Development of Viral Vectors for Use in Cardiovascular Gene Therapy

Cardiovascular disease represents the most common cause of mortality in the developed world but, despite two decades of promising pre-clinical research and numerous clinical trials, cardiovascular gene transfer has so far failed to demonstrate convincing benefits in the clinical setting. In this review we discuss the various targets which may be suitable for cardiovascular gene therapy and the viral vectors which have to date shown the most potential for clinical use. We conclude with a summary of the current state of clinical cardiovascular gene therapy and the key trials which are ongoing

Ex Vivo Modeling of Chemical Synergy in Prenatal Kidney Cystogenesis

Cyclic adenosine monophosphate (cAMP) drives genetic polycystic kidney disease (PKD) cystogenesis. Yet within certain PKD families, striking differences in disease severity exist between affected individuals, and genomic and/or environmental modifying factors have been evoked to explain these observations. We hypothesized that PKD cystogenesis is accentuated by an aberrant fetal milieu, specifically by glucocorticoids. The extent and nature of cystogenesis was assessed in explanted wild-type mouse embryonic metanephroi, using 8-Br-cAMP as a chemical to mimic genetic PKD and the glucocorticoid dexamethasone as the environmental modulator. Cysts and glomeruli were quantified by an observer blinded to culture conditions, and tubules were phenotyped using specific markers. Dexamethasone or 8-Br-cAMP applied on their own produced cysts predominantly arising in proximal tubules and descending limbs of loops of Henle. When applied together, however, dexamethasone over a wide concentration range synergized with 8-Br-cAMP to generate a more severe, glomerulocystic, phenotype; we note that prominent glomerular cysts have been reported in autosomal dominant PKD fetal kidneys. Our data support the idea that an adverse antenatal environment exacerbates renal cystogenesis

Measures of kidney function by minimally invasive techniques correlate with histological glomerular damage in SCID mice with adriamycin-induced nephropathy

Maximising the use of preclinical murine models of progressive kidney disease as test beds for therapies ideally requires kidney function to be measured repeatedly in a safe, minimally invasive manner. To date, most studies of murine nephropathy depend on unreliable markers of renal physiological function, exemplified by measuring blood levels of creatinine and urea, and on various end points necessitating sacrifice of experimental animals to assess histological damage, thus counteracting the principles of Replacement, Refinement and Reduction. Here, we applied two novel minimally invasive techniques to measure kidney function in SCID mice with adriamycin-induced nephropathy. We employed i) a transcutaneous device that measures the half-life of intravenously administered FITC-sinistrin, a molecule cleared by glomerular filtration; and ii) multispectral optoacoustic tomography, a photoacoustic imaging device that directly visualises the clearance of the near infrared dye, IRDye 800CW carboxylate. Measurements with either technique showed a significant impairment of renal function in experimental animals versus controls, with significant correlations with the proportion of scarred glomeruli five weeks after induction of injury. These technologies provide clinically relevant functional data and should be widely adopted for testing the efficacies of novel therapies. Moreover, their use will also lead to a reduction in experimental animal numbers

Comparative proteomics study of streptozotocin-induced diabetic nephropathy in rats kidneys transfected with adenovirus-mediated fibromodulin gene

BACKGROUND: Transforming Growth Factor-beta (TGF-β) activation appears to be crucial for tissue injury in Diabetic Nephropathy (DN). Fibromodulin, the small leucine-rich proteoglycan, has been proposed to be the potent TGF-β modulator. In this study, the therapeutic effects of fibromodulin in the kidneys of streptozotocin (STZ)-induced diabetic rats were investigated. METHODS: Diabetic rats received intraperitoneal (IP) injections of recombinant adenovirus expression vectors (RAd5) containing fibromodulin (RAd-FMOD) and were killed after 10 weeks. Proteins were isolated from the rat kidney and separated using two-dimensional gel electrophoresis. The differentially expressed proteins were analyzed using Matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF-MS). RESULTS: Ten spots were identified using MALDI-TOF-MS. The identified proteins were primarily responsible for cell metabolism, cytoskeleton formation, and oxidative stress. RAd-FMOD treatment markedly attenuated the albuminuria in diabetic rats. CONCLUSION: Taken together, these results provide a valuable clue in exploring the mechanism underlying the therapeutic effects of fibromodulin in diabetic nephropathy suggesting that it can be a potential agent in the treatment of this disease

Congenital disorders of the human urinary tract: recent insights from genetic and molecular studies.

The urinary tract comprises the renal pelvis, the ureter, the urinary bladder, and the urethra. The tract acts as a functional unit, first propelling urine from the kidney to the bladder, then storing it at low pressure inside the bladder which intermittently and completely voids urine through the urethra. Congenital diseases of these structures can lead to a range of diseases sometimes associated with fetal losses or kidney failure in childhood and later in life. In some of these disorders, parts of the urinary tract are severely malformed. In other cases, the organs appear grossly intact yet they have functional deficits that compromise health. Human studies are beginning to indicate monogenic causes for some of these diseases. Here, the implicated genes can encode smooth muscle, neural or urothelial molecules, or transcription factors that regulate their expression. Furthermore, certain animal models are informative about how such molecules control the development and functional differentiation of the urinary tract. In future, novel therapies, including those based on gene transfer and stem cell technologies, may be used to treat these diseases to complement conventional pharmacological and surgical clinical therapies

Histology of day three rudiments exposed to 100 µM 8-Br-cAMP (<i>cAMP</i>)-only.

<p><b>A and B.</b> Adjacent sections counterstained with hematoxylin. In A, several non-dilated tubules are stained brown (arrows), having bound <i>Dolichos biflorus</i> agglutinin; they most likely represent collecting ducts. The centre of each frame is dominated by a tubule which has a “U-turn”. Uromodulin was immunolocalised (brown color) in the undilated limb (indicated by the arrows in B). In contrast, epithelia in the adjacent limb, which is dilated (asterisk), were unreactive with the uromodulin antibody. The simplest deduction is that the dilatation is present in the descending limb of the loop of Henle. Bar is 100 µm.</p

F4/80 immunostaining of macrophages in rudiments at day 6 of culture.

<p>(<b>A</b>) Vehicle-only exposed organ. (<b>B</b>) Dexamethasone-only exposed organ. (<b>C</b>) 8-Br-cAMP-only exposed organ. (<b>D</b>) Organ exposed to both cystogens. Immunoreactive cells, presumed macrophages, are brown and some are indicted by arrows. Note that F4/80 macrophages were detected in all four conditions. In cystic explants, their numbers did not appear increased and, moreover, they were often located distant from cyst epithelia. Bar is 50 µm.</p