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Heme, as an essential cofactor and source of iron for cells, holds great promise in various areas, e.g., food and medicine. In this study, the model cyanobacteria Synechocystis sp. PCC6803 was used as a host for heme synthesis. The heme synthesis pathway and its competitive pathway were modified to obtain an engineered cyanobacteria with high heme production, and the total heme production of Synechocystis sp. PCC6803 was further enhanced by the optimization of the culture conditions and the enhancement of mixotrophic ability. The co-expression of hemC, hemF, hemH, and the knockout of pcyA, a key gene in the heme catabolic pathway, resulted in a 3.83-fold increase in the heme production of the wild type, while the knockout of chlH, a gene encoding a Mg-chelatase subunit and the key enzyme of the chlorophyll synthesis pathway, resulted in a 7.96-fold increase in the heme production of the wild type; further increased to 2.05 mg/L, its heme production was 10.25-fold that of the wild type under optimized mixotrophic culture conditions. Synechocystis sp. PCC6803 has shown great potential as a cell factory for photosynthetic carbon sequestration for heme production. This study provides novel engineering targets and research directions for constructing microbial cell factories for efficient heme production. [ABSTRACT FROM AUTHOR]

Background: Glucose-6-phosphate dehydrogenase (G6PD) plays an important role in vascular smooth muscle cell (VSMC) phenotypic switching, which is an early pathogenic event in various vascular remodeling diseases (VRDs). However, the underlying mechanism is not fully understood. Methods: An IP‒LC‒MS/MS assay was conducted to identify new binding partners of G6PD involved in the regulation of VSMC phenotypic switching under platelet-derived growth factor-BB (PDGF-BB) stimulation. Co-IP, GST pull-down, and immunofluorescence colocalization were employed to clarify the interaction between G6PD and voltage-dependent anion-selective channel protein 1 (VDAC1). The molecular mechanisms involved were elucidated by examining the interaction between VDAC1 and apoptosis-related biomarkers, as well as the oligomerization state of VDAC1. Results: The G6PD level was significantly elevated and positively correlated with the synthetic characteristics of VSMCs induced by PDGF-BB. We identified VDAC1 as a novel G6PD-interacting molecule essential for apoptosis. Specifically, the G6PD-NTD region was found to predominantly contribute to this interaction. G6PD promotes VSMC survival and accelerates vascular neointimal hyperplasia by inhibiting VSMC apoptosis. Mechanistically, G6PD interacts with VDAC1 upon stimulation with PDGF-BB. By competing with Bax for VDAC1 binding, G6PD reduces VDAC1 oligomerization and counteracts VDAC1–Bax-mediated apoptosis, thereby accelerating neointimal hyperplasia. Conclusion: Our study showed that the G6PD–VDAC1–Bax axis is a vital switch in VSMC apoptosis and is essential for VSMC phenotypic switching and neointimal hyperplasia, providing mechanistic insight into early VRDs. [ABSTRACT FROM AUTHOR]

The pseudocapacitive performance of MnO2 is intrinsically determined by its electronic structure, especially the spin state. However, the correlation between the electrochemical behavior and the spin state of electrode materials remains ill‐defined, and efficient spin regulation strategies for MnO2 are thus lacking. Herein, the study reports laser thermal shock of electrochemically deposited MnO2 for efficient spin regulation. The combined use of theoretical calculation and experimental investigation indicates that the thermal shock induces oxygen vacancy in MnO2 to reduce spin polarization and delocalize electron distribution. As a result, the electrical conductivity largely increases and the Na+ adsorption is reasonably optimized. By lasering an integrated electrode for only 83 s, a 54% increase of the specific capacitance is observed. For the first time, the pseudocapacitive capability of MnO2 is revealed by in situ electron paramagnetic resonance where the enhanced redox pair is correlated with evolution of Mn2+ during charge/discharge. Moreover, the commercial‐level mass‐loaded electrode also offers a decent performance enhancement after laser treatment, indicating the great prospect of this technology for real applications. This work innovatively correlates the pseudocapacitive performance of MnO2 with its spin state and offers a new avenue to optimize the electrochemical capability through spin regulation. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the epidemiology characteristics of Herpes simplex virus type 2 (HSV-2), Epstein-Barr virus (EBV) and Cytomegalovirus (CMV) infection in children from January 2018 to December 2023, in Nanjing, China., Methods: We conducted a retrospective analysis of 21,210, 49,494 and 32,457 outpatients and inpatients aged 1 day to 17 years who were subjected to the three herpesviruses (HSV-2, EBV, and CMV) nucleic acid testing from January 2018 to December 2023, respectively. Demographic information, laboratory findings, etc. were collected and analyzed. HSV-2, EBV and CMV nucleic acid testing were performed by real-time PCR., Results: The total rate of detection of the three herpesviruses for all specimens was 0.32% (67/21,210), 14.99% (7419/49,494), and 8.88% (2881/32,457), respectively. A declining trend in the incidence of viral infections over the years was observed for the three herpesviruses (all P <0.05). The detection rate for HSV-2, EBV, and CMV was highest among patients aged 1-3 years, 3-7 years, and 28 days to 1 year, respectively (all P <0.05). The presence of HSV-2 and CMV infection did not exhibit a discernible seasonal pattern, whereas EBV typically demonstrated an elevation during the summer and autumn., Conclusion: EBV and CMV were both prevalent among children in China, except for HSV-2. The annual prevalence of the three herpesviruses show decreasing trend from 2018 to 2023, and no difference in gender (except for EBV). EBV infections usually occur in the summer and autumn, whereas HSV-2 and CMV do not exhibit significant seasonality. The positivity rate of HSV-2 is highest in 1-3 years, EBV is highest in 3-7 years, and that of CMV is highest in 28 days to 1 year. Positive detection rates are higher in outpatients than in inpatients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wei, Zhang, Li, Liang, Cao and Ma.)