Ahi1 regulates the nuclear translocation of glucocorticoid receptor to modulate stress response.

Stress activates the nuclear translocation of glucocorticoid receptors (GR) to trigger gene expression. Abnormal GR levels can alter the stress responses in animals and therapeutic effects of antidepressants. Here, we reported that stress-mediated nuclear translocation of GR reduced Ahi1 in the stressed cells and mouse brains. Ahi1 interacts with GR to stabilize each other in the cytoplasm. Importantly, Ahi1 deficiency promotes the degradation of GR in the cytoplasm and reduced the nuclear translocation of GR in response to stress. Genetic depletion of Ahi1 in mice caused hyposensitivity to antidepressants under the stress condition. These findings suggest that AHI1 is an important regulator of GR level and may serve as a therapeutic target for stress-related disorders.

Effects of electroacupuncture at Guanyuan (CV 4) or Sanyinjiao (SP 6) on hypothalamus-pituitary-ovary axis and spatial learning and memory in female SAMP8 mice.

OBJECTIVE: To investigate the effects of electroacupuncture (EA) at the Guanyuan (CV 4) or Sanyinjiao (SP 6) acupoints on the hypothalamus-pituitary-ovary (HPO) axis and spatial learning and memory in female mice. METHODS: Nine-month-old female mice with senescence-accelerated mouse prone 8 (SAMP8) were divided into three groups: the disease model, EA-Guanyuan and EA-Sanyinjiao groups. Concurrently, 9-month old female mice with senescence-accelerated mouse resistance 1 (SAMR1) were set as the control model group. The two treatment groups were given the same pattern of EA stimulation. Gonadotropin-releasing hormone, luteinizing hormone, follicle-stimulating hormone (FSH) and Serum estradiol levels in the Hypothalamus-pituitary-ovary axis were assessed by enzyme-linked immunosorbent assay to determine the HPO axis function level. Spatial learning and memory were assessed by the Morris Water Maze (MWM) test. RESULTS: (a) HPO axis: compared with the control model group, the disease model group displayed a decrease in E2 levels (P < 0.01), and an increase in GnRH, LH and FSH levels (P < 0.01). E2 levels were increased in EA treatment groups compared with the disease model group (P < 0.05). In contrast, GnRH and LH and FSH levels were reduced (P < 0.05). EA-Sanyinjiao group was superior than EA-Guanyuan group on increasing E2 and declining GnRH levels (P < 0.01). (b) The MWM test demonstrated that the response latency in the EA-Sanyinjiao treatment group declined from day 2 to day 5 compared with the disease model group (P < 0.05), whereas the EA-Guanyuan treatment group showed no significant difference. CONCLUSION: EA can regulate hormone (E2, FSH, LH, GnRH) levels in the HPO axis and the spatial learning and memory ability in female SAMP8 mice. Moreover, this effect may have been more pronounced in the EA-Sanyinjiao group than the EA-Guanyuan group. The underlying mechanism of the EA-induced changes may be related to gonadal hormone shifts in the HPO axis, followed by an improvement in spatial learning and memory.

[Lower He-sea sequence and indication specificity analysis regarding Zusanli (ST 36), Shangjuxu (ST 37) and Xiajuxu (ST 39)].

Zusanli (ST 36), Shangjuxu (ST 37) and Xiajuxu (ST 39) are considered as the lower He-sea points, which are located along the leg lines of stomach meridian of foot Yangming from top to bottom. According to the corresponding zang-fu of lower He-sea points, the distribution order from top to bottom is stomach, large intestine and small intestine. This is significantly different from digestive physiology function sequence of stomach, small intestine and large intestine in modern medicine. However, it conforms to their anatomical position from top to bottom. In order to make a further confirmation that the indication specificity of Zusanli (ST 36), Shangjuxu (ST 37) and Xiajuxu (ST 39) is closely associated with anatomical location, a great number of ancient and modern literature is reviewed. It is found that the functions of the three acupoints are obviously related to stomach, large intestine and small intestine, respectively, indicating that the sequence of Zusanli (ST 36), Shangjuxu (ST 37) and Xiajuxu (ST 39) is related to anatomical position of corresponding zang-fu. This study conclusion could play an important role for exploring the significance of anatomical location in indication specificity of acupoints.

Loss of Ahi1 impairs neurotransmitter release and causes depressive behaviors in mice.

Major depression is becoming one of the most prevalent forms of psychiatric disorders. However, the mechanisms of major depression are still not well-understood. Most antidepressants are only effective in some patients and produce some serious side effects. Animal models of depression are therefore essential to unravel the mechanisms of depression and to develop novel therapeutic strategies. Our previous studies showed that Abelson helper integration site-1 (Ahi1) deficiency causes depression-like behaviors in mice. In this study, we characterized the biochemical and behavioral changes in Ahi1 knockout (KO) mice. In Ahi1 KO mice, neurotransmitters including serotonin and dopamine were significantly decreased in different brain regions. However, glutamate and GABA levels were not affected by Ahi1 deficiency. The antidepressant imipramine attenuated depressive behaviors and partially restored brain serotonin level in Ahi1 KO mice. Our findings suggest that Ahi1 KO mice can be used for studying the mechanisms of depression and screening therapeutic targets.

Apelin-36, a potent peptide, protects against ischemic brain injury by activating the PI3K/Akt pathway.

Apelin is an endogenous ligand of G protein-coupled receptor-apelin and angiotensin-1-like receptor (APJ). The biological effects of apelin-APJ system are reported in multiple systems including cardiovascular, endocrinal, and gastrointestinal system. Previous studies had shown that apelin-13 is a potential protective agent on cardiac ischemia; however, the role of apelin in the central nervous system remained unknown. In this study, we investigated therapeutic effects of apelin-36, a long form of apelin, in ischemic brain injury models. We found that apelin-36 reduced cerebral infarct volume in the middle cerebral artery occlusion (MCAO) model and the neonatal hypoxic/ischemic (H/I) injury model. Apelin-36 improved neurological deficits in the MCAO model and promoted long-term functional recovery after H/I brain injury. We further explored the protective mechanisms of apelin-36 on H/I brain injury. We clearly demonstrated that apelin-36 significantly reduced the levels of cleaved caspase-3 and Bax, two well-established apoptotic markers after H/I injury, indicating the anti-apoptotic activity of apelin-36 in ischemic injury. Since apelin-36 increased the level of phosphorylated Akt after H/I injury, we treated neonates with a specific PI3K inhibitor LY294002. We found that LY294002 decreased the phosphorylated Akt level and attenuated protective effects of apelin-36 on apoptosis. These suggested that the PI3K/Akt pathway was at least in part involved in the anti-apoptotic mechanisms of apelin-36. Our findings demonstrated that apelin-36 was a promising therapeutic agent on the treatment of ischemic brain injury.