Transplantation of Apoptosis-Resistant Endothelial Progenitor Cells Improves Renal Function in Diabetic Kidney Disease.

Background Diabetic kidney disease is associated with glomerulosclerosis and poor renal perfusion. Increased capillary formation and improved perfusion may help to halt or reverse the injury. Transplanting apoptosis-resistant p53-silenced endothelial progenitor cells (p53sh-EPCs) may help improve vascularization and renal perfusion and could be more beneficial than another stem cell such as the mouse mesenchymal stromal cell (mMSC). Methods and Results Hyperglycemia and proteinuria were confirmed at 8 to 10 weeks in streptozotocin-induced type1 diabetic C57Bl/6 mice, followed by transplantation of 0.3 million p53sh-EPCs, Null-EPCs (control), or mMSC under each kidney capsule. Urine was collected weekly for creatinine and protein levels. Blood pressure was measured by direct arterial cannulation and renal perfusion was measured by renal ultrasound. The kidneys were harvested for histology and mRNA expression. Reduction of protein/creatinine (AUC) was observed in p53sh-EPC-transplanted mice more than null-EPC (1.8-fold, P=0.03) or null-mMSC (1.6-fold, P=0.04, n=4) transplanted mice. Markers for angiogenesis, such as endothelial nitric oxide synthase (1.7-fold, P=0.06), were upregulated post p53sh-EPC transplantation compared with null EPC. However, vascular endothelial growth factor-A expression was reduced (7-fold, P=0.0004) in mMSC-transplanted mice, compared with p53sh-EPC-transplanted mice. Isolectin-B4 staining of kidney section showed improvement of glomerular sclerosis when p53sh-EPC was transplanted, compared with null-EPC or mMSC. In addition, mean and peak renal blood velocity (1.3-fold, P=0.01, 1.4-fold, P=0.001, respectively) were increased in p53sh-EPC-transplanted mice, relative to null-EPC transplanted mice. Conclusions Apoptosis-resistant p53sh EPC transplantation could be beneficial in the treatment of diabetic kidney disease by decreasing proteinuria, and improving renal perfusion and glomerular architecture.

Lysine substitutions convert a bacterial-agglutinating peptide into a bactericidal peptide that retains anti-lipopolysaccharide activity and low hemolytic activity.

GL13NH2 is a bacteria-agglutinating peptide derived from the sequence of the salivary protein parotid secretory protein (PSP, BPIFA2, SPLUNC2, C20orf70). The peptide agglutinates both Gram negative and Gram positive bacteria, and shows anti-lipopolysaccharide activity in vitro and in vivo. However, GL13NH2 does not exhibit bactericidal activity. To generate a more cationic peptide with potential bactericidal activity, three amino acid residues were replaced with lysine residues to generate the peptide GL13K. In this report, the antibacterial and anti-inflammatory activities of GL13K were characterized. GL13K had lost the ability to agglutinate bacteria but gained bactericidal activity. Substitution of individual amino acids in GL13K with alanine did not restore bacterial agglutination. GL13K was bactericidal against Pseudomonas aeruginosa, Streptococcus gordonii and Escherichia coli but not Porphyromonas gingivalis. Unlike the agglutinating activity of GL13NH2, the bactericidal activity of GL13K against P. aeruginosa was retained in the presence of saliva. Both GL13NH2 and GL13K exhibited anti-lipopolysaccharide activity. In GL13K, this activity appeared to depend on a serine hydroxyl group. GL13K protected mice from lipopolysaccharide-induced sepsis and the peptide exhibited a low level of hemolysis, suggesting that it may be suitable for in vivo application.

Hydrophobic oxime ethers: a versatile class of pDNA and siRNA transfection lipids.

The manipulation of the cationic lipid structures to increase polynucleotide binding and delivery properties, while also minimizing associated cytotoxicity, has been a principal strategy for developing next-generation transfection agents. The polar (DNA binding) and hydrophobic domains of transfection lipids have been extensively studied; however, the linking domain comprising the substructure used to tether the polar and hydrophobic domains has attracted considerably less attention as an optimization variable. Here, we examine the use of an oxime ether as the linking domain. Hydrophobic oxime ethers were readily assembled via click chemistry by oximation of hydrophobic aldehydes using an aminooxy salt. A facile ligation reaction delivered the desired compounds with hydrophobic domain asymmetry. Using the MCF-7 breast cancer, H1792 lung cancer and PAR C10 salivary epithelial cell lines, our findings show that lipoplexes derived from oxime ether lipids transfect in the presence of serum at higher levels than commonly used liposome formulations, based on both luciferase and green fluorescent protein (GFP) assays. Given the biological compatibility of oxime ethers and their ease of formation, this functional group should find significant application as a linking domain in future designs of transfection vectors.

Female mice are more susceptible to developing inflammatory disorders due to impaired transforming growth factor beta signaling in salivary glands.

OBJECTIVE: Transforming growth factor beta (TGFbeta) plays a key role in the onset and resolution of autoimmune diseases and chronic inflammation. The aim of this study was to delineate the precise function of TGFbeta signaling in salivary gland inflammation. METHODS: We impaired TGFbeta signaling in mouse salivary glands by conditionally inactivating expression of TGFbeta receptor type I (TGFbetaRI), either by using mouse mammary tumor virus-Cre mice or by delivering adenoviral vector containing Cre to mouse salivary glands via retrograde infusion of the cannulated main excretory ducts of submandibular glands. RESULTS: TGFbetaRI-conditional knockout (TGFbetaRI-coko) mice were born normal; however, female TGFbetaRI-coko mice developed severe multifocal inflammation in salivary and mammary glands and in the heart. The inflammatory disorder affected normal growth and resulted in the death of the mice at ages 4-5 weeks. Interestingly, male TGFbetaRI-coko mice did not exhibit any signs of inflammation. The female TGFbetaRI-coko mice also showed an increase in Th1 proinflammatory cytokines in salivary glands and exhibited an up-regulation of peripheral T cells. In addition, these mice showed an atypical distribution of aquaporin 5 in their salivary glands, suggesting likely secretory impairment. Administration of an adenoviral vector encoding Cre recombinase into the salivary glands resulted in inflammatory foci only in the glands of female TGFbetaRI-loxP-flanked (floxed) mice (TGFbetaRI-f/f mice), but not in those of male and female wild-type mice or male TGFbetaRI-f/f mice. CONCLUSION: These results suggest that female mice are uniquely more susceptible to developing inflammatory disorders due to impaired TGFbeta signaling in their salivary glands.

Neuron-specific TGF-beta signaling deficiency results in retinal detachment and cataracts in mice.

We generated a mouse model (cKO) with a conditional deletion of TGF-beta signaling in the retinal neurons by crossing TGF-beta receptor I (TGF-beta RI) floxed mice with nestin-Cre mice. Almost all of the newborn cKO mice had retinal detachment at the retinal pigment epithelium (RPE)/photoreceptor layer junction of the neurosensory retina (NSR). The immunostaining for chondroitin-6-sulfate showed a very weak reaction in cKO mice in contrast to intense staining in the photoreceptor layer in wild-type mice. Macroscopic cataracts, in one or both eyes, were observed in 50% of the mice by 6 months of age, starting as early as the first month after birth. The cKO mouse model demonstrates that the TGF-beta signaling deficiency in retinal cells leads to decreased levels of chondroitin sulfate proteoglycan in the retinal interphotoreceptor matrix. This in turn causes retinal detachment due to the loss of adhesion of the NSR to RPE.