Smooth muscle-specific deletion of MnSOD exacerbates diabetes-induced bladder dysfunction in mice

Bladder dysfunction in diabetes progresses gradually over time. However, the mechanisms of the development are not clear. We tested the hypothesis that oxidative stress plays a key role in the development of diabetic bladder dysfunction using an inducible smooth muscle (SM)-specific superoxide dismutase 2 (Sod2) gene knockout (SM-Sod2 KO) mouse model. Eight-week-old male Sod2lox/lox, SM-CreERT2(ki)Cre/+ mice and wild-type mice were assigned to diabetic or control groups. 4-Hydroxytamoxifen was injected into Sod2lox/lox, SM-CreERT2(ki)Cre/+ mice to activate CreERT2-mediated deletion of Sod2. Diabetes was induced by injection of streptozotocin, whereas control mice were injected with vehicle. Nine weeks later, bladder function was evaluated, and bladders were harvested for immunoblot analysis. Wild-type diabetic mice presented compensated bladder function along with increased nitrotyrosine and MnSOD in detrusor muscle. Induction of diabetes in SM-Sod2 KO mice caused deteriorated bladder function and even greater increases in nitrotyrosine compared with wild-type diabetic mice. Expression levels of apoptosis regulator Bax and cleaved caspase-3 were increased, but apoptosis regulator Bcl-2 expression was decreased in detrusor muscle of both diabetic groups, with more pronounced effects in SM-Sod2 KO diabetic mice. Our findings demonstrate that exaggerated oxidative stress can accelerate the development of bladder dysfunction in diabetic mice and the enhanced activation of apoptotic pathways in the bladder may be involved in the process.

Nephrological and urological complications of homozygous c.974G>A (p.Arg325Gln) OSGEP mutations

BACKGROUND

Galloway-Mowat syndrome (GAMOS) (OMIM #251300) is a severe autosomal recessive disease characterized by the combination of early-onset steroid-resistant nephrotic syndrome (SRNS) and microcephaly with brain anomalies caused by WDR73 as well as OSGEP, TP53RK, TPRKB, or LAGE3 mutations.

OBJECTIVE

We report on the hitherto undescribed urological and nephrological complications of the homozygous c.974G>A (p.Arg325Gln) OSGEP mutations in a 7-year-old Caucasian girl.

CASE DIAGNOSIS

The patient came to the attention of pediatric nephrology at the age of 3 years and 11 months, when she presented with status epilepticus due to profound hypomagnesemia (0.31 mmol/L, normal 0.65-1.05). A 24-h urine demonstrated a magnesium loss of 0.6 mmol/kg/day with associated proteinuria suggesting renal tubulopathy. Subsequently, she developed recurrent urinary tract infections (UTIs) and was diagnosed with neurogenic bladder dysfunction. The patient continued to have UTIs associated with seizures and sequential cultures growing multi-drug-resistant organisms despite of antibiotic prophylaxis. In addition, the proteinuria (median microalbumin/creatinine ratio 647 mg/mmol) increased, and she developed partial Fanconi syndrome. At age 7, she developed a large bladder calculus (3.3 × 3.2 cm) and three left non-obstructing renal calculi associated with elevated urinary cystine, hypercalciuria, and ongoing hypomagnesemia and required surgical intervention. Glomerular filtration rate (GFR) remained normal and she never developed frank nephrotic syndrome (average albumin 31 g/L).

CONCLUSIONS

It is unclear if patients with OSGEP mutations with tubular symptoms rather than nephrotic syndrome should be considered a different entity. Nephrological and urological complications of OSGEP mutations can be challenging and require a multidisciplinary approach.

[Clinicopathologic features and immunophenotype of pseudosarcomatous myofibroblastic proliferation of urinary bladder]

Objective: To investigate the clinicopathologic features, immunohistochemical phenotypes and biological behavior of pseudosarcomatous myofibroblastic proliferation (PMP) of the urinary bladder which may be misdiagnosed as a malignant neoplasm and undergo extensive treatment. Methods: Six cases of PMP of the urinary bladder were collected from 2001 to 2016 at Beijing Tiantan Hospital, Capital Medical University. The clinicopathologic features and immunophenotypic profile were studied by histopathological and immunohistochemical investigations with clinical follow-up. At the same time, the translocation of ALK gene was detected by fluorescence in situ hybridization (FISH). Immunohistochemistry was carried out using EnVision method for the expression of AE1/AE3, vimentin, EMA, SMA, Caldesmon, Calponin, desmin, ALK, Ki-67, MyoD1, myoglobin, CD34, S-100, CD117, CK7, CK20, GATA3, p63 and CK5/6. The related literature was reviewed. Results: There were two male and four female patients, significantly more common in women. The age of the patients was 27 to 53 years, and the median age was 35 years. The main clinical symptom was painless gross hematuria, one case with dysuria, and one case showed recurrent cystitis. There was no history of surgery and trauma. Follow-up ranged from 4 months to 13 years and showed five cases without recurrence and one case with recurrence. Microscopy showed submucosal lesion with inflammatory exudate and bleeding on the surface, in some cases extending to the superficial muscles of the bladder wall. The lesion was characterized by the proliferation of plump spindle cells, which were loose or dense in arrangement. There were varying degrees of acute and chronic inflammatory cells infiltration in the myxoid matrix. Spindle cells arranged in disorder, or a dense stranding, especially abundant in the cell region. The median mitotic rate was <2/10 HPF cells, but there were no pathological mitotic figures and without nuclear atypia in most spindle cells. Spindle cells with eosinophilic cytoplasm showed long tapering cytoplasmic projections. Oval or short spindle nuclei had vacuolization with prominent nucleoli, looking like ganglionic cells. There were scarce collagen fibers, and a few spindle cells degenerated with chromatin blurred. Some areas showed a granuloma-like pattern and neutrophils within vascular cavity. Immunohistochemically, the spindle cells were diffusely positive for vimentin, SMA and caldesmon. CKpan was strongly and diffusely positive. Desmin and calponin expression was varying. Ki-67 positive cells were about 35% to 55%, but the spindle cells were negative for myoglobin, S-100, CD117, CD34, p63 and CK5/6. FISH test showed that there was no ALK isolated signal in 6 cases of PMP, and so no positive cases were found. Conclusions: PMP of the urinary bladder is a benign non-neoplastic myofibroblastic proliferative lesion. Morphology is extremely easy to be misdiagnosed as malignant tumors, and therefore more attention should be paid to avoid this misdiagnosis.

microRNA regulation of Wnt signaling pathways in development and disease

Wnt signaling pathways and microRNAs (miRNAs) are critical regulators of development. Aberrant Wnt signaling pathways and miRNA levels lead to developmental defects and diverse human pathologies including but not limited to cancer. Wnt signaling pathways regulate a plethora of cellular processes during embryonic development and maintain homeostasis of adult tissues. A majority of Wnt signaling components are regulated by miRNAs which are small noncoding RNAs that are expressed in both animals and plants. In animal cells, miRNAs fine tune gene expression by pairing primarily to the 3'untranslated region of protein coding mRNAs to repress target mRNA translation and/or induce target degradation. miRNA-mediated regulation of signaling transduction pathways is important in modulating dose-sensitive response of cells to signaling molecules. This review discusses components of the Wnt signaling pathways that are regulated by miRNAs in the context of development and diseases. A fundamental understanding of miRNA functions in Wnt signaling transduction pathways may yield new insight into crosstalks of regulatory mechanisms essential for development and disease pathophysiology leading to novel therapeutics.

Identification of genes correlated with early-stage bladder cancer progression

Transitional cell carcinoma (TCC) of the bladder ranks fourth in incidence of all cancers in the developed world, yet the mechanisms of its origin and progression remain poorly understood. There are also few useful diagnostic or prognostic biomarkers for this disease. We have combined a transgenic mouse model for invasive bladder cancer (UPII-SV40Tag mice) with DNA microarray technology to determine molecular mechanisms involved in early TCC development and to identify new biomarkers for detection, diagnosis, and prognosis of TCC. We have identified genes that are differentially expressed between the bladders of UPII-SV40Tag mice and their age-matched wild-type littermates at 3, 6, 20, and 30 weeks of age. These are ages that correspond to premalignant, carcinoma in situ, and early-stage and later stage invasive TCC, respectively. Our preliminary analysis of the microarray data sets has revealed approximately 1,900 unique genes differentially expressed (> or =3-fold difference at one or more time points) between wild-type and UPII-SV40Tag urothelium during the time course of tumor development. Among these, there were a high proportion of cell cycle regulatory genes and a proliferation signaling genes that are more strongly expressed in the UPII-SV40Tag bladder urothelium. We show that several of the genes upregulated in UPII-SV40Tag urothelium, including RacGAP1, PCNA, and Hmmr, are expressed at high levels in superficial bladder TCC patient samples. These findings provide insight into the earliest events in the development of bladder TCC as well as identify several promising early-stage biomarkers.

Bladder dysfunction in a new mutant mouse model with increased superoxide--lack of nitric oxide?

PURPOSE

Nitric oxide mediates urethral smooth muscle relaxation and may also be involved in detrusor activity control. Mice with mutation in the Immp2l gene have high superoxide ion levels and a consequent decrease in the bioavailable amount of nitric oxide. We studied bladder function in this mouse model.

MATERIAL AND METHODS

Young male mutants at ages 4 to 6 months, old female mutants at age 18 months and healthy WT age matched controls were used. The detrusor contractile response to carbachol and electrical field stimulation was tested in isolated detrusor strips in organ baths. In vivo bladder function was evaluated by cystometry in conscious animals.

RESULTS

Young male mutants had significantly lower micturition and higher post-void residual volume than WT controls. They had pronounced voiding difficulty and strained when initiating micturition. Detrusor contractile responses to carbachol and electrical field stimulation were similar in mutant and WT mice. Old female mutant mice had lower bladder capacity and micturition volume, and higher micturition frequency and bladder-to-body weight ratio than WT controls. In the in vitro study detrusor strips from mutants showed a lower maximum response to carbachol.

CONCLUSIONS

Mice with mutation in the Immp2l gene have bladder dysfunction, mainly characterized by emptying abnormalities in young males and increased detrusor activity in old females. Detrusor function was preserved in young males and impaired in old females. These animals are a natural model of oxidative stress with low bioavailable nitric oxide. Thus, they are interesting tools in which to evaluate the role of these conditions on bladder dysfunction.

Familial transmission of urogenital prolapse and incontinence

PURPOSE OF REVIEW

To summarize recent evidence suggesting a genetic basis for the development of urogenital prolapse and stress urinary incontinence.

RECENT FINDINGS

Epidemiological evidence suggests that some women have a genetic predisposition to the development of urogenital prolapse and stress incontinence. Abnormal expression of various structural proteins is thought to be the molecular genetic mechanism for the development of these conditions. A group of families with an autosomal dominant pattern of transmission of urogenital prolapse with high penetrance has been identified. No similar cohort of families with familial stress incontinence currently exists, although candidate genes have been identified that appear to predispose women to urogenital prolapse and stress incontinence. Additionally, animal models of urogenital prolapse have been developed that closely parallel the development of prolapse in humans.

SUMMARY

A growing body of evidence suggests a genetic basis for the development of urogenital prolapse and stress incontinence. Candidate genes have been identified that may result in alteration of the normal metabolism of various structural proteins which may ultimately predispose some women to both urogenital prolapse and stress incontinence. Further research into the genetic basis of these conditions may provide a comprehensive understanding of the biological basis of these disorders.

Expression of transforming growth factor β1 gene, basic fibroblast growth factor gene and hydroxyproline in diabetes-induced bladder dysfunction in a rat model

AIMS

To investigate the content of hydroxyproline (Hyp) and the expression of transforming growth factor beta1 (TGF beta1) and basic fibroblast growth factor (bFGF) in the bladder 8 weeks after diabetes induction.

METHODS

Thirty wistar rats were divided into three groups: control (n = 10), streptozotocin-induced diabetic group (n = 10), TAD group (n = 10; diabetic rats were fed with Tadenan 100 mg kg(-1) day(-1)). Eight weeks later, the bladders were dissected. RT-PCR, immunohistochemistry, and ELISA were used to detect the expression of TGF beta1 and bFGF in the bladder. Also hydroxyproline (Hyp) was measured using a method based on alkaline hydrolysis.

RESULTS

The content of hydroxyproline in the diabetic group was greater than that of control group (P < 0.05); we found significantly increased expression of TGF beta1 mRNA and bFGF mRNA in the bladder from the diabetic group compared with the control group; immunohistochemical and ELISA studies showed a statistically significant increased expression of TGF beta1 protein and bFGF protein in the bladder from the diabetic group compared with the control group (P < 0.05). The content of hydroxyproline in TAD group was less than that of diabetic group (P < 0.05); mRNA expression of TGF beta1 and bFGF greatly decreased in TAD group compared with that of the diabetic group; immunohistochemical and ELISA studies showed decreased levels of TGF beta1 protein and bFGF protein in the bladder from TAD group compared with the diabetic group (P < 0.05).

CONCLUSIONS

Rats with streptozoticin-induced diabetes mellitus showed significant increase in hydroxyproline, TGF beta1 and bFGF levels in their bladders, which may be an important mechanism inducing diabetic cystopathy. Tadenan could effectively reduce hydroxyproline, TGF beta1, and bFGF levels.

TRPs in bladder diseases

This review attempts to provide an overview of the current knowledge of TRP proteins and their possible role in bladder function and disease. At present, there are 28 transient receptor potential (TRP) channels (subdivided into 7 categories or families) which are involved in a number of functions [G.A. Hicks, TRP channels as therapeutic targets: hot property, or time to cool down? Neurogastroenterology and Motility 18, (2006) 590-594., J.D. Levine, N. Alessandri-Haber, TRP channels: targets for the relief of pain, Biochimica et Biophysica Acta 1772, (2007) 989-1003.]. Of those belonging to the group 1 subfamily, a number of TRPV, TRPM and TRPA proteins associated with osmoregulation, thermal, chemical and mechanical signaling mechanisms have been shown to be expressed within the lower urinary tract. Though the biological role of many of these channels in urinary bladder function still remains elusive, TRPV1 is by far the best characterized and is thought to be involved in a number of bladder disorders [A. Szallasi, P.M. Blumberg, Vanilloid (Capsaicin) Receptors and Mechanisms, Pharmacological Reviews 51, (1999) 150-221., I. Nagy, P. Santha, G. Jansco, L. Urban, The role of the vanilloid (capsaicin) receptor (TRPV1) in physiology and pathology, European Journal of Pharmacology 500, (2004) 351-369.].

Using gene chips to identify organ-specific, smooth muscle responses to experimental diabetes: potential applications to urological diseases

OBJECTIVE

To identify early diabetes-related alterations in gene expression in bladder and erectile tissue that would provide novel diagnostic and therapeutic treatment targets to prevent, delay or ameliorate the ensuing bladder and erectile dysfunction.

MATERIALS AND METHODS

The RG-U34A rat GeneChip (Affymetrix Inc., Sunnyvale, CA, USA) oligonucleotide microarray (containing approximately 8799 genes) was used to evaluate gene expression in corporal and male bladder tissue excised from rats 1 week after confirmation of a diabetic state, but before demonstrable changes in organ function in vivo. A conservative analytical approach was used to detect alterations in gene expression, and gene ontology (GO) classifications were used to identify biological themes/pathways involved in the aetiology of the organ dysfunction.

RESULTS

In all, 320 and 313 genes were differentially expressed in bladder and corporal tissue, respectively. GO analysis in bladder tissue showed prominent increases in biological pathways involved in cell proliferation, metabolism, actin cytoskeleton and myosin, as well as decreases in cell motility, and regulation of muscle contraction. GO analysis in corpora showed increases in pathways related to ion channel transport and ion channel activity, while there were decreases in collagen I and actin genes.

CONCLUSIONS

The changes in gene expression in these initial experiments are consistent with the pathophysiological characteristics of the bladder and erectile dysfunction seen later in the diabetic disease process. Thus, the observed changes in gene expression might be harbingers or biomarkers of impending organ dysfunction, and could provide useful diagnostic and therapeutic targets for a variety of progressive urological diseases/conditions (i.e. lower urinary tract symptoms related to benign prostatic hyperplasia, erectile dysfunction, etc.).

Female, but not male, serotonin reuptake transporter (5-HTT) knockout mice exhibit bladder instability

Correlations exist between the incidence of depression, irritable bowel syndrome (IBS) and overactive bladder [Masand, P.S., Kaplan, D.S., Gupta, S., Bhandary, A.N., Nasra, G.S., Kline, M.D., Margo, K.L., 1995. Major depression and irritable bowel syndrome: is there a relationship? J. Clin. Psychiatry 56, 363-367.; Cukier, J.M., Cortina-Borja, M., Brading, A.F., 1997. A case-control study to examine any association between idiopathic detrusor instability and gastrointestinal tract disorder, and between irritable bowel syndrome and urinary tract disorder. Br. J. Urol. 79, 865-878.; Monga, A.K., Marrero, J.M., Stanton, S.L., Lemieux, M.C., Maxwell, J.D., 1997. Is there an irritable bladder in the irritable bowel syndrome? Br. J. Obstet. Gynaecol. 104, 1409-1412.; Zorn, B.H., Montgomery, H., Pieper, K., Gray, M., Steers, W.D., 1999. Urinary incontinence and depression. J. Urol. 162, 82-84.]. Furthermore, alterations in serotonergic neurotransmission may play a common role in the etiology of these disorders. Serotonin reuptake transporter knockout mice (5-HTT(-/-)) display phenotypes consistent with clinical features of mood and bowel disorders including anxiety and abnormal gastrointestinal motility [Holmes, A., Murphy, D.L., Crawley, J.N., 2003. Abnormal behavioral phenotypes of serotonin transporter knockout mice: parallels with human anxiety and depression. Biol. Psychiatry 54, 953-959.]. In the present study, we evaluated bladder function in 5-HTT(-/-) mice. We have found that female 5-HTT(-/-) mice exhibit bladder dysfunction, characterized by significant increases in the frequency of spontaneous non-voiding bladder contractions and decreases in void volume compared to control female mice. These differences were not observed in male knockout mice. These studies provide significant supporting data for a mechanistic link between alterations in 5-HT, depression, IBS and overactive bladder in women.

Anaplastic lymphoma kinase (ALK 1) staining and molecular analysis in inflammatory myofibroblastic tumours of the bladder: a preliminary clinicopathological study of nine cases and review of the literature

Inflammatory myofibroblastic tumours (IMFT) may arise at any anatomical site, including lung, soft tissues, retroperitoneum and bladder. Although morphologically similar, these lesions encompass a spectrum of entities with differing aetiology, ranging from reactive/regenerative proliferations to low-grade neoplasms with a risk of local recurrence, but no significant metastatic potential. Vesical IMFT usually presents as a polypoid mass with a pale firm cut surface and can be of considerable size, mimicking a malignant tumour clinically and radiologically. Its good outcome, however, warrants conservative surgical excision, emphasising the importance of identification and distinction from malignant tumours of the bladder that may require more radical surgery and/or adjuvant therapy. We conducted a preliminary retrospective, comparative immunocytochemical study of 20 bladder tumours, including nine IMFTs, five spindle cell (sarcomatoid) carcinomas, two rhabdomyosarcomas, two leiomyosarcomas and two neurofibromas. The results confirmed IMFT positivity for smooth muscle actin, desmin and cytokeratin in 78-89% cases, resulting in potential confusion with sarcomatoid carcinoma or leiomyosarcoma. In contrast, cytoplasmic anaplastic lymphoma kinase (ALK 1) staining was present in eight IMFT (89%), but was not seen in any other lesion examined. The ALK 1 staining was confirmed by fluorescence in situ hybridisation, with translocation of the ALK gene present in 15-60% tumour cells in four of six IMFT examined, but not in four cases of sarcomatoid carcinoma or three of leiomyosarcoma. In conclusion, ALK 1 staining may be of value in the distinction of vesical IMFT from morphologically similar entities, and often reflects ALK gene translocations in these lesions.

[Phenotypic changes in human bladder smooth muscle cell]

Tissue specimens were resected from 15 patients (age 7 to 82, average 52.2 years old) with bladder diseases; i.e., 2 with neurogenic bladder, 6 recipients of kidney transplantation with defunctionalized bladder, 3 with benign prostatic hypertrophy, 3 with bladder cancer and 1 with vesicoureteral reflux. We investigated the phenotypic expression of the bladder smooth muscle cells with bladder diseases. The ratio of non-contractile to contractile phenotypes (nc/c ratio) showed a rising tendency with aging. The increase of nc/c ratio was especially notable with neurogenic bladder. Phenotypic expression was observed in human bladder smooth muscle cells as reported in vascular smooth muscle cells. Several bladder diseases cause a conversion of contractile smooth muscle cell phenotype from contractile type to non-contractile type, and this modulation of smooth muscle cell phenotype may play an important role in detrusor function.

Gender comparison of muscarinic receptor expression and function in rat and human urinary bladder: differential regulation of M2 and M3 receptors?

Since symptoms of bladder dysfunction occur more frequently in women than in men and since muscarinic receptors are the physiologically most important system to mediate bladder contraction, we have compared the number, subtype distribution and function of muscarinic receptors in bladders from male and female rats. Muscarinic receptor function was also assessed in bladder strips from male and female human bladder. Male and female rats expressed a similar number of muscarinic receptors (144+/-5 vs. 140+/-6 fmol/mg protein in saturation radioligand binding). While competition binding curves for the moderately M(2)-selective methoctramine were not consistently better fitted by a two-site model, most competition curves for the M(3)-selective darifenacin were biphasic and yielded 29+/-10% and 31+/-7% high affinity sites (corresponding to M(3) receptors) in male and females, respectively. Immunoreactivity of alpha-subunits of the G-proteins G(q/11), G(i1/2), G(i3) and G(s) did not significantly differ between both genders. The muscarinic receptor agonist carbachol similarly stimulated inositol phosphate accumulation in bladder slices from male and female rats with calculated maximum responses of 69+/-17 and 77+/-18% over basal and pEC(50) values of 4.90+/-0.45 and 4.40+/-0.46, respectively. While darifenacin inhibited carbachol-stimulated inositol phosphate formation approximately 100-fold more potently than methoctramine, each antagonist was similarly potent in both genders. Carbachol concentration-dependently contracted bladder strips with a pEC(50) of 5.66+/-0.05 and 5.72+/-0.06 and maximum effects of 4.3+/-0.1 and 4.2+/-0.2 mN/mg wet weight in male and female rats, respectively. The contractile effect of carbachol was concentration-dependently antagonised by the non-selective atropine (1-30 nM), the M(1)-selective pirenzepine (1-30 M), the M(2)-selective methoctramine (1-10 microM) and the M(3)-selective darifenacin (10-100 nM), with the latter exhibiting a partly unsurmountable antagonism. The overall potency of all four antagonists suggested that contraction was mediated predominantly if not exclusively by M(3) receptors with no appreciable differences between both male and female rats. Similarly, the maximum effects (4.4+/-0.6 vs. 4.4+/-2.4 mN/mg) and pEC(50) (6.07+/-0.05 vs. 6.32+/-0.14) of carbachol did not differ between genders in bladder samples from 25 consecutive patients. We conclude that number und function of muscarinic receptors and the relative roles of their M(2) and M(3) subtypes do not differ between urinary bladders of male and female rats; at least with regard to overall muscarinic responsiveness this situation appears to be similar in humans.

Gene expression profiling of inflammatory bladder disorders

Inflammation underlies all major bladder pathologies including malignancy and represents a defense reaction to injury caused by physical damage, chemical substances, micro-organisms or other agents. During acute inflammation, activation of specific molecular pathways leads to an increased expression of selected genes whose products attack the insult, but ultimately should protect the tissue from the noxious stimulus. However, once the stimulus ceases, gene-expression should return to basal levels to avoid tissue damage, fibrosis, loss of function, and chronic inflammation. If this down-regulation does not occur, tissue fibrosis occurs as a serious complication of chronic inflammation. Although sensory nerve and most cells products are known to be key parts of the inflammatory puzzle, other key molecules are constantly being described that have a role in bladder inflammation. Therefore, as the database describing the repertoire of inflammatory mediators implicated in bladder inflammation increases, the central mechanisms by which injury can induce inflammation, cell damage, and repair often becomes less rather than more clear. To make sense of the vast knowledge of the genes involved in the inflammatory response may require analysis of the patterns of change and the elucidation of gene networks far more than definition of additional members of inflammatory cascades. This review discuss the appropriate use of microarray technology, which promises to solve both of these problems as well as identifying key molecules and mechanisms involved in the transition between acute and chronic inflammation.

Basic science research on the urinary bladder and interstitial cystitis: new genetic approaches

This article summarizes recent genetic research that promises to advance understanding of the functioning of the urinary bladder and further our knowledge about interstitial cystitis. Results reported at the Tenth International Research Symposium on Interstitial Cystitis and Bladder Research and in the current literature are presented. Three specific areas of genetic research are summarized: gene expression via DNA arrays, development of new animal models through transgenic or gene knockout approaches, and gene therapy. Advances in genetic research (specifically in gene therapy; development of new, genetically engineered mouse models; and study of gene expression using DNA array assays) will contribute to further understanding the functioning of the urinary bladder in health and disease.

Clinical and genetic study of Friedreich ataxia in an Australian population

Friedreich ataxia is an autosomal recessive disorder caused by mutations in the FRDA gene that encodes a 210-amino acid protein called frataxin. An expansion of a GAA trinucleotide repeat in intron 1 of the gene is present in more than 95% of mutant alleles. Of the 83 people we studied who have mutations in FRDA, 78 are homozygous for an expanded GAA repeat; the other five patients have an expansion in one allele and a point mutation in the other. Here we present a detailed clinical and genetic study of a subset of 51 patients homozygous for an expansion of the GAA repeat. We found a correlation between the size of the smaller of the two expanded alleles and age at onset, age into wheelchair, scoliosis, impaired vibration sense, and the presence of foot deformity. There was no significant correlation between the size of the smaller allele and cardiomyopathy, diabetes mellitus, loss of proprioception, or bladder symptoms. The larger allele size correlated with bladder symptoms and the presence of foot deformity. The duration of disease is correlated with wheelchair use and the presence of diabetes, scoliosis, bladder symptoms and impaired proprioception, and vibration sense but no other complications studied.

Decreased elastin gene expression in noncompliant human bladder tissue: a competitive reverse transcriptase-polymerase chain reaction analysis

PURPOSE

In low capacity noncompliant fibrotic bladders, as seen in patients with myelomeningocele, elevated storage pressures ultimately can lead to renal damage. Earlier studies have described an increased deposition of extracellular matrix protein, especially type III collagen, in the detrusor muscle. We analyzed elastin gene expression and quantified elastin gene alteration in the obstructed bladder, correlating urodynamically measured compliance with elastin messenger ribonucleic acid (mRNA) concentration.

MATERIALS AND METHODS

Using a reverse transcriptase-polymerase chain reaction quantitative technique elastin mRNA can be reliably measured in 5 to 8 mg. samples of bladder tissue. We compared tissue samples from patients with urodynamically demonstrated noncompliant bladders (less than 10 cc/cm. water) to a control group with normal bladder compliance (greater than 20 cc/cm. water). Tissue samples were homogenized and sonicated, and complementary deoxyribonucleic acid (cDNA) was synthetized from mRNA using reverse transcriptase. Wild type and mutant elastin cDNA were synthetized, and target elastin cDNA with unknown concentration was competitively co-amplified with known serial dilutions of the mutant template (competitive polymerase chain reaction). Computerized densitometry allowing cDNA concentration measurement was performed and competitive reverse transcriptase-polymerase chain reaction was repeated at least twice for every sample.

RESULTS

Elastin mRNA concentration ranged from 27.6 to 63.2 attomole per mg. in noncompliant bladders compared to 62 to 190 attomole per mg. in controls. The variation within the same sample was less than 10%. There was a statistically significant difference between mean plus or minus standard deviation elastin cDNA concentration in noncompliant bladders (37.48 attomole per mg. +/- 12.06) and controls (119.63+/-41.01 attomole per mg.).

CONCLUSIONS

A significant decrease in elastin mRNA matches the decreased deposition of elastic fibers noted in previous immunohistochemical studies. Our data suggest that this decrease is mainly due to a transcriptional down regulation of the elastin gene in noncompliant bladders.

Superimposed histologic and genetic mapping of chromosome 17 alterations in human urinary bladder neoplasia

Multistep alterations of chromosome 17 in the progression of human urinary bladder neoplasia were studied by superimposed histologic and genetic mapping. The p53 gene was included in the analysis as a model tumor suppressor gene that is frequently involved in urothelial carcinogenesis. The strategy provided a systematic approach to the study of multistep genomic alterations that occur as neoplasia progresses from precursor intraurothelial conditions to invasive cancer. This was accomplished by sampling the entire mucosa of the organ and displaying microscopically identified invasive cancer and precursor conditions in the form of a histologic map. Subsequent isolation of DNA provided a set of samples in which the search for genetic alterations was performed and superimposed on the histologic map. This approach disclosed multifocal allelic losses of chromosome 17 in the early preinvasive phases of urothelial neoplasia. The alterations were predominantly confined to the p12-13, q22-11 and q24-25 regions. Mutations and allelic losses of the p53 gene were mapped to early preinvasive phases of urothelial neoplasia. The data provide detailed analysis of chromosome 17 allelic losses that occur in the development and progression of urothelial neoplasia and represent the first step for genome-wide modeling of multistep human urothelial carcinogenesis.

Pathology of renal dysplasia and bladder aplasia-hypoplasia in a flock of sheep

Congenital renal disease was detected in a flock of sheep in the English Midlands over 2 successive years (1982 and 1983). A Suffolk ram was removed from the flock and test mated to unrelated Suffolk ewes in another flock; 14 of the resulting 43 lambs born in 1984 had an identical congenital renal disease. Kidneys were examined microscopically from 60 clinically affected neonatal lambs. Kidneys from 7 of the 60 clinically affected neonatal lambs (1, 1983; 6, 1984) were examined ultrastructurally and compared with kidneys from 3 healthy unrelated neonatal lambs. Most affected lambs examined (52/60) had bilaterally small kidneys (< or = 2 g) with fine intracortical cysts and distinct cortical and medullary zones. Kidneys were either grossly normal (3/60 lambs) or multicystic and of normal size to markedly enlarged (5/60 lambs). The bladder was absent or vestigial in most lambs. Microscopically, poorly differentiated ("primitive") tubules were present in renal cortex and medulla. Proximal convoluted tubules, where present, were formed by epithelial cells with distinctive round weakly autofluorescent intracytoplasmic inclusions with the ultrastructural appearance of atypical lysosomes. Loops of Henle, distal convoluted tubules, and juxtaglomerular-peripolar cell complexes were largely absent. Glomerular changes were minimal. Cystic dilatation of nephrons was restricted to proximal convoluted tubules lined by vacuolated epithelium. This distinctive congenital renal dysplasia of sheep was most likely inherited as a dominant trait with complete penetrance.

Fetal urinary tract obstruction and trisomy 18 mosaicism. A case report

Routine ultrasound examination has led increasingly to antepartum detection of fetal anomalies. Management decisions remain difficult, however, because information on the presence of other anomalies is frequently unobtainable. A case of fetal urinary tract obstruction, although apparently an isolated defect, proved to be associated with a lethal chromosome abnormality, trisomy 18 mosaicism.

Evidence for separate genetic defects in C3H/HeJ and C3HeB/FeJ mice, that affect susceptibility to gram-negative infections

Past studies have suggested a linkage between susceptibility to Salmonella typhimurium infection and the Lpsd genotype in C3H mice. Recently, this linkage was questioned by the finding that C3HeB/FeJ mice (Lpsn,Lpsn) were highly susceptible to systemic S. typhimurium infection. The present study shows a marked difference between C3H/HeJ and C3HeB/FeJ in their susceptibility to Gram-negative urinary tract infection. The number of E. coli and S. typhimurium recovered from the kidneys 24 hr after infection was 70 to 100 times higher in C3H/HeJ than in C3HeB/FeJ or C3H/HeN mice. Subsequently, in C3HeB/FeJ mice S. typhimurium multiplied to the level of C3H/HeJ mice, resulting in a shorter mean survival time of C3H/HeJ and C3HeB/FeJ compared with C3H/HeN mice. In contrast, E. coli remained localized to the urinary tract of C3H/HeJ mice but were eliminated from C3HeB/FeJ and C3H/HeN mice. Thus, experimental E. coli urinary tract infection appears to provide a method to differentiate the genetic defects of C3H/HeJ and C3HeB/FeJ mice. The results support an influence of the Lpsd genotype on clearance of Gram-negative bacteria from the kidneys of C3H mice.

Familial Visceral Myopathy

We report on a 13-year-old white body with familial visceral myopathy. The abnormalities of the gastrointestinal and urinary tracts are described and the literature regarding urologic implications of this disorder is reviewed.

Hereditary autosomal dominant form of bladder diverticula in male patients

We report on 1 family in which 7 male patients had solitary bladder diverticulum. This family represents an autosomal dominant form of this disease by which only men are affected. Diverticula of the bladder can be classified as congenital (primary) or acquired (secondary). Vesical diverticula are uncommon in children and occur either primarily, when the vesical mucosa protrudes through a congenital defect in the bladder wall, or secondarily to bladder outflow obstruction. In adults the occurrence of multiloculated secondary diverticula is mainly due to subvesical obstruction. This seemingly autosomal dominant form of solitary diverticula in men was mostly associated with bladder outlet obstruction.

Controlled genetic variation in a subchronic toxicity assay: susceptibility to induction of bladder hyperplasia in mice by 2-acetylaminofluorene

Five different dose levels of 2-acetylaminofluorene (2-AAF) were fed to weanling mice of 4 different genotypes from three unrelated F1 hybrids for 13 wk to determine differences in susceptibility to induction of bladder hyperplasia. Differences in the prevalence of hyperplasia per se and in the average grade of hyperplasia were interpreted as indicating greater susceptibility. On this basis, males of all genotypes were more susceptible than females. Among the genotypes, (AEX YS)F1 mice (AY) were most susceptible, followed closely by yellow A vy/A(BALB/cXVY)F1 mice (CV). Agouti A/a(BALB/cXVY)F1 mice were less susceptible than their yellow siblings and similar to the (C57BL/6XC3H)F1 mice. Neither body weight gain nor any of the biochemical parameters measured appeared to be affected at any dose level of 2-AAF. However, quantitative differences in several biochemical characteristics were detected among the genotypes. Serum gamma-glutamyl transpeptidase activity was higher in the AY mice than in the other hybrids. Among the CV mice, the yellow animals had lower glutathione S-transferase (GST) activity than their agouti siblings. Hepatic GST activity was lower in CV mice than in either of the other hybrids. Hepatic cytochrome P-450 and bs activities were similar in all hybrids.

Diabetes mellitus and optic atrophy in two siblings: a report on a new association and a review of the literature

Two siblings with diabetes mellitus and optic atrophy (Wolfram syndrome) are described. As often noted, they also had atonic urinary bladders. Only one of the siblings had some impairment of hearing. Other findings not previously reported that appeared in each subject were esophageal dysphagia and vertigo. An autopsy in one revealed brain stem hypoplasia and thinning and flattening of the optic nerves with atrophy of the lateral geniculate bodies.

Abnormal copper metabolism and deficient lysyl oxidase activity in a heritable connective tissue disorder

Biochemical abnormalities were studied in two brothers with bladder divericulas, inguinal hernias, slight skin laxity, and hyperelasticity and skeletal abnormalities including occipital exostoses. Lysyl oxidase activity was low in the medium of cultured skin fibroblasts, this abnormality being accompanied by reduced conversion of the newly synthesized collagen into the soluble form. Copper concentrations were markedly elevated in the cultured skin fibroblasts, but decreased in the serum and hair. Serum cerulophasmin levels were also low. The reduced lysyl oxidase activity is suggested to be responsible for ther clinical manifestations, but the deficiency in this copper-dependent enzyme may be secondary to the abnormalities in the metabolism of the cation. Nevertheless, a mutation directly affecting both lysyl oxidase and an intracellular copper transport protein cannot be excluded. The disease is tentatively classified as one subtype of the Ehlers-Danlos syndrome.

Monozygotic twins discordant for exstrophy of the urinary bladder

A pair of monozygotic male twins discordant for ectopia vesicae urinariae is described. There is no reason to think that any exogenic factors contributed to the aetiology. There was no consanguinity and no history of congenital anomalies on either side of the family. Published reports concerning family incidence and twin reports are reviewed.

Bladder diverticula and Menkes' syndrome

Multiple unusual diverticula of the bladder were observed in 3 of 4 children with Menkes' syndrome. This abnormality of the bladder in children with the kiky hair syndrome has only recently been recognized. The diverticula are best visualized on cystographic studies. The clinical manifestation which led to roentgen evaluation of the urinary tract in the 3 children was urinary tract infection or urine retention. Though the etiology of these diverticula is unknown, evidence is presented to suggest that they are acquired.

Juvenile diabetes mellitus, optic atrophy, hearing loss, diabetes insipidus, atonia of the urinary tract and bladder, and other abnormalities (Wolfram syndrome). A review of 88 cases from the literature with personal observations on 3 new patients

A review of 88 cases from the literature with personal observations on 3 new patients is given of the syndrome featured by juvenile diabetes mellitus, optic atrophy, hearing loss, diabetes insipidus, atonia of the urinary tract and bladder and other abnormalities. The postmortem in one of our cases is mentioned. The pattern of inheritance is autosomal recessive. The interpretation of the data on diabetes insipidus from the literature and in our three patients is also discussed. It can only be stated that neurohypophyseal diabetes insipidus can be a component of the syndrome and that in many cases--particularly in the presence of lesions of the efferent urinary tract--the possibility of nephrogenous diabetes insipidus can not be excluded with certainty. It seems probable that the same mechanism can be held responsible for the lesions of the olfactory, optic, vestibular and cochlear nerves, the hypophyseal form of diabetes insipidus, retarded sexual maturation, abnormal pupillary reaction, myelopathy and the electro-encephalographic, electroneurological and electromyographic changes in the Wolfram syndrome. The process underlying this affection of neural structures remains obscure.