Inhibition of monocyte chemoattractant protein-1 expression in tubular epithelium attenuates tubulointerstitial alteration in rat Goodpasture syndrome

Inhibition of monocyte chemoattractant protein-1 expression in tubular epithelium attenuates tubulointerstitial alteration in rat Goodpasture syndrome.BackgroundTo examine the role of monocyte chemoattractant protein-1 (MCP-1) expressed by tubular epithelium in tubulointerstitial alterations in situ, the level of MCP-1 mRNA in tubular epithelium was lowered selectively in the rat model of Goodpasture syndrome (GPS).MethodsIntravenously administered antisense oligodeoxynucleotide (ODN) is taken up by renal tubular epithelium and has been found to block expression of target genes in rats. MCP-1 antisense ODN was injected into GPS rats every second day from days 27 to 35 after immunization (this represents the time when renal MCP-1 mRNA level was increased and interstitial mononuclear cell infiltration was aggravated).ResultsIn addition to a reduction in the level of tubular MCP-1 mRNA, antisense ODN treatment attenuated monocyte infiltration significantly and preserved renal function in GPS rats. However, ODN injection did not affect glomerular MCP-1 expression and glomerular histopathology, and there were no significant changes in the urinary protein excretion rate.ConclusionOur findings provide direct evidence that MCP-1, expressed by tubular epithelium, plays a pivotal role in mediating secondary tubulointerstitial alterations in the GPS model

A New Calmodulin-Binding Protein Expresses in the Context of Secondary Cell Wall Biosynthesis and Impacts Biomass Properties in Populus

A greater understanding of biosynthesis, signaling and regulatory pathways involved in determining stem growth and secondary cell wall chemistry is important for enabling pathway engineering and genetic optimization of biomass properties. The present study describes a new functional role of PdIQD10, a Populus gene belonging to the IQ67-Domain1 family of IQD genes, in impacting biomass formation and chemistry. Expression studies showed that PdIQD10 has enhanced expression in developing xylem and tension-stressed tissues in Populus deltoides. Molecular dynamics simulation and yeast two-hybrid interaction experiments suggest interactions with two calmodulin proteins, CaM247 and CaM014, supporting the sequence-predicted functional role of the PdIQD10 as a calmodulin-binding protein. PdIQD10 was found to interact with specific Populus isoforms of the Kinesin Light Chain protein family, shown previously to function as microtubule-guided, cargo binding and delivery proteins in Arabidopsis. Subcellular localization studies showed that PdIQD10 localizes in the nucleus and plasma membrane regions. Promoter-binding assays suggest that a known master transcriptional regulator of secondary cell wall biosynthesis (PdWND1B) may be upstream of an HD-ZIP III gene that is in turn upstream of PdIQD10 gene in the transcriptional network. RNAi-mediated downregulation of PdIQD10 expression resulted in plants with altered biomass properties including higher cellulose, wall glucose content and greater biomass quantity. These results present evidence in support of a new functional role for an IQD gene family member, PdIQD10, in secondary cell wall biosynthesis and biomass formation in Populus

Autoreactive T-cells in Goodpasture's syndrome recognize the N-terminal NC1 domain on α3 type IV collagen

Autoreactive T-cells in Goodpasture's syndrome recognize the N-terminal NC1 domain on α3 type IV collagen. Goodpasture's syndrome is mediated by immunopathogenic autoantibodies to the α3 NC1 domain of type IV collagen. It is not known whether collaborating T-cells participate in this autoreactive response. Here we describe the first T-cell clone isolated from a Goodpasture patient autoreactive to α3 type IV collagen of glomerular basement membrane. To investigate cellular autoreactivity, T-cells from Goodpasture patients or controls were isolated and stimulated by purified native or recombinant type IV collagen proteins and synthetic oligopeptides. Cell surface markers, the T-cell receptor repertoire, and MHC-restriction were analyzed. T-cell clones specific for the α3(IV) NC1 domain were established in two Goodpasture patients, but not in controls. One of the three CD8+ T-cell clones was characterized further. It was MHC class I restricted (HLA-A11) and expressed the T-cell receptor Vβ 5.1. chain. This clone specifically recognized a motif at the N-terminal area of the α3(IV) NC1 domain (AA 51 to 59: GSPATWTTR). We conclude that autoreactive T-cells exists in Goodpasture patients and may play a crucial role in the inflammatory process. T-cell clones are autoreactive to the α3(IV) NC1 domain. At least for one of the clones, the T-cell epitope is different from the putative antibody-binding site