Role of Gonadotropin-releasing Hormone Stimulation Test in Diagnosing Gonadotropin Deficiency in Both Males and Females with Delayed Puberty.

BACKGROUND: Delayed puberty can result either from constitutional delay of growth and puberty (CDP) or idiopathic hypogonadotropic hypogonadism (IHH). Gonadotropin-releasing hormone (GnRH) stimulation test has been generally accepted as a current method for diagnosing delayed puberty. The objective of this research was to assess the cut-off values and the efficacy of GnRH stimulation test in the diagnosis of delayed puberty in both males and females. METHODS: A study of 91 IHH, 27 CDP patients, 6 prepubertal children, and 20 pubertal adults was undertaken. Blood samples were obtained at 0, 30, 60, and 120 min after GnRH administration and the levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured. For each parameter, the sensitivities and specificities were estimated, and the receiver operating characteristic (ROC) curves were constructed. RESULTS: The ROC curves indicated that a serum basal LH <0.6 IU/L or peak LH <9.74 IU/L resulted in moderate sensitivity (73.8% or 80.0%) and specificity (90.9% or 86.4%) in the diagnosis of HH in males. Serum basal LH <0.85 IU/L or basal FSH <2.43 IU/L resulted in moderate sensitivity (80.0% or 100.0%) and specificity (75.0% or 50.0%) in the diagnosis of HH in females. CONCLUSIONS: Our data suggest that isolated use of the gonadorelin stimulation test is almost sufficient to discriminate between HH and CDP in males, but unnecessary in females. The most useful predictor is serum basal or peak LH to differentiate these two disorders in males, but serum basal LH or FSH in females.

[Prepared the monoclonal antibody associated with hepatocellular carcinoma and analyzed its epitope].

AIM: To prepare the monoclonal antibodies associated with hepatocellular carcinoma (HCC) for diagnosis. METHODS: 3 BALB/c mice were immunized with high metastasis characteristic HCC cells (HCCLM-6). The splenocytes from the immunized mice were fused with murine myeloma cells (Sp2/0). The hybridoma cells were screened by ELISA after coating with the total protein and the culture supernatant of HCCLM-6 cells. The mAbs were characterized by immunohistochemical staining in the HCC tissues, and by indirect immunofIuorescent staining in different cell lines. The antigen and epitope recognized by the mAbs were identified by the screening premade Uni-ZAP human liver cDNA expression library. RESULTS: Twenty-eight hybridoma cells secreting mAbs were established. One clone of the hybridomas, QGA062, secreted specific mAb associated with HCC. The antigen recognized by the mAb QGA062 was identified as fibronectin (FN), and the epitope was localized among the peptide YTVSLVAIKGNQESPK. CONCLUSION: The mAb against a HCC-associated epitope in FN is established and characterized, will be a very useful reagent for diagnosis of HCC.

[Preparation and identification of PON2 monoclonal antibodies.].

AIM: To prepare and characterize the mouse monoclonal antibodies against human PON2 (paraoxonase 2). METHODS: A fragment of human PON2 gene of low homology with mice but of strong hydrophilicity and immunogenicity was selected for recombinant expression. Mice were immunized with the purified HIS fusion protein 3 times. The specificity and sensitivity of the anti-human PON2 monoclonal antibodies were characterized by Western blot and indirect immunofluorescence. RESULTS: HIS-PON2 and GST-PON2 fusion protein was highly expressed in E.coli with a molecular weight of 40 kDa and 46 kDa. Western blot analysis proved that the established monoclonal antibodies could specifically recognize the target proteins expressed in E.coli expression system. Indirect immunofluorescence analysis confirmed that PON2 protein was located in the cytoplasm of HepG2 cells. CONCLUSION: The monoclonal antibodies against human PON2 can specifically recognize natural protein expressed in human cells, Which can be used for further functional study of PON2 protein.

[Preparation and identification of monoclonal antibody against enoyl-CoA hydratase 1].

OBJECTIVE: To prepare monoclonal antibodies (mAbs) against enoyl-CoA hydratase 1 (ECH1). METHODS: Normal human liver tissues were homogenized, and the mitochondria were isolated by differential centrifugation. The total mitochondrial proteins were used to immunize BALB/c mice to prepare mAbs by routine hybridoma technique. The mAbs were characterized by ELISA, Western blotting and immunohistochemistry. The specificity of the antibody was identified by mass spectrometry (MS) following immunoprecipitation (IP) and confirmed by Uni-ZAP expression library screening. RESULTS: One clone of the hybridoma BGB095 secreting specific mAb against ECH1 was obtained. The mAb was identified to belong to Ig subclass IgG1 and could be used in ELISA, Western blotting, immunohistochemistry, and immunoprecipitation. CONCLUSION: A hybridoma cell line stably secreting specific mAb against ECH1 has been established. The specific mAb against ECH1 can be of great value for functional and distribution studies of ECH1.

[Expression of procalcitonin and characterization of antibodies against PCT].

AIM: To construct the expression vectors of procalcitonin (PCT), prepare polyclonal antibodies (pAbs) and monoclonal antibodies (mAbs) against PCT and identify their specific biological activity. METHODS: The recombinant expression plasmids of pGEX-4T-1-PCT and PET-32a-PCT were constructed using thyroid carcinoma cell line (TT cell) cDNA as template. The fusion protein of His-PCT was expressed in E.coli and used as immunogen. The specificity of antiserum against human PCT was characterized by ELISA, Western blot and indirect immunofluorescence. The mAbs against human PCT were identified by Western blot and indirect immunofluorescence. RESULTS: The recombinant expression plasmids of pGEX-4T-1-PCT and PET-32a-PCT were constructed and the fusion protein of His-PCT was expressed and purified. The antiserum against human PCT was prepared and the titer detected by ELISA was 1:256 000. The pAb specifically recognized the recombinant human PCT. Eight hybridoma cell lines secreting specific mAbs against PCT were established. The mAbs recognized the recombinant human PCT and four of them recognized the native PCT of TT cytoplasm in immunofluorescent assay. CONCLUSION: The successful preparation of polyclonal and monoclonal antibodies against human PCT is beneficial to further research into the pathological and physiological functions of PCT in severe bacterial infection and sepsis.

[Preparation and preliminary application of rabbit anti-human PON2 antibodies(paraoxonase-2)].

AIM: To preparation and characterize the rabbit polyclonal antibodies against human PON2 (paraoxonase-2). METHODS: A fragment of human PON2 gene which was of low homology with rabbits but of higher hydrophilicity and immunogenicity was selected for recombinant expression in prokaryotic expression system. The rabbits were immunized with the purified GST fusion protein 3 times. The specificity and sensitivity of the anti-human PON2 polyclonal antibodies were detected by Western blot and indirect immunofluorescence. RESULTS: The GST-PON2 fusion protein was highly expressed in Ecoli with a molecular weight of 46 kDa. Western blot analysis proved the rabbit polyclonal antibodies could specifically recognize 39 kDa native PON2 protein expressed in several cells and tissues, such as HeLa cells, U937 cells, and human liver tissue. Indirect immunofluorescence analysis confirmed that PON2 protein was located in the cytoplasm of SY5Y cells. CONCLUSION: The rabbit polyclonal antibodies against human PON2 can specifically recognize natural protein expressed in human cells and tissues, Which can be used for further study and clinical detection of human PON2.

[Preparation, characterization and application of monoclonal antibody against CPS1].

AIM: To prepare and characterize the monoclonal antibody (mAb) against human carbamyl phosphate synthetase I (CPSI) and make a study of its application. METHODS: Normal human liver tissues were homogenized, and their mitochondria were isolated by differential centrifugation. The total mitochondrial proteins were used to immunize BALB/c mice to prepare mAb using the routine hybridoma technique. The mAb was detected by ELISA, Western blot immunohistochemistry and immunofluorecent staining. The specificity of mAb was identified by mass spectrometry (MS) and immunoprecipitation (IP) and then confirmed by Uni-ZAP expression library screening. The antibody was used to isolate potential enzymatic complexes by immunocapturing. RESULTS: Three hybridoma cell lines BEH045, ACB271 and BFG021 secreting specific mAb against CPS1 were obtained. The Ig subclass of the mAb was IgG(1), which was used in ELISA, Western blot immunohistochemistry, immunoprecipitation, immunofluorecent staining and the isolation of potential enzymatic complexes. CONCLUSION: A hybridoma cell line which can secre specific mAb against CPSI stably has been established. The specific mAb against CPSI is of value to the research into the functions and distribution of CPSI.

[Generation and characterization of monoclonal antibody against HSD11B1].

AIM: To generate and identify monoclonal antibodies (mAb) against homo sapiens hydroxysteroid 11-beta dehydrogenase 1 (HSD11B1). METHODS: Normal human liver tissues were homogenized, and mitochondria were isolated by differential centrifugation. The total mitochondrial proteins were used to immunize BALB/c mice to generate mAb by hybridoma technique. The mAb were characterized by ELISA, Western blot and immunohistochemistry. The antibody specificity was identified by immunoprecipitation (IP), and confirmed by Uni-ZAP expression library screening. RESULTS: One hybridoma CBF245 secreting specific mAb against HSD11B1 was established. The Ig subclass of this mAb was IgG1, and it could be used in ELISA, Western blot, immunohistochemistry. Our data showed that the antigen recognized by CBF245 mAb was localized in the hepatocyte cytoplasm, with molecular weight of M(r) 35 000 in the mitochondria of human liver tissue. The CBF245 mAb was further confirmed by immunoscreening of Uni-ZAP XR liver cDNA expression library. CONCLUSION: A hybridoma cell line stably secreting specific mAb against HSD11B1 is established and characterized. This mAb reacted with HSD11B1 in ELISA, Western blot, immunohistochemistry assay, IP, and would be very useful for the HSD11B1 studies.

[Preparation and characterization of antibodies against clusterin].

AIM: To prepare rabbit polyclonal antibodies (pAb) and mouse monoclonal antibodies (mAbs) against human clusterin(CLU) and characterize these antibodies' properties. METHODS: CLU fragment was amplified from human liver cDNA library, and recombinant expression vectors pGEX-4T-1-CLU and PET-32a-CLU were constructed. GST-CLU fusion protein was expressed in E.coli and then used as the immunogen. Properties of antiserum against human CLU were identified by ELISA, Western blot, and the mAbs against human CLU was characterized by Western blot, indirect immunofluorescent staining and immunohistochemistry staining. RESULTS: The GST-CLU fusion protein was highly expressed with a molecular weight of M(r)54,000. Western blot analysis proved that the rabbit pAb could specifically recognize 52,000 and 58,000 proteins in human liver total protein. All of the nine established mAbs recognized recombinant human CLU protein, two of which specifically bound to proteins in the cytoplasm of HepG2 cells and four of which specifically bound to proteins in the cytoplasm of adult liver tissue. CONCLUSION: pAb and mAbs against human CLU were successfully prepared, which will provide efficient tools for functional studies of CLU expressed in human tumors.

[Method of antibody analysis based on visual protein array].

AIM: To establish a novel method for antibody analysis based on visual protein microarray. METHODS: The antibodies spotted on the aldehyde-modified slides were incubated with corresponding antigens labeled by biotin, followed by silver enhancement detection method, and the chromogenic images were scanned by CCD camera. RESULTS: The affinity and specificity of each antibody was assayed by this method and six antibodies were found to have higher specificity than the others. A detection limit of 0.4 microg/L was obtained for anti-globulinIIIC013, anti-albumin HPSIIB007, and anti-albumin HPSIIIB007. CONCLUSION: This method is simple, fast and visual. In addition, it needs less sample amount than traditional immunoassay and has potential to achieve high throughput.

[Generation and characterization of monoclonal antibody against GRHPR].

AIM: To generate monoclonal antibodies (mAb) against glyoxylate reductase/hydroxypyruvate reductase (GRHPR). METHODS: Normal human liver tissues were homogenized, and human liver cytosolic proteins were isolated by centrifugation. The total human liver cytosolic proteins were used to immunize BALB/c mice to prepare mAb by hybridoma technique. The mAbs were detected by ELISA, Western blot, and immunohistochemistry. The antibody specificities were identified by mass spectrometry (MS) following immunoprecipitation (IP) and confirmed by Uni-ZAP expression library screening. RESULTS: One hybridoma cell line, ADB291, secreting specific mAb against GRHPR was established. The Ig subclass of the mAb was IgG1(kappa). Data from immunohistochemistry showed that ADB291 can recognize hepatocyte cytoplasm. ADB291 mAb was used to isolate its protein antigen by IP. Proteins captured by the mAb were loaded to SDS-PAGE and subjected to Western blot and MALDI-TOF MS analysis. lambda expression Uni-ZAP XR pre-made liver cDNA library was screened with ADB291 hybridoma supernatants. All of our data demonstrated that ADB291 mAb specially reacted with GRHPR. CONCLUSION: A hybridoma cell line stably secreting specific mAb against GRHPR is established. The specific mAb against GRHPR would be very useful for the studies of GRHPR functions and distribution.

[Identification of protein antigen for antibody DBD02 by biopanning of T7 phage display library].

AIM: To identify the specificity of mAb DBD02, we developed and optimized a new method by biopanning of T7 Select human liver cDNA phage display library. METHODS: After two rounds of biopanning, eluted phages were subjected to Dot blot using mAb DBD02 as primary antibody. The positive PFUs (plaque forming unit) which recognized by DBD02 were further confirmed by Western blot, PCR and sequencing. RESULTS: The antigen recognized by DBD02 was identified as alcohol dehydrogenase. And the epitope for mAb DBD02 was further mapped within a peptide of 22 amino acids (QDYKKPIQEVLKEMTDG-GVDFS). CONCLUSION: Our data indicate that biopanning of T7 phage display library by mAbs is time, cost, and labor-saving and specific tool for protein antigen identification.

[Preparation and identification of monoclonal antibody against Homo sapiens hemoglobin alpha 2 (HBA2)].

This study was purposed to prepare and identify monoclonal antibodies (McAbs) against Homo sapiens hemoglobin alpha 2 (HBA2). Normal human fetal liver tissues were homogenized, and human liver nuclear proteins were isolated by centrifugation. The total human fetal liver nuclear proteins were used to immunize BALB/c mice for preparing McAbs by hybridoma technique. The McAbs specificity was identified by ELISA, Western blot, and immunohistochemistry. The antigen was identified by Uni-ZAP expression library screening. The results showed that one hybridoma cell line, AEE091, secreting specific McAb against HBA2 was established. The Ig subclass of this McAb was IgG1 (kappa). Data from immunohistochemistry assay showed that AEE091 could recognize human liver nuclear protein. Using AEE091 McAb, isolation of the protein antigen by IP revealed that AEE091 McAb could recognize 15 kD protein. Screening the Uni-ZAP XR pre-made liver cDNA library with AEE091 hybridoma cell supernatants demonstrated that AEE091 McAb specially reacted with HBA2. It is concluded that a hybridoma cell line stably secreting specific McAb against HBA2 is established. The specific McAb against HBA2 would be very useful for studying HBA2 function and screening thalassemia.

[Preparation and identification of monoclonal antibody against UGP2].

The study was aimed to generate monoclonal antibodies (mAbs) against homo sapiens UDP-glucose pyrophosphorylase 2 (UGP2). Normal human liver tissues homogenized, and cytosolic proteins isolated by centrifugation were used to immunize BALB/c mice to generate mAbs by hybridoma technique. The mAbs were identified by ELISA, Western blot, and immunohistochemistry assay. The antibody specificity was confirmed by Uni-ZAP expression library screening. The results indicated that one hybridoma BAD062 secreting specific mAb against UGP2 was established. The Ig subclass of this mAb was IgG(2b) (kappa), and it could be used in ELISA, Western blot, immunohistochemistry assay. The antigen recognized by BAD062 mAb was localized in the hepatocyte cytoplasm, with molecular weight of 56 kD in the cytosolic proteins of human liver tissue. The BAD062 mAb was further confirmed by immunoscreening of Uni-ZAP XR liver cDNA expression library. It is concluded that a hybridoma cell line stably secretes specific mAb against UGP2. This mAb reacted with UGP2 in ELISA, Western blot, immunohistochemistry assay, and would be very useful for the UGP2 studies.

[Recombinant human VEGF-D induces the angiogenesis of the chick embryo chorioallantoic membrane].

Vascular endothelial growth factor-D (VEGF-D) and vascular endothelial growth factor receptor-2, -3 (VEGFR-2, -3) with their corresponding signaling pathway play significant roles in the development of the embryonic vascular system and pathological lymphangiogenesis. The study was aimed to express and purify the GST-VEGF-D fusion protein, and to explore the angiogenesis effect of VEGF-D. The total RNA was extracted from human fetal lung tissue, and the mature form of VEGF-D was expanded by polymerase chain reaction (PCR), then the plasmid pGEX-5X-1/VEGF-D was reconstructed and the GST-VEGF-D fusion protein expressed in transformed E.coli BL21-DE3. The results showed that the molecular mass of this fusion protein was 38 kD and compassed more than 15% of the total bacteria proteins. The fusion protein was recognized by anti-GST and anti-VEGF-D antibodies. The soluble GST-VEGF-D fusion protein could interact with VEGFR-3/Fc and was able to stimulate the proliferation of human erythroleukemia cell line (HEL) cells. The data of chick embryo chorioallantoic membrane (CAM) experiments indicated that GST-VEGF-D could induce the CAM angiogenesis. It is concluded that the GST-VEGF-D fusion protein with biological activity was successfully expressed, and which may provide an experimental model for the investigation of the VEGF-D-induced angiogenesis and lymphangiogenesis.

Heat shock protein 70 inhibits alpha-synuclein fibril formation via interactions with diverse intermediates.

alpha-Synuclein (AS) is a main component of Lewy bodies in midbrain dopamine neurons pathologically characteristic of Parkinson's disease. We show that heat shock protein (Hsp) 70 inhibits AS fibril formation via preventing the formation of prefibrillar AS (PreAS), binding with PreAS to impede nuclei formation, and binding with nuclei to retard fibril elongation. Also, Hsp70 suppresses the PreAS-induced permeabilization of vesicular membrane through interactions with PreAS. The substrate-binding domain alone is sufficient for Hsp70 to inhibit AS fibril formation. The binding of Hsp70 with PreAS only requires the substrate-binding subdomain, and the binding with AS nuclei requires the C-terminal lid subdomain as well. The results may form the molecular basis for elucidating the mechanism of AS fibril formation and the crucial roles of chaperones in protecting proteins from toxic conversion in many conformational diseases.

[Preparation and characterization of monoclonal antibody against human LSECtin].

AIM: To prepare and characterize monoclonal antibody (mAb) against human LSECtin (liver and lymph node sinusoidal endothelial cell C-type lectin) protein. METHODS: BALB/c mice were immunized with prokaryotically expressed human LSECtin protein. The splenocytes from the immunized mice were fused with murine myeloma cells (Sp2/0) and then the mAb-positive hybridoma cells were screened by indirect ELISA. Reaction of mAb to LSECtin antigen was characterized by Western blot, indirect immunofluorescent staining, immunohistochemical staining and FCM. RESULTS: Eight hybridoma cells secreting mAbs were established. The isotypes of the mAbs were IgG. Ascites titers were between 1:10(6) - 1:10(7). All the mAbs recognized human LSECtin protein on LSECtin-transfected 3T3 cells and six of the mAbs specifically recognized liver sinusoidal endothelial cells. CONCLUSION: Eight anti-LSECtin mAbs have been obtained. The characterization of the mAbs indicate that they show fine specificity by Western blot, indirect immunofluorescent staining, immunohistochemical staining and FCM, which can provide a powerful reagent for the functional study of LSECtin.

[Preparation and identification of the rabbit antibody against human sialin].

AIM: To prepare the rabbit antibody against human sialin and identify its properties. METHODS: Recombinant expression vector pGEX-5X-1-sialin was constructed, in which the sialin cDNA encoding the 1-38 aa was fused to the C-terminal of the gene encoding the GST protein. The GST-sialin (N1-38) fusion protein was expressed in E. coli JM109 at 37 degrees C in the presence of IPTG at 0.1 mmol/L for induction for 3 hours, purified by GSTrap FF, and then used as the immunogen to prepare the rabbit polyclonal antibody. The properties of antiserum against human sialin were identified by ELISA, Western blot and immunocytochemistry. RESULTS: The recombinant expression plasmid pGEX-5X-1-sialin was constructed. The GST-sialin (N1-38) fusion protein was highly expressed with a molecular weight of 30 kDa, and the yield of the fusion protein was about 20% to 30% in total E. coli protein. The titre of antiserum against human sialin was 1:32,000. Western blot analysis proved the rabbit polyclonal antibody could identify both GST-sialin (N1-38) fusion protein and GST. Besides, it specially recognized a 55 kDa band expressed in the human submandibular gland (HSG) cell line. The antigen recognized by the antibody was located in the cytoplasm and nucleus of HSG cell. CONCLUSION: The successful preparation of the polyclonal antibody against human sialin will provide efficient affinity reagent for further functional study of sialin expressed in human salivary glands.

[Preparation and characterization of monoclonal antibody against DCXR].

AIM: To prepare monoclonal antibodies (mAbs) against Dicarbonyl/L-xylulose reductase (DCXR). METHODS: Normal human liver tissues were homogenized, and mitochondria were isolated by differential centrifugation. The total mitochondrial proteins were used to immunize BALB/c mice to prepare mAbs by routine hybridoma technique. The mAbs were detected by ELISA, Western blot and immunohistochemistry. The antibody specificities were identified by mass spectrometry (MS) following immunoprecipitation (IP) and confirmed by Uni-ZAP expression library screening. RESULTS: One clone of hybridoma AFF091 secreting specific mAb against DCXR was obtained. The Ig subclass of the mAb was IgG1 and it can be used in ELISA, Western blot, immunohistochemistry, and immunoprecipitation. CONCLUSION: A hybridoma cell line stably secreting specific mAb against DCXR was established. The specific mAb against DCXR would be very useful for investigation of DCXR functions and distribution.