Modulation of vigabatrin induced cerebellar injury: the role of caspase-3 and RIPK1/RIPK3-regulated cell death pathways.

Vigabatrin is the drug of choice in resistant epilepsy and infantile spasms. Ataxia, tremors, and abnormal gait have been frequently reported following its use indicating cerebellar involvement. This study aimed, for the first time, to investigate the involvement of necroptosis and apoptosis in the VG-induced cerebellar cell loss and the possible protective role of combined omega-3 and vitamin B12 supplementation. Fifty Sprague-Dawley adult male rats (160-200 g) were divided into equal five groups: the control group received normal saline, VG200 and VG400 groups received VG (200 mg or 400 mg/kg, respectively), VG200 + OB and VG400 + OB groups received combined VG (200 mg or 400 mg/kg, respectively), vitamin B12 (1 mg/kg), and omega-3 (1 g/kg). All medications were given daily by gavage for four weeks. Histopathological changes were examined in H&E and luxol fast blue (LFB) stained sections. Immunohistochemical staining for caspase-3 and receptor-interacting serine/threonine-protein kinase-1 (RIPK1) as well as quantitative real-time polymerase chain reaction (qRT-PCR) for myelin basic protein (MBP), caspase-3, and receptor-interacting serine/threonine-protein kinase-3 (RIPK3) genes were performed. VG caused a decrease in the granular layer thickness and Purkinje cell number, vacuolations, demyelination, suppression of MBP gene expression, and induction of caspases-3, RIPK1, and RIPK3 in a dose-related manner. Combined supplementation with B12 and omega-3 improved the cerebellar histology, increased MBP, and decreased apoptotic and necroptotic markers. In conclusion, VG-induced neuronal cell loss is dose-dependent and related to both apoptosis and necroptosis. This could either be ameliorated (in low-dose VG) or reduced (in high-dose VG) by combined supplementation with B12 and omega-3.

Postnatal Administration of Homocysteine Induces Cerebellar Damage in Rats: Protective Effect of Folic Acid.

A widely held view suggests that homocysteine (Hcy) can contribute to neurodegeneration through promotion of oxidative stress. There is evidence that homocysteine is toxic to cerebellar Purkinje neurons in vitro; however, in vivo action of Hcy on Purkinje cell has not been investigated so far. Thus, this study was designed to evaluate the Hcy effects on neonatal rat cerebellum and cerebellar oxidative stress. We also evaluated the folic acid effects on biochemical alterations elicited by hyperhomocysteinemia (hHcy) in the cerebellum. Group I received normal saline, group II received Hcy subcutaneously twice a day at 8-h intervals (0.3-0.6 µmol/g body weight), group III received Hcy + folic acid (0.011 µmol/g body weight), and group IV received folic acid on postnatal day (PD) 4 until 25. On day 25, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in the cerebellum and motor cortex were assayed. Malondialdehyde (MDA) levels were also evaluated as a marker of lipid peroxidation. Rotarod and locomotor activity tests were performed in PD 25-27. Our results indicated that administration of Hcy increased plasma, cortical, and cerebellar total Hcy levels; reduced GPx activity; and induced lipid peroxidation in the cerebellum. Hcy impaired performance on the rotarod in rats. However, treatment with folic acid significantly attenuated motor coordination impairment, GPx activity reduction, the lipid peroxidation process, and significantly reduced plasma total Hcy levels. Histological analysis indicated that Hcy could decrease Purkinje cell count and folic acid prevented this toxic effect. We conclude that Hcy can induce neurotoxicity and folic acid has neuroprotective effects against cerebellar Hcy toxicity.

Laser Acupuncture at HT7 Improves the Cerebellar Disorders in Valproic Acid-Rat Model of Autism.

The novel therapeutic strategy against autism is essential due to the limited therapeutic efficacy. Based on the benefit of laser acupuncture at HT7 acupoint on the neurological disorders related with oxidative stress and inflammation, its benefit on oxidative stress, neuroinflammation, and GABAergic/glutamatergic imbalance in cerebellum of autism have been considered. To elucidate this issue, male rat pups were induced autistic-like conditions by valproic acid (VPA) and treated with laser acupuncture at HT7 acupoint once daily between postnatal Day 14 and Day 40. At the end of study, the changes of oxidative stress markers, the expressions of cytokines interleukin 6 (IL-6) and glutamic acid decarboxylase (GAD) proteins (65 kDa and 67 kDa) together with gamma-aminobutyric acid transaminase (GABA-T) activity and density of Purkinje cell in the cerebellum were assessed. The results showed that laser acupuncture HT7 decreased oxidative stress, IL-6 expression, and GABA-T activity but increased the expressions of GAD 65 kDa together with the density of Purkinje cells in the cerebellum. Therefore, laser acupuncture at HT7 is the potential strategy to improve the cerebellar disorders in VPA-rat model of autism. The mechanism may occur partly via the decrease of oxidative stress status, inflammation, and the improved GABAergic function.

[Effect of electroacupuncture on expression of myocardial PI 3 K, HIF-1alpha and VEGF in rats with cerebral-cardiac syndrome].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the expression of myocardial 1-phosphatidylinositol 3-kinase (PI 3 K), hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) in rats with cerebral-cardiac syndrome (CCS), so as to reveal its mechanism underlying reducing ischemic myocardial injury. METHODS: Forty SD rats were randomly and equally divided into sham-operation, model, EA and non-acupoint (the lateral-superior side of the hip) groups (10 rats/group). CCS model was established by injection of collagenase (1 U/microL) and heparin (7 U/microL) into the right caudate nucleus. Following modeling, EA (1.5 mA, 2 Hz, 20 min) was applied to "Shuigou" (GV 26), "Fengfu" (GV 16), "Neiguan" (PC 6) and "Xinshu" (BL 15) acupoints, once daily for three consecutive days. The expression levels of PI 3 K,HIF-1alpha and VEGF in the myocardium were detected by immunohistochemistry. RESULTS: Compared with the sham-operation group, the expression levels of myocardial PI 3 K, HIF-1a and VEGF proteins were significantly increased in the model group (P<0.01). While in comparison with the model group, there were little increase in the non-acupoint group (P>0.05) and considerable increase in the expression levels of the 3 myocardial proteins in the EA group (P<0.05). CONCLUSION: EA intervention has a function in upregulating the expression of myocardial VEGF, HIF-1alpha and PI 3 K proteins in CCS rats, which maybe contribute to its protective effect on ischaemic myocardial injury.

An unliganded thyroid hormone receptor causes severe neurological dysfunction.

Congenital hypothyroidism and the thyroid hormone (T(3)) resistance syndrome are associated with severe central nervous system (CNS) dysfunction. Because thyroid hormones are thought to act principally by binding to their nuclear receptors (TRs), it is unexplained why TR knock-out animals are reported to have normal CNS structure and function. To investigate this discrepancy further, a T(3) binding mutation was introduced into the mouse TR-beta locus by homologous recombination. Because of this T(3) binding defect, the mutant TR constitutively interacts with corepressor proteins and mimics the hypothyroid state, regardless of the circulating thyroid hormone concentrations. Severe abnormalities in cerebellar development and function and abnormal hippocampal gene expression and learning were found. These findings demonstrate the specific and deleterious action of unliganded TR in the brain and suggest the importance of corepressors bound to TR in the pathogenesis of hypothyroidism.

Proton magnetic resonance spectroscopy (1H MRS) in patients with sporadic cerebellar degeneration.

The authors studied 23 patients with cerebellar degeneration including multiple systemic atrophy (MSA) and cerebellar cortical atrophy (CCA) by proton magnetic resonance spectroscopy (1H-MRS). 1H-MRS allowed noninvasive measurement of the signal intensities derived from N-acetylaspartate (NAA), creatine + phosphocreatine (CRE), and choline-containing compounds (CHO). There was significant reduction of the NAA/CRE level in the frontal cortex, putamen, cerebellar hemisphere and cerebellar vermis of patients with MSA, and in the frontal cortex, cerebellar hemisphere and cerebellar vermis of patients with CCA as compared with those of normal controls. There was significant reduction of the NAA/CRE level also in the putamen of patients with MSA as compared with that of patients with CCA. These results indicated the presence of a degenerative process and/or functional impairment in the frontal cortex and putamen of patients with MSA and in the frontal cortex of patients with CCA, in addition to a degenerative process in the cerebellum. There was a significant correlation between the NAA/CRE level and the severity of clinical signs. 1H-MRS is valuable in providing information regarding the pathophysiology and the progress of cerebellar degenerative diseases.

Cerebellar calcification--ultrastructure and histochemistry.

The histochemistry and ultrastructure of calcified cerebellar deposits described by Tonge et al. (1977) are reported. The deposits were located by electron microscopy in the walls of blood vessels outside the basement membrane and, in most lesions, consisted of short fibrillar material arranged in multiple lamellae. A number of nonlaminated small bodies were present also. The material coated the vessel walls discontinuously with major and minor protrusions into adjacent nervous tissue. Histochemical analysis detected the presence of sialopolysaccharides in the lesions in adults and in a case of plumbism in a child, with minor differences in the type of sialic acid. X-ray fluorescence analysis supported by histochemical data indicated that, initially, the calcium was bound to the sialic acid and that calcium phosphate appeared in the lesions at a later date. The authors conclude that the lesion is formed by elaboration of sialopolysaccharides at the site but the possibility was not excluded that the polysaccharide may have been derived from a transudate across the vessel wall.