[Effect of "Zhibian" (BL 54)-to-"Shuidao" (ST 28) needle insertion on the expression of Fas/FADD/Caspase-8 of death receptor pathway in rats with primary ovarian insufficiency].

OBJECTIVE: To explore the effect of "Zhibian" (BL 54)-to-"Shuidao" (ST 28) needle insertion on the ovarian function in the rats with primary ovarian insufficiency (POI) and the potential effect mechanism based on the Fas/FADD/Caspase-8 of death receptor pathway. METHODS: Forty-eight female SD rats were randomly divided into a blank group, a model group, a medication group and an acupuncture group, with 12 rats in each group. Except in the blank group, the rats in the other groups were intraperitoneally injected with cyclophosphamide to establish the POI model. In the acupuncture group, after successful modeling, the intervention was given with "Zhibian" (BL 54)-to- "Shuidao" (ST 28) needle insertion, once daily, 30 min in each intervention; and the duration of intervention was 4 weeks. In the medication group, estradiol valerate tablets were administered intragastrically, 0.09 mg•kg-1•d-1, for 4 weeks. The general situation and the estrous cycle of the rats were compared among groups. Using ELISA, the levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) in the serum were detected. HE staining was adopted to observe the morphological changes of ovarian tissue of rats. The protein expression of Fas, FADD and Caspase-8 in ovarian tissue was detected with immunohistochemistry and Western blot. RESULTS: After modeling, except the rats of the blank group, the rats of the other groups had dry fur, lost hair, low spirits, reduced food intake, increased urination and loose stool. After intervention, the stool became regular gradually in the acupuncture group and the medication group. The percentage of estrous cycle disturbance was increased in the rats of the model group when compared with the blank group (P<0.01); in comparison with the model group, the percentages of estrous cycle disturbance were reduced in the acupuncture group and the medication group after intervention (P<0.01). When compared with the blank group, the body mass and E2 content in the serum were lower (P<0.01), the levels of FSH and LH in the serum and the protein expression levels of Fas, FADD and Caspase-8 were increased (P<0.01) in the model group. Compared with the model group, the body mass and E2 contents in the serum were higher (P<0.01), the levels of FSH and LH in the serum and the protein expression levels of Fas, FADD and Caspase-8 were reduced (P<0.01) in the acupuncture group and the medication group. CONCLUSION: "Zhibian" (BL 54)-to-"Shuidao" (ST 28) needle insertion can effectively improve the ovarian function of POI rats, and its effect mechanism may be related to regulating the serum sex hormone levels, reducing the expression of Fas, FADD and Caspase-8 in ovarian tissue and retarding apoptosis of ovarian cells.

[Effect of penetrative needling of "Zhibian" (BL54) through "Shuidao" (ST28) on expression of TRAIL and its receptors in rats with premature ovarian insufficiency].

OBJECTIVE: To observe the effect of penetrative needling of "Zhibian" (BL54) through "Shuidao" (ST28) on the expressions of death receptor pathway-related protein tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptors, as death receptor 4 (DR4), death receptor 5 (DR5), decoy receptor 1 (DcR1) and decoy receptor 2 (DcR2) in premature ovarian insufficiency (POI) rats, so as to explore its mechanisms underlying improvement of POI. METHODS: Forty female SD rats were randomly divided into blank control, model, penetrative needling and medication (estradiol valerate) groups, with 10 rats in each group. The POI model was established by intraperitoneal injection of cyclophosphamide (D1: 50 mg·kg-1·d-1, D2 to D15: 8 mg·kg-1·d-1, for a total of 15 d). After successful modeling, the rats in the penetrative needling group received penetrative needling of BL54 through ST28, with the needle retained for 30 min, once a day for a total of 4 weeks. Rats of the medication group received gavage of estradiol valerate (0.09 mg·kg-1·d-1) once daily for 4 weeks. After the intervention, the content of serum follicles of stimulation hormone (FSH),lateinizing hormone (LH),estradiol (E2) and vascular endothelial growth factor (VEGF) were assayed using enzyme-linked immunosorbent assay, and histopathological changes of ovarian tissue and the number of follicles were observed under light microscope after H.E. staining. The expression levels of TRAIL, DR4, DR5, DcR1, DcR2, and Fas-associated death domain (FADD) in ovarian tissues were detected using quantitative real-time PCR, and the immunoactivity of ovarian TRAIL, DR4 and DR5 detected using immunohistochemistry. The body weight and the damp weight of ovary were measured for calculating the ovarian coefficient. RESULTS: Compared with the blank control group, the E2 and VEGF contents, ovarian coefficient, and the number of the primary, secondary and sinus follicles were significantly decreased (P<0.01) in the model group, whereas FSH and LH contents, the atretic follicle number, TRAIL, DR4 and DR5 immunoactivity, and the expression levels of TRAIL, DR4, DR5 and FADD mRNAs considerably increased in the model group (P<0.01). In comparison with the model group, the decrease of the VEGF content, ovarian coefficient, and the number of the primary, secondary and sinus follicles, and the increase of the atretic follicle number, TRAIL, DR4 and DR5 immunoactivity, and expression levels of TRAIL, DR4, DR5 and FADD mRNAs were reversed in both penetrative needling and medication groups (P<0.01, P<0.05). The number of primary follicles was significantly more in the medication group than in the penetrative needling group (P<0.01). CONCLUSION: Penetrative needling of BL54 and ST28 can improve ovarian weight and promote follicular development in POI rats, which may be associated with its function in down-regulating the expression of pro-apoptotic proteins TRAIL, DR4, DR5 and FADD of the death receptor pathway to inhibit apoptosis of ovarian granulosa cells.

Targeted Proteomics Combined with Affinity Mass Spectrometry Analysis Reveals Antagonist E7 Acts As an Intracellular Covalent Ligand of Orphan Receptor GPR52.

The GPR52, a class A orphan G protein-coupled receptor (GPCR), is regarded as a promising therapeutic target for the treatment of Huntington's disease and multiple psychiatric disorders. Although the recently solved structure of GPR52 has revealed a binding mechanism likely shared by all reported agonists, the small molecule antagonist E7 cannot fit into this agonist-binding pocket, and its interaction mode with the receptor remains unknown. Here, we employed targeted proteomics and affinity mass spectrometry approaches to uncover a unique binding mode of E7 which acts as a covalent and allosteric ligand of GPR52. Among three Cys residues identified in this study to form covalent conjugates with E7, the intracellular C1564.40 makes the most significant contribution to the antagonism activity of E7. Discovery of this novel intracellular site for covalent attachment of an antagonist would facilitate the design of GPR52-selective negative allosteric modulators which could serve as potential therapeutics for treating Huntington's disease.

Accelerating the Throughput of Affinity Mass Spectrometry-Based Ligand Screening toward a G Protein-Coupled Receptor.

Affinity mass spectrometry (MS) enables rapid screening of compound mixtures for ligands bound to a specific protein target, yet its current throughput is limited to individually assay pools of 400-2000 compounds. Typical affinity MS screens implemented in pharmaceutical industry laboratories identify putative ligands based on qualitative analysis of compound binding to the target whereas no quantitative information is acquired to discriminate high- and low-affinity ligands in the screening phase. Furthermore, these screens require purification of a stabilized form of the protein target, which poses a great challenge for membrane receptor targets. Here, we describe a new, potentially general affinity MS strategy that allows screening of 20,000 compounds in one pool for highly efficient ligand discovery toward a G protein-coupled receptor (GPCR) target. Quantitative measurement of compound binding to the receptor enables high-affinity ligand selection using both the purified receptor and receptor-embedded cell membranes. This high-throughput, label-free and quantitative affinity MS screen resulted in discovery of three new antagonists of the A2A adenosine receptor.