Transcription factor PBX4 regulates limb development and haematopoiesis in mice

The mammalian Pre-B cell leukaemia transcription factors 1-4 (PBX1-4) constitutes the PBC class of the homeodomain (HD)-containing proteins, which play important roles in diverse developmental processes. The functions and the underlying molecular mechanisms of PBX1-3 but not PBX4 have been extensively studied, and they have been reported to direct essential morphogenetic processes and organogenesis. In the present study, we generated knockin mice of FLAG-tagged PBX4 and the Pbx4 knockout (KO) mice and carried out in-depth characterisation of PBX4 expression and function. PBX4 was initially detected only in the testis among several organs of the adult mice and was expressed in spermatocytes and spermatids. However, no abnormality in spermatogenesis, but growth retardation and premature death after birth were observed in most adult Pbx4 KO mice. These animals were inactive and had shorter hindlimbs and lower numbers of reticulocytes and lymphocytes, probably caused by abnormalities at earlier developmental stages. Pbx4 mRNAs were indeed detected in several embryonic cell types related to limb development by in situ hybridisation and single-cell RNA-sequencing analysis. Pbx4 protein was also detected in the bone marrow of adult mice with a lower level compared with that in the testis. PBX4 preferentially binds to the promoters of a large number of genes including those for other HD-containing proteins and ribosomal proteins whose mutations are related to anaemia. PBX4-binding sites are enriched in motifs similar to those of other HD-containing proteins such as PKNOX1 indicating that PBX4 may also act as a co-transcription factor like other PBC proteins. Together, these results show that PBX4 participates in limb development and haematopoiesis while its function in spermatogenesis has not been revealed by gene KO probably due to the complementary effects of other genes.

Two transcriptional cascades orchestrate cockroach leg regeneration

The mystery of appendage regeneration has fascinated humans for centuries, while the underlying regulatory mechanisms remain unclear. In this study, we establish a transcriptional landscape of regenerating leg in the American cockroach, Periplaneta americana, an ideal model in appendage regeneration studies showing remarkable regeneration capacity. Through a large-scale in vivo screening, we identify multiple signaling pathways and transcription factors controlling leg regeneration. Specifically, zfh-2 and bowl contribute to blastema cell proliferation and morphogenesis in two transcriptional cascades: bone morphogenetic protein (BMP)/JAK-STAT-zfh-2-B-H2 and Notch-drm/bowl-bab1. Notably, we find zfh-2 is working as a direct target of BMP signaling to promote cell proliferation in the blastema. These mechanisms might be conserved in the appendage regeneration of vertebrates from an evolutionary perspective. Overall, our findings reveal that two crucial transcriptional cascades orchestrate distinct cockroach leg regeneration processes, significantly advancing the comprehension of molecular mechanism in appendage regeneration.

[Research on the formulation and revision of standard limits for antimony,boron and vanadium in the "Standards for Drinking Water Quality (GB5749-2022)" in China]

China is rich in antimony, boron, and vanadium mineral resources, which have been detected in environmental water bodies and drinking water. During the revision process of the "Standards for Drinking Water Quality (GB5749-2006)", research and evaluation are focused on three indicators: antimony, boron and vanadium. Vanadium is added and the limit value of boron is adjusted. This study reviews and discusses the technical contents related to the revision of the antimony, boron and vanadium, including the environmental presence levels, exposure status, health effects, and the revision of the standard limits of these three indicators. Suggestions are also made for the implementation of this standard.

[Establishment and validation of a nomogram-based predictive model for idiopathic aldosteronism]

Objective: To establish and validate a nomogram-based predictive model for idiopathic hyperaldosteronism (IHA). Methods: This cross-sectional study was conducted with the collected clinical and biochemical data of patients with primary aldosteronism (PA) including 249 patients with unilateral primary aldosteronism (UPA) and 107 patients with IHA, who were treated at the Department of Endocrinology of the First Affiliated Hospital of Chongqing Medical University from November 2013 to November 2022. Plasma aldosterone concentration (PAC) and plasma renin concentration (PRC) were measured by chemiluminescence. Stepwise regression analysis was applied to select the key predictors of IHA, and a nomogram-based scoring model was developed. The model was validated in another external independent cohort of patients with PA including 62 patients with UPA and 43 patients with IHA, who were diagnosed at the Department of Endocrinology, First Affiliated Hospital of Zhengzhou University. An independent-sample t test, Mann-Whitney U test, and χ² test were used for statistical analysis. Results: In the training cohort, in comparison with the UPA group, the IHA group showed a higher serum potassium level [M(Q₁, Q₃), 3.4 (3.1, 3.8) mmol/L vs. 2.7 (2.1, 3.1) mmol/L] and higher PRC [4.0 (2.1, 8.2) mU/L vs. 1.5 (0.6, 3.4) mU/L] and a lower PAC post-saline infusion test (SIT) [305 (222, 416) pmol/L vs. 720 (443, 1 136) pmol/L] and a lower rate of unilateral adrenal nodules [33.6% (36/107) vs. 81.1% (202/249)]; the intergroup differences in these measurements were statistically significant (all P<0.001). Serum potassium level, PRC, PAC post-SIT, and the rate of unilateral adrenal nodules showed similar performance in the IHA group in the validation cohort. After stepwise regression analysis for all significant variables in the training cohort, a scoring model based on a nomogram was constructed, and the predictive parameters included the rate of unilateral adrenal nodules, serum potassium concentration, PAC post-SIT, and PRC in the standing position. When the total score was ≥14, the model showed a sensitivity of 0.65 and specificity of 0.90 in the training cohort and a sensitivity of 0.56 and specificity of 1.00 in the validation cohort. Conclusion: The nomogram was used to successfully develop a model for prediction of IHA that could facilitate selection of patients with IHA who required medication directly.

[Effects of surgical procedures and general anesthesia exposure within 2 hours in early childhood on neurodevelopmental outcomes in school-age]

Objective: To observe the effect of surgical procedures and general anesthesia exposure (<2 h) in early childhood on neurodevelopmental outcomes in school-age. Methods: A total of 147 children aged 6-12 years old, who received surgery under general anesthesia (<2 h) at the age of 0-2 years in Children's Hospital of Nanjing Medical Universityfrom June 2009 to December 2012 were retrospectively enrolled in this study (from June 2018 to December 2021) as exposure group, including 76 males and 71 females, with a mean age of (8.8±1.6) years. All the cases were divided into single-exposure group (n=65) and multiple-exposure group (≥2 times, n=82) according to different times of anesthesia exposure. According to the cohort of exposure group, 160 healthy children of the same age with no history of surgery under general anesthesia were recruited from the community from June 2018 to December 2021 as the control group, including 87 males and 73 females, and aged (8.6±1.9) years. A variety of standardized neurological tests including Wechsler intelligence scale for children fourth edition (WSC-Ⅳ), integrated visual and auditory continuous performance test (IVA-CPT), Swanson Nolan and Pelham, version Ⅳ (SNAP-Ⅳ), children sensory integration capacity development rating scale (CSIC), and social living ability scale were performed in all subjects by a child health specialist who failed to know the details. The primary outcome was the full-scale IQ (FSIQ) in WISC-Ⅳ, and the secondary outcomes were IVA-CPT, SNAP-Ⅳ, CSIC, and social living ability scale. Results: The FSIQ of single-exposure, multiple-exposure and control groups was 105.4±14.1, 100.9±10.2 and 103.6±13.5, respectively, with no statistically significant difference (F=2.37, P=0.095). The FSIQ of different first age exposure groups (aged 0-6 months, 7-12 months and 1-2 years) was 99.8±10.2, 104.5±10.5 and 104.4±14.5, respectively, with no statistically significant difference (F=2.39, P=0.095). The FSIQ of different exposure duration groups (0-59 min, 60-119 min and control group) was 102.8±11.3, 103.0±13.7 and 103.6±13.5, respectively, with no statistically significant difference (F=0.13, P=0.882). As for the secondary outcomes, the scores of visual persistence quotient in single-exposure, multiple-exposure and control groups were 94.8±10.5, 94.0±10.9 and 100.6±17.7, with a statistically significant difference (F=6.96, P=0.001). In terms of locomotion in social living ability scale, the score of the three groups was 10.0±0.2, 10.2±0.6 and 10.4±0.7, respectively, with a statistically significant difference (F=10.61, P<0.001), but all were within the standard range. Conclusions: The surgical procedures and general anesthesia exposure within 2 hours in early childhood has no effect on the overall FSIQ in school age, but has a slight impacts on the visual persistence quotient of IVA-CPT and the locomotion score of social living ability scale.

[Comparison of time series and case-crossover analyses in environmental epidemiology]

Time-series and case-crossover are two main study designs in environmental epidemiology. However, due to the differences in design principles and model construction between the two analyses, the results of the two analyses may not be consistent. Herein, we examined the short-term effect of cold spells on cardiovascular mortality in Nanjing using both time series and case-crossover analyses, aiming to provide a basis for the selection of appropriate research design in environmental epidemiology.

The Axolotl's journey to the modern molecular era

The salamander Ambystoma mexicanum, commonly called "the axolotl" has a long, illustrious history as a model organism, perhaps with one of the longest track records as a laboratory-bred vertebrate, yet it also holds a prominent place among the emerging model organisms. Or rather it is by now an "emerged" model organism, boasting a full cohort molecular genetic tools that allows an expanding community of researchers in the field to explore the remarkable traits of this animal including regeneration, at cellular and molecular precision-which had been a dream for researchers over the years. This chapter describes the journey to this status, that could be helpful for those developing their respective animal or plant models.

Light Dark Matter Search with Ionization Signals in XENON1T

We report constraints on light dark matter (DM) models using ionization signals in the XENON1T experiment. We mitigate backgrounds with strong event selections, rather than requiring a scintillation signal, leaving an effective exposure of (22±3) tonne day. Above ∼0.4  keV_{ee}, we observe <1  event/(tonne day keV_{ee}), which is more than 1000 times lower than in similar searches with other detectors. Despite observing a higher rate at lower energies, no DM or CEvNS detection may be claimed because we cannot model all of our backgrounds. We thus exclude new regions in the parameter spaces for DM-nucleus scattering for DM masses m_{χ} within 3-6  GeV/c^{2}, DM-electron scattering for m_{χ}>30  MeV/c^{2}, and absorption of dark photons and axionlike particles for m_{χ} within 0.186-1  keV/c^{2}.

Search for Light Dark Matter Interactions Enhanced by the Migdal Effect or Bremsstrahlung in XENON1T

Direct dark matter detection experiments based on a liquid xenon target are leading the search for dark matter particles with masses above ∼5  GeV/c^{2}, but have limited sensitivity to lighter masses because of the small momentum transfer in dark matter-nucleus elastic scattering. However, there is an irreducible contribution from inelastic processes accompanying the elastic scattering, which leads to the excitation and ionization of the recoiling atom (the Migdal effect) or the emission of a bremsstrahlung photon. In this Letter, we report on a probe of low-mass dark matter with masses down to about 85  MeV/c^{2} by looking for electronic recoils induced by the Migdal effect and bremsstrahlung using data from the XENON1T experiment. Besides the approach of detecting both scintillation and ionization signals, we exploit an approach that uses ionization signals only, which allows for a lower detection threshold. This analysis significantly enhances the sensitivity of XENON1T to light dark matter previously beyond its reach.

Constraining the Spin-Dependent WIMP-Nucleon Cross Sections with XENON1T

We report the first experimental results on spin-dependent elastic weakly interacting massive particle (WIMP) nucleon scattering from the XENON1T dark matter search experiment. The analysis uses the full ton year exposure of XENON1T to constrain the spin-dependent proton-only and neutron-only cases. No significant signal excess is observed, and a profile likelihood ratio analysis is used to set exclusion limits on the WIMP-nucleon interactions. This includes the most stringent constraint to date on the WIMP-neutron cross section, with a minimum of 6.3×10^{-42}  cm^{2} at 30  GeV/c^{2} and 90% confidence level. The results are compared with those from collider searches and used to exclude new parameter space in an isoscalar theory with an axial-vector mediator.

First Results on the Scalar WIMP-Pion Coupling, Using the XENON1T Experiment

We present first results on the scalar coupling of weakly interacting massive particles (WIMPs) to pions from 1  t yr of exposure with the XENON1T experiment. This interaction is generated when the WIMP couples to a virtual pion exchanged between the nucleons in a nucleus. In contrast to most nonrelativistic operators, these pion-exchange currents can be coherently enhanced by the total number of nucleons and therefore may dominate in scenarios where spin-independent WIMP-nucleon interactions are suppressed. Moreover, for natural values of the couplings, they dominate over the spin-dependent channel due to their coherence in the nucleus. Using the signal model of this new WIMP-pion channel, no significant excess is found, leading to an upper limit cross section of 6.4×10^{-46}  cm^{2} (90% confidence level) at 30  GeV/c^{2} WIMP mass.

Vacuum Sealing Drainage Therapy for Refractory Infectious Wound on 16 Renal Transplant Recipients

BACKGROUND

Refractory infectious wounds on renal transplantation (RT) recipients significantly prolong hospital stay, increase medical costs, and threaten allograft survival. Vacuum sealing drainage (VSD) therapy is a new technique for managing wounds based on the principle of application of controlled negative pressure. The aim of this study was to summarize the efficacy and safety of VSD therapy in the management of refractory infectious wounds following RT.

MATERIALS AND METHODS

This is a retrospective study of a cohort of 661 consecutive patients who received renal transplants over a period of 3 years in which the data were collected and analyzed retrospectively.

RESULTS

Out of the 661 patients, 16 (2.4%) developed refractory wound infection following RT. Nineteen organisms were identified by culture from all patients, including 10 patients infected with 1 or more bacteria, 2 patients with fungal infection, and 4 patients with both. Specifically, mucormycosis was demonstrated in 4 patients, pan-resistant Klebsiella pneumoniae in 2 patients, and Acinetobacter baumannii in 2 patients. All 16 patients were treated with VSD therapy for a median of 37 days (range, 6-111 days). The number of VSD sets used ranged from 4 to 28 sets (mean, 11.1 sets). A combination of antibiotics, debridement, and VSD therapy lead to 100% (16 of 16) wound healing. No VSD-relevant adverse events were observed.

CONCLUSIONS

VSD therapy is an effective and safe adjunct to conventional treatment modalities for the management of refractory wound infection following RT.

Dark Matter Search Results from a One Ton-Year Exposure of XENON1T

We report on a search for weakly interacting massive particles (WIMPs) using 278.8 days of data collected with the XENON1T experiment at LNGS. XENON1T utilizes a liquid xenon time projection chamber with a fiducial mass of (1.30±0.01)  ton, resulting in a 1.0 ton yr exposure. The energy region of interest, [1.4,10.6]  keV_{ee} ([4.9,40.9] keV_{nr}), exhibits an ultralow electron recoil background rate of [82_{-3}^{+5}(syst)±3(stat)]  events/(ton yr keV_{ee}). No significant excess over background is found, and a profile likelihood analysis parametrized in spatial and energy dimensions excludes new parameter space for the WIMP-nucleon spin-independent elastic scatter cross section for WIMP masses above 6  GeV/c^{2}, with a minimum of 4.1×10^{-47}  cm^{2} at 30  GeV/c^{2} and a 90% confidence level.

Liver Transplant Recipients With End-Stage Renal Disease Largely Benefit From Kidney Transplantation

BACKGROUND

The incidence of end-stage renal disease (ESRD) after liver transplant (LT) has increased. The actual benefit of kidney transplantation (KT) is not completely understood in LT recipients with ESRD.

METHODS

We analyzed Scientific Registry of Transplant Recipients data for all KT candidates with prior LT from 1998 to 2014; the benefits of KT relative to remaining on dialysis were compared by means of multivariate Cox proportional hazards regression analysis.

RESULTS

The number of these KT candidates with prior LT has tripled from 98 in 1998 to 323 in 2015; LT recipients with ESRD remaining on dialysis have a 2.5-times increase in the risk of liver graft failure and a 3.6-times increase in the risk of patient death compared with these patients receiving KT. The adjusted liver graft and patient survival rates after donors from donation after cardiac death or expanded-criteria donor kidney transplantation were significantly higher than in patients remaining on dialysis in LT recipients with ESRD.

CONCLUSIONS

The number of referrals to KT with prior LT is increasing at a rapid rate. Remaining on dialysis in LT recipients with ESRD has profound increased risks of liver graft failure and patient death in comparison to receiving a KT. LT recipients with ESRD can benefit from expanded-criteria donor and donation after cardiac death kidney transplantation.

First Dark Matter Search Results from the XENON1T Experiment

We report the first dark matter search results from XENON1T, a ∼2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042±12)-kg fiducial mass and in the [5,40]  keV_{nr} energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93±0.25)×10^{-4}  events/(kg×day×keV_{ee}), the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10  GeV/c^{2}, with a minimum of 7.7×10^{-47}  cm^{2} for 35-GeV/c^{2} WIMPs at 90% C.L.

Search for Electronic Recoil Event Rate Modulation with 4 Years of XENON100 Data

We report on a search for electronic recoil event rate modulation signatures in the XENON100 data accumulated over a period of 4 yr, from January 2010 to January 2014. A profile likelihood method, which incorporates the stability of the XENON100 detector and the known electronic recoil background model, is used to quantify the significance of periodicity in the time distribution of events. There is a weak modulation signature at a period of 431_{-14}^{+16} day in the low energy region of (2.0-5.8) keV in the single scatter event sample, with a global significance of 1.9σ; however, no other more significant modulation is observed. The significance of an annual modulation signature drops from 2.8σ, from a previous analysis of a subset of this data, to 1.8σ with all data combined. Single scatter events in the low energy region are thus used to exclude the DAMA/LIBRA annual modulation as being due to dark matter electron interactions via axial vector coupling at 5.7σ.

[Genotype distribution of human enteroviruses isolated from swage in Shanghai during year 2013-2014]

Objective: To explore the time and genotype distribution of human enterovirus (HEV) isolated from sewage in Shanghai in 2013-2014. Methods: One sewage sample each was collected from two local sewage plants located in Minhang District and Jiading District on the same day at the day 24-28 of every month from 2013 to 2014. Each sample weighed 1 L. The specimens were concentrated by anionic membrane absorption, eluted with beef extract solution, and then used to inoculate RD, HEp-2, and L20B cell lines. A total of 249 enterovirus strains were isolated from sewage samples during the study period, including 185 non-polio enterovirus (NPEV) and 64 poliovirus (PV) strains, which were identified as vaccine strains. RT-PCR and Sanger sequencing were performed to identify HEV genotypes. Homologous analysis of VP1 sequences was conducted using BioEdit (version 7.0.0). Phylogenetic analysis was performed using the neighbor-joining method based on the alignment of VP1 gene sequences using MEGA (version 4.0.2). Results: Among 185 NPEV strains, 178 strains were successfully sequenced and classified into 15 genotypes, including coxsackievirus group B (CVB) 2, 3, and 5; enteric cytopathic human orphan (ECHO) virus 1, 3, 6, 7, 11, 13, 19, 20, 24, 25, and 30; and coxsackievirus group A 4. CVB5 and ECHO6 genotypes accounted for 33.5% (56 strains) and 24.9% (43 strains) of NPEV isolates, respectively. During the study period, HEV isolates were mainly isolated in summer and autumn in Minhang District. ECHO6 strains were frequently isolated from June 2013 to July 2014. Thereafter, the number of ECHO6 strains gradually reduced in the second half of 2014. CVB5 strains demonstrated scattered distribution from 2013 to the first half of 2014 and gradually increased in the second half of 2014. The distribution of ECHO6 and CVB5 strains in Jiading District was similar to that in Minhang District. In 2013-2014, CVB5 strains comprised C6 and C8 subgenotypes, which belong to two transmission chains and show large differences compared with foreign strains isolated during the same period. ECHO6 strains comprised C6, C8, and D9 subgenotypes, which belong to three transmission chains. Moreover, ECHO6 subgenotype D9 was a dominant subgenotype in Shanghai, with broad geographical distribution both at home and abroad. Conclusion: Poliovirus was identified as a vaccine strain in environmental surveillance from June 2013 to April 2014 in Shanghai. Several transmission strains of ECHO6 and CVB5 were identified, which were the dominant serotypes.

Kidney Transplantation From Brain-Dead Donors: Initial Experience in China

BACKGROUND

Experience with kidney transplantation from brain-dead donors remains limited in China. Our objective was to evaluate the outcomes of kidney transplantation from brain-dead donors (group 1), compared with those from living ones of the same age (group 2).

METHODS

Clinical data of kidney transplantation from brain-dead donors and living donors in the same age range (18-45 years) performed between May 2007 and December 2011 were analyzed retrospectively. Recipients were analyzed for posttransplantation serum creatinine, creatinine clearance (calculated by the Cockcroft-Gault formula), the number of acute rejection episodes and delayed graft function, and patient/graft survival.

RESULTS

Mean donor age was comparable between the 2 groups (31.9 ± 6.5 vs 32.8 ± 7.0 years; P = .268). The terminal serum creatinine level of donors was 125.5 ± 63.5 μmol/L in group 1 (n = 30) and 65.1 ± 13.7 μmol/L in group 2 (n = 110; P = .000). Recipient creatinine clearance was comparable between the 2 groups 1 month posttransplantation and thereafter. Acute rejection episodes were seen in 7 cases in recipients of group 1 (15.9%) and in 15 cases in recipients of group 2 (13.6%; P = .716). The incidence of delayed graft function was higher in recipients of group 1 (18.2%) than that of group 2 (3.6%; P = .002). The 1-, 3-, and 5-year patient/graft survival rate was comparable between the 2 groups.

CONCLUSIONS

Our study demonstrated kidney transplantation from brain-dead donors achieved acceptable graft function and patient/graft survival in the 5-year follow-up, encouraging the use of this approach.

TRPV2 in the development of experimental colitis

Colitis is still a significant disease challenge in humans, but its underlying mechanism remains to be fully elucidated. The transient receptor potential vanilloid (TRPV) ion channel plays an important pathological role in host immunity, as deficiency of TRPV compromises host defence in vivo and in vitro. Using a DSS-induced colitis mouse model, the function of TRPV2 in the development of colitis was investigated, utilizing TRPV2(-/-) and Wt mice. Less severe colitis was observed in TRPV2(-/-) , compared to that of Wt mice, at the clinical, histopathological and immunohistochemical levels. Compared to Wt mice, reduced severity of colitis in TRPV2(-/-) mice may be due to less intestinal inflammation via reduced recruitment of macrophages. The TRPV2 pathway contributes to the development of colitis. These data provide useful information for potential therapeutic intervention in colitis patients.

Kidney transplantation from donors after brain or cardiac death in China--a clinical analysis of 94 cases

BACKGROUND

We analyzed outcomes of kidney transplantation (KTx) from donation after brain death (DBD) or cardiac death (DCD) in China under the current level of the health care system.

METHODS

Among 94 KTx performed from February 2007 to March 2012 in two organ transplant centers in the south of China, 50 KTx were used DBD and 44 DCD donors. We retrospectively analyzed the clinical outcomes.

RESULTS

At a mean follow-up of 25.5 months, the 1-year and 2-year graft survival rates were 96.8% and 95.2% respectively. Delayed graft function (DGF) occurred in 27.7% recipients, three of whom lost graft function. Among six observed acute rejection episodes, five were reversed. When compared to the DCD group in DBD patients were apt to recover from DGF. Serum creatinine decreased more promptly in the DBD than in DCD group. Serum creatinine in the DCD group increased after months 12, when it was significantly higher than that in the DBD group (P < .05).

CONCLUSIONS

Kidney transplantation from DBD donors showed good outcomes with few complications. Although KTx from DCD donors showed a higher DGF rate and longer duration of graft recovery, we achieved favorable short-term clinical outcome using this source.

Myocardial protection by Salvia miltiorrhiza Injection in streptozotocin-induced diabetic rats through attenuation of expression of thrombospondin-1 and transforming growth factor-β1

OBJECTIVES

To investigate the myocardially protective effects of Salvia miltiorrhiza injection in streptozotocin-induced diabetic rats and the possible mechanisms involved.

METHODS

Adult male Sprague-Dawley rats were randomized into three groups (n = 10 per group): diabetes, no treatment (Sm-); diabetes, S. miltiorrhiza injection (Sm+); control (no diabetes; saline treatment). After model induction and 4 weeks' treatment, heart function of five rats from each group was tested by Langendorff isolated in vivo heart perfusion. In the remaining rats, pathological changes of the myocardium were observed by haematoxylin and eosin staining, and protein levels of thrombospondin-1 (TSP-1) and transforming growth factor-β1 (TGF-β1) were assessed by immunohistochemistry.

RESULTS

Left ventricular systolic end pressure and left ventricular developed pressure were significantly improved in the Sm+ group compared with the Sm- group. Pathological changes were ameliorated through significantly reduced TSP-1 and TGF-β1 protein levels.

CONCLUSIONS

S. miltiorrhiza injection may improve the heart function of diabetic rats and protect against cardiomyopathy by downregulating TSP-1 and TGF-β1 in myocardial tissue.

Ghrelin contributes to derangements of glucose metabolism induced by rapamycin in mice

AIMS/HYPOTHESIS

Rapamycin impairs glucose tolerance and insulin sensitivity. Our previous study demonstrated that rapamycin significantly increases the production of gastric ghrelin, which is critical in the regulation of glucose metabolism. Here, we investigated whether ghrelin contributes to derangements of glucose metabolism induced by rapamycin.

METHODS

The effects of rapamycin on glucose metabolism were examined in mice receiving ghrelin receptor antagonist or with Ghsr1a gene knockout. Changes in GLUT4, c-Jun N-terminal kinase (JNK) and phosphorylated ribosomal protein S6 (pS6) were investigated by immunofluorescent staining or western blotting. Related hormones were detected by radioimmunoassay kits.

RESULTS

Rapamycin impaired glucose metabolism and insulin sensitivity not only in normal C57BL/6J mice but also in both obese mice induced by a high fat diet and db/db mice. This was accompanied by elevation of plasma acylated ghrelin. Rapamycin significantly increased the levels of plasma acylated ghrelin in normal C57BL/6J mice, high-fat-diet-induced obese mice and db/db mice. Elevation in plasma acylated ghrelin and derangements of glucose metabolism upon administration of rapamycin were significantly correlated. The deterioration in glucose homeostasis induced by rapamycin was blocked by D: -Lys3-GHRP-6, a ghrelin receptor antagonist, or by deletion of the Ghsr1a gene. Ghrelin receptor antagonism and Ghsr1a knockout blocked the upregulation of JNK activity and downregulation of GLUT4 levels and translocation in the gastrocnemius muscle induced by rapamycin.

CONCLUSIONS/INTERPRETATION

The current study demonstrates that ghrelin contributes to derangements of glucose metabolism induced by rapamycin via altering the content and translocation of GLUT4 in muscles.

Kidney transplantation from donation after cardiac death donors in China--a single-center experience

OBJECTIVE

To report clinical outcomes of kidney transplantation from cardiac death donors (DCD) in China, and to investigate its feasibility to expand the organ donor pool.

PATIENTS AND METHODS

We retrospectively studied clinical data of 46 DCD kidneys from 31 donors from February 2007 to August 2011. Recipients were followed for patient and graft survival.

RESULTS

We discarded the organs from 3 of 29 (10.3%) DCD donors and 7 of 42 (16.7%) kidneys that displayed renal thrombosis. Of the 39 recipients engrafted with DCD kidneys successfully, the mean follow-up was 16 months, (range = 50 days to 43 months). Delayed graft function (DGF) occurred in 15 (38.5%) recipients, who except one recovered within 3 months. Three biopsy-proven acute rejection episodes were observed in two recipients (5.1%). All patients survived through the follow-up. The graft survival rate was 97.4% at 12 months and 94.9% at 24 months. A 45-year-old male recipient who received a pair of grafts from a 6-year-old child survived with good renal function.

CONCLUSION

Although kidney transplantations from DCD donors showed a higher rate of DGF with a longer duration of graft recovery, we achieved favorable short-term clinical outcome in terms of graft survival and function. Donation after cardiac death can expand the organ donor pool in China.

Resistance to lipopolysaccharide-induced endotoxic shock in heterozygous Zfp191 gene-knockout mice

Zinc finger protein 191, ZNF24 and Zfp191 in both humans and mice belong to the SCAN domain subfamily of Krüppel-like zinc finger transcription factors. Previous studies have suggested that Zfp191 is a pleiotropic factor involved in embryonic development, hematopoiesis and tumorigenesis. However, little is known about its target genes or its role in other physiological and pathological processes. We have identified the putative target genes of Zfp191, using an in silico genome-wide scan. Three hundred and fifty-five putative target genes were identified, which were enriched into the pathways of immune response according to the pathway analysis. These targets indicated that Zfp191 may function as a mediator of the immune response. This was verified in mice heterozygous for Zfp191 (Zfp191(+/-)) using a lipopolysaccharide (LPS)-induced endotoxic shock model. After LPS injection, Zfp191(+/-) mice produced significantly less IL-1β and IL-6 compared to wild-type mice and were resistant to LPS-induced endotoxic shock. The loss of Zfp191 may suppress systemic inflammation by reducing these cytokine levels during LPS-induced endotoxic shock.

Ethanol-induced neurodegeneration in NRSF/REST neuronal conditional knockout mice

The transcription regulator, neuron-restrictive silencer factor (NRSF), also known as repressor element-1 silencing transcription factor (REST), plays an important role in neurogenesis and various neuronal diseases such as ischaemia, epilepsy, and Huntington's disease. In these disease processes, neuronal loss is associated with abnormal expression and/or localization of NRSF. Previous studies have demonstrated that NRSF regulates the effect of ethanol on neuronal cells in vitro, however, the role of NRSF in ethanol-induced neuronal cell death remains unclear. We generated nrsf conditional knockout mice using the Cre-loxP system to disrupt neuronal expression of nrsf and its truncated forms. At postnatal day 6, ethanol significantly increased the expression of REST4, a neuron-specific truncated form of NRSF, in the brains of wild type mice, and this effect was diminished in nrsf conditional knockout mice. The apoptotic effect of ethanol was pronounced in multiple brain regions of nrsf conditional mutant mice. These results indicate that NRSF, specifically REST4, may protect the developing brain from ethanol, and provide new evidence that NRSF can be a therapeutic target in foetal alcohol syndrome (FAS).

Hypermethylation of hepatic Gck promoter in ageing rats contributes to diabetogenic potential

AIMS/HYPOTHESIS

Hepatic glucokinase (GCK) is a key enzyme in glucose utilisation. Downregulation of its activity is associated with insulin resistance and type 2 diabetes mellitus. However, it is unknown whether hepatic Gck expression is influenced by age and is involved in ageing-mediated diabetes, and whether the degree of methylation of the hepatic Gck promoter is correlated with the transcription of Gck. To address the question, we evaluated hepatic Gck transcription and promoter methylation in young (14 weeks), adult (40 weeks) and aged (80 weeks) rats.

METHODS

Hepatic glycogen, Gck expression and the kinase activity of GCK were measured in three age groups. The CpG methylation status was determined by both bisulphite direct sequencing and clone sequencing of the PCR amplificates of Gck promoter. The causal relationship between Gck methylation and mRNA expression was confirmed by treating rat primary hepatocytes with 5-aza-2'-deoxycytidine (5-Aza-CdR).

RESULTS

We have shown an age-associated decline in hepatic glycogen, Gck expression levels and the kinase activity of hepatic GCK. The eleven CpG sites studied displayed age-related progressive methylation changes in hepatic Gck promoter, which were confirmed by two methods: direct and clone sequencing. After 5-Aza-CdR treatment of rat primary hepatocytes, there was a fourfold increase in Gck expression.

CONCLUSIONS/INTERPRETATION

Our results demonstrate that an age-related increase in methylation is negatively associated with hepatic Gck expression, suggesting that DNA methylation could be involved in increasing age-dependent susceptibility to hepatic insulin resistance and diabetes. Thus, the epigenetic modification of the hepatic Gck promoter may represent an important marker for diabetogenic potential during the ageing process.

Leaf scorch symptoms are not correlated with bacterial populations during Pierce's disease

Xylella fastidiosa (Xf) is a xylem-limited bacterium that lives as a harmless endophyte in most plant species but is pathogenic in several agriculturally important crops such as coffee, citrus, and grapevine (Vitis vinifera L.). In susceptible cultivars of grapevine, Xf infection results in leaf scorch, premature leaf senescence, and eventually vine death; a suite of symptoms collectively referred to as Pierce's disease. A qPCR assay was developed to determine bacterial concentrations in planta and these concentrations were related to the development of leaf-scorch symptoms. The concentration of Xf in leaves of experimental grapevines grown in the greenhouse was similar to the concentration of Xf in leaves of naturally infected plants in the field. The distribution of Xf was patchy within and among leaves. Some whole leaves exhibited severe leaf-scorch symptoms in the absence of high concentrations of Xf. Despite a highly sensitive assay and a range of Xf concentrations from 10(2) to 10(9) cells g(-1) fresh weight, no clear relationship between bacterial population and symptom development during Pierce's disease was revealed. Thus, high and localized concentrations of Xf are not necessary for the formation of leaf-scorch symptoms. The results are interpreted as being consistent with an atiology that involves a systemic plant response.

Expression and bioactivity of recombinant human lysozyme in the milk of transgenic mice

Human milk lysozyme is an important protein for innate immunity, but human breast milk is a fairly poor source for commercial production of this enzyme. Research on the expression of recombinant human lysozyme (rHlys) is therefore potentially valuable to the dairy industry. In this study, 2 different kinds of transgenic mice, PBC-hLY and PBC-sighLY, were generated and used as system models to express rHlys. Six lines of PBC-hLY transgenic mice with human lysozyme genomic DNA-based constructs were generated, and a maximum expression level of rHlys approaching 0.154 mg/mL was achieved. Antibacterial activity of the whey from PBC-hLY female transgenic mice was determined by a turbidimetric assay. Results showed that antibacterial activity of the whey was strongly enhanced, and confirmed that rHlys retained full activity. For rHlys to be secreted efficiently into the milk of transgenic mice, 5 lines of mice were also generated, in which the signal peptide DNA of bovine beta-casein was substituted for that of lysozyme in PBC-hLY transgenic mice. Compared with PBC-hLY transgenic mice, both the expression levels of rHlys and the antibacterial activity of the whey were much higher in the PBC-sighLY transgenic mice. The concentration of rHlys in one of these mice amounted to 1.405 mg/mL-3 times higher than the level in human whey. The antibacterial activity of the whey was also 3 times higher than that of human whey. The rHlys from both PBC-hLY and PBC-sighLY transgenic mice had the same antibacterial activity as human milk lysozyme. The effect of the signal peptide and copy numbers of the transgene on expression of rHlys was also evaluated. This work will certainly permit a better understanding of how mammary gland bioreactor systems can be applied to produce rHlys in other mammals, such as cattle.

A genome scan for quantitative trait loci associated with body weight at different developmental stages in chickens

A genome scan to detect quantitative trait loci (QTL) affecting body weight in chickens was conducted on 238 F(2) chickens from a reciprocal cross of Silky Fowl and White Plymouth Rock using 125 microsatellite markers covering 23 autosomes and the Z chromosome. Two types of QTL were considered: static QTL (SQ) and developmental QTL (DQ). Static QTL affected the body weight from hatch to time t, and DQ affected the body weight from time t-1 to time t. Six SQ and nine DQ were detected. Of these QTL, four reached a genome-wide significance of 5% or better, with SQ1 and DQ1 being the most significant QTL. Static QTL1 was on chromosome 1 between GCT0006 and MCW0106 and explained 4.05-9.80% of the phenotypic variation in body weights from 3 to 12 weeks of age. At 9, 10 and 11 weeks, the genome-wide significance thresholds of SQ1 were <1%. Developmental QTL1 was located on chromosome 1 between MCW0168 and GCT0006, and explained 2.75% of the phenotypic variation for body weight from week 7 to 8 with a genome-wide significance level <1%. The results suggest that body weight from hatch to time t and developmental growth from time t-1 to time t may involve two different sets of genes or gene actions.

Gene expression profile of transgenic mouse kidney reveals pathogenesis of hepatitis B virus associated nephropathy

Hepatitis B virus (HBV)-associated nephritis has been reported worldwide. Immune complex deposition has been accepted as its pathogenesis, although the association between the presence of local HBV DNA and viral antigen and the development of nephritis remains controversial. To understand better the roles played by HBV protein expression in the kidney, the global gene expression profile was studied in the kidney tissue of a lineage of HBV transgenic mouse (#59). The mice expressed HBsAg in serum, and HBsAg and HBcAg in liver and kidney, but without virus replication. Full-length HBV genome (adr subtype, C genotype) isolated from a chronic HBV carrier was used to establish the transgenic mice #59. Similarly manipulated mice that did not express HBV viral antigens served as controls. Southern blotting, hybridization with HBV probe, and immuno-histochemical staining were used to study HBV gene expression. mRNA extracted from the kidney tissue was analyzed using Affymetrix microarrays. HBsAg and HBcAg were located mainly in the cytoplasm of tubular epithelium. Altogether 520 genes were "up-regulated" more than twofold and 76 genes "down-regulated" more than twofold in the kidney. The complement activation, blood coagulation, and acute-phase response genes were markedly "up-regulated". Compared to the controls, the level of serum C3 protein was decreased in #59 mice, while the level of C3 protein from kidney extract was increased. Results indicate that expression of HBsAg and HBcAg in tubular epithelial cells of the kidney per se can up-regulate complement-mediated inflammatory gene pathways, in addition to immune complex formation.

[Isolation and expression profiling of the Pto-like gene SsPto from Solanum surattense]

A novel Pto-like gene (designated as SsPto) is cloned from yellow-fruit nightshade (Solanum surattense). The full-length cDNA of SsPto is 1331 bp long with an open reading frame of 960 bp encoding a polypeptide of 320 amino acid residues. The deduced SsPto protein has a calculated molecular weight of 36.21 kDa with an isoelectric point of 6.18. Multiple sequence alignment shows that SsPto protein shares 71.4% and 71.6% identities to Pto proteins from Lycopersicon pimpinellifolium and L. hirsutum respectively. Genomic Southern blot analysis indicates the presence of a small family of SsPto in the S. surattense genome. SsPto is found to be constitutively expressed in the S. surattense plant with the highest expression in stems. However, under induction by TMV for 6 days, SsPto expresses the highest in roots. Further expression analysis reveals that the signaling components of defense/stress pathways, such as methyl jasmonate (MeJA), salicylic acid (SA), gibberellic acid (GA3) and hydrogen peroxide (H2O2), up-regulate the SsPto transcript levels over the control. Cold treatment, nevertheless, has no significant effect on SsPto expression whereas SsPto expression is down-regulated by dark treatment. Our findings suggest that this novel stress- and pathogen-inducible SsPto from S. surattense may participate not only in the defense/stress responsive pathways, but also in diverse processes of plant's growth and development.

Modulation of Na(+),K(+) pumping and neurotransmitter uptake by beta-amyloid

Micromolar concentrations of beta-amyloid (Abeta), a 40/42-amino-acid-long proteolytic fragment (Abeta(1-40/42)) of the amyloid precursor protein, was shown previously to play a crucial role in pathogenesis of Alzheimer's disease. We used the Xenopus oocyte expression system to investigate specific effects of micromolar concentrations of Abeta(1-42) on the neurotransmitter transporters for gamma-aminobutyric acid (GABA), GAT1, and for the excitatory amino acid glutamate, EAAC1, which are driven by the transmembrane Na(+) gradient that is regulated by the Na(+),K(+)-ATPase. Brief treatment with Abeta(1-42), up to 80 min, leads to a significant inhibition of ion translocation by the Na(+),K(+)-ATPase (30-40%); also glutamate uptake is inhibited (20%) while GABA uptake is not affected. Since reduced glutamate uptake will result in elevated, neurotoxic concentrations of extracellular glutamate, we investigated the effects of Abeta(1-42) and the smaller fragments, Abeta(12-28) and Abeta(25-35), on EAAC1 in more detail. Prolonged incubation in 1 microM Abeta(1-42) leads to further, strong inhibition of glutamate uptake and EAAC1-mediated current (after 4 h inhibition amounts to more than 80%). Abeta(12-28) is less effective with 50% inhibition after 4 h of incubation at 20 microM. Abeta(1-42) and Abeta(12-28) affect EAAC1-mediated current to a similar extent as the rate of glutamate uptake. The effects on EAAC1-mediated current are irreversible if Abeta were applied for longer time periods. Peptides directly microinjected into the oocyte are ineffective suggesting that the observed effect were mediated by extracellular proteins. Abeta(25-35) hardly affects EAAC1-mediated current or glutamate uptake. The results demonstrate that Abeta specifically inhibits the Na(+),K(+) pump and EAAC1. The domain between amino acids 12 and 28 of Abeta seems to play a crucial role for inhibition of EAAC1. The inhibition of EAAC1 by neurotoxic, elevated extracellular glutamate levels may contribute to Alzheimer's pathogenesis.

Up-regulation of γ-aminobutyric acid transporter I mediates ethanol sensitivity in mice

Ethanol is among the most widely abused drugs in the world. Chronic ethanol consumption leads to ethanol tolerance and addiction, and impairs learning and memory. Na+/Cl- dependent GABA transporters play an important role in controlling the concentration of GABA in the synaptic cleft, and thus they control the intensity and duration of synaptic transmission of GABA. It has been suggested that GABAergic system is involved in ethanol consumption, tolerance and addiction, because chronic ethanol consumption alters the expression of GABAA receptors and drugs on GABA receptors affect ethanol actions. The results of the present study reveal that that activity of GABA transporters in mouse brain after 15-min acute ethanol injection or after chronic ethanol consumption is increased. Moreover, mice pre-injected with a competitive or a noncompetitive antagonist of gamma-aminobutyric acid transporter subtype 1 (GAT1) showed high sensitivity to the sedative/hypnotic effects of ethanol. In contrast, transgenic mice overexpressing GAT1 displayed low sensitivity to ethanol, as shown by the righting reflex test. Mice overexpressing GAT1 survived a lethal dose of ethanol (9 g/kg, i.p.) longer, maintained locomotor activity longer after a sub-lethal dose (1.75 g/kg, i.p.) and exhibited a higher median lethal dose than wild-type littermates. These results suggest that GAT1 plays an important role in sensitivity to ethanol, and might be a therapeutic target for alcoholism prevention and treatment. Acute and chronic ethanol administration resulted in the increase of GABA transporter function. Use of GAT1 selective inhibitors and GAT1 overexpressing mice thus demonstrate that GAT1 should be an important protein mediating sensitivity to ethanol in mice.

Effect of Cr Addition on the Methane Aromatization Performance of the Mo/HZSM-5 Catalyst

The promotional effect of Cr addition on the methane aromatization performance of the Mo/HZSM-5 catalyst was investigated. It was found that much higher methane conversion was obtained over Mo–Cr/HZSM-5 catalyst than over Mo/HZSM-5. The results indicate that when the Cr/Mo molar ratio is 0.07, the methane conversion and aromatics selectivity reach 11.6 and 97.3% respectively at a reaction temperature of 973 K. Raising the temperature is beneficial to the methane conversion and 15.82% conversion is obtained at 1023 K. Modern measurements such as isopropyl alcohol decomposition and temperature desorption of ammonia (NH3-TPD) were used to characterized the catalysts. The results of isopropyl alcohol decomposition show that the surface acidity of Mo–Cr/HZSM-5 is increased at high temperature. The NH3-TPD findings imply that the Mo–Cr/HZSM-5 catalyst has much stronger acidity and more acid sites than Mo/HZSM-5, most likely one of the reasons for the enhanced activity for methane aromatization using Mo–Cr/HZSM-5 catalyst.

Norepinephrine transporter (NET) is expressed in cardiac sympathetic ganglia of adult rat

The sympathetic nervous system plays a cardinal role in regulating cardiac function through releasing the neurotransmitter norepinephrine (NE). In comparison with central nervous system, the molecular mechanism of NE uptake in myocardium is not clear. In present study, we proved that in rat the CNS type of NE transporter (NET) was also expressed in middle cervical-stellate ganglion complex (MC-SG complex) which is considered to control the activity of heart, but not expressed in myocardium. The results also showed that NET expression level in right ganglion was significantly higher than in the left, rendering the greater capacity of NE uptake in right ventricle, a fact which may contribute to the maintenance of right ventricular function under pathologic state.

A novel mechanism of dopamine neurotoxicity involving the peripheral extracellular and the plasma membrane dopamine transporter

Chinese hamster ovary cells stably expressing a rat dopamine transporter (designated D8 cells) and neuroblastoma SK-N-SH cells were used as two model systems to study dopamine neurotoxicity. Within 24 h, 1-10 mM dopamine induced D8 cells into apoptosis while 20-200 microM dopamine induced SK-N-SH cells into cell death. The viability of both cell types decreased in a dose-dependent manner. However, the dopamine uptake activity of D8 cells at 10 mM was not significantly higher than the uptake at 100 microM, suggesting that it was not the high concentration of intracellular dopamine that induced D8 cells into apoptosis, but rather dopamine found in the extracellular space. Furthermore, cocaine, an inhibitor of dopamine uptake, could not block cell death induced by dopamine. Forskolin, an agonist of protein kinase A (PKA), stimulated dopamine uptake in D8 cells and blocked apoptosis induced by the drug. These results suggest that the dopamine transporter mediates a dopamine-dependant apoptotic signal transduction pathway that is independent of dopamine uptake into the cell.

Genetic modification of hematopoietic progenitor cells for combined resistance to 4-hydroperoxycyclophosphamide, vincristine, and daunorubicin

AIM

To investigate whether human peripheral blood hematopoietic progenitor cells (PBPC) modified with human aldehyde dehydrogenase class-3 gene (ALDH-3) and multidrug resistance gene 1 (MDR1) would increase chemotherapy resistance to 4-hydroperoxycyclophosphamide (4-HC) and -glycoprotein effluxed drugs.

METHODS

A bicistronic retroviral vector G1Na-ALDH3-IRES-MDR1 cDNA was constructed and used to transfect the packaging cell lines PA317 by electroporation. CD34+ PBPC were isolated with a high-gradient magnetic cell sorting system (MACS), and then were transfected with supernatant of retrovirus containing human ALDH-3 and MDR1 cDNA. PCR, RT-PCR, Southern blot, Northern blot, FACS, and MTT assay were used to evaluate the transfection and expression of the transgene in target cells.

RESULTS

The bicistronic retroviral vector construction was verified by PCR and restriction endonuclease analysis. Dual drug resistance genes were integrated into the genomic DNA of CD34+ PBPC and expressed efficiently. The efficiency of gene transfection in CD34+ PBPC was tested to be 18 % on colonies. Nested PCR and Neor rescue assay indicated that no helper virus was present in this system. Compared with the untransduced cells, transgene recipient cells conferred 4.5-fold resistance to 4-HC, 6.6-fold and 7.8-fold resistance to P-glycoprotein effluxed drug, vincristine and daunorubicin, respectively.

CONCLUSION

Efficient transduction of two different types of drug resistance genes into human peripheral blood hematopoietic progenitor cells and the co-expression may decrease cumulative myelosuppression of combination chemotherapy.

Peptide derived from insulin with regulatory activity of dopamine transporter

A nonapeptide derived from the C terminus of the insulin B chain, H(2)N-Arg-Gly-Phe-Phe-Tyr-Thr-Pro-Lys-Ala-COOH, was found to strongly inhibit dopamine (DA) uptake by rat dopamine transporter (DAT) stably expressed in CHO cells (designated D8 cells). The kinetic experiments on D8 cells gave a curve typical of competitive inhibition with an IC(50)=6.9 microM. This inhibitory effect was also confirmed by experiments on striatal synaptosomes. The rat administered with the nonapeptide unilaterally into substantia nigra showed dose-dependent velocity and duration of the round movement contralateral to the nonapeptide-injected side. In addition, the nonapeptide dose-dependently reduced the binding of the tritium-labeled cocaine analog (-)-2 beta-carbomethoxy-3 beta-(4-fluorophenyl)tropane (WIN35,428) to DAT of D8 cells, which suggests that the nonapeptide may inhibit the transport activity of DAT in the way as cocaine does. Meanwhile, the peptide DOI (insulin with 8 amino acid residues deleted at the C terminus of the B chain) shows a significantly stimulating effect on DAT uptake activity in D8 cells. So insulin is proposed as a kind of neuropeptide precursor in the brain and insulin-derived peptides may be involved in the process of regulating the DA system, and these peptides may be developed into new medicines for disorders concerning the DA system such as Parkinson's disease and cocaine addiction.