Polymorphisms in microRNA target sites influence susceptibility to schizophrenia by altering the binding of miRNAs to their targets

Single nucleotide polymorphisms (SNPs) in 3' untranslated regions (3' UTRs) of genes may affect miRNA binding to messenger RNA and contribute to the risk of disease. Whether the SNPs that modify miRNA binding in the 3' UTR are involved in schizophrenia-related genes remains unclear. We selected 803 SNPs from the 3' UTRs of 425 candidate genes for schizophrenia. The potential target SNPs were recognized by Gibbs free energy of miRNA binding. Some SNPs were associated in the literature with schizophrenia or other related neurological diseases. A case-control study of nine SNPs not previously reported as significant in any disease was carried out in a Chinese-Han cohort. We found that rs3219151 (C>T, GABRA6) showed significant decreased risk for schizophrenia (OR=0.8121, p=0.008, p(adjust)=0.03). Further, two putative target SNPs, rs165599 (COMT) and rs10759 (RGS4) reported in several references previously, were selected for analysis by luciferase assay to determine their modification to miRNA binding. We found that miR-124 showed significantly repressed 3' UTR binding to RGS4 mRNA from the rs10759-C allele (p<0.05). Our results suggest that rs3219151 of GABRA6 was associated significantly to decrease the risk of schizophrenia, rs10759 (RGS4) was possible to increase the risk of schizophrenia by miRNA altering the binding of miRNAs to their targets influencing susceptibility to schizophrenia.

Induction of CD4+CD25+ T cells and control of cardiac allograft rejection by CD40/CD40L costimulatory pathway blockade in mice

BACKGROUND

Rejection is a major problem in organ transplantation. We speculated that dendritic cells (DCs) with low expression of CD40 may inhibit T-cell responses providing protective effects on organ transplantions.

METHODS

RNA interference (RNAi) is an effective approach to degrade RNA levels of a target gene. We used RNAi to reduce CD40 levels in mouse bone marrow-derived DCs. Allogeneic T-lymphocyte proliferation stimulated by DCs was assessed in mixed lymphocyte reactions. A mouse model of heterotopic abdominal heart transplantation was performed to evaluate survival times and histologic grade of acute rejection at 7 days after transplantation. CD4(+)CD25(+) regulatory T cells (Tregs) in peripheral blood were quantified by flow cytometry.

RESULTS

Mouse DCs with reduced CD40 expression lowered the proliferation of recipient T cells. More DCs with silenced CD40 delayed cardiac allograft rejection.

CONCLUSIONS

Reduction of CD40 in DCs induced peripheral Tregs and delayed cardiac allograft rejection.

Smooth muscle cell phenotypic diversity between dissected and unaffected thoracic aortic media

AIM

Smooth muscle cell (SMC) phenotypic switching in the aortic media may play a critical role in the pathogenesis of thoracic aortic dissection (TAD). However, few investigations are available and most of the observations are based on histological examinations without in vitro evidence. This study, which was performed both in vivo and in vitro, was designed to investigate SMC phenotypic diversity between dissected and unaffected aortic media.

METHODS

Using optimized explant technique, aortic medial SMCs were obtained from patients with TAD and controls. In vivo and in vitro expression of α-smooth muscle actin (α-SMA), smooth muscle-myosin heavy chain 2 (SM-MHC-2), smooth muscle-calponin (SM-Calponin), Vimentin, osteopontin (OPN) and non-muscle myosin heavy chain B (SMemb) were evaluated by immunostaining and immunoblotting. SMC proliferation was also analyzed.

RESULTS

Although the majority of SMCs from the dissected media displayed an elongated, spindle- or triangle-like shape as control SMCs, there were some oval or flat, quadrate cells in the dissection cultures. In contrast with controls, SMCs derived from the dissected media uniformly showed the negative staining for the contractile proteins and the intense staining for the synthetic markers. Similarly, in vitro protein levels of α-SMA, SM-MHC-2, SM-Calponin and Vimentin were significantly decreased to 60.1% (P<0.05), 12.0% (P<0.01), 23.1% (P<0.01) and 32.5% (P<0.01) respectively, whereas those of OPN and SMemb were markedly elevated by5.7- and 10.3-fold respectively (P<0.01 for both). In vivo expression of the phenotypic markers showed the parallel results. Furthermore, SMCs derived from the dissected media exhibited the enhanced proliferation (P<0.05).

CONCLUSION

We have established a simple and potent method to acquire SMCs from the dissected and unaffected aortic media. Compared to the contractile SMCs in the unaffected media, those in the dissected media manifest phenotypic switching from the contractile to the synthetic type. The primary cultures can be subsequently used as in vitro models and contribute to further elucidating the etiopathogenesis of TAD.

USP33 regulates centrosome biogenesis via deubiquitination of the centriolar protein CP110

Centrosome duplication is critical for cell division, and genome instability can result if duplication is not restricted to a single round per cell cycle. Centrosome duplication is controlled in part by CP110, a centriolar protein that positively regulates centriole duplication while restricting centriole elongation and ciliogenesis. Maintenance of normal CP110 levels is essential, as excessive CP110 drives centrosome over-duplication and suppresses ciliogenesis, whereas its depletion inhibits centriole amplification and leads to highly elongated centrioles and aberrant assembly of cilia in growing cells. CP110 levels are tightly controlled, partly through ubiquitination by the ubiquitin ligase complex SCF(cyclin F) during G2 and M phases of the cell cycle. Here, using human cells, we report a new mechanism for the regulation of centrosome duplication that requires USP33, a deubiquitinating enzyme that is able to regulate CP110 levels. USP33 interacts with CP110 and localizes to centrioles primarily in S and G2/M phases, the periods during which centrioles duplicate and elongate. USP33 potently and specifically deubiquitinates CP110, but not other cyclin-F substrates. USP33 activity antagonizes SCF(cyclin F)-mediated ubiquitination and promotes the generation of supernumerary centriolar foci, whereas ablation of USP33 destabilizes CP110 and thereby inhibits centrosome amplification and mitotic defects. To our knowledge, we have identified the first centriolar deubiquitinating enzyme whose expression regulates centrosome homeostasis by countering cyclin-F-mediated destruction of a key substrate. Our results point towards potential therapeutic strategies for inhibiting tumorigenesis associated with centrosome amplification.

Effects of footwear on impact forces and soft tissue vibrations during drop jumps and unanticipated drop landings

The purpose of this study was to explore the footwear effects on impact forces and soft-tissue vibrations during landing. 12 male basketball players were instructed to perform drop jumps and unanticipated drop landings from 30 cm, 45 cm, and 60 cm heights in basketball shoes (BS) and control shoes (CS). 3D kinematics, ground reaction force (GRF), and soft-tissue vibrations of the leg, and acceleration of the shoe heel counter were measured simultaneously. The results showed no significant shoe effect on the characteristics of the impact force nor on the resonance frequency and peak transmissibility of soft-tissue vibrations during the impact phase of the drop jump. For the unanticipated drop landings, however, the magnitude of both peak GRF and peak loading rate were significantly lower with BS compared to CS across all 3 heights (p<0.05); meanwhile BS showed a significant decrease in GRF frequency compared to CS at 45 cm (p<0.05) and 60 cm (p<0.01) heights. Furthermore, the peak transmissibility in BS was significantly lower than that in CS for both the quadriceps and hamstrings during the 60 cm unanticipated drop landing (p<0.05). These findings provide preliminary evidence suggesting that if the neuromuscular system fails to prepare properly for an impact during landing, a shoe intervention may be an effective method for minimizing impact force and reducing soft tissue resonance.

Microbiologic characteristics of pathogenic bacteria from hospitalized trauma patients who survived Wenchuan earthquake

The purpose of this study is to investigate the microbiological characterization of pathogenic bacteria isolated from trauma patients after Wenchuan earthquake in 2008. Most infections were identified in the patients over 60 years of age, with an incidence rate of 78.5%, and more infections in wound (43.3%) and respiratory tract (37.1%) sites were identified. A total of 97 non-duplicated clinical pathogens were isolated from 91 trauma patients. Of those pathogens, 62 (63.9%) were Gram-negative bacilli, 23 (23.7%) were Gram-positive cocci, 9 (9.3%) were fungi, and 3 (3.1%) were anaerobes, such as Clostridium perfringens. The distribution spectrum of pathogens isolated from trauma patients after earthquake was different to that from non-earthquake trauma patients in our hospital at the same time. The most prevalent pathogenic isolates were Escherichia coli (15.4%), Acinetobacter baumannii (14.4%), Staphylococcus aureus (12.3%), Burkholderia cepacia (11.3%), and Enterococcus spp. (9.3%). The drug susceptibility results showed that most of the Gram-negative bacilli, except for Pseudomonas aeruginosa and Burkholderia cepacia, were susceptible to imipenem, but resistant to the first- and the second-generation cephalosporins. Most of the Gram-positive cocci were susceptible to vancomycin, linezolid, and Synercid/dalfopristin. Characteristics of pathogenic bacterium isolated from trauma patients after earthquake have been demonstrated which play an important role in the appropriate treatment of infections.

True reference nanosensor realized with silicon nanowires

Conventional gate oxide layers (e.g., SiO(2), Al(2)O(3), or HfO(2)) in silicon field-effect transistors (FETs) provide highly active surfaces, which can be exploited for electronic pH sensing. Recently, great progress has been achieved in pH sensing using compact integrateable nanowire FETs. However, it has turned out to be much harder to realize a true reference electrode, which--while sensing the electrostatic potential--does not respond to the proton concentration. In this work, we demonstrate a highly effective reference sensor, a so-called reference FET, whose proton sensitivity is suppressed by as much as 2 orders of magnitude. To do so, the Al(2)O(3) surface of a nanowire FET was passivated with a self-assembled monolayer of silanes with a long alkyl chain. We have found that a full passivation can be achieved only after an extended period of self-assembling lasting several days at 80 °C. We use this slow process to measure the number of active proton binding sites as a function of time by a quantitative comparison of the measured nonlinear pH-sensitivities to a theoretical model (site-binding model). Furthermore, we have found that a partially passivated surface can sense small changes in the number of active binding sites reaching a detection limit of δN(s) ≈ 170 μm(-2) Hz(-1/2) at 10 Hz and pH 3.

Cell permeability, migration, and reactive oxygen species induced by multiwalled carbon nanotubes in human microvascular endothelial cells

Multiwalled carbon nanotubes (MWCNT) have elicited great interest in biomedical applications due to their extraordinary physical, chemical, and optical properties. Intravenous administration of MWCNT-based medical imaging agents and drugs in animal models was utilized. However, the potential harmful health effects of MWCNT administration in humans have not yet been elucidated. Furthermore, to date, there are no apparent reports regarding the precise mechanisms of translocation of MWCNT into target tissues and organs from blood circulation. This study demonstrates that exposure to MWCNT leads to an increase in cell permeability in human microvascular endothelial cells (HMVEC). The results obtained from this study also showed that the MWCNT-induced rise in endothelial permeability is mediated by reactive oxygen species (ROS) production and actin filament remodeling. In addition, it was found that MWCNT promoted cell migration in HMVEC. Mechanistically, MWCNT exposure elevated the levels of monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule 1 (ICAM-1) in HMVEC. Taken together, these results provide new insights into the bioreactivity of MWCNT, which may have implications in the biomedical application of MWCNT in vascular targeting, imaging, and drug delivery. The results generated from this study also elucidate the potential adverse effects of MWCNT exposure on humans at the cellular level.

Cell permeability, migration, and reactive oxygen species induced by multiwalled carbon nanotubes in human microvascular endothelial cells

Multiwalled carbon nanotubes (MWCNT) have elicited great interest in biomedical applications due to their extraordinary physical, chemical, and optical properties. Intravenous administration of MWCNT-based medical imaging agents and drugs in animal models was utilized. However, the potential harmful health effects of MWCNT administration in humans have not yet been elucidated. Furthermore, to date, there are no apparent reports regarding the precise mechanisms of translocation of MWCNT into target tissues and organs from blood circulation. This study demonstrates that exposure to MWCNT leads to an increase in cell permeability in human microvascular endothelial cells (HMVEC). The results obtained from this study also showed that the MWCNT-induced rise in endothelial permeability is mediated by reactive oxygen species (ROS) production and actin filament remodeling. In addition, it was found that MWCNT promoted cell migration in HMVEC. Mechanistically, MWCNT exposure elevated the levels of monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule 1 (ICAM-1) in HMVEC. Taken together, these results provide new insights into the bioreactivity of MWCNT, which may have implications in the biomedical application of MWCNT in vascular targeting, imaging, and drug delivery. The results generated from this study also elucidate the potential adverse effects of MWCNT exposure on humans at the cellular level.

Novel functions of endocytic player clathrin in mitosis

Clathrin has been widely recognized as a pivotal player in endocytosis, in which several adaptors and accessory proteins are involved. Recent studies suggested that clathrin is also essential for cell division. Here this review mainly focuses on the clathrin-dependent mechanisms involved in spindle assembly and chromosome alignment. In mitosis, clathrin forms a complex with phosphorylated TACC3 to ensure spindle stability and proper chromosome alignment. The clathrin-regulated mechanism in mitosis requires the crosstalk among clathrin, spindle assembly factors (SAFs), Ran-GTP and mitotic kinases. Meanwhile, a coordinated mechanism is required for role transitions of clathrin during endocytosis and mitosis. Taken together, the findings of the multiple functions of clathrin besides endocytosis have expanded our understanding of the basic cellular activities.

Detection of rpoB, katG and inhA gene mutations in Mycobacterium tuberculosis clinical isolates from Chongqing as determined by microarray

The emergence of multidrug-resistance Mycobacterium tuberculosis is an increasing threat to tuberculosis control programmes. Susceptibility testing of Mycobacterium tuberculosis complex isolates by traditional methods requires a minimum of 14 days. This can be reduced significantly if molecular analysis is used. DNA sequencing is a good method for detecting mutation, but cannot be used routinely because of its relatively high cost. A sensitive and specific microarray has been designed to detect mutations in the rifampin resistance determining region of rpoB and loci in katG and inhA associated with isoniazid (INH) resistance. A panel of Mycobacterium tuberculosis isolates containing 13 different rpoB genotypes, two mutation genotypes within codon 315 of katG and one mutation genotypes at inhA was used to validate the microarray. The results obtained indicate that 100% of rifampicin-resistant M. tuberculosis strains isolated in Chongqing had rpoB mutations, with 531-Ser and 526-His being the most common positions substituted. Of the total 50 INH resistant isolates, 82% had a katG315 mutation and 18% had an inhA mutation. All the mutations detected by the microarray method were also confirmed by conventional DNA sequencing. It is demonstrated that the microarray is an efficient, specialized technique and can be used as a rapid method for detecting rifampin and isoniazid resistance.

An approach to the correlation between vitiligo and autoimmune thyroiditis in Chinese children

BACKGROUND

Vitiligo is a common skin depigmenting disease, which is thought to have, at least partly, an autoimmune aetiology.

AIM

To explore the correlation between paediatric vitiligo and other associated diseases, with an emphasis on autoimmune thyroiditis (AT).

METHODS

In total, 363 paediatric patients (198 boys, 165 girls) with vitiligo and 93 healthy children (55 boys, 38 girls) were screened for autoimmune thyroiditis. The two groups were matched for age and gender. Children with vitiligo were split into two groups according to type (segmental and nonsegmental vitiligo). Demographic data, clinical features and examinations were recorded using questionnaires. Thyroid function tests including free triiodothyronine, free thyroxine and thyroid-stimulating hormone were performed. Anti-thyroid peroxidase antibody) and anti-thyroglobulin antibody levels were assessed as well. Other associated diseases were also monitored in this study.

RESULTS

Of the 363 patients, 43 (11.8%) had abnormal levels of studied thyroid parameters, compared with 4 of the 93 controls (4.3%); the difference was significant (P = 0.04). The alterations of thyroid parameters and the incidence of AT in patients with nonsegmental vitiligo were both significantly different (P < 0.05, P = 0.04) relative to the segmental vitiligo group. Of the 363 patients, 67 (18.5%) had other associated diseases. There were no differences in the rates of other associated diseases between patients with segmental vitiligo and those with nonsegmental vitiligo (P > 0.05).

CONCLUSIONS

A significant incidence of thyroid dysfunction was found in paediatric patients with nonsegmental vitiligo. As vitiligo usually appears before the development of the thyroid disease, it may be advantageous to screen thyroid functions and antibody levels in all paediatric patients with vitiligo, especially those with nonsegmental vitiligo.

Clathrin recruits phosphorylated TACC3 to spindle poles for bipolar spindle assembly and chromosome alignment

Transforming acidic coiled-coil-containing protein 3 (TACC3) has been implicated in mitotic spindle assembly, although the mechanisms involved are largely unknown. Here we identify that clathrin heavy chain (CHC) binds specifically to phosphorylated TACC3 and recruits it to spindle poles for proper spindle assembly and chromosome alignment. Phosphorylation of Xenopus TACC3 at serine 620 (S620) and S626, but not S33, is required for its binding with CHC. Knockdown of CHC by RNA interference (RNAi) abolishes the targeting of TACC3 to spindle poles and results in abnormal spindle assembly and chromosome misalignment, similar to the defects caused by TACC3 knockdown. Furthermore, the binding of CHC with phosphorylated TACC3 is inhibited by importin β and this inhibition is reversed by the presence of the GTP-binding nuclear protein Ran in the GTP-bound state. Together, these results indicate that the recruitment of phosphorylated TACC3 to spindle poles by CHC ensures proper spindle assembly and chromosome alignment, and is regulated by Ran.

Development of community nursing in Zhejiang Province, China: a report of the driving measures

BACKGROUND

Community nursing is playing an important role in health care worldwide.

METHODS

We reviewed recent developments in community nursing in the Zhejiang province of China and reported that the locally tailored practical guidelines, education programmes and management models are the driving measures for promoting local community nursing.

RESULTS

In 2008, Zhejiang had 1200 community primary health-care service centres, an increase of 56% and 6789 service stations, a twofold increase, compared with 2004. At present, 27 000 community nurses, together with the same number of family doctors, are working in community health-care service centres and stations. Community nursing in Zhejiang has grown not only by numbers but also by the greatly improved infrastructures and functions of its community primary health care.

CONCLUSION

It is the multi-pronged approach that has led to the change being successful in a local health-care system.