[Cerebral cavernous malformation 3 gene deficiency promotes early changes in Alzheimer disease-like lesions induced by low lead exposure].

Objective: To investigate the effects of cerebral cavernous malformation 3 (CCM3) gene knockout on the lead exposure-induced blood-brain barrier malfunction in mice brain, and the relationship between CCM3 knockout and the Alzheimer's disease (AD). Methods: Wide type (WT) mice and CCM3(+)/- mice were divided into 4 groups, control group and lead exposed group in WT as well as CCM3(+/-) mice. Lead exposed groups were treated with 0.05% lead acetate in drinking water for 12 weeks, while control group drink deionized water freely. Blood lead and brain lead levels in each group were detected by graphite furnace atomic absorption spectrometry. The brain tissue of each group was made into paraffin sections, whose morphology were observed by HE staining. The expression of Aß(1-42) in brain tissue was detected by immunohistochemistry and the brain capillaries were labeled by VRGFR2. The protein expression of Claudin-5, ZO-1, and p-Tau was detected by Western blot. The brain tissue RNA was extracted and the relative expression of LRP-1 mRNA was detected by qRT-PCR. Results: The levels of blood lead WT (216.07±84.16) and CCM3(+/-) (189.64±101.86) µg/L in lead exposed group were higher than those in control group WT (19.52±11.46) and CCM3(+/-) (11.79±8.20) µg/L, the difference was statistically significant (t=4.18, P=0.006; t=3.79, P=0.016). The levels of brain lead WT (1.78±0.69) and CCM3(+/-) (1.74±0.66) µg/L were higher than those in control group WT (1.06±0.87) and CCM3(+/-) (0.97±0.64) µg/L, the difference was statistically significant (t=3.67, P=0.018; t=3.88, P=0.015). The HE staining showed no obvious lesions in the brain of each group of mice. The results of immunohistochemistry showed that there was no Aß(1)-42 deposition in the brain of mice in each group. The numbers of microvessels in the brain of CCM3(+/-) mice in the lead exposed group were decreased. Compared with the relative expression levels of Claudin-5 (WT: 1.30±0.03, CCM3(+/-): 1.07±0.08) in control group mice brain, the relative expression of Claudin-5 (WT: 0.96±0.04, CCM3(+/-): 0.59±0.01) was decreased with statistical significance (F=199.27, P<0.001). The relative expression level of LRP-1 gene mRNA in brain of lead exposed group (WT: 0.32±0.10, CCM3(+/-): 0.06±0.01) was higher than that of unexposed group (WT:1.00±0.06, CCM3(+/-):2.12±0.18), the difference was statistically significant (F=288.29, P<0.001). The relative expression level of LRP-1 gene mRNA in brain of CCM3(+)/- mice exposed to lead was lower than that of WT mice ((0.06±0.01)vs(0.32±0.10), t=26.90, P<0.001). Conclusion: The mice did not show significant AD-like lesions under low-does lead exposure, but resulted in early damage of brain blood-brain barrier and early changes of AD-like lesions in mice, with CCM3(+/-) mice being sensitive to lead exposure stronger than that of WT mice, suggesting that deletion of CCM3 gene may be one of the potential risk factors for accelerating the development of AD in mice exposed to lead.

Cavernous angioma after chemotherapy for desmoplastic/nodular medulloblastoma associated with anhidrotic ectodermal dysplasia.

PURPOSE: While cavernous angioma (CVA) after cranial irradiation has been documented, its development after high-dose chemotherapy with autologous peripheral blood stem cell transplantation (PBSCT) has not. We present a patient with desmoplastic/nodular medulloblastoma (DNMB) associated with anhidrotic ectodermal dysplasia (AED) who developed CVA 2 years after high-dose chemotherapy and PBSCT. METHODS: A 1-year-old boy with ingravescent vomiting was admitted to our institute. He presented with a large head, a depressed nasal bridge, low-set ears, thick lips with peg-shaped teeth, hypohidrosis, sparse hair, thin atrophic skin, scaly dermatitis with frontal bossing, and a bulging anterior fontanel. Neuroradiological examination revealed multiple cerebellar masses with heterogeneous enhancement and speckled calcifications and severe obstructive hydrocephalus. The histological diagnosis of surgical specimens was DNMB, and he underwent postoperative multiple-drug chemotherapy with autologous PBSCT. The outcome was favorable and he did not undergo radiotherapy. RESULTS: After 2 years, intracranial hemorrhage was detected at his regular radiological check-up and he again underwent surgery. The histological diagnosis was CVA. CONCLUSIONS: To our knowledge, this is the first report of AED-associated DNMB and CVA.

Propranolol inhibits cavernous vascular malformations by ß1 adrenergic receptor antagonism in animal models.

Propranolol, a pleiotropic ß-adrenergic blocker, has been anecdotally reported to reduce cerebral cavernous malformations (CCMs) in humans. However, propranolol has not been rigorously evaluated in animal models, nor has its mechanism of action in CCM been defined. We report that propranolol or its S(-) enantiomer dramatically reduced embryonic venous cavernomas in ccm2 mosaic zebrafish, whereas R-(+)-propranolol, lacking ß antagonism, had no effect. Silencing of the ß1, but not ß2, adrenergic receptor mimicked the beneficial effects of propranolol in a zebrafish CCM model, as did the ß1-selective antagonist metoprolol. Thus, propranolol ameliorated cavernous malformations by ß1 adrenergic antagonism in zebrafish. Oral propranolol significantly reduced lesion burden in 2 chronic murine models of the exceptionally aggressive Pdcd10/Ccm3 form of CCM. Propranolol or other ß1-selective antagonists may be beneficial in CCM disease.