Association between the Clara cell secretory protein (CC16) G38A polymorphism and the progression of IgA nephropathy

AIMS

Clara cell secretory protein (CC16) is a protein with anti-inflammatory and immunomodulatory properties. Moreover, both CC16 gene knockout and antisense-transgenic mouse models developed glomerulonephritis resembling IgA nephropathy (IgAN). In the present study, we evaluated the influence of the G38A polymorphism in the CC16 gene exon 1 on the development and progression of IgAN.

METHODS

Korean patients with biopsy-proven IgAN (n=267) with a minimal follow-up of 4 years (mean +/- SD 103.8 +/- 52.6 months) were recruited. Healthy normal subjects (n=315) were included as controls. The G38A polymorphism was determined using the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

GG, GA and AA genotype frequencies were 36.3, 50.2 and 13.5% in IgAN patients, respectively, and 34.3, 50.2 and 15.5% in controls (chi2 = 0.596, p = 0.742). The G allele frequency was 0.614 in IgAN patients and 0.594 in controls (chi2 = 0.429, p = 0.512). Moreover, the GG genotype frequencies were 40.4% in patients showing stable disease course and 26.6% in those with progressive disease (chi2 = 4.029, p = 0.045). Patients with the GG genotype showed a better outcome by Kaplan-Meier analysis in terms of renal survival (p = 0.043). The CC16 polymorphism remained an independent risk factor for progression after multivariate analysis (Cox regression model, HR for CC16 AA genotype: 2.34, 95% CI 1.19-4.64, p = 0.014).

CONCLUSION

Our results suggest that CC 16 gene G38A polymorphism is not associated with the development of IgAN, but that it is an important marker of progression in IgAN.

In vitro bioactivity and osteoblast response of porous NiTi synthesized by SHS using nanocrystalline Ni-Ti reaction agent

Porous NiTi with an average porosity of 55 vol % and a general pore size of 100-600 microm was synthesized by self-propagating high temperature synthesis (SHS) with the addition of mechanically alloyed nanocrystalline Ni-Ti as the reaction agent. The SHS of porous NiTi using elemental powders was also performed for comparison. To enhance the bioactivity of the metal surface, porous NiTi synthesized by nanocrystalline Ni-Ti was subjected to chemical treatment to form a layer of TiO(2) coating. The porous NiTi with TiO(2) coating was subsequently immersed in a simulated body fluid (SBF) to investigate its apatite forming ability. The effects of the addition of nanocrystalline Ni-Ti as reaction agent and the application of apatite coating on osteoblastic behavior were studied in primary cultures of human osteoblast cells. Results showed that the main phases in porous NiTi synthesized by elemental powders were NiTi, Ti(2)Ni, and unreacted free Ni. By using nanocrystalline Ni-Ti as reaction agent, the secondary intermetallic phase of Ti(2)Ni was significantly reduced and the free Ni was eliminated. TiO(2) coating with anatase phase was formed on the surface of porous NiTi after the chemical treatment. A layer consisting of nanocrystalline carbonate-containing apatite was formed on the surface of TiO(2) coating after soaking in SBF. The preliminary cell culture studies showed that the porous NiTi synthesized with the addition of nanocrystalline Ni-Ti attracted marked attachment and proliferation of the osteoblast cells. This gives the evidence of the potential biomedical applications of the porous NiTi.

Differential dengue cross-reactive and neutralizing antibody responses in BALB/c and Swiss albino mice induced by immunization with flaviviral vaccines and by infection with homotypic dengue-2 virus strains

We investigated whether cross-reactive and/or cross-protective antibodies against dengue virus could be generated in 6-week-old BALB/c mice by immunization with currently approved flaviviral vaccines, i.e., Japanese encephalitis (JE) BIKEN and yellow fever (YF) 17D. Cross-reactivity with dengue antigens was apparent in at least one-third each of JE-vaccinated mouse sera and of JE/YF-vaccinated mouse sera by dengue enzyme immunoassay, but was not detected in sera of mice immunized with YF vaccine alone. All the immunized BALB/c mice failed to generate neutralizing antibodies against the New Guinea C laboratory (NGC-lab) strain of dengue virus type 2. In addition, we determined the specificity of neutralizing antibodies elicited in 3-week-old Swiss albino mice against two homotypic dengue-2 strains, i.e., NGC-lab and Singapore 1999 (SING/99). Although sera from virus-inoculated mice displayed better neutralization against the corresponding strain, antibodies elicited by NGC-lab exhibited a significantly poorer neutralizing response against the SING/99 strain compared to antibodies elicited by SING/99 against NGC-lab. The differences may be related to sequence variations of approximately 3% between the envelope proteins of both strains. Amino acid disparities at positions 71 (Glu --> Ala), 112 (Ser --> Gly) and 124 (Ile --> Asn), which are found in dengue-2 neutralization escape mutants, were also found in the SING/99 strain. The envelope sequence differences may explain diminished binding of NGC-lab-induced neutralizing antibodies to neutralizing epitopes within the envelope of the SING/99 strain, resulting in a lower titer of neutralizing antibodies against another strain of the same serotype.

Biomimetic deposition of apatite coating on surface-modified NiTi alloy

TiO(2) coatings were prepared on NiTi alloy by heat treatment in air at 300, 400, 600 and 800 degrees C. The heat-treated NiTi alloy was subsequently immersed in a simulated body fluid for the biomimetic deposition of the apatite layer onto the surface of TiO(2) coating. The apatite coatings as well as the surface oxide layer on NiTi alloy were characterized using scanning electron microscopy equipped with energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. Results showed the samples heat-treated at 600 degrees C produced a layer of anatase and rutile TiO(2) on the surface of NiTi. No TiO(2) was detected on the surface of NiTi after heat treatment at 300 and 400 degrees C by X-ray diffraction, while rutile was formed on the surface of the 800 degrees C heat-treated sample. It was found that the 600 degrees C heat-treated NiTi induced a layer consisted of microcrystalline carbonate containing hydroxyapatite on its surface most effectively, while 300 and 400 degrees C heat-treated NiTi did not form apatite. This was due to the presence of anatase and/or rutile in the 600 and 800 degrees C heat-treated NiTi which could provide atomic arrangements in their crystal structures suitable for the epitaxy of apatite crystals, and anatase had better apatite-forming ability than rutile. XPS and Raman results revealed that this apatite layer was a carbonated and non-stoichiometric apatite with Ca/P ratio of 1.53, which was similar to the human bone. The formation of apatite on 600 degrees C heat-treated NiTi following immersion in SBF for 3 days indicated that the surface modified NiTi possessed excellent bioactivity.

On-line coal analysis using fast neutron-induced gamma-rays

On-line measurement of bulk elemental composition is often best achieved with highly penetrative neutron-gamma techniques. CSIRO has developed and implemented one such technique, neutron inelastic-scattering and thermal-capture analysis (NITA). A distinctive feature of NITA is its use of fast neutron sources to generate inelastic scattering reactions, thus exciting gamma-rays from industrially important elements such as carbon and oxygen. A full-scale prototype for on-line coal quality measurement has been tested under simulated industrial conditions. The effect of sample compositional inhomogeneity and stream thickness will be discussed.

Intravitreal triamcinolone improves vision in eyes with chronic diabetic macular oedema refractory to laser photocoagulation

PURPOSE

To evaluate the clinical and visual outcome of an intravitreal injection of triamcinolone in patients with diabetic macular oedema refractory to laser treatment.

MATERIAL AND METHODS

Prospective, interventional nonrandomised case series of 24 eyes of 24 patients that underwent intravitreal injection of 4 mg triamcinolone for chronic diabetic macular oedema refractory to previous laser treatment. All patients had best corrected visual acuity (bcva) on the LogMAR scale, near vision, slit-lamp biomicroscopy for the presence of clinically significant macular oedema, and intraocular pressure check at 1, 3, and 6 months.

RESULTS

The average duration of macular oedema before the injection was 38.2 months (range=6-120 months) with the mean number of laser treatments before the injection being 2.2 (range=1-5). The visual acuity improved in 19 of the 23 (83%) eyes at 1 month, 16 of the 21 eyes (76%) at 3 months and six of 11 eyes (55%) at 6 months follow-up. The mean bcva improved by an average of 10, nine, and six letters, respectively, compared to the baseline at 1, 3, and 6 months (P=0.0002 at 1 month and 0.001 at 3 months with the Wilcoxon signed-ranked test). The intraocular pressure rose by an average of 2.4, 2.8, and 2.7 mmHg at the same follow-up visits.

CONCLUSION

Intravitreal triamcinolone appears to be promising in the short term, for improving the vision in eyes with chronic diabetic macular oedema unresponsive to conventional laser treatment. Randomised controlled trials utilising varying doses of steroid are now required to define optimum treatment regimens.

Association of C-509T and T869C polymorphisms of transforming growth factor-beta1 gene with susceptibility to and progression of IgA nephropathy

AIMS

Transforming growth factor (TGF)-beta1 is a cytokine with both beneficial anti-inflammatory effects and detrimental profibrotic activity in the pathophysiology and progression of glomerulonephritides. The transcriptional activity of the gene for TGF-beta1 and the plasma levels of TGF-beta1 protein are associated with C-509T polymorphism at the promoter region, and with T869C (Leu 10Pro) polymorphism at codon 10, of the TGF-beta1 gene.

METHODS

Using PCR-RFLP and the amplification refractory mutation system PCR, we investigated the C-509T and T869C polymorphisms, respectively, to elucidate whether allele frequency differences exist between IgA nephropathy (IgAN) patients who were followed up for at least 3 years (n = 108) and a normal population (n = 55). We also determined the correlations between the TGF-beta1 polymorphisms and the progression of IgAN.

RESULTS

In C-509T polymorphism, there were significant differences in genotype frequency between IgAN patients and normal controls (CC: CT: TT, 20:29:33 vs. 11:31:13, chi2 = 6.299, p = 0.043). In Kaplan-Meier survival analysis, the patients with TT genotype showed a poorer renal survival than those with CC + CT genotypes (p = 0.042). In T869C polymorphism, there were also significant differences in genotype frequency between IgAN patients and normal controls (TT : TC : CC, 4 : 79 : 25 vs. 0 : 52 : 2, chi2 = 12.552, p = 0.002). The initial serum creatinine (Scr) level was higher in the patients with CC genotype than in those with TT + TC genotypes. In Kaplan-Meier survival analysis, the patients with CC genotype showed a poorer renal survival than those with TT + TC genotypes, but not to a statistically significant extent (p = 0.076). In the combined survival analyses, the high TGF-beta1 producer group showed a poor renal survival rate (p = 0.014).

CONCLUSION

Compared to normal population, the frequencies of genotypes producing high TGF-beta1 protein were higher in IgAN patients. Moreover, patients with genotypes producing high TGF-beta1 plasma levels showed a poor renal survival rate.

Bidirectional on/off switch for controlled targeting of proteins to subcellular compartments

A regulatable fusion protein was constructed for controlling the localization of plasmid products. A ligand-inducible nuclear localization signal, nuclear export signal (NES) and a truncated form of the ligand binding domain of the progesterone receptor were attached to the desired protein. Enhanced green fluorescent protein (EGFP) was used as a model protein and its trafficking between the nucleus and cytoplasm was studied using fluorescence microscopy in response to the ligand, mifepristone. It was found that the protein trafficking into the nucleus was dose dependent with ligand concentration. Increasing the ligand dose from 1 to 100 nM enhanced import and reduced the rate of export of the fusion protein from the nucleus to the cytoplasm. This study demonstrates the feasibility of using an export signal and a ligand-inducible nuclear import signal as a bi-directional on/off switch with potential use for controlled targeting of therapeutic proteins to subcellular compartments.

Peritoneal implantation of ureter in a cadaveric kidney transplant recipient

We report here a case of a kidney transplant recipient in whom the ureter was initially implanted into the peritoneum. Excessive ultrafiltration volume and reversal of serum vs dialysate creatinine ratio when the patient was recommenced on continuous ambulatory peritoneal dialysis first suggested the diagnosis which was subsequently confirmed by a plain abdominal x-ray demonstrating placement of ureteric stent in the peritoneum. This rare complication was successfully corrected with surgical re-implantation of ureter into the bladder and 5 years later, the patient remains well with good graft function.

A fiber optic biosensor (FOBS) to monitor mutans streptococci in human saliva

A fiber optic biosensor (FOBS) to monitor mutans streptococci activity in human saliva is developed. The biosensor utilizes e fiber optic evanescent wave spectroscopy to monitor a bacterial mediated biochemical reaction. To achieve this, a short length of the cladding is removed; the fiber core surface is treated and coated with a thin film of porous glass medium using sol-gel technique. The mutans streptococci mediated reaction with sucrose is monitored using a photosensitive indicator, which is immobilized within the porous glass coating. Spectroscopic analysis shows that the transmitted intensity at 597 nm increases conspicuously when monitored for 120 min. Two distinct phases are observed, one from 0 to 60 min and the other from 60 to 120 min. A negative correlation coefficient between the rate of increase in absorption peak intensity recorded by the FOBS and the decrease in pH measured using the pH meter, was calculated to be rho=-0.994. This investigation highlights the potential benefits of this sensor to monitor mutans streptococci activity in saliva.

Reactivity of sera from cases of Plasmodium vivax malaria towards three recombinant antigens based on the surface proteins of the parasite

Sera collected in South Korea, from 61 cases of Plasmodium vivax malaria and, as controls, 40 healthy volunteers, were tested in ELISA for IgG or IgM reacting with any of three recombinant P. vivax proteins. The antigens used, representing the parasite's major merozoite surface protein (MSP), circumsporozoite surface protein (CSP) and Duffy-binding protein (DBP), had all been expressed in an Escherichia coli system and purified. The ELISA results were recorded as optical densities (OD). The highest ratio observed between the mean OD for a malaria serum and that for a control serum was that for IgG against MSP, although CSP gave a higher ratio than MSP or DBP in the IgM ELISA. In the ELISA for IgG, the OD for MSP were found to be correlated with those for DBP (r = 0.53; P < 0.5) but the OD for CSP were not correlated with those for MSP or DBP. As the most intense reactions observed were those between the IgG from the malaria sera and the recombinant MSP, the latter antigen may be useful in diagnostic tests and as a component of any vaccine used to protect against P. vivax malaria.

Hemagglutinin-neuraminidase sequence and phylogenetic analyses of mumps virus isolates from a vaccinated population in Singapore

During 1999-2000, a sustained mumps outbreak in the highly vaccinated population in Singapore was attributed to vaccine failure associated with the Rubini vaccine strain. To explain this phenomenon, the complete nucleotide and amino acid sequences of the hemagglutinin-neuraminidase (HN) gene of eight mumps virus isolates from patients with parotitis in Singapore were determined and compared with those of known vaccine strains. Phylogenetic trees constructed on the basis of HN nucleotide and amino acid sequences showed that the Singapore mumps virus isolates were more closely related to the Urabe strain and belonged to a different cluster from the Rubini and Jeryl-Lynn strains. The Rubini vaccine showed only approximately 93% nucleotide and approximately 96% amino acid sequence similarity to Urabe and Singapore isolates. Compared with the vaccine strains, six of the eight isolates lacked the extracellular glycosylation site at residues 400-402. Other significant amino acid disparities (e.g., at residue 354) may also affect the antigenic properties of the HN protein. These findings suggest that the evolution and adaptation of the currently circulating mumps virus strains in the community has led to the emergence of genetically distinct viral strains. The low vaccine efficacy of the Rubini strain represents a major reason for the recent mumps resurgence and failure of mumps immunization in Singapore.

Sequence and phylogenetic analysis of SH, G, and F genes and proteins of Human respiratory syncytial virus isolates from Singapore

To study the genetic variability and molecular epidemiology of Human respiratory syncytial virus (HRSV) occurring in Singapore, nucleotide sequencing of three membrane-associated genes (SH, G and F) of four local isolates was performed. Comparison of their nucleotide and amino acid sequences with those of the prototype strains A2 (subgroup A) and CH-18537 (subgroup B) indicated that the Singapore isolates belong to the subgroup A. Comparison of the Singapore isolates with the reference strain A2 showed that whereas the G protein was the most divergent with up to 15% difference, the F and SH proteins showed less diversity of only up to 4%. Each gene exhibited its distinct variable and conserved regions. The N- and O-glycosylation sites within the G protein of the isolates were analyzed to ascertain their potential implications on the antigenicity of the viral glycoprotein. Based on the second variable region of the G protein, phylogenetic analysis of the Singapore isolates with 91 previously identified genotypes of subgroup A revealed that more than one genotype (GA2 and GA5) may circulate in the local population at a given time. This epidemiological study reflects the pattern of genetic relationships between the HRSV isolates from Singapore to those from other parts of the world.

Total protein measurement using a fiber-optic evanescent wave-based biosensor

A novel method and instrumental system to determine the total protein concentration in a liquid sample is described. It uses a fiber optic total protein sensor (FOPS) based on the principles of fiber optic evanescent wave spectroscopy. The FOPS applies a dye-immobilized porous glass coating on a multi-mode optical fiber. The evanescent waves at the fiber optic core-cladding interface are used to monitor the protein-induced changes in the sensor element. The FOPS offers a single-step method for quantifying protein concentrations without destroying the sample. The response time and reusability of the FOPS are evaluated. This unique sensing method presents a sensitive and accurate platform for the quantification of protein.

Scanning electron microscopic and energy dispersive spectrometric investigations on the effect of XeCl excimer laser on human dentin with smear layer

The purpose of this study was to study the effect of XeCl excimer laser on smear layer covered dentine of extracted human teeth. Twenty-four freshly extracted human molar teeth were collected and randomly divided into one control group and three experimental groups of six teeth each (groups A-D). The teeth in the experimental groups were irradiated with XeCl 308-nm excimer laser at a fluence of 0.4 J cm-2 and a constant pulse repetition rate of 25 Hz. Group A was used as the control, while groups B, C and D were irradiated at different exposure times of 3, 5 and 7 s, respectively. Subsequently these teeth specimens were subjected to scanning electron microscopic (SEM) examination and energy dispersive X-ray (EDX) spectrometric analysis. The SEM examination revealed melting of the smear layer covered dentin to conceal the underlying dentinal tubules. At a longer exposure time (7 s), dentin melted to form large grains and this resulted in non-uniform closure of underlying dentinal tubules. Under the conditions of this study, it is concluded that the pulsed XeCl 308-nm excimer laser at a fluence of 0.4 J cm-2, with an exposure time of 5 s uniformly occluded exposed smear layer covered dentine with no conspicuous variation in chemical structure.

A survey of visual impairment in children attending the Royal Blind School, Edinburgh using the WHO childhood visual impairment database

PURPOSE

To assess the aetiology and changing patterns of childhood blindness in one school for the blind in the UK and to assess the use of the World Health Organisation Prevention of Blindness (WHO/PBL) methodology and reporting form in a developed country.

METHODS

One hundred and seven children in one school for the blind and visually impaired in Edinburgh were examined using the WHO/PBL childhood blindness assessment form.

RESULTS

Of the 107 children examined, 87 (81%) were blind or severely visually impaired (corrected visual acuity of <6/60 (20/200) in the better eye). Perinatal related blindness (40%), hereditary disease (26%) and developmental factors (26%) formed the three largest aetiological categories.

CONCLUSION

The pattern of childhood blindness seen in this study was similar to reports from other developed countries. The WHO/PBL reporting form allows detailed comparisons between countries and over time. Additional fields for more detailed reporting of cerebral visual impairment and associated handicaps would increase the usefulness of the WHO/PBL form for population-based studies and for use in developed countries.

Interdependent effect of angiotensin-converting enzyme and platelet-activating factor acetylhydrolase gene polymorphisms on the progression of immunoglobulin A nephropathy

In order to investigate the interdependent action of the insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene and polymorphism in exon 11 (C1136-->T; Ala379Val) of the platelet-activating factor acetylhydrolase (PAF-AH) gene, which encodes a functional antagonist of PAF, on the progression of immunoglobulin A (IgA) nephropathy, we analysed both polymorphisms in patients with primary IgA nephropathy, who were followed-up for longer than 3 years. During the follow-up (87.3 +/- 50.0 months), the disease progressed in 38 of the 191 patients (19.9%). The D allele of the ACE gene in the absence of the T allele of the PAF-AH gene did not affect the prognosis [odds ratio (OR), 3.6; 95% confidence interval (CI), 0.8-16.4] and neither did the T allele in the absence of the D allele (OR, 3.0; 95% CI, 0.4-24.2). However, the presence of both was a significant prognostic factor (OR, 6.6; 95% CI, 1.4-31.3). After adjusting for other risk factors, the presence of both proved to be an independent risk factor (OR, 4.5; 95% CI, 1.6-12.7). These results suggest that the interdependent effects of ACE and PAF-AH polymorphisms on the progression of IgA nephropathy might be more important than the effect of the individual polymorphisms.

The analysis of Plasmodium vivax Duffy receptor binding domain gene sequence from resurgent Korea isolates

The Duffy binding domain gene structures of Plasmodium vivax facilitate the invasion of erythrocytes. Human erythrocytes that lack Duffy blood group antigens are resistant to invasion by P. vivax. We have sequenced the Duffy binding domain gene from eight P. vivax isolates collected from malaria cases in South Korea. When compared to isolates from other regions in the world, the amino acid sequences of the Korean isolates showed unique variations in region II. From 606 sequenced amino acids, 32 variations were found. Of these, three variations were regularly found in positions 424, 437 and 503 of the Sal-1 amino acid sequence. In region III, six isolates had a loss of the 30 bp (FAESTKSAE) insert. However, six isolates had 6 bp (SD) inserts at the end of region III. Two cases had a reverse pattern. Our results suggest that the P. vivax currently found in South Korea are unique when compared to other isolates and can be divided, by the analysis of their molecular structure, into two strains.

Cellular senescence, cancer and aging: the telomere connection

Telomeres are the repetitive DNA sequences and specialized proteins that form the distinctive structure that caps the ends of linear chromosomes. Telomeres allow cells to distinguish the chromosome ends from double strand DNA breaks. The telomeric structure prevents the degradation or fusion of chromosome ends, and thus is essential for maintaining the integrity and stability of eukaryotic genomes. In addition, and perhaps less widely appreciated, telomeres may also indirectly influence gene expression. The length, structure and organization of telomeres are regulated by a host of telomere-associated proteins, and can be influenced by basic cellular processes such as cell proliferation, differentiation, and DNA damage. In mammalian cells, telomere length and/or telomere structure have been linked to both cancer and aging. Here, we briefly review what is known about mammalian telomeres and the proteins that associate with them, and discuss the cellular and organismal consequences of telomere dysfunction and the evidence that cells with dysfunctional telomeres can contribute to cancer and aging phenotypes.

C. elegans clk-2, a gene that limits life span, encodes a telomere length regulator similar to yeast telomere binding protein Tel2p

An important quest in modern biology is to identify genes involved in aging. Model organisms such as the nematode Caenorhabditis elegans are particularly useful in this regard. The C. elegans genome has been sequenced [1], and single gene mutations that extend adult life span have been identified [2]. Among these longevity-controlling loci are four apparently unrelated genes that belong to the clk family. In mammals, telomere length and structure can influence cellular, and possibly organismal, aging. Here, we show that clk-2 encodes a regulator of telomere length in C. elegans.

Differential expression of various cytokine and chemokine genes between proliferative and non-proliferative glomerulonephritides

BACKGROUND

Intraglomerular cellular proliferation is one of the major determinants for dividing various glomerulonephritis (GN) into two groups, such as proliferative versus non-proliferative. Cytokines and chemokines are involved in the pathogenetic pathways and would affect the functional and histologic sequelae. We hypothesized that the morphological difference might be based on the differential intrarenal expression of various cytokines and chemokines. We quantified the intrarenal gene expression of various cytokines and chemokines, and correlated it with clinical parameters.

METHODS

Total RNA was extracted from 54 proliferative GN (PGN) core biopsy specimens and 42 non-proliferative GN (NPGN) specimens. Using the internal competitors, RT-PCR was instituted to quantify mRNAs.

RESULTS

The magnitude of the gene expressions of IL-2, IFN-gamma, and IFN-gamma/IL-10 ratio were significantly higher in PGN than in NPGN. RANTES and IL-8 had more abundant gene messages in PGN. It was shown that Th1 cytokine was upregulated if GN was mediated by immune complexes regardless of cellular proliferation. But chemokines had the elevated levels of expression in PGN among immune complex-mediated GN. Up-regulation of the IFN-gamma/IL-10 ratio and TNF-alpha was associated with poor renal function at the time of biopsy. Renal tissues from the patients with a non-nephrotic range of proteinuria showed abundant messages for proinflammatory cytokines and chemokines.

CONCLUSION

Th1, proinflammatory cytokines, and chemokines were more abundant in proliferative GN, and correlated with unfavorable clinical parameters. We propose that the clinical manifestations and diverse histologic features of human GN are associated with differential expressions of specific cytokines and chemokines.

Overexpression of and RNA interference with the CCAAT enhancer-binding protein on long-term facilitation of Aplysia sensory to motor synapses

In the marine mollusk Aplysia, the CCAAT/enhancer-binding protein, ApC/EBP, serves as an immediate early gene in the consolidation of long-term facilitation in the synaptic connection between the sensory and motor neurons of the gill-withdrawal reflex. To further examine the role of ApC/EBP as a molecular switch of a stable form of long-term memory, we cloned the full-length coding regions of two alternatively spliced forms, the short and long form of ApC/EBP. Overexpression of each isoform by DNA microinjection resulted in a l6-fold increase in the expression of the coinjected luciferase reporter gene driven by an ERE promoter. In addition, when we overexpressed ApC/EBP in Aplysia sensory neurons, we found that the application of a single pulse of 5-HT that normally induced only short-term facilitation now induced long-term facilitation. Conversely, when we attempted to block the synthesis of native ApC/EBP by microinjecting double-strand RNA or antisense RNA, we blocked long-term facilitation in a sequence-specific manner. These data support the idea that ApC/EBP is both necessary and sufficient to consolidate short-term memory into long-term memory. Furthermore, our results suggest that this double-strand RNA interference provides a powerful tool in the study of the genes functioning in learning and memory in Aplysia by specifically inhibiting both the constitutive and induced expression of the genes.

Uteroglobin gene polymorphisms affect the progression of immunoglobulin A nephropathy by modulating the level of uteroglobin expression

Uteroglobin (UG) is an anti-inflammatory/immunomodulatory protein. Targeted disruption of UG rendered mouse glomerulonephritis resembling immunoglobulin (Ig)A nephropathy (IgAN). Sequence analysis on exon 1 of UG showed several putative binding sites for transcription factors, and polymorphisms in this site might influence the expression level of UG as a competitive protein. We speculated that the single nucleotide polymorphism at the 38th nucleotide (A to G) from the transcription initiation site of UG exon 1 would impact the progression of IgA nephropathy (IgAN). Polymerase chain reaction-restriction fragment length polymorphism and single-strand conformation polymorphism were instituted to determine the genetic polymorphism. Luciferase assay was performed using the gene constructs containing a region 404-bp long located upstream of UG exon 1 initiation site to analyse whether this polymorphism would affect the expression level. UG polymorphism was distributed no differently in patients with IgAN (n = 111) compared to 60 healthy control subjects. An excess of A genotype was found in one patient having progressive disease (P = 0.03) and the risk for the disease progression increased as the number of A alleles increased (P for trend = 0.03) after follow-up for 116 months. The odds ratio for progression with the AA genotype was 4.9 (95% Cl = 1.0-23.9) compared to patients having the GG genotype. Significant interactive effects of hypertension and genetic polymorphisms of UG on the disease progression were observed (P for interaction = 0.001). In the luciferase assay, the gene construct with A at the 38th site showed a decreased activity of 74 +/- 8.4% compared to that showed by G gene construct. Our results suggest that polymorphism at the 5' UTR region of UG exon 1 is an important marker for the progression of IgAN and may modulate the level of protein expression.