Elsevier

Neuropharmacology

Volume 39, Issue 5, April 2000, Pages 873-880
Neuropharmacology

Vitamin D3 attenuates cortical infarction induced by middle cerebral arterial ligation in rats

https://doi.org/10.1016/S0028-3908(99)00255-5Get rights and content

Abstract

We have previously reported that intracerebral administration of glial cell line derived neurotrophic factor (GDNF) reduces the extent of middle cerebral arterial (MCA) ligation-induced cortical infarction in rats. Recent studies have shown that application of 1,25 dihydroxyvitamin D3 (D3) enhances GDNF mRNA expression in vitro. The purpose of the present study was to investigate if administration of D3 in vivo will protect against ischemic brain injury. Adult male Sprague–Dawley rats were injected daily with D3 or with saline for four or eight days. Animals received a 90-min right MCA ligation on the 4th or 8th day after anesthesia with chloral hydrate. Animals were sacrificed for tri-phenyl-tetrazolium chloride (TTC) staining 24 h after the onset of reperfusion. A subset of animals receiving eight days of D3 or saline treatment were used for blood gas and cerebral GDNF protein level analysis. We found that pretreatment with D3 for four days did not attenuate the ischemic injury. However, animals receiving eight days of D3 injections showed a significant reduction in the amount of infarction in the cortex. Eight day D3 treatment did not alter blood gases or blood pressure; however, it did increase calcium levels. Pretreatment with D3 significantly increased GDNF levels in the cortex. In conclusion, our data indicate that D3 reduces ischemia- induced brain damage and supports the hypothesis that this effect may be through the up-regulation of GDNF mechanisms in cortex.

Introduction

Ischemic or hypoxic brain injury, a major problem world wide, often causes irreversible brain damage and is the third leading cause of death in the USA (Brown et al., 1996, Menotti et al., 1996, Tuomilehto et al., 1996). The mechanisms of brain damage include release of excitatory amino acids, depolarization-induced calcium entry, intracellular nitric oxide or free radical generation, damage to mitochondrial respiratory enzymes, and induction of programmed cell death. Treatment for this disorder is still only palliative. Up to now, there are no effective pharmacotherapies for this illness.

Neurotrophic factors may play important roles during neuronal damage. Transforming growth factor (TGF)-β1 transcript expression is enhanced in the hippocampus following transient forebrain ischemia (Knuckey et al., 1996). Similarly, the expression of glial cell line-derived neurotrophic factor (GDNF) is up-regulated in the ischemic cortex after transient middle cerebral arterial occlusion (Abe and Hayashi, 1997). GDNF mRNA and/or GDNF receptor alpha-1 (GFR α1) mRNA are up-regulated in the sciatic nerve and in the CNS after injury in mice (Naveilhan et al., 1997), and in hippocampus after systemic administration of kainate acid in rats (Humpel et al., 1994).

The induction of neurotrophic factors during ischemia or neuronal damage may play a supportive role. GDNF or neurotrophin (NT)-4, have been shown to increase the survival of corticospinal neurons in vitro (Junger and Varon, 1997). Moreover, we, and others, recently found that pretreatment with GDNF reduces cortical infarction, nitric oxide release (Wang et al., 1997) and TUNEL labeling in cortex during stroke (Abe et al., 1997, Kitagawa et al., 1998). Our recent findings also indicate that transplantation of GDNF enriched tissue, such as fetal kidney, to the ischemic cortex protects against ischemia/reperfusion-induced injuries in adult rat brain (Chiang et al., 1999). These data suggest that GDNF has protective effects against cerebral ischemia.

Trophic factors can be up-regulated by different treatments. Recent studies have indicated that 1,25 dihydroxyvitamin D3 (D3), an active metabolite of vitamin D, is a potent inducer of trophic factors in vitro. D3 augments GDNF expression in C6 glioma cells (Naveilhan et al., 1996) and GDNF release in human U-87 MG glioblastoma cells (Verity et al., 1999), increases NGF (Veenstra et al., 1997b) and TGF-β2 (Veenstra et al., 1997a) expression in neuroblastoma cells, and elevates NT3/NT4 mRNA levels in astrocytes (Neveu et al., 1994). D3 has synergic effects with TGF-β1-induced NGF release from astrocytes (Hahn et al., 1997). Taken together, these data suggest that D3 can up-regulate various trophic factors, including GDNF, in vitro. Moreover since D3, unlike GDNF, is able to cross the blood–brain barrier, it is thus possible that systemic administration of this compound could protect against ischemic brain injury indirectly via an elevation of trophic factors.

In the present study, we examined the protective effects of D3 in the MCA occlusion model of cerebral ischemia in vivo. We found systemic administration of D3 markedly increases GDNF expression and attenuates cortical infarction induced by MCA ligation, suggesting that the protective effect of D3 may be probably mediated through the up-regulation of GDNF expression in the cortex.

Section snippets

Animals and chemicals

A total of 60 adult male Sprague–Dawley rats (weight >300 g) were used for this study. Of these, 32 rats were used for the middle cerebral arterial (MCA) ligation study. These animals were further divided into three groups: D3×4 [n=7, received daily 1,25(OH)2 Vitamin D3 (Calcitriol, Abbottlab,) intraperitoneal (i.p.) injections for four days starting from three days before MCA ligation], D3×8 [n=11, received daily D3 i.p. injections for eight consecutive days starting from seven days before MCA

Cortical infarction

We and others have previously reported that ligation of the MCA for 90 min and reperfusion for 24 h causes cortical infarction in rats (Chen et al., 1986, Du et al., 1996). In the present experiments, we found that MCA ligation induced infarction in all animals pretreated with saline (Fig. 1). Three parameters were used to analyze the severity of infarction: (A) the volume of infarction, the product of infarcted area in all slices and thickness of each slice (2 mm), (B) the area of the largest

Discussion

Proteins in the TGF-β1 superfamily were initially considered to provide trophic influences only for developing neurons. Recent studies, however, indicate that these trophic factors also have reparative and protective functions during hypoxia and ischemia. We, and others, have reported that application of GDNF, a member in TGF-β1 superfamily, to the cerebral cortex reduces the incidence of cortical TUNEL (+) cells, ameliorates ischemia induced brain edema (Abe et al., 1997), and prevents

Acknowledgements

This study was supported by the National Institute on Drug Abuse.

References (44)

  • M. Reeben et al.

    The messenger RNAs for both glial cell line-derived neurotrophic factor receptors, c-ret and GDNFR alpha, are induced in the rat brain in response to kainate-induced excitation

    Neuroscience

    (1998)
  • T.D. Veenstra et al.

    Effects of 1,25-dihydroxyvitamin D3 on growth of mouse neuroblastoma cells

    Developmental Brain Research

    (1997)
  • T.D. Veenstra et al.

    1,25-dihydroxyvitamin D3 regulates the expression of N-myc, c-myc, protein kinase C, and transforming growth factor-beta2 in neuroblastoma cells

    Biochemistry and Biophysiology Research Communications

    (1997)
  • L. Verlinden et al.

    Differentiation induction of HL60 cells by 1,25(OH)2D3, all trans retinoic acid, rTGF-beta2 and their combinations

    Journal of Steroid Biochemistry and Molecular Biology

    (1997)
  • Y. Wang et al.

    Ketamine antagonizes hypoxia-induced dopamine release in rat striatum

    Brain Research

    (1995)
  • G.K. Whitfield et al.

    Genomic actions of 1,25-dihydroxyvitamin D3

    Journal of Nutrition

    (1995)
  • R.N. Barnett et al.

    Performance of “kits” used for clinical chemical analysis of calcium in serum

    American Journal of Clinical Pathology

    (1973)
  • R.D. Brown et al.

    Stroke incidence, prevalence, and survival: secular trends in Rochester, Minnesota, through 1989

    Stroke

    (1996)
  • S.T. Chen et al.

    A model of focal ischemic stroke in the rat: reproducible extensive cortical infarction

    Stroke

    (1986)
  • Chiang, Y.H., Lin, S.Z., Borlongan, C.V., Hoffer, B.J., Morales, M.F., Wang, Y., 1999. Transplantation of fetal kidney...
  • C. Du et al.

    Very delayed infarction after mild focal cerebral ischemia: a role for apotosis

    Journal of Cerebral Blood Flow and Metabolism

    (1996)
  • M. Hahn et al.

    Effect of calcitriol in combination with corticosterone, interleukin-1beta, and transforming growth factor-beta1 on nerve growth factor secretion in an astroglial cell line

    Journal of Neurochemistry

    (1997)
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