RESUMO
Progesterone shows anti-inflammatory and promyelinating effects in mice with experimental autoimmune encephalomyelitis (EAE), a commonly used model for multiple sclerosis (MS). Because neurosteroids have been implicated as protective factors for MS and EAE, we analysed the expression of neurosteroidogenic enzymes in the compromised spinal cord of EAE mice. EAE was induced in female C57Bl6 mice, which were then killed on day 16 after induction. Progesterone was given by pellet implantation 1 week before EAE induction. Untreated EAE mice showed decreased mRNAs for the steroidogenic acute regulatory protein (Star), voltage-dependent anion channel (VDAC), cholesterol side-chain cleavage (P450scc), 5α-reductase, 3α-hydroxysteroid dehydrogenase (3α-HSOR) and aromatase, whereas changes of 3ß-hydroxysteroid dehydrogenase (3ß-HSD) were not significant. mRNA translocator protein (18 kDa) (TSPO) was elevated, concomitantly with a reactive microgliosis. EAE mice also showed abnormal mitochondrial ultrastructure in axons and neuronal bodies, as well as reduced expression of fission and fusion protein mRNAs. Progesterone pretreatment before EAE induction increased Star, VDAC, P450scc, 5α-reductase type I, 3α-HSOR and aromatase mRNAs and did not modify 3ß-HSD. TSPO mRNA was decreased, possibly as a result of reversal of microgliosis. Progesterone pretreatment also improved mitochondrial ultrastructure and increased fission/fusion protein mRNAs. These mitochondrial effects may be part of the progesterone recovery of neurosteroidogenesis. The enzymes 3ß-HSD, 3α-HSOR and 5α-reductase are also responsible for the formation of androgens. Because MS patients and EAE rodents show changes of central androgen levels, it is likely that, together with progestins and oestrogens, neuroandrogens afford neuroprotection for EAE and MS. The data reviewed suggest that enhanced synthesis of neurosteroids contributes in an auto/paracrine manner to reinforce the neuroprotective and anti-inflammatory effects of exogenous progesterone given to EAE mice.
Assuntos
Encefalomielite Autoimune Experimental/tratamento farmacológico , Inflamação/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Neurotransmissores/biossíntese , Progesterona/uso terapêutico , Animais , Encefalomielite Autoimune Experimental/metabolismo , Inflamação/metabolismo , Mitocôndrias/metabolismo , Fármacos Neuroprotetores/farmacologia , Progesterona/farmacologiaRESUMO
Wobbler mutant mice suffer from progressive motoneuron degeneration and glial cell reactivity in the spinal cord. To prevent development of these abnormalities, we employed Nestorone, a high-affinity progesterone receptor agonist endowed with neuroprotective, promyelinating and anti-inflammatory activities in experimental brain ischemia, preventing neuroinflammation and chemical degeneration. Five-month-old Wobbler mice (wr-/wr-) received s.c. injections of 200µg/day/mouse of Nestorone in vegetable oil or vehicle for 10days. Control NFR/NFR mice (background strain for Wobbler) received vehicle only. Vehicle-treated Wobblers showed typical spinal cord abnormalities, such as vacuolated motoneurons, decreased immunoreactive choline-acetyltransferase, decreased expression of glutamine synthase (GS), increased glial fibrillary acidic protein-positive (GFAP) astrogliosis and curved digits in forelimbs. These cell-specific abnormalities were normalized in Nestorone-treated Wobblers. In addition, vehicle-treated Wobblers showed Iba1+ microgliosis, high expression of the microglial marker CD11b mRNA and up-regulation of the proinflammatory markers TNFα and iNOS mRNAs. In Nestorone-treated Wobblers, Iba1+ microgliosis subsided, whereas CD11b, TNFα and iNOS mRNAs were down-regulated. NFκB mRNA was increased in Wobbler spinal cord and decreased by Nestorone, whereas expression of its inhibitor IκBα was increased in Nestorone-treated Wobblers compared to control mice and vehicle-treated Wobblers. In conclusion, our results showed that Nestorone restraining effects on proinflammatory mediators, microgliosis and astrogliosis may support neurons in their resistance against degenerative processes.
Assuntos
Anti-Inflamatórios/farmacologia , Doença dos Neurônios Motores/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Norprogesteronas/farmacologia , Receptores de Progesterona/agonistas , Medula Espinal/efeitos dos fármacos , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Astrócitos/patologia , Modelos Animais de Doenças , Gliose/tratamento farmacológico , Gliose/patologia , Gliose/fisiopatologia , Masculino , Camundongos Mutantes , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Doença dos Neurônios Motores/patologia , Doença dos Neurônios Motores/fisiopatologia , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Neuroimunomodulação/efeitos dos fármacos , Neuroimunomodulação/fisiologia , Receptores de Progesterona/metabolismo , Medula Espinal/metabolismo , Medula Espinal/patologia , Resultado do TratamentoRESUMO
Progesterone is a neuroprotective, promyelinating and anti-inflammatory factor for the nervous system. Here, we review the effects of progesterone in models of motoneurone degeneration and neuroinflammation. In neurodegeneration of the Wobbler mouse, a subset of spinal cord motoneurones showed increased activity of nitric oxide synthase (NOS), increased intramitochondrial NOS, decreased activity of respiratory chain complexes, and decreased activity and protein expression of Mn-superoxide dismutase type 2 (MnSOD2). Clinically, Wobblers suffered several degrees of motor impairment. Progesterone treatment restored the expression of neuronal markers, decreased the activity of NOS and enhanced complex I respiratory activity and MnSOD2. Long-term treatment with progesterone increased muscle strength, biceps weight and survival. Collectively, these data suggest that progesterone prevented neurodegeneration. To study the effects of progesterone in neuroinflammation, we employed mice with experimental autoimmune encephalomyelitis (EAE). EAE mice spinal cord showed increased mRNA levels of the inflammatory mediators tumour necrosis factor (TNF)α and its receptor TNFR1, the microglial marker CD11b, inducible NOS and the toll-like receptor 4. Progesterone pretreatment of EAE mice blocked the proinflammatory mediators, decreased Iba1+ microglial cells and attenuated clinical signs of EAE. Therefore, reactive glial cells became targets of progesterone anti-inflammatory effects. These results represent a starting point for testing the usefulness of neuroactive steroids in neurological disorders.
Assuntos
Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/tratamento farmacológico , Doenças Neurodegenerativas/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Progesterona/farmacologia , Progestinas/farmacologia , Animais , CamundongosRESUMO
It is now recognised that progesterone plays a protective role for diseases of the central nervous system. In the Wobbler mouse, a model of motoneurone degeneration, progesterone treatment prevents spinal cord neuropathology and clinical progression of the disease. However, neuropathological and functional abnormalities have also been discovered in the brain of Wobbler mice and patients with amyotrophic lateral sclerosis. The present study examined the hippocampus of control and afflicted Wobbler mice and the changes in response to progesterone treatment. Mice received either a single progesterone implant (20 mg for 18 days). We found that the hippocampal pathology of the untreated Wobblers involved a decreased expression of brain-derived neurotrophic factor (BDNF) mRNA, decreased astrogliosis in the stratum lucidum, stratum radiatum and stratum lacunosum-moleculare, decreased doublecortin (DCX)-positive neuroblasts in the subgranular zone of the dentate gyrus and a decreased density of GABA immunoreactive hippocampal interneurones and granule cells of the dentate gyrus. Although progesterone did not change the normal parameters of control mice, it attenuated several hippocampal abnormalities in Wobblers. Thus, progesterone increased hippocampal BDNF mRNA expression, decreased glial fibrillary acidic protein-positive astrocytes and increased the number of GABAergic interneurones and granule cells. The number of DCX expressing neuroblasts and immature neurones remained impaired in both progesterone-treated and untreated Wobblers. In conclusion, progesterone treatment exerted beneficial effects on some aspects of hippocampal neuropathology, suggesting its neuroprotective role in the brain, in agreement with previous data obtained in the spinal cord of Wobbler mice.
Assuntos
Hipocampo/efeitos dos fármacos , Progesterona/farmacologia , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Proteína Duplacortina , Feminino , Imunofluorescência , Proteína Glial Fibrilar Ácida/metabolismo , Hipocampo/anormalidades , Hipocampo/metabolismo , Hibridização In Situ , Masculino , Camundongos , RNA Mensageiro/genéticaRESUMO
Previous results have shown a depletion of brain-derived neurotrophic factor (BDNF) mRNA in the degenerating motoneurons from clinically afflicted Wobbler mice, whereas progesterone treatment reverts this depletion. We now compared progesterone regulation of BDNF in motoneurons and oligodendrocytes of Wobbler mice at the progressive (EP, 1-3 months), symptomatic (SYM, 5-8 months old), and late stages (LS, 12-13 months). As controls we used NFR/NFR mice. Controls and Wobbler mice of different ages remained untreated or received a 20 mg progesterone pellet during 18 days. BDNF mRNA was determined in the ventral, intermediolateral, and dorsal gray matter by film autoradiography and in motoneurons using in situ hybridization. A depletion of BDNF mRNA already occurred at the EP stage of Wobblers, but progesterone was inactive at this period. In contrast, progesterone upregulated the low levels of BDNF mRNA in SYM Wobblers in the three gray matter regions analyzed. Progesterone also increased BDNF mRNA in LS Wobblers, according to grain counting procedures. BDNF protein analyzed by enzyme-linked immunosorbent assay (ELISA) in ventral horns or immunostaining of motoneurons was normal in steroid-naive SYM Wobblers. BDNF protein was decreased by progesterone, suggesting increased anterograde transport and/or release of neuronal BDNF. Wobbler mice also showed depletion of CC1-immunopositive oligodendrocytes, whereas progesterone treatment enhanced the density of BDNF+ and CC1+ oligodendrocytes in EP, SYM, and LS Wobblers. Our results suggest that BDNF could be involved in progesterone effects on motoneurons at the SYM and LS periods, whereas effects on oligodendrocytes occurred at all stages of the Wobbler disease. These steroid actions may be important to arrest the ongoing neurodegeneration.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Doença dos Neurônios Motores/metabolismo , Doença dos Neurônios Motores/patologia , Neuroglia/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Progesterona/administração & dosagem , Fatores Etários , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Modelos Animais de Doenças , Progressão da Doença , Ensaio de Imunoadsorção Enzimática , Regulação da Expressão Gênica/genética , Camundongos , Camundongos Mutantes Neurológicos , Doença dos Neurônios Motores/tratamento farmacológico , Doença dos Neurônios Motores/genética , Mutação , Neuroglia/metabolismo , Neurônios/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Transporte Vesicular/genéticaRESUMO
Progesterone provides neuroprotection after spinal cord injury, but the molecular mechanisms involved in this effect are not completely understood. In this work, expression of two binding proteins for progesterone was studied in intact and injured rat spinal cord: the classical intracellular progesterone receptor (PR) and 25-Dx, a recently discovered progesterone membrane binding site. RT-PCR was employed to determine their relative mRNA levels, whereas cellular localization and relative protein levels were investigated by immunocytochemistry. We observed that spinal cord PR mRNA was not up-regulated by estrogen in contrast to what is observed in many brain areas and in the uterus, but was abundant as it amounted to a third of that measured in the estradiol-stimulated uterus. In male rats with complete spinal cord transection, levels of PR mRNA were significantly decreased, while those of 25-Dx mRNA remained unchanged with respect to control animals. When spinal cord-injured animals received progesterone treatment during 72 h, PR mRNA levels were not affected and remained low, whereas 25-Dx mRNA levels were significantly increased. Immunostaining of PR showed its intracellular localization in both neurons and glial cells, whereas 25-Dx immunoreactivity was localized to cell membranes of dorsal horn and central canal neurons. As the two binding proteins for progesterone differ with respect to their response to lesion, their regulation by progesterone, their cellular and subcellular localizations, their functions may differ under normal and pathological conditions. These observations point to a novel and potentially important role of the progesterone binding protein 25-Dx after injury of the nervous system and suggest that the neuroprotective effects of progesterone may not necessarily be mediated by the classical progesterone receptor but may involve distinct membrane binding sites.
Assuntos
Proteínas de Transporte/metabolismo , Progesterona/farmacologia , Receptores de Progesterona/metabolismo , Traumatismos da Medula Espinal/metabolismo , Medula Espinal/metabolismo , Animais , Proteínas de Transporte/genética , Modelos Animais de Doenças , Estradiol/farmacologia , Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica , Masculino , Proteínas de Membrana , Regeneração Nervosa/fisiologia , Progesterona/sangue , Progesterona/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Progesterona/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologia , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/patologiaRESUMO
Progesterone (P4) can be synthesized in both central and peripheral nervous system (PNS) and exerts trophic effects in the PNS. To study its potential effects in the spinal cord, we investigated P4 modulation (4 mg/kg/day for 3 days) of two proteins responding to injury: NADPH-diaphorase, an enzyme with nitric oxide synthase activity, and glial fibrillary acidic protein (GFAP), a marker of astrocyte reactivity. The proteins were studied at three levels of the spinal cord from rats with total transection (TRX) at T10: above (T5 level), below (L1 level) and caudal to the lesion (L3 level). Equivalent regions were dissected in controls. The number and area of NADPH-diaphorase active or GFAP immunoreactive astrocytes/0.1 mm(2) in white matter (lateral funiculus) or gray matter (Lamina IX) was measured by computerized image analysis. In controls, P4 increased the number of GFAP-immunoreactive astrocytes in gray and white matter at all levels of the spinal cord, while astrocyte area also increased in white matter throughout and in gray matter at the T5 region. In control rats P4 did not change NADPH-diaphorase activity. In rats with TRX and not receiving hormone, a general up-regulation of the number and area of GFAP-positive astrocytes was found at all levels of the spinal cord. In rats with TRX, P4 did not change the already high GFAP-expression. In the TRX group, instead, P4 increased the number and area of NADPH-diaphorase active astrocytes in white and gray matter immediately above and below, but not caudal to the lesion. Thus, the response of the two proteins to P4 was conditioned by environmental factors, in that NADPH-diaphorase activity was hormonally modulated in astrocytes reacting to trauma, whereas up-regulation of GFAP by P4 was produced in resting astrocytes from non-injured animals.
Assuntos
Astrócitos/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , NADPH Desidrogenase/metabolismo , Progesterona/fisiologia , Traumatismos da Medula Espinal/metabolismo , Medula Espinal/citologia , Animais , Astrócitos/enzimologia , Imuno-Histoquímica , Masculino , Ratos , Ratos Sprague-Dawley , Medula Espinal/enzimologia , Medula Espinal/metabolismo , Traumatismos da Medula Espinal/enzimologia , Traumatismos da Medula Espinal/patologiaRESUMO
Using the KC 146 monoclonal antibody recognizing the B-form of the progesterone receptor (PR) and immunocytochemical techniques, we investigated if PR-immunoreactive cells are present in the rat spinal cord. Neurons from ventral horn Lamina IX, glial cells in gray and white matter and ependymal cells were PR-positive. Evidence for estrogen-inducibility of PR in ovariectomized rats was not observed. There were no significant gender differences in neuronal PR immunostaining intensity in the spinal cord, measured by computerized image analysis. In pituitary and uterus from estrogenized female rats, PR showed a strict nuclear localization, whereas in neurons and glial cells of the spinal cord, PR localized in cytoplasm and/or nucleus and in some cell processes. This receptor may be implicated in some of the biological effects of progesterone described in the spinal cord.
Assuntos
Neuroglia/química , Neurônios/química , Receptores de Progesterona/análise , Medula Espinal/química , Medula Espinal/citologia , Animais , Anticorpos Monoclonais , Especificidade de Anticorpos , Estrogênios/farmacologia , Feminino , Imuno-Histoquímica , Masculino , Ovariectomia , Ratos , Ratos Sprague-Dawley , Receptores de Progesterona/imunologia , Fatores SexuaisRESUMO
Lifelong occupational histories obtained by interview prior to death were compared to death certificate data for 87 male bladder cancer patients in Utah. Agreement was defined as identical Bureau of Census codes, after predetermined groupings were made. Usual occupation, defined as that with the longest duration, agreed with the death certificate occupation for 54% of the individuals; usual industry agreed for 72%. Most recent occupation and industry agreed for 47% and 53%, respectively. For 69%, at least one interview occupation agreed with the death certificate occupation, and at least one industry agreed for 84%. Variables affecting agreement were duration of the job and education. Also examined were interview data about employment either during the last 15 years or prior to age 65 years, obtained from 112 male colon cancer patients. The Bureau of Census codes were in agreement for occupation in 63% and for industry in 65%. Duration of the job and education were related to percent agreement. We conclude that occupations and industries listed on death certificates reflect at least part of the work history of the majority of individuals.