The magnitude and regulation of antibody responses to antigens injected into the central nervous system

Imperial Users onl

Efeito inibidor do crescimento tumoral pela metionina-encefalina

A metionina-enceflalina (Met-Ehk) é um pentapeptídeo opióide derivado do pró-normônio proencefalina A. presente em células neuroendócrinas e hematopoéticas. Estudos experimentais evidenciam seu papel na indução, ativação e controle de eventos imunomodula-dores, inclusive com potente efeito inibidor do crescimento tumoral. O presente estudo demonstra que o efeito inibidor da Met-Enk no crescimento de um fibro-histiocitoma, em camundongos BALB/cJ, é influenciado pelo protocolo utilizado, via de administração e dose do pentapeptídeo opióide utilizada no tratamento. A administração de Met_Enk por via intracerebral retardou de forma eficiente o processo de tumorigênese, aumentando a sobrevida dos animais e reduzindo de forma significativa a área tumoral final. Dose baixa (0,25 mg/kg) de Met-Enk administrada por via intracerebral foi ainda mais potente no controle da tumorigênese

Circulating Cell-Free DNA as a Prognostic and Molecular Marker for Patients with Brain Tumors under Perillyl Alcohol-Based Therapy

Tumor infiltration into brain tissue usually remains undetected even by high-resolution imaging. Molecular markers are used to increase diagnostic accuracy, but with limited continuous monitoring application. We evaluated the potential of circulating cell-free DNA (cfDNA) as a molecular indicator of the response to therapy by the intranasal administration (ITN) of perillyl alcohol (POH) in brain tumors. The cohort included 130 healthy subjects arranged as control-paired groups and patients at terminal stages with glioblastoma (GBM, n = 122) or brain metastasis (BM, n = 55) from stage IV adenocarcinomas. Serum cfDNA was isolated and quantified by fluorimetry. Compared with the controls (40 ng/mL), patients with brain tumors before ITN-POH treatment had increased (p < 0.0001) cfDNA median levels: GBM (286 ng/mL) and BM (588 ng/mL). ITN-POH treatment was significantly correlated (rho = −0.225; p = 0.024) with survival of >6 months at a concentration of 599 ± 221 ng/mL and of <6 months at 1626 ± 505 ng/mL, but a sharp and abrupt increase of cfDNA and tumor recurrence occurred after ITN-POH discontinuation. Patients under continuous ITN-POH treatment and checked with brain magnetic resonance imaging (MRI) compatible with complete response had cfDNA levels similar to the controls. cfDNA may be used as a noninvasive prognostic and molecular marker for POH-based therapy in brain tumors and as an accurate screening tool for the early detection of tumor progression

Persistent mdx diaphragm alterations are accompanied by increased expression and activity of calcium and muscle-specific proteins

The mdx mouse model of Duchenne Muscular Dystrophy (DMD) presents sarcolemma instability and develops a mild multi-stage dystrophinopathy characterized by intense myonecrosis with inflammatory infiltrate at 4-weeks; muscular regeneration at 12-weeks and persistent fibrosis onwards. Mdx diaphragm muscle has a more severe phenotype with structural and functional deterioration that closely resembles the diaphragm impairment responsible for DMD human patients' morbidity. Herein, we compared calcium deposits, activity of calciumrelated proteases, and expression of muscle-specific proteins in mdx diaphragm at 4-weeks and 12-weeks. We found increased calcium deposits mainly at 12- weeks, concomitant with high activity of calpains and matrix metalloprotease-9, but decreased expression of Myh4 (Myhc IIb) and Atp2a1 (SERCA1), and high expression of the myogenic regulatory factors Myod1 and Myog. Our results suggest that increased calcium deposits and persistent activity of calcium dependent proteases throughout the disease are involved in the degeneration and regeneration processes in the mdx diaphragm

Resolution of skeletal muscle inflammation in mdx dystrophic mouse is accompanied by increased immunoglobulin and interferon-γ production

Mdx mouse, the animal model of Duchenne muscular dystrophy, develops an X-linked recessive inflammatory myopathy with an apparent sustained capacity for muscle regeneration. We analysed whether changes in the skeletal muscle during myonecrosis and regeneration would correlate with functional alterations in peripheral lymphoid tissues. Here we show that during the height of myonecrosis, mdx mice display marked atrophy of peripheral lymph nodes and extensive muscle inflammation. In contrast, enlargement of draining lymph nodes with accumulation of CD4+ CD44+, CD4+ CD25+, CD8+ CD44+ T lymphocytes and type-2 B cells was consistently observed during amelioration of the muscle lesion. In addition, regeneration of the muscular tissue was accompanied by concomitant increase of immunoglobulin-secreting cells in regional lymph nodes and bone marrow. Double immunolabelling analysis revealed intense B cell proliferation and formation of germinal centre in the follicles of dystrophic regional lymph nodes. Furthermore, lymph node cells produced large amounts of IFN-γ but not IL-4, IL-6 or IL-10 after in vitro mitogen stimulation with Concanavalin A. As these alterations occurred mainly during the recovery period, we suggested that local activation of the immune system could be an influence which mitigates the myonecrosis of muscular tissue in the mdx dystrophic mouse

Comparative study of calcium and calcium-related enzymes with differentiation markers in different ages and muscle types in mdx mice.

Sarcolemma instability and increased calcium influx in muscle fibers are characteristics of the Duchenne muscular dystrophy. Excessive calcium activates calcium-dependent enzymes, such as calpains (CAPN) and matrix metalloproteases (MMP). Here, we analyzed calcium deposits, the activity of CAPN and MMP and the expression of Myh, SERCA and myogenic regulatory factors in different skeletal muscles during myonecrosis (4-weeks) and regeneration (12-weeks) phases of the mdx muscular pathology. Alizarin red staining was used to assess calcium deposits, casein and gelatin zymography were performed to evaluate CAPN and MMP activity, and qPCR was used to evaluate the expression of Myh, Capn, Atp2a1 and Atp2a2, Myod1 and Myog. We observed the following characteristics in mdx muscles: (i) calcium deposits almost exclusively in mdx muscles, (ii) lower CAPN1 activity in mdx muscles, (iii) higher CAPN2 activity in mdx muscles (only at 12 wks), (iv) autolyzed CAPN activity exclusively in mdx muscles, (v) lower expression of Capn1 and higher expression of Capn2 in mdx muscles; (vi) lower expression of Atp2a1 and Atp2a2 in mdx muscles, (vii) higher MMP (pre pro MMP2, pro MMP2, MMP2 and MMP9) activity in mdx muscles, (viii) MMP2 activity exclusively in mdx muscles at 12 wks, (ix) MMP9 activity exclusively in mdx muscles, (x) higher expression of Myog in mdx muscles at 12 wks, and (xi) lower expression of Myh (Myh7, Myh2, Myh1, Myh4) in mdx muscles, particularly Myh7 and Myh2. The collection of our results provides valuable information for a better characterization of mdx pathology phenotyp