Possible molecular mechanisms of cryoablation-induced impotence in a rat model.

OBJECTIVES: Cryoablation of the prostate has been reported to induce impotence as a consequence of cavernosal nerve injury. This study is designed to investigate the early and late effects of cavernosal nerve cryoablation on growth factor expression and erectile function in a rat model. METHODS: Forty male rats were divided into two groups (n=20 each). The first group underwent unilateral cavernosal nerve freezing (experimental group). Before their euthanization at 1 and 3 months (10 rats each), erectile function was assessed by electrostimulation of the cavernous nerves. The second group served as the control and was killed at the same time points. Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques were used to identify protein and gene expression of nerve growth factor (NGF), transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), and insulin-like growth factor-1 (IGF-1) in the rat penis and pelvic ganglia. RESULTS: Electrostimulation of the frozen nerve after 3 months revealed a significantly higher maximal intracavernosal pressure and a shorter latency period than in the 1-month group. At 3 months, immunoblot showed upregulation of NGF, TGF-alpha, and the precursor form of IGF-1 protein expression in the penile tissue; RT-PCR showed downregulation of NGF gene expression in the pelvic ganglia of the frozen side. CONCLUSIONS: The results show that erectile function decreased at 1 month and then partially recovered 3 months after cavernosal nerve freezing. This alteration in erectile function was associated with differential gene and protein expression of the growth factors (NGF, TGF-alpha, EGF, and IGF-1). Further studies are required to elucidate the potential role of these growth factors in the prevention and treatment of cryoablation-induced impotence.

Peyronie's disease is associated with an increase in transforming growth factor-beta protein expression.

PURPOSE: Transforming growth factor-beta (TGF-beta) has been implicated in many chronic fibrotic conditions such as pulmonary and hepatic fibrosis. We postulated that TGF-beta may play a role in the pathogenesis of Peyronie's disease. MATERIALS AND METHODS: Tissues from the tunica albuginea of 30 Peyronie's disease patients (study group) and from 6 patients without Peyronie's disease, who had undergone penile prosthesis surgery for organic impotence (control group), were subjected to histological examination using Hart and trichrome stains and Western blotting for the detection of TGF-beta protein expression. RESULTS: The results of these experiments demonstrate that all tissue from Peyronie's disease patients showed a variety of histological changes of the tunica, ranging from chronic inflammatory cellular infiltration to complete calcification and ossification of the tissues. The most prominent changes observed in the majority of patients were focal or diffused elastosis, fenestration and disorganization of the collagen bundles. TGF-beta1 protein expression was detected in 26 patients (86%), while only 7 (23%) and 5 (17%) patients showed TGF-beta2 and TGF-beta3 protein expression, respectively. One patient in the control group showed fibrosis of the tunica albuginea and protein expression of TGF-beta1 and TGF-beta2. This patient had undergone surgery for the revision of his prosthesis twice. Five patients from the control group showed normal histological patterns of the tunica albuginea and no protein expression for TGF-beta1, TGF-beta2 and TGF-beta3. CONCLUSIONS: TGF-beta1 protein expression is significantly associated with Peyronie's disease, which may provide a new insight and the potential for the prevention and treatment of this disease.

Discordant distribution of IgM and IgG antibodies to DNA and RNA in monozygotic twins with systemic lupus erythematosus.

Sera from six sets of twins (five monozygotic and one dyzygotic) in whom one or both has systemic lupus erythematosus (SLE) were evaluated for antibodies to DNA and RNA. Sera from three monozygotic twin sets were further studied to determine the distribution of 19S and 7S antibodies to DNA and RNA. The presence of significant binding of polyriboadenylic acid and of native DNA correlated with the presence of clinical SLE in this study. Sucrose density gradient fractionation studies of the sera revealed that the clinically normal twins had some binding of Poly A and DNA limited to the 19S region, whereas the twins with SLE generally had significant levels of 19S and 7S antibodies to DNA and/or Poly A. On the other hand, concordance for presence or absence of antibodies to doublestranded RNA was demonstrated within each twin set irrespective of concordance or discordance for clinical SLE. These results suggest that genetic factors may be important in determining which nucleic acids antigens become immunogenic, but genetic factors alone do not determine the immunoglobulin class distribution of antibodies to nucleic acids.

Lymphocytes binding polyriboadenylic acid and synthesizing antibodies to nucleic acids in autoimmune and normal mice.

Splenic lymphocytes from both normal and autoimmune mice bind significant quantities of polyriboadenylic acid (poly rA) when incubated with radiolabeled poly rA for 40 min at 37 degrees C. This poly rA binding is specifically inhibited by an excess of nonradioactive poly rA and by anti-mouse immunoglobulin. Poly rA binding is decreased by exposing spleen cells to Pronase and is restored by subsequent culture for 18 to 72 hr. Poly rA-binding activity is associated more with bone marrow-derived than with thymus-derived lymphocytes. These results suggest the presence of autoantigen-binding lymphocytes in normal as well as autoimmune mice. Furthermore, spleen cells from normal and autoimmune mice cultured for 72 hr synthesize and secrete antibodies to poly rA and DNA. These antibodies can be recovered from the culture supernatants by a solid immunoadsorbent technique and antibody immunoprecipitation. The synthesis of antibodies to nucleic acids by normal spleen cells suggests that autoreactive lymphocytes may be released from normal immunoregulatory control during in vitro culture conditions.

Immunologic regulation of spontaneous antibodies to DNA and RNA I. Significance of IgM and IgG antibodies in SLE patients and asymptomatic relatives.

Nine individuals from four families of patients with systemic lupus erythematosus (SLE) were studied by sucrose density gradient fractionation and filter radioimmunoassay for the presence of 19S IgM and 7S IgG antibodies to DNA, poly rA, and poly rA-poly rU. One individual in each family was totally asymptomatic, and at least one had actively systemic lupus erythematosus (SLE). The results indicate: (1) a correlation between 7S antibody to DNA and RNA and active SLE, and (2) the presence of 19S antibody to RNA in the asymptomatic relatives. These findings suggest that SLE may be a disorder of immunological regulation. The distribution of antibodies between IgM and IgG is closely related to disease severity. the asymptomatic relatives may have a partial regulatory abnormality resulting in the limited production of IgM antibodies to RNA. SLE patients may have a more complex failure of regulation permitting the additional synthesis of IgG antibodies to DNA and RNA.

Clinical studies of antibodies binding polyriboadenylic acid in systemic lupus erythematosus.

Antibodies of polyriboadenylic acid (poly rA) are demonstrated by filter radioimmunoassay in 75% of patients with systemic lupus erythematosus (SLE), in 54% of patients with discoid lupus erythematosus, and in only 0-7% of normal controls and patients with rheumatoid arthritis or Sjögren's syndrome. These antibodies are distinct from antibodies to single- and double-stranded DNA and double-stranded RNA. Poly rA binding is associated with IgM and IgG serum fractions. Because poly rA may have a role in the transcription of mRNA in mammalian cells and viruses, antibodies to poly rA may be important clues to virologic and immunogenetic mechanisms in the pathogenesis of SLE.

Antibodies binding polyriboadenylic acid in systemic lupus erythematosus. Immunochemical characterization and isolation by affinity chromatography.

Antibodies specific for polyriboadenylic acid (poly rA) are present in sera from patients with systemic lupus erythematosus and from NZB/NZW F1 mice. The specificity of these antibodies was established by inhibition of [3H]poly rA binding and by affinity chromatography. Poly rA binding was associated with the 19S and 7S regions when serum was fractionated by sucrose density gradient untracentrifugation. Young NZB/NZW F1 mice (1-5 months) had only 19S anti-poly rA, whereas old NZB/NZW F1 mice (2 years) had activity in both 19S and 7S regions, suggesting a possible age-dependent switching mechanism in the spontaneous development of antibodies to nucleic acids. The gamma-globulin fraction from an SLE patient was subjected to affinity chromatography on a column of poly rA covalently linked to Sepharose. An enriched population of IgG antibodies binding only poly rA, but not native or denatured DNA, was isolated in this manner. This procedure may have broad biological applicability for the preparation of isolated immunospecific anti-nucleic acid antibodies.