PRODH safeguards human naive pluripotency by limiting mitochondrial oxidative phosphorylation and reactive oxygen species production.

Naive human embryonic stem cells (hESCs) that resemble the pre-implantation epiblasts are fueled by a combination of aerobic glycolysis and oxidative phosphorylation, but their mitochondrial regulators are poorly understood. Here we report that, proline dehydrogenase (PRODH), a mitochondria-localized proline metabolism enzyme, is dramatically upregulated in naive hESCs compared to their primed counterparts. The upregulation of PRODH is induced by a reduction in c-Myc expression that is dependent on PD0325901, a MEK inhibitor routinely present in naive hESC culture media. PRODH knockdown in naive hESCs significantly promoted mitochondrial oxidative phosphorylation (mtOXPHOS) and reactive oxygen species (ROS) production that triggered autophagy, DNA damage, and apoptosis. Remarkably, MitoQ, a mitochondria-targeted antioxidant, effectively restored the pluripotency and proliferation of PRODH-knockdown naive hESCs, indicating that PRODH maintains naive pluripotency by preventing excessive ROS production. Concomitantly, PRODH knockdown significantly slowed down the proteolytic degradation of multiple key mitochondrial electron transport chain complex proteins. Thus, we revealed a crucial role of PRODH in limiting mtOXPHOS and ROS production, and thereby safeguarding naive pluripotency of hESCs.

Repurposing promethazine hydrochloride to inhibit biofilm formation against Burkholderia thailandensis.

Melioidosis is a severe infectious disease caused by Burkholderia pseudomallei, an intracellular pathogen with a high mortality rate and significant antibiotic resistance. The high mortality rate and resistance to antibiotics have drawn considerable attention from researchers studying melioidosis. This study evaluated the effects of various concentrations (75, 50, and 25 µg/mL) of promethazine hydrochloride (PTZ), a potent antihistamine, on biofilm formation and lipase activity after 24 h of exposure to B. thailandensis E264. A concentration-dependent decrease in both biofilm biomass and lipase activity was observed. RT-PCR analysis revealed that PTZ treatment not only made the biofilm structure loose but also reduced the expression of btaR1, btaR2, btaR3, and scmR. Single gene knockouts of quorum sensing (QS) receptor proteins (∆btaR1, ∆btaR2, and ∆btaR3) were successfully constructed. Deletion of btaR1 affected biofilm formation in B. thailandensis, while deletion of btaR2 and btaR3 led to reduced lipase activity. Molecular docking and biological performance results demonstrated that PTZ inhibits biofilm formation and lipase activity by suppressing the expression of QS-regulated genes. This study found that repositioning PTZ reduced biofilm formation in B. thailandensis E264, suggesting a potential new approach for combating melioidosis.

Metabolome and Genome Analysis of a Novel Endophytic Fungus Aureobasidium pullulans KB3: Discovery of Polyketones and Polyketone Biosynthesis Pathway.

Endophytic fungi associated with plants may contain undiscovered bioactive compounds. Under standard laboratory conditions, most undiscovered compounds are inactive, whereas their production could be stimulated under different cultivation conditions. In this study, six endophytic fungi were isolated from the bark of Koelreuteria paniculata in Quancheng Park, Jinan City, Shandong Province, one of which was identified as a new subspecies of Aureobasidium pullulans, named A. pullulans KB3. Additionally, metabolomic tools were used to screen suitable media for A. pullulans KB3 fermentation, and the results showed that peptone dextrose medium (PDM) was more beneficial to culture A. pullulans KB3 for isolation of novel compounds. Sphaerolone, a polyketone compound, was initially isolated from A. pullulans KB3 via scaled up fermentation utilizing PDM. Additionally, the whole-genome DNA of A. pullulans KB3 was sequenced to facilitate compound isolation and identify the biosynthesis gene clusters (BGCs). This study reports the multi-omics (metabolome and genome) analysis of A. pullulans KB3, laying the foundation for discovering novel compounds of silent BGCs and identifying their biosynthesis pathway.

Sesquiterpenes from Wikstroemia lungtzeensis with anti-neuroinflammatory effects.

An anti-neuroinflammatory activities-guided phytochemical research of Wikstroemia lungtzeensis was performed for the first time. Three undescribed carotane-type sesquiterpenes, excoecafolinols C-E (1-3), and nine known sesquiterpene derivatives were isolated from the effective ethyl acetate extract of W. lungtzeensis. Their structures were determined based on multiple spectroscopic techniques and electronic circular dichroism (ECD) spectra. Furthermore, the anti-neuroinflammatory activities of the identified compounds were evaluated in lipopolysaccharide-stimulated BV-2 cells. Among them, six components (1, 2, 4, 7, 11, 12) exhibited significant inhibitory effects on nitric oxide (NO) production, with IC50 values ranging from 10.48 to 49.41 µM (positive control minocycline, IC50 53.20 µM). Carotane-type sesquiterpenes (1, 2, 4) with high content and significant inhibitory effects, are considered to be major active ingredients of W. lungtzeensis, which might serve as potential therapeutic agents for neurodegenerative diseases.

Research Progress on Biological Evidence Identification in Fire Scenes.

Biological evidence is relatively common evidence in criminal cases, and it has strong probative power because it carries DNA information for individual identification. At the scene of fire-related cases, the complex thermal environment, the escape of trapped people, the firefighting and rescue operations, and the deliberate destruction of criminal suspects will all affect the biological evidence in the fire scene. Scholars at home and abroad have explored and studied the effectiveness of biological evidence identification in fire scenes, and found that the blood stains, semen stains, bones, etc. are the main biological evidence which can be easily recovered with DNA in fire scenes. In order to analyze the research status and development trend of biological evidence in fire scenes, this paper systematically sorts out the relevant research, mainly including the soot removal technology, appearance method of typical biological evidence, and possibility of identifying other biological evidence. This paper also prospects the next step of research direction, in order to provide reference for the identification of biological evidence and improve the value of biological evidence in fire scenes.

Forensic Identification and Evaluation of 25 Obstetric Brachial Plexus Palsy Medical Damage Cases.

OBJECTIVES: To analyze the high risk factors of obstetric brachial plexus palsy (OBPP), and to explore how to evaluate the relationship between fault medical behavior and OBPP in the process of medical damage forensic identification. METHODS: A retrospective analysis was carried out on 25 cases of medical damage liability disputes related to OBPP from 2017 to 2021 in Beijing Fayuan Judicial Science Evidence Appraisal Center. The shortcomings of hospitals in birth weight assessment, delivery mode selection, labor process observation and shoulder dystocia management, and the causal relationship between them and the damage consequences of the children were summarized. RESULTS: Fault medical behavior was assessed as the primary cause in 2 cases, equal cause in 10 cases, secondary cause in 8 cases, minor cause in 1 case, no causal relationship in 1 case, and unclear causal force in 3 cases. CONCLUSIONS: In the process of forensic identification of OBPP, whether medical behaviors fulfill diagnosis and treatment obligations should be objectively analyzed from the aspects of prenatal evaluation, delivery mode notification, standardized use of oxytocin, standard operation of shoulder dystocia, etc. Meanwhile, it is necessary to fully consider the objective risk of different risk factors and the difficulty of injury prevention, and comprehensively evaluate the causal force of fault medical behavior in the damage consequences.

Inhibition of the ATR-DNAPKcs-RB axis drives G1/S-phase transition and sensitizes triple-negative breast cancer (TNBC) to DNA holliday junctions.

Targeting the DNA damage response (DDR) is a promising strategy in oncotherapy, as most tumor cells are sensitive to excess damage due to their repair defects. Ataxia telangiectasia mutated and RAD3-related protein (ATR) is a damage response signal transduction sensor, and its therapeutic potential in tumor cells needs to be precisely investigated. Herein, we identified a new axis that could be targeted by ATR inhibitors to decrease the DNA-dependent protein kinase catalytic subunit (DNAPKcs), downregulate the expression of the retinoblastoma (RB), and drive G1/S-phase transition. Four-way DNA Holliday junctions (FJs) assembled in this process could trigger S-phase arrest and induce lethal chromosome damage in RB-positive triple-negative breast cancer (TNBC) cells. Furthermore, these unrepaired junctions also exerted toxic effects to RB-deficient TNBC cells when the homologous recombination repair (HRR) was inhibited. This study proposes a precise strategy for treating TNBC by targeting the DDR and extends our understanding of ATR and HJ in tumor treatment.

The Acetic Acid Produced by Lactobacillus Species Regulates Immune Function to Alleviate PEDV Infection in Piglets.

Porcine epidemic diarrhea virus (PEDV) infection results in significant mortality among newborn piglets, leading to substantial economic setbacks in the pig industry. Short-chain fatty acids (SCFA), the metabolites of intestinal probiotics, play pivotal roles in modulating intestinal function, enhancing the intestinal barrier, and bolstering immune responses through diverse mechanisms. The protective potential of Lactobacillus delbrueckii, Lactobacillus johnsonii, and Lactococcus lactis was first noted when administered to PEDV-infected piglets. Histological evaluations, combined with immunofluorescence studies, indicated that piglets receiving L. lactis displayed less intestinal damage, with diminished epithelial cell necrosis and milder injury levels. Differences in immunofluorescence intensity revealed a significant disparity in antigen content between the L. lactis and PEDV groups, suggesting that L. lactis might suppress PEDV replication, the intestine. We then assessed short-chain fatty acid content through targeted metabolomics, finding that acetate levels markedly varied from other groups. This protective impact was confirmed by administering acetate to PEDV-infected piglets. Data suggested that piglets receiving acetate exhibited resistance to PEDV. Flow cytometry analyses were conducted to evaluate the expression of innate and adaptive immune cells in piglets. Sodium acetate appeared to bolster innate immune defenses against PEDV, marked by elevated NK cell and macrophage counts in mesenteric lymph nodes, along with increased NK cells in the spleen and macrophages in the bloodstream. Acetic acid was also found to enhance the populations of CD8+ IFN-γ T cells in the blood, spleen, and mesenteric lymph, CD4+ IFN-γ T cells in mesenteric lymph nodes and spleen, and CD4+ IL-4+T cells in the bloodstream. Transcriptome analyses were carried out on the jejunal mucosa from piglets with PEDV-induced intestinal damage and from healthy counterparts with intact barriers. Through bioinformatics analysis, we pinpointed 189 significantly upregulated genes and 333 downregulated ones, with the PI3K-AKT, ECM-receptor interaction, and pancreatic secretion pathways being notably enriched. This transcriptomic evidence was further corroborated by western blot and qPCR. Short-chain fatty acids (SCFA) were found to modulate G protein-coupled receptor 41 (GPR41) and 43 (GPR43) in porcine intestinal epithelial cells (IPEC-J2). Post-acetic acid exposure, there was a notable upsurge in the ZO-1 barrier protein expression in IPEC-J2 compared to the unexposed control group (WT), while GPR43 knockdown inversely affected ZO-1 expression. Acetic acid amplified the concentrations of phosphorylated PI3K and AKT pivotal components of the PI3K/AKT pathway. Concurrently, the co-administration of AKT agonist SC79 and PI3K inhibitor LY294002 revealed acetic acid's role in augmenting ZO-1 expression via the P13K/AKT signaling pathway. This study demonstrates that acetic acid produced by Lactobacillus strains regulates intestinal barrier and immune functions to alleviate PEDV infection. These findings provide valuable insights for mitigating the impact of PEDV in the pig industry.

Hepatic arterial infusion chemotherapy and trastuzumab in gastric cancer with liver metastases: a case report.

Background: Gastric cancer is a common cancer worldwide and is responsible for over one million new cases in 2020 and an estimated 769,000 deaths, ranking fifth for incidence and fourth for mortality globally. Incidence rates are highest in Eastern Asia and Eastern Europe. Gastric cancer is highly heterogeneous and progresses rapidly. The prognosis of gastric cancer with liver metastases is poor, and clinical treatment remains challenging. Human epidermal growth factor receptor 2 (HER2) positivity is correlated to a bad prognosis for gastric cancer. Trastuzumab combined with systemic chemotherapy is the preferred treatment for HER2-positive advanced gastric cancer. However, intravenous chemotherapy has severe systemic toxicity, which reduces the local drug concentration and tumor uptake rate, and the effect is unsatisfactory. Case summary: We reported a 66-year-old patient with HER2-positive advanced gastric cancer with jaundice due to multiple liver metastases, after 6 cycles of trastuzumab combined with hepatic arterial infusion chemotherapy (HAIC), the tumor retracted significantly, the jaundice subsided, and the patient recovered well. The patient achieved disease control with an intensive regimen followed by less toxic maintenance therapy. Trastuzumab combined with capecitabine maintenance therapy followed up for more than 16 months. Conclusion: HAIC plus trastuzumab may be a tolerable treatment option for patients with severe liver metastases from HER2-positive gastric cancer to achieve local control and prolong survival.