Reversal of opiate-induced apoptosis by human recombinant growth hormone in murine foetus primary hippocampal neuronal cell cultures

Abstract

Previous studies have shown that chronic opiates may inhibit cell growth and trigger apoptosis leading to impaired cognitive capabilities in both humans and other mammals. In contrast, growth hormone (GH) has been demonstrated to stimulate cell growth and counteract apoptosis. GH has also been shown to improve learning and memory in both human and rodents. In this work, we demonstrate that GH may reverse opiate-induced apoptosis in cells derived from prenatal mouse hippocampus. Primary hippocampal cell cultures derived from 16-day-old fetal mouse neurons were treated with morphine for 7 days during growth in the absence or presence of recombinant human GH (rhGH). The release of lactate dehydrogenase (LDH) into the culture media and the level of cleaved caspase-3 were measured. Results indicate that morphine (15 M) decreased the cell content in a concentration-dependent manner and increased LDH release and caspase-3 activity. Thus, fetal mouse neurons treated with morphine showed less viability compared with controls. Interestingly, the addition of rhGH (1 M) counteracted the morphine-induced effect on the cell density. Furthermore, the hormone attenuated the effects on LHD release and caspase-3 activity elicited by morphine. These results suggest that the hormone is capable of preventing or even repairing morphine-induced damage to hippocampal cells.apoptosis ͉ morphine ͉ caspase-3 ͉ lactate dehydrogenase

Peripheral administration of GH induces cell proliferation in the brain of adult hypophysectomized rats

“…Interestingly, there is sometimes an association between substances promoting regeneration by enhancing cell proliferation and cell survival. Although GH treatment has not previously been shown to enhance cell proliferation in the adult brain, it has been shown in primary cultures of murine fetal hippocampus to enhance cell survival via suppressing the apoptotic marker caspase-3 (Svensson et al 2008).…”

Cognitive Impairments in Drug Addicts

“…In addition, a recent study showed that chronic morphine significantly and dosedependently attenuates neuronal cell density in cultured hippocampal cells from murine fetus (Svensson et al, 2008). The ability of morphine as well as other opioids to inhibit cell growth and induce apoptosis is already known from previous work as described earlier in this section (see section 4).…”

“…The ability of morphine as well as other opioids to inhibit cell growth and induce apoptosis is already known from previous work as described earlier in this section (see section 4). Therefore, the decline observed in neurite outgrowth in the mouse hippocampal primary cell cultures (Nyberg, 2009;Svensson et al, 2008) was expected, and a consequence of this decline should be that markers of apoptosis, such as lactate dehydrogenase (LDH) and caspase-3, will be affected. In fact, the activity and level of these enzymes were found to be significantly enhanced (Svensson et al, 2008).…”

“…Therefore, the decline observed in neurite outgrowth in the mouse hippocampal primary cell cultures (Nyberg, 2009;Svensson et al, 2008) was expected, and a consequence of this decline should be that markers of apoptosis, such as lactate dehydrogenase (LDH) and caspase-3, will be affected. In fact, the activity and level of these enzymes were found to be significantly enhanced (Svensson et al, 2008). The enhanced activity of LDH in morphine-treated hippocampal cells strongly indicates that morphine may induce apoptosis in cells of this brain area.…”

“…This enzyme was also investigated in order to clarify whether the reduction seen in the hippocampal cell density involves elements related to apoptosis. It was noted that the level of cleaved caspase-3, measured by Western blot analysis, was significantly enhanced by chronic morphine (Svensson et al, 2008). …”