 (IL-18) expression in the peri-contusional cortex were measured using ELISA. Behavioral experiments, brain water content, Evans blue extravasation, lactate dehydrogenase (LDH) release, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining were also performed. The results showed that Ac-FLTD-CMK administration significantly downregulated caspase-1 p20, caspase-11 p20, GSDMD N-terminal, IL-1β, and IL-18 expression; reduced LDH release; alleviated neuronal death; attenuated brain edema and blood-brain barrier damage; and improved neurobehavioral function. These findings indicate that Ac-FLTD-CMK treatment suppresses pyroptosis and protects mice against TBI.
Brain metastasis is a devastating clinical condition globally as one of the most common central nervous system malignancies. The current study aimed to assess the effect of defibrotide, an Food and Drug Administration-approved drug, against brain metastasis and the underlying molecular mechanisms. Two tumor cell lines with high brain metastasis potential, PC-9 and 231-BR, were subjected to defibrotide treatment of increasing dosage. The metastasis capacity of the tumor cells was evaluated by cell invasion and migration assays. Western blotting was employed to determine the levels of tight junction proteins in the blood–brain barrier (BBB) including Occludin, Zo-1, and Claudin-5, as well as metastasis-related proteins including CXCR4, MMP-2, and MMP-9. The in-vitro observations were further verified in nude mice, by monitoring the growth of xenograft tumors, mouse survival and brain metastasis foci following defibrotide treatment. Defibrotide inhibited proliferation, migration, invasion, and promotes lactate dehydrogenase release of brain metastatic tumor cells, elevated the levels of BBB tight junction proteins and metastasis-related proteins. Such beneficial role of defibrotide was mediated by its inhibitory action on the SDF-1/CXCR4 signaling axis both in vitro and in vivo, as CXCR4 agonist SDF1α negated the anti-tumoral effect of defibrotide on mouse xenograft tumor growth, mouse survival and brain metastasis. Defibrotide inhibits brain metastasis through activating the adenosine A2A receptors, which in turn inhibits the SDF-1/CXCR4 signaling axis. Our study hereby proposes defibrotide as a new and promising candidate drug against brain metastasis of multiple organ origins.
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