Aberrant expression of the human hyaluronan synthase 2 (HAS2) gene has been implicated in the pathology of malignancy, pulmonary arterial hypertension, osteoarthritis, asthma, thyroid dysfunction, and large organ fibrosis. Renal fibrosis is associated with increased cortical synthesis of hyaluronan (HA), an extracellular matrix glycosaminoglycan, and we have shown that HA is a correlate of interstitial fibrosis in vivo. Our previous in vitro data have suggested that both HAS2 transcriptional induction and subsequent HAS2-driven HA synthesis may contribute to kidney fibrosis via phenotypic modulation of the renal proximal tubular epithelial cell (PTC). Post-transcriptional regulation of HAS2 mRNA synthesis by the natural antisense RNA HAS2-AS1 has recently been described in osteosarcoma cells, but the antisense transcript was not detected in kidney. In this study, PTC stimulation with IL-1␤ or TGF-␤1 induced coordinated temporal profiles of HAS2-AS1 and HAS2 transcription. Constitutive activity of the putative HAS2-AS1 promoter was demonstrated, and transcription factor-binding sequence motifs were identified. Knockdown of Sp1/Sp3 expression by siRNA blunted IL-1␤ induction of both HAS2-AS1 and HAS2, and Smad2/Smad3 knockdown similarly attenuated TGF-␤1 stimulation. Inhibition of IL-1␤-stimulated HAS2-AS1 RNA induction using HAS2-AS1-specific siRNAs also suppressed upregulation of HAS2 mRNA transcription. The thermodynamic feasibility of HAS2-AS1/HAS2 heterodimer formation was demonstrated in silico, and locus-specific cytoplasmic doublestranded RNA was detected in vitro. In summary, our data show that transcriptional induction of HAS2-AS1 and HAS2 occurs simultaneously in PTCs and suggest that transcription of the antisense RNA stabilizes or augments HAS2 mRNA expression in these cells via RNA/mRNA heteroduplex formation.The linear non-sulfated glycosaminoglycan hyaluronan (HA) 5 is a ubiquitous component of the vertebrate extracellular matrix with a multiplicity of cellular functions in both physiological and pathophysiological contexts (1-8). HA is synthesized at the cell membrane by the HA synthase (HAS) enzymes, encoded in humans by the corresponding multigene family HAS1-3 (9 -11).Frequently associated with the fibrotic response in major organs, HA is a highly effective biomarker for liver fibrosis (12,13). Similarly, in lung fibrosis, accumulation of HA has been observed (14, 15), and in some cases, up-regulated HAS2 transcription has also been reported (14). For all progressive renal diseases, the rate of progression correlates with the degree of corticointerstitial fibrosis. Increased HA synthesis and extracellular matrix expansion in the renal corticointerstitium are common features of kidney fibrosis (16), and our recent studies on renal biopsy samples from diabetic nephropathy patients demonstrate that HA is a correlate of interstitial fibrosis in vivo (17). A number of our in vitro studies have suggested that HA may contribute to renal fibrosis via regulation of the renal proximal tubular epithelia...

The coordination chemistry of a Rh(III) porphyrin building block was investigated with a view to the construction of heterometallic arrays of porphyrins. The Rh(III) porphyrin was found to coordinate methanol in the solid state and weakly in CDCl(3) solution. Crystallization afforded five coordinate pi stacked Rh(III) porphyrins. The distribution of products from reaction of Rh(III) porphyrin with DABCO, 4,4'-bipyridine, and 4,4'-bipyrimidine could be displaced toward dimeric species by silica gel column chromatography or recrystallization which served to remove excess ligand. Weak coordination to nitriles was observed, although it was sufficiently strong to organize a dimeric complex of 5,5'-dicyano-2,2'-bipyridine in the solid state. Complexes with 4,4'-bipyrimidine and 5,5'-dicyano-2,2'-bipyridine possess uncoordinated chelating nitrogen atoms. Larger heterometallic porphyrin arrays were assembled using a combination of Sn(IV) and Rh(III) porphyrin coordination chemistry. A Sn(IV) porphyrin acted as a core around which were coordinated two isonicotinate groups, carboxylic acid functionalized porphyrins, or porphyrin trimer dendrons. Rh(III) porphyrins were coordinated to pyridyl groups at the periphery of these entities. In this way an eleven porphyrin array, with four different porphyrin metalation states, was assembled. The diamagnetic nature of both the Rh(III) and Sn(IV) porphyrins, the slow ligand exchange kinetics on the NMR time scale, and tight ligand binding permitted the porphyrin arrays to be analyzed by two-dimensional (1)H NMR techniques.

Cyclic peptides have come under scrutiny as potential antimicrobial therapeutic agents. Combinatorial split-and-pool synthesis of cyclic peptides can afford single compound per well libraries for antimicrobial screening, new lead identification, and construction of quantitative structure-activity relationships (QSAR). Here, we report a new sequencing protocol for rapid identification of the members of a cyclic peptide library based on automated computer analysis of mass spectra, obviating the need for library encoding/decoding strategies. Furthermore, the software readily integrates with common spreadsheet and database packages to facilitate data visualization and archiving. The utility of the new MS-sequencing approach is demonstrated using sonic spray ionization ion trap MS and MS/MS spectrometry on a single compound per bead cyclic peptide library and validated with individually synthesized pure cyclic D,L-alpha-peptides.

The synthesis and characterization of a butadiyne linked Rh(III) porphyrin dimer containing a 4,4‘-bipyridine ligand are presented. The crystal structure is compared to the crystal structures of complexes of a monomeric Rh porphyrin with 4,4‘-bipyridine and pyridine, and with the results of molecular modeling.