Disorders of selenium metabolism and selenoprotein function

Abstract

The spectrum of diseases related to inborn defects of selenium utilization, transport, and metabolism is expanding. However, only few examples are already known, resulting from defects in one selenoprotein gene and two genes involved in selenoprotein biosynthesis, respectively. Complex syndromes with impaired muscle function, stunted growth, neurosensory and/or immune defects may point to the involvement of impaired selenium metabolism and selenoprotein function, necessitating specific diagnostic procedures.

Mice Lacking Selenoprotein P and Selenocysteine Lyase Exhibit Severe Neurological Dysfunction, Neurodegeneration, and Audiogenic Seizures

“…Patients with mutations in the selenocysteine insertion sequence-binding protein 2 (SBP2), an RNA-binding protein required for the translation of selenoprotein mRNAs (34), were found to have deficient selenoprotein levels and to exhibit multiple deficits, including hearing loss at high frequencies, muscle weakness, gait abnormalities, and cognitive impairments (35). Similarly, mutations in the selenocysteine synthase (SepSecS) gene were reported to cause progressive cerebello-cerebral atrophy, a syndrome characterized by progressive microcephaly, mental retardation, severe spasticity, and generalized seizures (36,37). In the clinical literature, there is also evidence for a relationship between low selenium status and epilepsy in children (38 -40).…”

Protective Effects of Riboflavin and Selenium on Brain Microsomal Ca2+-ATPase and Oxidative Damage Caused by Glyceryl Trinitrate in a Rat Headache Model

“…Selenium is a cofactor in the GSH-Px enzyme. GSH is used as a substrate to the synthesis the GSH-Px [12][13][14]. If the free radical production increases proportionally to the consumption of GSH-Px enzyme activities, GSH levels also decline.…”

“…2 The effects of selenium (Se) and riboflavin (RBF) on electroencephalography records in brain of headache-induced rats (n=8 and mean±SD) migraines [21]. The selenium-dependent GSH-Px antioxidant enzyme is responsible for the reduction of hydro-and organic peroxides in the presence of GSH [12][13][14]. GSH is the most abundant thiol antioxidant in mammalian cells and maintains thiol redox in the cells.…”

“…Selenium as a GSH-Px enzyme cofactor is also incorporated into the selenoproteins that are involved in antioxidant defenses [9]. Selenium is incorporated in mammalian proteins as selenocysteine or selenomethionine, both of which are dietary forms of selenium, although selenomethionine is the major form [13,14]. Selenium is implicated as the neuroprotective agent in several neuronal diseases including epilepsy [15,16] and pain [17].…”

The relationship between selenium and gastrointestinal inflammatory diseases

“…Az emberi szervezetben 6-14 mg szelén található, amely főként a pajzsmirigyben, májban, szívizomban, hasnyálmirigy-ben, herében raktározódik. Biológiai hatását azáltal fejti ki, hogy fontos alkotója egyes antioxidáns fehérjék-nek, enzimeknek (1. táblázat) [2]. A szelén és a hormonok közötti kapcsolat először állatok megfi gyelésénél vetődött fel, amikor szelénhiányos hím állatokban csök-kent fertilitást állapítottak meg [3].…”