Effects And Mechanisms Of Aquaporin-4 Knockout On The Reproductive Function In Female CD1 Mice

The aquaporins (AQPs) are a family of small (~30 kDa/monomer), hydrophobic, integral membrane proteins that are expressed widely in the animal and plant kingdoms, 13 members having been identified so far in mammals. Their unique permeability characteristics and distribution in numerous tissues indicate diverse roles in the regulation of water homeostasis. Aquaporin-4 (AQP4) is a predominant water channel protein in mammalian brains. Studies aimed at determining the cellular distribution of AQP4 in the CNS have revealed that AQP4 protein expression is restricted to the ependymal cell lining of the ventricles and glial cell membranes, where the most abundant expression was found in perivascular glial processes. This pattern of distribution suggests that AQP4 may play a critical role in balancing the water homeostasis in the brain, and may be the important structural foundation of astrocytes in regulating brain functions.AQP4 is ubiquitously expressed in the hypothalamus, which is closely related to the neuroendocrine function, with a remarkable prevalence in periventricular areas (including preoptic region) and arcuate nucleus. At the same time, these two brain regions are importantly involved in neuroendocrine regulation of gonadotropin-releasing hormone (GnRH) neurons, which are controlled by astrocytes via different mechanisms including regulation of neuron communication, neurosecretion, and synaptic plasticity. GnRH is required for secretion...