Expression of GDNF receptors GFRα1 and RET is preserved in substantia nigra pars compacta of aging Asian Indians

Alladi, Phalguni Anand; Mahadevan, Anita; Shankar, Susarla Krishna; Raju, T.R.; Muthane, Uday B.

doi:10.1016/j.jchemneu.2010.03.007

Cited by 41 publications

(26 citation statements)

References 56 publications

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“…Western blot analysis showed that GFR ␣ 1, AR and SHBG immunoreactive bands were of a similar size to those observed in other species [Becchis et al, 1999;Arenas et al, 2001;Alladi et al, 2010]. The analysis of ER ␤ protein in bullfrog testicular extracts yielded two immunoreactive bands of approximately 55 kDa which are coincident to other species [Arenas et al, 2001;Selva et al, 2004].…”

Section: Discussionsupporting

confidence: 61%

Primordial Germ Cells (Spermatogonial Stem Cells) of Bullfrogs Express Sex Hormone-Binding Globulin and Steroid Receptors during Seasonal Spermatogenesis

Caneguim

Beltrame

Luz

et al. 2012

Cells Tissues Organs

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In vertebrate species, testosterone seems to inhibit spermatogonial differentiation and proliferation. However, this androgen can also be converted, via aromatase, into estrogen which stimulates spermatogonial differentiation and mitotic activity. During seasonal spermatogenesis of adult bullfrogs Lithobates catesbeianus, primordial germ cells (PGCs) show enhanced testosterone cytoplasm immunoexpression in winter; however, in summer, weak or no testosterone immunolabelling was observed. The aim of this study was to confirm if PGCs express stem cell markers – alkaline phosphatase (AP) activity and GFRα1 (glial-cell-line-derived neurotrophic factor) – and verify whether testosterone is maintained in these cells by androgen receptors (ARs) and/or sex hormone-binding globulin (SHBG) in winter. Furthermore, regarding the possibility that testosterone is converted into estrogen by PGCs in summer, the immunoexpression of estrogen receptor (ER)β was investigated. Bullfrog testes were collected in winter and in summer and were embedded in glycol methacrylate for morphological analyses or in paraffin for the histochemical detection of AP activity. GFRα1, AR, SHBG and ERβ expression were detected by Western blot and immunohistochemical analyses. The expression of AP activity and GFRα1 in the PGCs suggest that these cells are spermatogonial stem cells. In winter, the cytoplasmic immunoexpression of ARs and SHBG in the PGCs indicates that testosterone is maintained by these proteins in these cells. The cytoplasmic immunoexpression of ERβ, in summer, also points to an ER-mediated action of estrogen in PGCs. The results indicate a participation of testosterone and estrogen in the control of the primordial spermatogonia during the seasonal spermatogenesis of L. catesbeianus.

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Section: Discussionsupporting

confidence: 61%

Primordial Germ Cells (Spermatogonial Stem Cells) of Bullfrogs Express Sex Hormone-Binding Globulin and Steroid Receptors during Seasonal Spermatogenesis

Caneguim

Beltrame

Luz

et al. 2012

Cells Tissues Organs

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“…Normal aging process does not seem to be associated with significant changes on GDNF expression or on its downstream signaling system (Alladi et al, 2010;Dass et al, 2006). However, animal models of accelerated aging found a significant reduction in brain GDNF expression leading to reduced neuronal viability.…”

Section: Discussionmentioning

confidence: 97%

Circulating Glial-derived neurotrophic factor is reduced in late-life depression

Diniz

Teixeira

Talib

et al. 2012

Journal of Psychiatric Research

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“…The same procedure of autopsy, tissue handling and other procedures were uniformly maintained for all the samples in this study. Similar tissues from the human brain bank have been earlier utilized extensively as control samples in PD research [24][25][26][27] and other studies [28][29][30][31][32].…”

Section: Methodsmentioning

confidence: 99%

Increased Oxidative Damage and Decreased Antioxidant Function in Aging Human Substantia Nigra Compared to Striatum: Implications for Parkinson’s Disease

et al. 2011

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Parkinson's disease (PD) is characterized by selective degeneration and loss of dopaminergic neurons in the substantia nigra (SN) of the ventral mid brain leading to dopamine depletion in the striatum. Oxidative stress and mitochondrial damage have been implicated in the death of SN neurons during the evolution of PD. In our previous study on human PD brains, we observed that compared to SN, striatum was significantly protected against oxidative damage and mitochondrial dysfunction. To understand whether brain aging contributes to the vulnerability of midbrain to neurodegeneration in PD compared to striatum, we assessed the status of oxidant and antioxidant markers, glutathione metabolic enzymes, glial fibrillary acidic protein (GFAP) expression and mitochondrial complex I(CI) activity in SN (n = 23) and caudate nucleus (n = 24) during physiological aging in human brains. We observed a significant increase in protein oxidation (P < 0.001), loss of CI activity (P = 0.04) and increased astrocytic proliferation indicated by GFAP expression (P < 0.001) in SN compared to CD with increasing age. These changes were attributed to significant decrease in antioxidant function represented by superoxide dismutase (SOD) (P = 0.03), glutathione (GSH) peroxidase (GPx) (P = 0.02) and GSH reductase (GR) (P = 0.03) and a decreasing trend in total GSH and catalase with increasing age. However, these parameters were relatively unaltered in CD. We propose that SN undergoes extensive oxidative damage, loss of antioxidant and mitochondrial function and increased GFAP expression during physiological aging which might make it more vulnerable to neurotoxic insults thus contributing to selective degeneration during evolution of PD.

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Expression of GDNF receptors GFRα1 and RET is preserved in substantia nigra pars compacta of aging Asian Indians

Cited by 41 publications

References 56 publications

Primordial Germ Cells (Spermatogonial Stem Cells) of Bullfrogs Express Sex Hormone-Binding Globulin and Steroid Receptors during Seasonal Spermatogenesis

Primordial Germ Cells (Spermatogonial Stem Cells) of Bullfrogs Express Sex Hormone-Binding Globulin and Steroid Receptors during Seasonal Spermatogenesis

Circulating Glial-derived neurotrophic factor is reduced in late-life depression

Increased Oxidative Damage and Decreased Antioxidant Function in Aging Human Substantia Nigra Compared to Striatum: Implications for Parkinson’s Disease

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