Stress-Induced Glucocorticoid Release Upregulates Uncoupling Protein-2 Expression and Enhances Resistance to Endotoxin-Induced Lethality.

OBJECTIVE: Although psychological and/or physiological stress has been well documented to influence immune responses, the precise mechanism for immunomodulation remains to be elucidated. The present work describes the role of the hypothalamic-pituitary-adrenal (HPA) axis in the mechanism of stress-mediated enhanced-resistance to lethality after lipopolysaccharide (LPS) injection. METHODS/RESULTS: Preconditioning with restraint stress (RS) resulted in enhanced activation of the HPA axis in response to LPS injection and suppressed LPS-induced release of proinflammatory cytokines and nitric oxide metabolites. Melanocortin 2 receptor-deficient mice (MC2R(-/-)) failed to increase plasma levels of glucocorticoids in response to LPS injection, and exhibited high sensitivity to LPS-induced lethality with enhanced release of proinflammatory cytokines as compared with MC2R(+/-) mice. Real-time PCR analysis revealed that RS induced upregulation of uncoupling protein-2 (UCP2) in macrophages in the lung and the liver of MC2R(+/-), but not of MC2R(-/-), mice. In addition, RS increased UCP2-dependent uncoupling activity of isolated mitochondria from the liver of MC2R(+/-), but not of MC2R(-/-), mice. In vitro study revealed that corticosterone and dexamethasone directly increased UCP2 expression in mouse RAW 264.7 macrophages and suppressed the generation of LPS-induced mitochondrial reactive oxygen species (ROS) and TNF-α production. Knockdown of UCP2 by small interfering RNA blunted the dexamethasone action for suppressing LPS-induced mitochondrial ROS and TNF-α production. CONCLUSION: The present work suggests that RS enhances activation of the HPA axis to release glucocorticoids and upregulation of UCP2 in macrophages, thereby increasing the resistance to endotoxin-induced systemic inflammation and death.

Nanomechanical properties and molecular structures of in vitro mineralized tissues on anodically-oxidized titanium surfaces.

The biomechanical stability of mineralized tissues at the interface between implant surface and bone tissue is of critical importance. Anodically oxidized titanium prepared in a chloride solution results in enhanced mineralization of adherent osteoblasts and has antimicrobial activity against oral microorganisms. We evaluated the nanomechanical properties and molecular structures of the in vitro mineralized tissues developing around anodically oxidized titanium surfaces with and without preparation in chloride solution. Anodically oxidized titanium surfaces showed superior osteogenic gene expressions than those of thermally oxidized and bare titanium surfaces. Preparation of anodically oxidized titanium in chloride enhanced the production of mineralized tissue around it. However, the mineralized tissue around anodically oxidized titanium prepared without chloride had increased mineral:matrix and cross-linking ratios, resulting in higher hardness and lower elasticity. FROM THE CLINICAL EDITOR: In this study anodically oxidized titanium was used to enhance the biomechanical stability of mineralized tissues at the implant surface -- bone tissue interface. The mineralized tissue around anodically oxidized titanium prepared without chloride had increased mineral:matrix and cross-linking ratios, resulting in higher hardness and lower elasticity.

Transmission Cycle of Shimokoshi-Type Orientia tsutsugamushi in Shimane Prefecture, Japan.

To demonstrate the transmission cycle of Shimokoshi-type Orientia tsutsugamushi in Shimane Prefecture, field rodents were captured from areas where four human infections caused by the pathogen have been reported. The rodents were investigated for the transmission cycle of the pathogen based on the pathogen's genome, antibodies against the pathogen, and the vector of the pathogen (Leptotrombidium palpale). In addition, the vector was captured from the soil in the study area. A total of 44 rodents were captured. No O. tsutsugamushi DNA was detected in the blood or spleen samples by real-time polymerase chain reaction. However, a specific antibody against the pathogen was detected in 2 out of 44 (4.5%) rodents using the indirect immunoperoxidase method, indicating the presence of the pathogen in the study area. Although 29 L. palpale were identified, DNA detection was not performed because of the insufficient number of vectors, based on the DNA detection rate in previous studies. However, the identification of the vector, as well as the specific antibody in rodents, suggests the presence of the transmission cycle of Shimokoshi-type O. tsutsugamushi in Shimane Prefecture.

Impact of acute coronary syndrome on early in-stent neoatherosclerosis as shown by optical coherence tomography.

Background: Patients with acute coronary syndrome (ACS) have a higher risk of requiring target vessel revascularisation after percutaneous coronary intervention (PCI) than patients with stable angina. Neoatherosclerosis is a significant risk factor for very late stent thrombosis, and the presence of neoatherosclerosis is independently associated with major adverse cardiac events. Aims: In this study, we used optical coherence tomography (OCT) to investigate the impact of ACS on neoatherosclerosis within 1 year after PCI. Methods: We investigated 102 patients (122 lesions) who had undergone PCI using a second-generation drug-eluting stent (DES) from March 2017 to November 2020 and were followed up with OCT within 1 year. The patients were categorised into the ACS group or non-ACS group according to their clinical findings at the time of target lesion treatment. We used OCT to investigate the presence of neoatherosclerosis. Results: The ACS group comprised 23 (22.5%) patients. There were no differences in the patients' clinical characteristics between the groups. The total stent length tended to be shorter in the ACS group than in the non-ACS group (24 mm vs 32 mm, respectively; p=0.09), but this difference was not statistically significant. The median duration from PCI was 290 days. Neoatherosclerosis was more frequent in ACS lesions (39% vs 4%; p<0.01), and implantation of a DES in ACS lesions was an independent predictor of neoatherosclerosis occurrence (odds ratio 9.70; p<0.01). Conclusions: This observational study using OCT indicates that stenting for ACS lesions is associated with early in-stent neoatherosclerosis.

Lysyl oxidase like-2 reinforces unsatisfactory ossification induced by bone morphogenetic protein-2: relating nanomechanical properties and molecular changes.

Bone morphogenetic protein-2 (BMP2) is among the most popular anabolic agents and substantially increase bone volume related to enhanced osteoblast differentiation. Here we demonstrate a remarkable deterioration in the nanomechanical properties of mineralized tissue induced from osteoblasts solely by the function of BMP2. Mineralized tissue of primary osteoblasts cultured with BMP2 shows molecular features of both bone and cartilage, but depletion of lysyl oxidase family members leads to poor nanomechanical properties of the mineralized tissue. Lysyl oxidase like-2 supplementation reinforces the inferior mineralized tissue induced from osteoblasts by BMP2 through intermolecular cross-linking of type II or type X collagen-rich extracellular matrix. This may also mimic a consolidation of bone fracture gaps, despite the fact that the distribution of the bone properties in such microenvironments has been poorly elucidated. These findings confirm the importance of testing newly induced bone down to the microscale and nanoscale in bone tissue engineering. FROM THE CLINICAL EDITOR: Bone morphogenetic protein-2 is known to substantially increase bone volume related to enhanced osteoblast differentiation; however, this team of investigators report a remarkable deterioration in the nanomechanical properties of mineralized tissue induced from osteoblasts solely by the function of BMP2.

Complete Genome Sequence of Corynebacterium ulcerans Strain TSU-28, Harboring Two Diphtheria Toxin Genes, Isolated from a Patient with Diphtheria-Like Symptoms.

Diphtheria toxin-producing Corynebacterium ulcerans is an emerging zoonotic pathogen that causes severe disease in humans. Here, we report the complete genome sequence of C. ulcerans strain TSU-28, harboring two diphtheria toxin genes, which was isolated from the throat of a patient with diphtheria-like symptoms in 2019 in Japan.

Rapid detection and discrimination of potentially toxigenic Corynebacterium ulcerans and Corynebacterium pseudotuberculosis by multiplex real-time PCR and amplicon melting curve analysis.

We developed a multiplex real-time PCR assay with amplicon melting curve analysis to rapidly discriminate Corynebacterium ulcerans from Corynebacterium pseudotuberculosis and detect the bacterial diphtheria toxin gene. This assay should be a valuable tool for identification of potentially toxigenic C. ulcerans.

Development of an RT-LAMP Assay for the Rapid Detection of SFTS Virus.

Detection of severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) during the early phase of the disease is important for appropriate treatment, infection control, and prevention of further transmission. The reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a nucleic acid amplification method that amplifies the target sequence under isothermal conditions. Here, we developed an RT-LAMP with a novel primer/probe set targeting a conserved region of the SFTSV L segment after extraction of viral RNA (standard RT-LAMP). Both the Chinese and Japanese SFTSV strains, including various genotypes, were detected by the standard RT-LAMP. We also performed RT-LAMP using the same primer/probe set but without the viral RNA extraction step (called simplified RT-LAMP) and evaluated the diagnostic efficacy. The sensitivity and specificity of the simplified RT-LAMP were 84.9% (45/53) and 89.5% (2/19), respectively. The simplified RT-LAMP can detect SFTSV in human sera containing >103.5 copies/mL viral RNA. The two RT-LAMP positive but quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) negative samples were positive in the conventional RT-PCR, suggesting that there was no false positive reaction in the RT-LAMP. Both the standard and simplified RT-LAMP are useful for detecting the SFTSV genome in patients during the early phase of the disease.