Clomiphene citrate administration to normogonadotropic subfertile men: Blood hormone changes and activation of acid phosphatase in seminal fluid

Rönnberg, Lars; Vihko, Pirkko; Sajanti, E; Vihko, R.

doi:10.1111/j.1365-2605.1981.tb00721.x

Cited by 54 publications

(26 citation statements)

References 22 publications

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“…Although it is unknown whether SEVI or SEM amyloids contribute more towards the viral enhancing activity of semen, it is noteworthy that SEMs are more abundant than PAP, the precursor for SEVI. While the concentration of full-length SEM proteins is estimated to be 10–20 mg/ml in semen (Yoshida et al, 2003), PAP is only 1–2 mg/ml (Ronnberg et al, 1981). Failure of the amyloid-specific WO1 antibody to pull out SEVI from seminal fluid may be due to a higher abundance of the SEM proteins.…”

Section: Discussionmentioning

confidence: 99%

Peptides Released by Physiological Cleavage of Semen Coagulum Proteins Form Amyloids that Enhance HIV Infection

Roan

Müller

Liu

et al. 2011

Cell Host & Microbe

151

266

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SUMMARY Semen serves as a vehicle for HIV and promotes sexual transmission of the virus, which accounts for the majority of new HIV cases. The major component of semen is the coagulum, a viscous structure composed predominantly of spermatozoa and semenogelin proteins. Due to the activity of the semen protease PSA, the coagulum is liquefied and semenogelins are cleaved into smaller fragments. Here, we report that a subset of these semenogelin fragments form amyloid fibrils that greatly enhance HIV infection. Like SEVI, another amyloid fibril previously identified in semen, the semenogelin fibrils exhibit a cationic surface and enhance HIV virion attachment and entry. Whereas semen samples from healthy individuals greatly enhance HIV infection, semenogelin-deficient semen samples from patients with ejaculatory duct obstruction are completely deficient in enhancing activity. Semen thus harbors distinct amyloidogenic peptides derived from different precursor proteins that commonly enhance HIV infection and likely contribute to HIV transmission.

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Section: Discussionmentioning

confidence: 99%

Peptides Released by Physiological Cleavage of Semen Coagulum Proteins Form Amyloids that Enhance HIV Infection

Roan

Müller

Liu

et al. 2011

Cell Host & Microbe

151

266

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“…PAP is one of the predominant proteins secreted by the epithelial cells of the prostate [2] and is present in high amounts (1000–2000 mg/L) in human semen [35]. It is a highly glycosylated enzyme and is reported to be present either in the intracellular form or as the secretory form [36], [37].…”

Section: Discussionmentioning

confidence: 99%

Prostate Secretory Protein of 94 Amino Acids (PSP94) Binds to Prostatic Acid Phosphatase (PAP) in Human Seminal Plasma

et al. 2013

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Prostate Secretory Protein of 94 amino acids (PSP94) is one of the major proteins present in the human seminal plasma. Though several functions have been predicted for this protein, its exact role either in sperm function or in prostate pathophysiology has not been clearly defined. Attempts to understand the mechanism of action of PSP94 has led to the search for its probable binding partners. This has resulted in the identification of PSP94 binding proteins in plasma and seminal plasma from human. During the chromatographic separation step of proteins from human seminal plasma by reversed phase HPLC, we had observed that in addition to the main fraction of PSP94, other fractions containing higher molecular weight proteins also showed the presence of detectable amounts of PSP94. This prompted us to hypothesize that PSP94 could be present in the seminal plasma complexed with other protein/s of higher molecular weight. One such fraction containing a major protein of ∼47 kDa, on characterization by mass spectrometric analysis, was identified to be Prostatic Acid Phosphatase (PAP). The ability of PAP present in this fraction to bind to PSP94 was demonstrated by affinity chromatography. Co-immunoprecipitation experiments confirmed the presence of PSP94-PAP complex both in the fraction studied and in the fresh seminal plasma. In silico molecular modeling of the PSP94-PAP complex suggests that β-strands 1 and 6 of PSP94 appear to interact with domain 2 of PAP, while β-strands 7 and 10 with domain 1 of PAP. This is the first report which suggests that PSP94 can bind to PAP and the PAP-bound PSP94 is present in human seminal plasma.

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“…Immunohistochemical (IHC) staining of normal human prostate archival specimens with anti-PAcP antibody (Ab) show very high levels of PAcP protein in the cytosolic area of differentiated epithelial cells [49,50,75]. While some PAcP proteins are retained intracellularly; others are secreted into the prostatic fluid [76]. Further, immunocytochemical staining with anti-PAcP Ab shows strong, positive staining in the cytosolic area of permeabilized prostate carcinoma cells, but not the intact cells [77].…”

Section: Pacp Structure and Isoformsmentioning

confidence: 99%

Cellular prostatic acid phosphatase, a PTEN-functional homologue in prostate epithelia, functions as a prostate-specific tumor suppressor

Muniyan

Ingersoll

Batra

et al. 2014

Biochimica et Biophysica Acta (BBA) - Reviews on Cancer

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The inactivation of tumor suppressor genes (TSGs) plays a vital role in the progression of human cancers. Nevertheless, those ubiquitous TSGs have been shown with limited roles in various stages of diverse carcinogenesis. Investigation on identifying unique TSG, especially for early stage of carcinogenesis, is imperative. As such, the search for organ-specific TSGs has emerged as a major strategy in cancer research. Prostate cancer (PCa) has the highest incidence in solid tumors in US males. Cellular prostatic acid phosphatase (cPAcP) is a prostate-specific differentiation antigen. Despite intensive studies over the past several decades on PAcP as a PCa biomarker, the role of cPAcP as a PCa-specific tumor suppressor has only recently been emerged and validated. The mechanism underlying the pivotal role of cPAcP as a prostate-specific TSG is, in part, due to its function as a protein tyrosine phosphatase (PTP) as well as a phosphoinositide phosphatase (PIP), an apparent functional homologue to Phosphatase and tensin homolog (PTEN) in PCa cells. This review is focused on discussing the function of this authentic prostate-specific tumor suppressor and the mechanism behind the loss of cPAcP expression leading to prostate carcinogenesis. We review other phosphatases’ roles as TSGs which regulate oncogenic PI3K signaling in PCa and discuss the functional similarity between cPAcP and PTEN in prostate carcinogenesis.

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Clomiphene citrate administration to normogonadotropic subfertile men: Blood hormone changes and activation of acid phosphatase in seminal fluid

Cited by 54 publications

References 22 publications

Peptides Released by Physiological Cleavage of Semen Coagulum Proteins Form Amyloids that Enhance HIV Infection

Peptides Released by Physiological Cleavage of Semen Coagulum Proteins Form Amyloids that Enhance HIV Infection

Prostate Secretory Protein of 94 Amino Acids (PSP94) Binds to Prostatic Acid Phosphatase (PAP) in Human Seminal Plasma

Cellular prostatic acid phosphatase, a PTEN-functional homologue in prostate epithelia, functions as a prostate-specific tumor suppressor

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