Vascular smooth muscle cell apoptosis promotes transplant arteriosclerosis through inducing the production of SDF-1α

Transplant arteriosclerosis is a leading cause of late allograft loss. Medial smooth muscle cell (SMC) apoptosis is considered to be an important event in transplant arteriosclerosis. However, the precise contribution of medial SMC apoptosis to transplant arteriosclerosis and the underlying mechanisms remain unclear. We transferred wild-type p53 to induce apoptosis of cultured SMCs. We found that apoptosis induces the production of SDF-1α from apoptotic and neighboring viable cells, resulting in increased SDF-1α in the culture media. Conditioned media from Ltv-p53-transferred SMCs activated PI3K/Akt/mTOR and MAPK/Erk signaling in a SDF-1α-dependent manner and thereby promoted mesenchymal stem cell (MSC) migration and proliferation. In a rat aorta transplantation model, lentivirus-mediated BclxL transfer selectively inhibits medial SMC apoptosis in aortic allografts, resulting in a remarkable decrease of SDF-1α both in allograft media and in blood plasma, associated with diminished recruitment of CD90(+)CD105(+) double-positive cells and impaired neointimal formation. Systemic administration of rapamycin or PD98059 also attenuated MSC recruitment and neointimal formation in the aortic allografts. These results suggest that medial SMC apoptosis is critical for the development of transplant arteriosclerosis through inducing SDF-1α production and that MSC recruitment represents a major component of vascular remodeling, constituting a relevant target and mechanism for therapeutic interventions.

Will posttranslational modifications of brain proteins provide novel serological markers for dementias?

Drug development for dementias is significantly hampered by the lack of easily accessible biomarkers. Fluid biomarkers of dementias provide indications of disease stage, but have little prognostic value, cannot detect early pathological changes, and can only be measured in CSF (cerebrospinal fluid) which significantly limits their applicability. In contrast, imaging based biomarkers can provide indications of probability of disease progression, yet are limited in applicability due to cost, radiation and radio-tracers. These aspects highlight the need for other approaches to the development of biomarkers of dementia, which should focus on not only providing information about pathological changes, but also on being measured easily and reproducibly. For other diseases, focus on development of assays monitoring highly specific protease-generated cleavage fragments of proteins has provided assays, which in serum or plasma have the ability to predict early pathological changes. Proteolytic processing of brain proteins, such as tau, APP, and α-synuclein, is a key pathological event in dementias. Here, we speculate that aiming biomarker development for dementias at detecting small brain protein degradation fragments of generated by brain-derived proteases specifically in blood samples could lead to the development of novel markers of disease progression, stage and importantly of treatment efficacy.

A varicella outbreak in a school with high one-dose vaccination coverage, Beijing, China

BACKGROUND

Varicella vaccine is available in the private sector in China, with a single dose currently recommended for children aged ≥12 months. We investigated a varicella outbreak in a school in Beijing with high varicella vaccination coverage to describe the outbreak, examine risk factors for vaccine failure, and calculate vaccine effectiveness.

METHODS

A varicella case was defined as an acute generalized maculopapular rash without other apparent cause in a student without prior varicella attending the elementary school during August 30-December 28, 2010. Varicella among vaccinated students (breakthrough varicella) was defined as varicella occurring >42 days after vaccination. Students' vaccination status was verified with immunization records and clinical presentations were collected from health care practitioners.

RESULTS

Of the 951 students, 934 (98%) had no prior varicella history. Among these students, 916 had received 1 dose of varicella vaccine and 2 had received 2 doses (98% vaccination coverage) before the outbreak. A total of 87 cases occurred during the outbreak; most had breakthrough varicella (86/87, 99%) and mild disease (83/87, 95%). Age at vaccination (<15 months vs. ≥15 months) and time since vaccination before outbreak (<5 years vs. ≥5 years) were not associated with development of breakthrough varicella. Single-dose varicella vaccination was 89% effective in preventing any varicella and 99% in preventing moderate/severe varicella.

CONCLUSION

Single-dose varicella vaccination is highly effective in reducing varicella incidence and mitigating disease severity, but not high enough to prevent outbreak. A two-dose program might help to prevent varicella outbreaks in Beijing.

Vitreous surgery for macular hole-related retinal detachment after phacoemulsification cataract extraction: 10-year retrospective review

PURPOSE

To evaluate the visual and anatomical results of surgery for macular hole-related retinal detachment (MHRD) after phacoemulsification cataract extraction.

METHODS

Data for all patients who underwent surgery for MHRD after phacoemulsification cataract extraction from 1 December 1998 to 30 September 2008 in one hospital were evaluated. Patient characteristics, best-corrected visual acuity (VA) preoperatively and at last examination, surgical technique, anatomical success, and follow-up period were extracted and analysed statistically.

RESULTS

A total of 13 625 eyes of 10 076 patients who had phacoemulsification cataract surgery were included. In the follow-up period, 10 cases of MHRD in nine patients were observed, of which seven eyes had high myopia. The mean axial length was 30.97 ± 1.36 mm (29.19, 32.97) and mean myopia was-19.35 ± 1.93 (-7.5,-3.5) dioptres. Overall anatomical success was achieved in 90% (9 out of 10 eyes). There was no statistically significant difference (P=0.240) between the logarithm of the MAR VA before the phacoemulsification cataract extraction and after MHRD surgical repair. VA increased in three eyes but decreased in the other seven after MHRD surgery.

CONCLUSIONS

As a primary procedure, vitreous surgery combined with other necessary adjunct procedures such as membrane peeling and retinal tamponade seems to be successful in achieving anatomical success. However, VA improvement is dependent on the type of macular lesion and not the surgical procedure.

Investigation of two novel biochemical markers of inflammation, matrix metalloproteinase and cathepsin generated fragments of C-reactive protein, in patients with ankylosing spondylitis

OBJECTIVES

Ankylosing spondylitis (AS) is a chronic inflammation of the spine and the sacroiliac joints. Current markers of inflammation, such as C-reactive protein (CRP), are reflecting the production of an acute phase reactant rather than tissue specific inflammation, but the use of CRP as a diagnostic and prognostic marker for AS has not provided the sought accuracy and specificity. We hypothesized that local enzymatic activity in the disease-affected tissue, which is associated with extensive tissue turnover may, by cleavage, modify the CRP produced in the liver. These cleavage products may provide additional information on systemic inflammation as compared to that of full-length CRP. We investigated whether these CRP degradation products would provide additional diagnostic value in AS patients compared to full-length CRP.

METHODS

CRP fragments were identified by mass-spectrometry. Two fragments were selected for ELISA development. One assay exclusively identified a matrix metalloproteinase (MMP) generated fragment, CRP-MMP, whereas the other assay identified a cathepsin generated fragment, CRP-CAT. Full-length CRP, CRP-MMP and CRP-CAT were measured in serum samples from 40 AS patients and 40 sex- and age-matched controls.

RESULTS

Full-length CRP was not elevated in AS patients compared to controls, whereas CRP-MMP was elevated by 25% (p<0.001) and CRP-CAT by 50% (p<0.0001). The Area Under Curve of the Receiver-Operator Characteristic curve of CRP-CAT was the highest with 77%.

CONCLUSIONS

MMP and cathepsin degraded CRP provided more discriminative diagnostic potential compared to that of full-length CRP in this current study. These data suggest that different pools of CRP may provide insight into the inflammation processes in AS.

Overexpression of ribosomal RNA in prostate cancer is common but not linked to rDNA promoter hypomethylation

Alterations in nucleoli, including increased numbers, increased size, altered architecture and increased function are hallmarks of prostate cancer cells. The mechanisms that result in increased nucleolar size, number and function in prostate cancer have not been fully elucidated. The nucleolus is formed around repeats of a transcriptional unit encoding a 45S ribosomal RNA (rRNA) precursor that is then processed to yield the mature 18S, 5.8S and 28S RNA species. Although it has been generally accepted that tumor cells overexpress rRNA species, this has not been examined in clinical prostate cancer. We find that indeed levels of the 45S rRNA, 28S, 18S and 5.8S are overexpressed in the majority of human primary prostate cancer specimens as compared with matched benign tissues. One mechanism that can alter nucleolar function and structure in cancer cells is hypomethylation of CpG dinucleotides of the upstream rDNA promoter region. However, this mechanism has not been examined in prostate cancer. To determine whether rRNA overexpression could be explained by hypomethylation of these CpG sites, we also evaluated the DNA methylation status of the rDNA promoter in prostate cancer cell lines and the clinical specimens. Bisulfite sequencing of genomic DNA revealed two roughly equal populations of loci in cell lines consisting of those that contained densely methylated deoxycytidine residues within CpGs and those that were largely unmethylated. All clinical specimens also contained two populations with no marked changes in methylation of this region in cancer as compared with normal. We recently reported that MYC can regulate rRNA levels in human prostate cancer; here we show that MYC mRNA levels are correlated with 45S, 18S and 5.8S rRNA levels. Further, as a surrogate for nucleolar size and number, we examined the expression of fibrillarin, which did not correlate with rRNA levels. We conclude that rRNA levels are increased in human prostate cancer, but that hypomethylation of the rDNA promoter does not explain this increase, nor does hypomethylation explain alterations in nucleolar number and structure in prostate cancer cells. Rather, rRNA levels and nucleolar size and number relate more closely to MYC overexpression.

MMP mediated type V collagen degradation (C5M) is elevated in ankylosing spondylitis

OBJECTIVES

Type V collagen has been demonstrated to control fibril formation. The aim of this study was to develop an ELISA capable of detecting a fragment of type V collagen generated by MMP-2/9 and to evaluate the assay as biomarker for ankylosing spondylitis (AS).

DESIGN AND METHODS

A fragment unique to type V collagen and generated by both MMP-2/9 cleaved at the amino acid position 1317 (C5M) was selected for ELISA development. 40 AS patients and 40 age-matched controls were evaluated.

RESULTS

An ELISA detecting C5M with inter- and intra-assay variations of 9.1% and 4.4% was developed. C5M levels were significantly higher in AS patients compared to controls, 229% (p<0.0001). The diagnostic AUC was 83%.

CONCLUSIONS

This ELISA is the first for detecting type V collagen degradation. AS patients had highly elevated levels of MMP mediated type V collagen degradation. The prognostic and diagnostic values need to be further investigated in additional clinical settings.

Levels of Circulating MMCN-151, a Degradation Product of Mimecan, Reflect Pathological Extracellular Matrix Remodeling in Apolipoprotein E Knockout Mice

AIM

Arterial extracellular matrix (ECM) remodeling by matrix metalloproteinases (MMPs) is one of the major hallmarks of atherosclerosis. Mimecan, also known as osteoglycin has been implicated in the integrity of the ECM. This study assessed the validity of an enzyme-linked immunosorbent assay (ELISA) developed to measure a specific MMP12-derived fragment of mimecan, MMCN-151, in apolipoprotein-E knockout (ApoE-KO) mice.

METHODS AND RESULTS

A mouse monoclonal antibody raised against MMCN-151 was used to develop a competitive ELISA. The assay was validated using samples from 20 ApoE-KO and 20 wild type [C57 BL/6] male mice fed a normal or high-fat diet (HFD) for up to 20 weeks. The technical reliability of the assay was established with intra-assay variability <2% and inter-assay variability <10%. The lowest limit of quantification of MMCN-151 was 0.5 ng/ml. ApoE-KO mice fed a HFD for 20 weeks had four-fold increased circulating levels of MMCN-151 compared to baseline, whereas MMCN-151 levels in control mice on HFD increased two-fold compared with baseline. After 10 weeks of a HFD, a significant difference in MMCN-151 levels was observed between ApoE-KO and control mice (P = 0.005) and became more significant at 20 weeks (P = 0.002).

CONCLUSIONS

The newly developed assay is a reliable detector of MMCN-151 levels which ultimately may be useful indicators of arterial remodeling in patients affected by atherosclerotic disease.

Serological survey of antibodies to influenza A viruses in a group of people without a history of influenza vaccination

A serological survey for antibodies to influenza viruses was performed in China on a group of people without a history of influenza vaccination. Using the haemagglutination inhibition (HI) assay, we found seropositivity rates for seasonal H3N2 to be significantly higher than those for seasonal H1N1. Samples positive for antibodies to the pandemic (H1N1) 2009 virus increased from 0.6% pre-outbreak to 4.5% (p <0.01) at 1 year post-outbreak. Interestingly, HI and neutralization tests showed that 1.4% of people in the group have antibodies recognizing H9N2 avian influenza viruses, suggesting that infection with this subtype may be more common than previously thought.

Rapid detection of Vibrio metschnikovii in aquatic products by real-time PCR

PCR and SYBR Green I real-time PCR techniques were applied to the rapid detection of Vibrio metschnikovii by designing primers based on infC (initiation factor 3) gene sequence. The specificity, sensitivity, and practical applications of the methods have been also analyzed. The methods showed high detecting specificity with no cross amplifications of other closely related and nonrelated species; they provide a simple and rapid tool for V. metschnikovii detection with high sensitivity and specificity.

Randomised clinical trial: the effects of perioperative probiotic treatment on barrier function and post-operative infectious complications in colorectal cancer surgery - a double-blind study

BACKGROUND

Infection following abdominal operation remains a major factor affecting the morbidity of patients after surgery.

AIM

To determine the effects of perioperative administration of probiotics on the gut barrier function and the surgical outcome in patients undergoing elective colorectal surgery.

METHODS

One hundred patients with colorectal carcinoma were randomly divided into the control group (n = 50) and the probiotics group (n = 50). The probiotics were given orally for 6 days preoperatively and 10 days post-operatively. Outcomes were measured by bacterial translocation, gut permeability, the effect on the faecal microbiota, and the clinical outcomes such as infectious-related complications and gut defecation function.

RESULTS

Compared with the control group, probiotics group had increased transepithelial resistance (P < 0.05), reduced transmucosal permeation of horseradish peroxidase and lactulose/mannitol ratio, reduced bacterial translocation (P < 0.05), decreased ileal-bile acid binding protein (P < 0.05) and positive rate of blood bacterial DNA (P < 0.05) and an enhanced mucosal tight junction protein expression. They had decreased blood enteropathogenic bacteria and increased faecal bacterial variety. The post-operative recovery of peristalsis, incidence of diarrhoea, and infectious-related complications were also improved.

CONCLUSION

Probiotics can improve the integrity of gut mucosal barrier by benefiting the faecal microbiota, and decreasing infectious complications in patients with colorectal cancer undergoing colorectomy.

Association of single-nucleotide polymorphisms in HLA class II/III region with knee osteoarthritis

OBJECTIVE

A genome-wide association study and a replication using Japanese, Spanish and Greek Caucasian populations have recently indicated two single-nucleotide polymorphisms (SNPs) (rs7775228 and rs10947262) associated with knee Osteoarthritis (OA) susceptibility. We have further evaluated the association in knee OA subjects from Han Chinese and Australian Caucasian origin.

METHODS

Two independent case-control association studies were performed using Han Chinese and Australian Caucasian populations. The two SNPs were genotyped in patients who had primary symptomatic knee OA with radiographic confirmation and/or received total knee replacement surgery as well as in matched controls. They were subjected to statistic analyses.

RESULTS

A total of 991 OA patients and 1536 controls were genotyped. No significant difference was detected in genotype or allele frequencies of the two SNPs between knee OA and control groups in the two populations (all P>0.05). The association was also negative even after stratification by sex, body mass index (BMI) and Kellgren/Lawrence scores. The significant heterogeneity was detected between Chinese and Japanese (both P<0.05). In the Caucasian samples, no significant heterogeneity was detected (both P>0.05). The result of meta-analysis showed significant association between knee OA and rs10947262 in total subjects [summary OR=1.26, 95%confidence intervals (CI)=1.07-1.27, P=3 × 10(-8)] and in Caucasian samples (summary OR=1.28, 95%CI=1.04-1.57, P=0.02).

CONCLUSION

We demonstrated no association between the two SNPs in human leukocyte antigen (HLA) class II/III region and knee OA in Han Chinese population. A significant association was detected between SNP rs10947262 and knee OA in Caucasian subjects. Further replication studies are required to identify the impact of controversial association.

Enhanced anorexigenic signaling in lean obesity resistant syndecan-3 null mice

Obesity is associated with increased risk of diabetes, cardiovascular disease and several types of cancers. The hypothalamus is a region of the brain critical in the regulation of body weight. One of the critical and best studied hypothalamic circuits is comprised of the melanocortinergic orexigenic agouti-related protein (AgRP) and anorexigenic α-melanocyte stimulating hormone (α-MSH) neurons. These neurons project axons to the same hypothalamic target neurons and balance each other's activity leading to body weight regulation. We previously showed that the brain proteoglycan syndecan-3 regulates feeding behavior and body weight, and syndecan-3 null (SDC-3(-/-)) mice are lean and obesity resistant. Here we show that the melanocortin agonist Melanotan II (MTII) potently suppresses food intake and activates the hypothalamic paraventricular nuclei (PVN) in SDC-3(-/-) mice based on c-fos immunoreactivity. Interestingly, we determined that the AgRP neuropeptide is reduced in the PVN of SDC-3(-/-) mice compared to wild type mice. In contrast, neuropeptide Y, coexpressed in the AgRP neuron, is not differentially expressed nor is the counteracting neuropeptide α-MSH. These findings are unprecedented and indicate that AgRP protein localization can be selectively regulated within the hypothalamus resulting in altered neuropeptide response and tone.

Liquids at large negative pressures: water at the homogeneous nucleation limit

An isochoric cooling method for obtaining unprecedented tensions on liquids was used to determine the homogeneous nucleation limit for stretching of water at a variety of water densities. At densities in the range 0.55 to 0.68 gram per milliliter (g/ml), the data agree with the homogeneous nucleation temperatures measured by Skripov for superheated water at positive pressures. At densities between 0.68 and 0.93 g/ml, cavitation occurred only at negative pressures (that is, under tension). The cavitation tensions measured were in excellent agreement with those predicted by Fisher's 1948 vapor nucleation theory. A maximum tension of 140 megapascals (=1400 bars) was reached at 42 degrees C, which lies on an extrapolation of the line of isobaric density maxima. At higher densities, cavitation of droplets that survived heterogeneous nucleation failed to occur at all unless provoked, at much lower temperatures, by freezing. This observation confirms the existence of a density maximum at 42 degrees C and -140 megapascals and hence greatly strengthens the basis for Speedy's conjecture of a reentrant spinodal for water.

A novel assay for extracellular matrix remodeling associated with liver fibrosis: An enzyme-linked immunosorbent assay (ELISA) for a MMP-9 proteolytically revealed neo-epitope of type III collagen

OBJECTIVES

Accumulation of extracellular matrix (ECM) components and increased matrix-metalloprotease (MMPs) activity are hallmarks of fibrosis. We developed an ELISA for quantification of MMP-9 derived collagen type III (CO3) degradation.

DESIGN AND METHODS

A monoclonal antibody targeting a specific MMP-9 cleaved fragment of CO3 was used for development of a competitive ELISA. The assay was investigated in serum and tissues from bile duct ligated rats (BDL).

RESULTS

The ELISA showed no cross-reaction with either intact CO3, or other collagens. The intra- and inter-assay CV were below 10%. Liver fibrosis was demonstrated in BDL animals by semi quantitative scoring (P<0.0001). Serum levels of CO3-610 increased 2.5 fold in BDL animals (P<0.001). The CO3-610 levels were 5 fold higher in ex vivo cultures of fibrotic livers compared to controls (P<0.001).

CONCLUSION

We have developed a novel ELISA for measuring a specific fragment CO3 generated by MMP-9 important in pathogenesis of liver fibrosis.

Autophagy and the ubiquitin-proteasome system in cardiac dysfunction

The ubiquitin-proteasome system (UPS) and autophagy are two major intracellular protein degradation pathways. The UPS mediates the removal of soluble abnormal proteins as well as the targeted degradation of most normal proteins that are no longer needed. Autophagy is generally responsible for bulky removal of defective organelles and for sequestering portions of cytoplasm for lysosomal degradation during starvation. Impaired or inadequate protein degradation in the heart is associated with and may be a major pathogenic factor for a wide variety of cardiac dysfunctions, while enhanced protein degradation is also implicated in the development of cardiac pathology. It was generally assumed that the UPS and autophagy serve distinct functions. Therefore, the functional roles of the UPS and autophagy in the hearts have been largely investigated separately. However, recent advances in understanding the shared mechanisms contributing to UPS alteration and the induction of autophagy have helped reveal the link and interplay between the two proteolytic systems in the heart. These links are exemplified by scenarios in which inadequate UPS proteolytic function leads to activation of autophagy, helping alleviate proteotoxic stress. It is becoming increasingly clear that a coordinated and complementary relationship between the two systems is critical to protect cells against stress. Several proteins including p62, NBR1, HDAC6, and co-chaperones appear to play an important role in harmonizing and mobilizing the consortium formed by the UPS and autophagy.