Antibiotic Resistance Profile and Bio-Control of Multidrug-Resistant Escherichia coli Isolated from Raw Milk in Vietnam Using Bacteriophages.

E. coli is an important zoonotic pathogen capable of causing foodborne illness and bovine mastitis. Bacteriophages have been increasingly considered a promising tool to control unwanted bacteria. The aim of this study is to determine the antibiotic resistance profile of E. coli isolated from raw milk and the efficacy of phage in controlling multidrug-resistant E. coli in raw milk. Antibiotic susceptibility testing showed the highest resistance rates of E. coli isolates to co-trime (27.34%) and ampicillin (27.34%), followed by streptomycin (25.18%), tetracycline (23.02%), and the lowest resistance rates to ciprofloxacin, gentamycin, and ceftazidime, all at a rate of 2.16%. All isolates were susceptible to meropenem. Of the 139 E. coli isolates, 57 (41.01%) were resistant to at least one antibiotic, and 35 (25.18%) were classified as MDR strains. Molecular characterization indicated that 5 (3.6%) out of the 139 isolates were STEC strains carrying stx1 gene. Seven (5.04%) isolates were phenotypically identified as ESBLEC, and four isolates (2.88%) were resistant to colistin. The results of the genotypic test revealed that four out of seven ESBLEC strains carried both blaTEM and blaCTX-M-1, two harbored blaTEM, and one possessed blaCTX-M-1, while mcr-1 was detected in all four colistin-resistant E. coli isolates. In particular, one isolated E. coli strain (EM148) was determined to be a multidrug-resistant strain simultaneously carrying blaTEM, blaCTX-M-1, and mcr-1. A total of eight phages were successfully recovered from raw milk. The application of phage PEM3 significantly reduced viable counts of multidrug-resistant host EM148 in raw milk by at least 2.31 log CFU/mL at both 24 °C and 4 °C.

Prevalence and Antibiotic Resistance Profile of Clostridium perfringens Isolated from Pork and Chicken Meat in Vietnam.

Clostridium perfringens is one of the most important zoonotic pathogens as it can cause food poisoning in humans and necrotic enteritis in both animals and humans. Meat, especially pork and chicken meat, is considered the main vehicle for the transmission of C. perfringens from animals to humans. The purpose of this study was to determine the prevalence, toxinotype, and antimicrobial resistance profile of C. perfringens isolated from pork and chicken meat sold in Vietnam. The isolation results showed that 15/50 (30%) of pork samples and 8/50 (16%) of chicken meat samples were contaminated with C. perfringens. The isolates exhibited their highest resistance rate to tetracycline (21/23; 91.30%) and clindamycin (10/23; 43.48%). On the contrary, their lowest resistance rates were observed in response to imipenem (2/23; 8.70%) and cefoxitin (1/23; 4.35%). In particular, 34.78% (8/23) of C. perfringens isolates were identified to be multidrug-resistant strains. The results of toxin genotyping indicated that all isolates were positive for the cpa gene and belonged to type A.

After action review of the COVID-19 surveillance system in Quang Ninh Province, Vietnam, in 2020.

Surveillance is the backbone of any response to an infectious disease outbreak, and comprehensive evaluation of surveillance systems is crucial. However, structured evaluations of surveillance systems during the COVID-19 pandemic are scarce. We conducted an after action review (AAR) of the performance of the COVID-19 surveillance system in Quang Ninh Province, Vietnam, during 2020 using the COVID-19-specific AAR methodology developed by the World Health Organization in combination with guidance from the US Centers for Disease Control and Prevention (CDC). We conducted a stakeholder survey, document reviews, and key informant interviews with staff from Quang Ninh CDC's COVID-19 surveillance system. The COVID-19 surveillance system was based on the pre-existing surveillance system in the province. The system's strengths were early preparation for emergency response, strong governance and central coordination, and multidisciplinary collaboration. Stakeholders agreed that the system proved useful and adaptive to the fast-evolving COVID-19 situation but was weakened by overly complex systems, redundant administrative processes, unclear communication channels, and lack of resources. Overall, the surveillance systems in Quang Ninh province proved effective in containing COVID-19 and adaptive in a fast-changing epidemiological context. Several recommendations were made based on identified areas of concern that are of relevance for COVID-19 surveillance systems in Vietnam and similar settings.

After action review of the COVID-19 surveillance system in Quang Ninh Province, Vietnam, in 2020.

Surveillance is the backbone of any response to an infectious disease outbreak, and comprehensive evaluation of surveillance systems is crucial. However, structured evaluations of surveillance systems during the COVID-19 pandemic are scarce. We conducted a after action review (AAR) of the performance of the COVID-19 surveillance system in Quang Ninh Province, Vietnam, during 2020 using the COVID-19-specific AAR methodology developed by the World Health Organization in combination with guidance from the US Centers for Disease Control and Prevention (CDC). We conducted a stakeholder survey, document reviews, and key informant interviews with staff from Quang Ninh CDC's COVID-19 surveillance system. The COVID-19 surveillance system was based on the pre-existing surveillance system in the province. The system's strengths were early preparation for emergency response, strong governance and central coordination, and multidisciplinary collaboration. Stakeholders agreed that the system proved useful and adaptive to the fast-evolving COVID-19 situation but was weakened by overly complex systems, redundant administrative processes, unclear communication channels, and lack of resources. Overall, the surveillance systems in Quang Ninh province proved effective in containing COVID-19 and adaptive in a fast-changing epidemiological context. Several recommendations were made based on identified areas of concern that are of relevance for COVID-19 surveillance systems in Vietnam and similar settings.

Green Fabrication of Heterostructured CoTiO3/TiO2 Nanocatalysts for Efficient Photocatalytic Degradation of Cinnamic Acid.

In this work, CoTiO3/TiO2 (CTO/Ti) heterostructures were prepared by a hydrothermal procedure in a neutral medium using perovskite CoTiO3 and tetraisopropyl titanate. Characteristics of the synthesized catalysts were analyzed by various techniques including X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, UV-vis diffuse reflectance spectroscopy, Brunauer-Emmett-Teller adsorption-desorption, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and point of zero charges. The activity in the photodegradation of cinnamic acid (CA) under UV-A irradiation of the CTO/Ti heterostructure was investigated and compared with individual materials TiO2 (Ti-w) and CoTiO3 (CTO). The investigation showed that the heterostructured CoTiO3/TiO2 catalyst with optimal composition (5% CTO) exhibited much higher photocatalytic activity for degradation of cinnamic acid than individual CoTiO3 and TiO2. Under the optimal conditions (C cat = 0.75 g/L, Q air = 0.3 L/min, and pH = 3.8) the 90 min conversion of cinnamic acid reached 80.9% on 5CTO/Ti, much higher than those of CTO (4.6%) and Ti-w (75.2%). It was found that the enhancement in activity for the CA removal of the CTO/Ti heterostructure was due to the construction of a heterojunction structure between TiO2(Ti-w) and CoTiO3 that resulted in an increase in the specific surface area and porosity, reduction of the band gap energy, and higher efficient separation of charge carriers on the surface to prevent recombination. Alternatively, a comparison of the recyclability of 5CTO/Ti and Ti-w was made for CA degradation. The results showed a decrease in the CA conversion by 38% on 5CTO/Ti and 48% on Ti-w after six reaction cycles.

The use of composting for the disposal of African swine fever virus-infected swine carcasses.

African swine fever (ASF) has been considered as one of the most important and devastating swine diseases with high mortality rates. Since effective vaccines and treatment are not available, mass euthanasia of infected and exposed pigs has been known to be the best measure to control ASF. Although composting has been proved to be a safe method for the rapid disposal of animal carcasses during outbreaks, there is no information about the effect of composting on the viability of ASF virus in swine carcasses. This study investigates the survival of the ASF virus in swine carcasses during composting. The findings suggested that the DNA of the ASF virus was detected in all samples tested. On the contrary, infectious ASF virus particles were rapidly destroyed at day 3.

LC3A-mediated autophagy regulates lung cancer cell plasticity.

ABBREVIATIONS: ATG14: autophagy related 14; CDH2: cadherin 2; ChIP-qPCR: chromatin immunoprecipitation quantitative polymerase chain reaction; CQ: chloroquine; ECAR: extracellular acidification rate; EMT: epithelial-mesenchymal transition; EPCAM: epithelial cell adhesion molecule; MAP1LC3A/LC3A: microtubule associated protein 1 light chain 3 alpha; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MAP1LC3C/LC3C: microtubule associated protein 1 light chain 3 gamma; NDUFV2: NADH:ubiquinone oxidoreductase core subunit V2; OCR: oxygen consumption rate; ROS: reactive oxygen species; RT-qPCR: reverse-transcriptase quantitative polymerase chain reaction; SC: scrambled control; shRNA: short hairpin RNA; SNAI2: snail family transcriptional repressor 2; SOX2: SRY-box transcription factor 2; SQSTM1/p62: sequestosome 1; TGFB/TGF-ß: transforming growth factor beta; TOMM20: translocase of outer mitochondrial membrane 20; ZEB1: zinc finger E-box binding homeobox 1.

ID4 predicts poor prognosis and promotes BDNF-mediated oncogenesis of colorectal cancer.

Inhibitors of DNA binding and cell differentiation (ID) proteins regulate cellular differentiation and tumor progression. Whether ID family proteins serve as a linkage between pathological differentiation and cancer stemness in colorectal cancer is largely unknown. Here, the expression of ID4, but not other ID family proteins, was enriched in LGR5-high colon cancer stem cells. Its high expression was associated with poor pathological differentiation of colorectal tumors and shorter survival in patients. Knockdown of ID4 inhibited the growth and dissemination of colon cancer cells, while enhancing chemosensitivity. Through gene expression profiling analysis, brain-derived neurotrophic factor (BDNF) was identified as a downstream target of ID4 expression in colorectal cancer. BDNF knockdown decreased the growth and migration of colon cancer cells, and its expression enhanced dissemination, anoikis resistance and chemoresistance. ID4 silencing attenuated the epithelial-to-mesenchymal transition pattern in colon cancer cells. Gene cluster analysis revealed that ID4 and BDNF expression was clustered with mesenchymal markers and distant from epithelial genes. BDNF silencing decreased the expression of mesenchymal markers Vimentin, CDH2 and SNAI1. These findings demonstrated that ID4-BDNF signaling regulates colorectal cancer survival, with the potential to serve as a prognostic marker in colorectal cancer.

Controlling Phase Composition, Properties and Activity of TiO2 Nano-Photocatalyst Synthesized by Hydrothermal Technique in the Degradation of Cinnamic Acid Solution.

In this work, titanium oxide catalysts were synthesized by the hydrothermal method from titanium isopropoxide (TTIP) as a precursor under acidic (Ti-A1 and Ti-A2), neutral (Ti-W) and alkaline (Ti-B) media. Characteristics of the catalysts were identified by various methods including X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller adsorption, UV-Vis diffuse reflectance spectroscopy, transmission electron microscopy, and Raman spectroscopy. The phase composition and PZC value of the obtained catalysts depended on the hydrothermal medium and the amount of TTIP: pure anatase and brookite phase formed at neutral and alkaline medium, respectively; whereas acidic medium favored the formation of anatase/rutile mixed phase and anatase phase decreased with the increasing amount of TTIP. The band gap energy of the synthesized catalysts was approximately 3.08-3.23 eV. Photocatalytic activity of synthesized catalysts was surveyed in the degradation of cinnamic acid (CA) solution at various pH in the region from 3.8 to 9.0 under UV irradiation. Photocatalytic oxidation was favorable in an acidic environment. At acidic pH values (3.8 and 5.0), the CA conversion was in the order of Ti-A2 ≥ Ti-A1 > Ti-P25 > Ti-W ≫ Ti-B, whereas it followed Ti-P25 > Ti-A1 > Ti-A2 ≈ Ti-W > Ti-B at pH 7.0 as well as pH 9.0.

Activation of latent transforming growth factor-ß1, a conserved function for pregnancy-specific beta 1-glycoproteins.

STUDY QUESTION: Do all 10 human pregnancy-specific beta 1-glycoproteins (PSGs) and murine PSG23 activate latent transforming growth factor-ß1 (TGF-ß1)? SUMMARY ANSWER: All human PSGs and murine PSG23 activated latent TGF-ß1. WHAT IS KNOWN ALREADY: Two of the 10 members of the PSG1 family, PSG1 and PSG9, were previously shown to activate the soluble small latent complex of TGF-ß1, a cytokine with potent immune suppressive functions. STUDY DESIGN, SIZE, DURATION: Recombinant PSGs were generated and tested for their ability to activate the small latent complex of TGF-ß1 in a cell-free ELISA-based assay and in a bioassay. In addition, we tested the ability of PSG1 and PSG4 to activate latent TGF-ß bound to the extracellular matrix (ECM) or on the membranes of the Jurkat human T-cell line. PARTICIPANTS/MATERIALS, SETTING, METHODS: Recombinant PSGs were generated by transient transfection and purified with a His-Trap column followed by gel filtration chromatography. The purified PSGs were compared to vehicle (PBS) used as control for their ability to activate the small latent complex of TGF-ß1. The concentration of active TGF-ß was measured in an ELISA using the TGF-ß receptor II as capture and a bioassay using transformed mink epithelial cells that express luciferase in response to active TGF-ß. The specificity of the signal was confirmed using a TGF-ß receptor inhibitor. We also measured the binding kinetics of some human PSGs for the latent-associated peptide (LAP) of TGF-ß using surface plasmon resonance and determined whether PSG1 and PSG4 could activate the large latent complex of TGF-ß1 bound to the ECM and latent TGF-ß1 bound to the cell membrane. All experiments were performed in triplicate wells and repeated three times. MAIN RESULTS AND THE ROLE OF CHANCE: All human PSGs activated the small latent complex of TGF-ß1 (P < 0.05 vs. control) and showed similar affinities (KD) for LAP. Despite the lack of sequence conservation with its human counterparts, the ability to activate latent TGF-ß1 was shared by a member of the murine PSG family. We found that PSG1 and PSG4 activated the latent TGF-ß stored in the ECM (P < 0.01) but did not activate latent TGF-ß1 bound to glycoprotein A repetitions predominant (GARP) on the surface of Jurkat T cells. LIMITATIONS, REASONS FOR CAUTION: The affinity of the interaction of LAP and PSGs was calculated using recombinant proteins, which may differ from the native proteins in their post-translational modifications. We also utilized a truncated form of murine PSG23 rather than the full-length protein. For the studies testing the ability of PSGs to activate membrane-bound TGF-ß1, we utilized the T-cell line Jurkat and Jurkat cells expressing GARP rather than primary T regulatory cells. All the studies were performed in vitro. WIDER IMPLICATIONS OF THE FINDINGS: Here, we show that all human PSGs activate TGF-ß1 and that this function is conserved in at least one member of the rodent PSG family. In vivo PSGs could potentially increase the availability of active TGF-ß1 from the soluble and matrix-bound latent forms of the cytokine contributing to the establishment of a tolerogenic environment during pregnancy. LARGE-SCALE DATA: None. STUDY FUNDING/COMPETING INTEREST(S): The research was supported by a grant from the Collaborative Health Initiative Research Program (CHIRP). No conflicts of interests are declared by the authors.

Different fermentation strategies by Schizochytrium mangrovei strain pq6 to produce feedstock for exploitation of squalene and omega-3 fatty acids.

Schizochytrium mangrovei strain PQ6 was investigated for coproduction of docosahexaenoic acid (C22: 6ω-3, DHA) and squalene using a 30-L bioreactor with a working volume of 15 L under various batch and fed-batch fermentation process regimes. The fed-batch process was a more efficient cultivation strategy for achieving higher biomass production rich in DHA and squalene. The final biomass, total lipid, unsaponifiable lipid content, and DHA productivity were 105.25 g · L-1 , 43.40% of dry cell weight, 8.58% total lipid, and 61.66 mg · g-1  · L-1 , respectively, after a 96 h fed-batch fermentation. The squalene content was highest at 48 h after feeding glucose (98.07 mg · g-1 of lipid). Differences in lipid accumulation during fermentation were correlated with changes in ultrastructure using transmission electron microscopy and Nile Red staining of cells. The results may be of relevance to industrial-scale coproduction of DHA and squalene in heterotrophic marine microalgae such as Schizochytrium.

MicroRNA-30 inhibits antiapoptotic factor Mcl-1 in mouse and human hematopoietic cells after radiation exposure.

We previously reported that microRNA-30 (miR-30) expression was initiated by radiation-induced proinflammatory factor IL-1ß and NFkB activation in mouse and human hematopoietic cells. However, the downstream effectors of miR-30 and its specific role in radiation-induced cell death are not well understood. In the present study, we evaluated effects of radiation on miR-30 expression and activation of intrinsic apoptotic pathway Bcl-2 family factors in in vivo mouse and in vitro human hematopoietic cells. CD2F1 mice and human CD34+ cells were exposed to different doses of gamma-radiation. In addition to survival studies, mouse blood, bone marrow (BM) and spleen cells and human CD34+ cells were collected at 4 h, and 1, 3 and 4 days after irradiation to determine apoptotic and stress response signals. Our results showed that mouse serum miR-30, DNA damage marker γ-H2AX in BM, and Bim, Bax and Bak expression, cytochrome c release, and caspase-3 and -7 activation in BM and/or spleen cells were upregulated in a radiation dose-dependent manner. Antiapoptotic factor Mcl-1 was significantly downregulated, whereas Bcl-2 was less changed or unaltered in the irradiated mouse cells and human CD34+ cells. Furthermore, a putative miR-30 binding site was found in the 3' UTR of Mcl-1 mRNA. miR-30 directly inhibits the expression of Mcl-1 through binding to its target sequence, which was demonstrated by a luciferase reporter assay, and the finding that Mcl-1 was uninhibited by irradiation in miR-30 knockdown CD34+ cells. Bcl-2 expression was not affected by miR-30. Our data suggest miR-30 plays a key role in radiation-induced apoptosis through directly targeting Mcl-1in hematopoietic cells.

Circulating IL-18 Binding Protein (IL-18BP) and IL-18 as Dual Biomarkers of Total-Body Irradiation in Mice.

We have previously reported that circulating interleukin-18 (IL-18) can be used as a radiation biomarker in mice, minipigs and nonhuman primates. In this study, we further determined the serum levels of IL-18 binding protein (IL-18BP), a natural endogenous antagonist of IL-18, in CD2F1 mice 1-13 days after total-body gamma irradiation (TBI) with different doses (5-10 Gy). We compared the changes in blood lymphocyte, neutrophil and platelet counts as well as the activation of the proapoptotic executioner caspase-3 and caspase-7, and the expression of the inflammatory factor cyclooxygenase 2 (COX-2) in spleen cells, with the changes of IL-18BP and IL-18 in mouse serum. We also evaluated the significance, sensitivity and specificity of alterations in radiation-induced IL-18BP. IL-18 increased from day 1-13 after TBI in a dose-dependent manner that was paralleled with an increase in IL-18 receptor alpha (IL-18Rα) in irradiated mouse spleen cells. IL-18BP rapidly increased (25-63 fold) in mouse serum on day 1 after different doses of TBI. However, it returned to baseline within 3 days after 5-7 Gy doses and within 7 days after 8 Gy dose, and was unaltered thereafter. In contrast, high doses of radiation (9 and 10 Gy) significantly sustained a higher level of IL-18BP in mouse serum and later induced a second phase of increase in IL-18BP on day 9-13 after irradiation, which coincided with the onset of animal mortality. Consistent with this observation, highly activated caspase-3 and -7 in 8-10 Gy irradiated mouse spleen cells exhibited reduced or no activity 24 h after 5 Gy, although radiation induced an inflammatory response, as shown by COX-2 expression in all irradiated cells. Our data suggest that the radiation-induced differential elevation of IL-18 and IL-18BP in animal serum is a dynamic and discriminative indicator of the severity of injury after exposure to ionizing radiation. These findings support the inclusion of the dual biomarkers IL-18BP and IL-18 in the development of a multifactorial strategy for radiation dose and injury assessment.

Delta-tocotrienol suppresses radiation-induced microRNA-30 and protects mice and human CD34+ cells from radiation injury.

We reported that microRNA-30c (miR-30c) plays a key role in radiation-induced human cell damage through an apoptotic pathway. Herein we further evaluated radiation-induced miR-30 expression and mechanisms of delta-tocotrienol (DT3), a radiation countermeasure candidate, for regulating miR-30 in a mouse model and human hematopoietic CD34+ cells. CD2F1 mice were exposed to 0 (control) or 7-12.5 Gy total-body gamma-radiation, and CD34+ cells were irradiated with 0, 2 or 4 Gy of radiation. Single doses of DT3 (75 mg/kg, subcutaneous injection for mice or 2 µM for CD34+ cell culture) were administrated 24 h before irradiation and animal survival was monitored for 30 days. Mouse bone marrow (BM), jejunum, kidney, liver and serum as well as CD34+ cells were collected at 1, 4, 8, 24, 48 or 72 h after irradiation to determine apoptotic markers, pro-inflammatory cytokines interleukin (IL)-1ß and IL-6, miR-30, and stress response protein expression. Our results showed that radiation-induced IL-1ß release and cell damage are pathological states that lead to an early expression and secretion of miR-30b and miR-30c in mouse tissues and serum and in human CD34+ cells. DT3 suppressed IL-1ß and miR-30 expression, protected against radiation-induced apoptosis in mouse and human cells, and increased survival of irradiated mice. Furthermore, an anti-IL-1ß antibody downregulated radiation-induced NFκBp65 phosphorylation, inhibited miR-30 expression and protected CD34+ cells from radiation exposure. Knockdown of NFκBp65 by small interfering RNA (siRNA) significantly suppressed radiation-induced miR-30 expression in CD34+ cells. Our data suggest that DT3 protects human and mouse cells from radiation damage may through suppression of IL-1ß-induced NFκB/miR-30 signaling.

Circulating interleukin-18 as a biomarker of total-body radiation exposure in mice, minipigs, and nonhuman primates (NHP).

We aim to develop a rapid, easy-to-use, inexpensive and accurate radiation dose-assessment assay that tests easily obtained samples (e.g., blood) to triage and track radiological casualties, and to evaluate the radioprotective and therapeutic effects of radiation countermeasures. In the present study, we evaluated the interleukin (IL)-1 family of cytokines, IL-1ß, IL-18 and IL-33, as well as their secondary cytokines' expression and secretion in CD2F1 mouse bone marrow (BM), spleen, thymus and serum in response to γ-radiation from sublethal to lethal doses (5, 7, 8, 9, 10, or 12 Gy) at different time points using the enzyme-linked immune sorbent assay (ELISA), immunoblotting, and cytokine antibody array. Our data identified increases of IL-1ß, IL-18, and/or IL-33 in mouse thymus, spleen and BM cells after total-body irradiation (TBI). However, levels of these cytokines varied in different tissues. Interestingly, IL-18 but not IL-1ß or IL-33 increased significantly (2.5-24 fold) and stably in mouse serum from day 1 after TBI up to 13 days in a radiation dose-dependent manner. We further confirmed our finding in total-body γ-irradiated nonhuman primates (NHPs) and minipigs, and demonstrated that radiation significantly enhanced IL-18 in serum from NHPs 2-4 days post-irradiation and in minipig plasma 1-3 days post-irradiation. Finally, we compared circulating IL-18 with the well known hematological radiation biomarkers lymphocyte and neutrophil counts in blood of mouse, minipigs and NHPs and demonstrated close correlations between these biomarkers in response to radiation. Our results suggest that the elevated levels of circulating IL-18 after radiation proportionally reflect radiation dose and severity of radiation injury and may be used both as a potential biomarker for triage and also to track casualties after radiological accidents as well as for therapeutic radiation exposure.

Delta-tocotrienol protects mice from radiation-induced gastrointestinal injury.

We recently demonstrated that natural delta-tocotrienol (DT3) significantly enhanced survival in total-body irradiated (TBI) mice, and protected mouse bone marrow cells from radiation-induced damage through Erk activation-associated mTOR survival pathways. Here, we further evaluated the effects and mechanisms of DT3 on survival of radiation-induced mouse acute gastrointestinal syndrome. DT3 (75-100 mg/kg) or vehicle was administered as a single subcutaneous injection to CD2F1 mice 24 h before 10-12 Gy (60)Co total-body irradiation at a dose rate of 0.6 Gy/min and survival was monitored. In a separate group of mice, jejunum sections were stained with hematoxylin and eosin and the surviving crypts in irradiated mice were counted. Apoptosis in intestinal epithelial cells was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining and bacterial translocation from gut to heart, spleen and liver in irradiated mice were evaluated. DT3 (75 mg/kg) significantly enhanced survival in mice that received 10, 10.5, 11 or 12 Gy TBI. Administration of DT3 protected intestinal tissue, decreased apoptotic cells in jejunum and inhibited gut bacterial translocation in irradiated mice. Furthermore, DT3 significantly inhibited radiation-induced production of pro-inflammatory factors interleukin-1ß and -6 and suppressed expression of protein tyrosine kinase 6 (PTK6), a stress-induced kinase that promotes apoptosis in mouse intestinal cells. Our data demonstrate that administration of DT3 protected mice from radiation-induced gastrointestinal system damage.

Primary antiphospholipid syndrome and necrotizing pancreatitis: a diagnostic challenge.

The objective of this study was to report an unusual case of primary antiphospholipid syndrome (APS)-associated severe necrotizing pancreatitis. Since the APS was first recognized in the 1980s, a number of manifestations of the disorder have been described. We report primary APS presenting as severe necrotizing pancreatitis. This is the first such case to date that fulfills the revised Sapporo classification criteria. A 38-year-old previously healthy woman presented with new-onset hypertensive emergency and acute kidney injury. She subsequently developed severe epigastric pain attributable to necrotizing pancreatitis and extensive splenic infarcts. Biopsies of both the pancreas and kidney revealed thrombotic microangiopathy. Her lupus anticoagulant was positive on both weeks 1 and 12 of her disease course. A diagnosis of primary APS was made. Despite 6 months of aggressive care, she died of sepsis.

Genistein nanoparticles protect mouse hematopoietic system and prevent proinflammatory factors after gamma irradiation.

Previous studies demonstrated that genistein protects mice from radiation-induced bone marrow failure. To overcome genistein's extremely low water solubility, a nanoparticle suspension of genistein has been formulated for more rapid dissolution. In the current study, we evaluated the radioprotective effects of a nanoparticle formulation of genistein on survival and hematopoietic recovery in mice exposed to total-body gamma irradiation. A single intramuscular injection of a saline-based genistein nanosuspension (150 mg/kg) administered to CD2F1 mice 24 h before 9.25 Gy (60)Co radiation exposure resulted in a 30-day survival rate of 95% compared to 25% in vehicle-treated animals. In mice irradiated at 7 Gy, the genistein nanosuspension increased mouse bone marrow cellularity from approximately 2.9% (vehicle treated) to 28.3% on day 7 postirradiation. Flow cytometry analysis demonstrated decreased radiation-induced hematopoietic stem and progenitor cell (HSPC, Lineage(-)/cKit(+)) death from 77.0% (vehicle) to 43.9% (genistein nanosuspension) with a significant recovery of clonogenicity 7 days after irradiation. The genistein nanosuspension also attenuated the radiation-induced elevation of proinflammatory factors interleukin 1 beta (IL-1ß), IL-6 and cyclooxygenase-2 (COX-2) in mouse bone marrow and spleen, which may contribute to protecting HSPCs.

Micro-RNA30c negatively regulates REDD1 expression in human hematopoietic and osteoblast cells after gamma-irradiation.

We recently demonstrated that a novel cell stress response gene REDD1 protects human fetal osteoblast cell line (hFOB) cells from γ-radiation-induced premature senescence. Here we show that levels of endogenous REDD1 are very low in human hematopoietic progenitor CD34+ cells regardless of radiation, but highly expressed in differentiated hematopoietic cells (14 day cultured CD34+ cells) in response to radiation, which might be associated with radiation tolerance of the latter cells. To further understand the mechanisms of radiation-induced damage in different cells, microRNA (miRNA)-arrays were performed using purified miRNAs from CD34+ and hFOB cells before and post-irradiation and real-time reverse transcription (RT)-PCR was used to validate the expression profiles of miRNAs in the radiation-damaged cells. The results indicate that γ-radiation downregulated 16 miRNAs in CD34+ cells and 14 in hFOB cells. Radiation-induced upregulation was observed for 15 miRNAs in CD34+ cells and 18 miRNAs in hFOB cells. The profiles of radiation-induced miRNA expression were completely different in CD34+ vs. hFOB cells. Radiation up-regulated miRNA (miR)-30b, miR-30c and miR-30d in CD34+ cells, whereas it inhibited miR-30c expression in hFOB cells. Since miR-30 has potential target sites located in the 3'untranslated region (UTR) of the REDD1 gene and radiation regulated miR-30c expression in both CD34+ and hFOB cells, we further explored the effects of miR-30c on REDD1 expression using miR-30c inhibitor and precursor (pre-miR-30c). The results show that pre-miR-30c transfection suppressed REDD1 expression in 14 day cultured CD34+ cells and hFOB cells and resulted in hFOB cell death. In contrast, inhibition of miR-30c expression significantly enhanced clonogenicity in CD34+ cells. Our data suggest that CD34+ and hFOB cells have different miRNA expression patterns after irradiation and miR-30c plays a key role in radiation-induced cell damage which might be through regulation of REDD1 expression.

REDD1 protects osteoblast cells from gamma radiation-induced premature senescence.

Radiotherapy is commonly used for cancer treatment. However, it often results in side effects due to radiation damage in normal tissue, such as bone marrow (BM) failure. Adult hematopoietic stem and progenitor cells (HSPC) reside in BM next to the endosteal bone surface, which is lined primarily by hematopoietic niche osteoblastic cells. Osteoblasts are relatively more radiation-resistant than HSPCs, but the mechanisms are not well understood. In the present study, we demonstrated that the stress response gene REDD1 (regulated in development and DNA damage responses 1) was highly expressed in human osteoblast cell line (hFOB) cells after γ irradiation. Knockdown of REDD1 with siRNA resulted in a decrease in hFOB cell numbers, whereas transfection of PCMV6-AC-GFP-REDD1 plasmid DNA into hFOB cells inhibited mammalian target of rapamycin (mTOR) and p21 expression and protected these cells from radiation-induced premature senescence (PS). The PS in irradiated hFOB cells were characterized by significant inhibition of clonogenicity, activation of senescence biomarker SA-ß-gal, and the senescence-associated cytokine secretory phenotype (SASP) after 4 or 8 Gy irradiation. Immunoprecipitation assays demonstrated that the stress response proteins p53 and nuclear factor κ B (NFkB) interacted with REDD1 in hFOB cells. Knockdown of NFkB or p53 gene dramatically suppressed REDD1 protein expression in these cells, indicating that REDD1 was regulated by both factors. Our data demonstrated that REDD1 is a protective factor in radiation-induced osteoblast cell premature senescence.