Neutralization of CX3CL1 Attenuates TGF-ß-Induced Fibroblast Differentiation Through NF-κB Activation and Mitochondrial Dysfunction in Airway Fibrosis.

BACKGROUND: Severe asthma, characterized by inflammation and airway remodeling, involves fibroblast differentiation into myofibroblasts expressing α-SMA. This process leads to the production of fibronectin and connective tissue growth factor (CTGF), driven by factors such as transforming growth factor (TGF)-ß. Furthermore, the persistent presence of myofibroblasts is associated with resistance to apoptosis and mitochondrial dysfunction. The chemokine (C-X3-C motif) ligand 1 (CX3CL1) plays a role in tissue fibrosis. However, it is currently unknown whether neutralization of CX3CL1 decreases TGF-ß-induced fibroblast differentiation and mitochondrial dysfunction in normal human lung fibroblasts (NHLFs). METHODS: CX3CL1/C-X3-C motif chemokine receptor 1 (CX3CR1), CX3CL1 was analyzed by immunofluorescence (IF) or immunohistochemical (IHC) staining of ovalbumin-challenged mice. CX3CL1 release was detected by ELISA. TGF-ß-induced CTGF, fibronectin, and α-SMA expression were evaluated in NHLFs following neutralization of CX3CL1 (TP213) treatment for the indicated times by Western blotting or IF staining. Mitochondrion function was detected by a JC-1 assay and seahorse assay. Cell apoptosis was observed by a terminal uridine nick-end labeling (TUNEL) assay. RESULTS: An increase in CX3CL1 expression was observed in lung tissues from mice with ovalbumin-induced asthma by IF staining. CX3CR1 was increased in the subepithelial layer of the airway by IHC staining. Moreover, CX3CR1 small interfering (si)RNA downregulated TGF-ß-induced CTGF and fibronectin expression in NHLFs. CX3CL1 induced CTGF and fibronectin expression in NHLFs. TGF-ß-induced CX3CL1 secretion from NHLFs. Furthermore, TP213 decreased TGF-ß-induced CTGF, fibronectin, and α-SMA expression in NHLFs. Mitochondrion-related differentially expressed genes (DEGs) were examined after CX3CL1 neutralization in TGF-ß-treated NHLFs. TP213 alleviated TGF-ß-induced mitochondrial dysfunction and apoptosis resistance in NHLFs. CX3CL1 induced p65, IκBα, and IKKα phosphorylation in a time-dependent manner. Furthermore, CX3CL1-induced fibronectin expression and JC-1 monomer were decreased by p65 siRNA. TP213 reduced TGF-ß-induced p65 and α-SMA expression in NHLFs. CONCLUSIONS: These findings suggest that neutralizing CX3CL1 attenuates lung fibroblast activation and mitochondrial dysfunction. Understanding the impacts of CX3CL1 neutralization on fibroblast mitochondrial function could contribute to the development of therapeutic strategies for managing airway remodeling in severe asthma.

USP24-i-101 targeting of USP24 activates autophagy to inhibit drug resistance acquired during cancer therapy.

Drug resistance in cancer therapy is the major reason for poor prognosis. Addressing this clinically unmet issue is important and urgent. In this study, we found that targeting USP24 by the specific USP24 inhibitors, USP24-i and its analogues, dramatically activated autophagy in the interphase and mitotic periods of lung cancer cells by inhibiting E2F4 and TRAF6, respectively. USP24 functional knockout, USP24C1695A, or targeting USP24 by USP24-i-101 inhibited drug resistance and activated autophagy in gefitinib-induced drug-resistant mice with doxycycline-induced EGFRL858R lung cancer, but this effect was abolished after inhibition of autophagy, indicating that targeting USP24-mediated induction of autophagy is required for inhibition of drug resistance. Genomic instability and PD-L1 levels were increased in drug resistant lung cancer cells and were inhibited by USP24-i-101 treatment or knockdown of USP24. In addition, inhibition of autophagy by bafilomycin-A1 significantly abolished the effect of USP24-i-101 on maintaining genomic integrity, decreasing PD-L1 and inhibiting drug resistance acquired in chemotherapy or targeted therapy. In summary, an increase in the expression of USP24 in cancer cells is beneficial for the induction of drug resistance and targeting USP24 by USP24-i-101 optimized from USP24-i inhibits drug resistance acquired during cancer therapy by increasing PD-L1 protein degradation and genomic stability in an autophagy induction-dependent manner.

First-in-Class Dual EZH2-HSP90 Inhibitor Eliciting Striking Antiglioblastoma Activity In Vitro and In Vivo.

Structural analysis of tazemetostat, an FDA-approved EZH2 inhibitor, led us to pinpoint a suitable site for appendage with a pharmacophoric fragment of second-generation HSP90 inhibitors. Resultantly, a magnificent dual EZH2/HSP90 inhibitor was pinpointed that exerted striking cell growth inhibitory efficacy against TMZ-resistant Glioblastoma (GBM) cell lines. Exhaustive explorations of chemical probe 7 led to several revelations such as (i) compound 7 increased apoptosis/necrosis-related gene expression, whereas decreased M phase/kinetochore/spindle-related gene expression as well as CENPs protein expression in Pt3R cells; (ii) dual inhibitor 7 induced cell cycle arrest at the M phase; (iii) compound 7 suppressed reactive oxygen species (ROS) catabolism pathway, causing the death of TMZ-resistant GBM cells; and (iv) compound 7 elicited substantial in vivo anti-GBM efficacy in experimental mice xenografted with TMZ-resistant Pt3R cells. Collectively, the study results confirm the potential of dual EZH2-HSP90 inhibitor 7 as a tractable anti-GBM agent.

Development of a prediction model for emergency medical service witnessed traumatic out-of-hospital cardiac arrest: A multicenter cohort study.

BACKGROUND/PURPOSE: To develop a prediction model for emergency medical technicians (EMTs) to identify trauma patients at high risk of deterioration to emergency medical service (EMS)-witnessed traumatic cardiac arrest (TCA) on the scene or en route. METHODS: We developed a prediction model using the classical cross-validation method from the Pan-Asia Trauma Outcomes Study (PATOS) database from 1 January 2015 to 31 December 2020. Eligible patients aged ≥18 years were transported to the hospital by the EMS. The primary outcome (EMS-witnessed TCA) was defined based on changes in vital signs measured on the scene or en route. We included variables that were immediately measurable as potential predictors when EMTs arrived. An integer point value system was built using multivariable logistic regression. The area under the receiver operating characteristic (AUROC) curve and Hosmer-Lemeshow (HL) test were used to examine discrimination and calibration in the derivation and validation cohorts. RESULTS: In total, 74,844 patients were eligible for database review. The model comprised five prehospital predictors: age <40 years, systolic blood pressure <100 mmHg, respiration rate >20/minute, pulse oximetry <94%, and levels of consciousness to pain or unresponsiveness. The AUROC in the derivation and validation cohorts was 0.767 and 0.782, respectively. The HL test revealed good calibration of the model (p = 0.906). CONCLUSION: We established a prediction model using variables from the PATOS database and measured them immediately after EMS personnel arrived to predict EMS-witnessed TCA. The model allows prehospital medical personnel to focus on high-risk patients and promptly administer optimal treatment.

NCI677397 targeting USP24-mediated induction of lipid peroxidation induces ferroptosis in drug-resistant cancer cells.

Cancer represents a profound challenge to healthcare systems and individuals worldwide. The development of multiple drug resistance is a major problem in cancer therapy and can result in progression of the disease. In our previous studies, we developed small-molecule inhibitors targeting ubiquitin-specific peptidase 24 (USP24) to combat drug-resistant lung cancer. Recently, we found that the USP24 inhibitor NCI677397 induced ferroptosis, a type of programmed cell death, in drug-resistant cancer cells by increasing lipid reactive oxygen species (ROS) levels. In the present study, we investigated the molecular mechanisms and found that the targeting of USP24 by NCI677397 increased gene expression of most lipogenesis-related genes, such as acyl-CoA synthetase long-chain family member 4 (ACSL4), and activated autophagy. In addition, the activity of several antioxidant enzymes, such as glutathione peroxidase 4 (GPX4) and dihydrofolate reductase (DHFR), was inhibited by NCI677397 treatment via an increase in protein degradation, thereby inducing lipid ROS production and lipid peroxidation. In summary, we demonstrated that NCI677397 induced a marked increase in lipid ROS levels, subsequently causing lipid peroxidation and leading to the ferroptotic death of drug-resistant cancer cells. Our study provides new insights into the clinical use of USP24 inhibitors as ferroptosis inducers (FINs) to block drug resistance during chemotherapy.

Spontaneous Pneumocephalus: A Case Report with a Literature Review.

BACKGROUND: Pneumocephalus is defined as gas in the intracranial space. Common causes include head trauma, surgery, and diagnostic/therapeutic procedures resulting from the direct disruption of the dura. Spontaneous or nontraumatic pneumocephalus is an uncommon condition, often caused by infection, either due to insidious disruption of the dura or gas-forming pathogens. CASE REPORT: Herein, we report a rare case of spontaneous pneumocephalus associated with meningitis in a patient who received conservative treatment without surgical intervention. Blood culture revealed group A streptococcus. The pneumocephalus subsided gradually with antibiotic treatment, and no neurological deficits remained. A follow-up brain computed tomography scan showed the absence of pneumocephalus, but it showed progressive hydrocephalus. The patient was discharged on the 21st day of hospitalization. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Spontaneous pneumocephalus associated with meningitis is rare. It should always raise the suspicion of meningitis and prompt suitable treatment. Emergency physicians should always be vigilant for this particular possibility on brain computed tomography.

Effect of crew ratio of advanced life support-trained personnel on patients with out-of-hospital cardiac arrest: A systematic review and meta-analysis.

BACKGROUND/PURPOSE: This review aimed to investigate the effect of crew ratios of on-scene advanced life support (ALS)-trained personnel on patients with out-of-hospital cardiac arrest (OHCA). METHODS: We systematically searched PubMed, Ovid EMBASE, and the Cochrane Central Register of Controlled Trials databases from the inception date until September 30, 2022, for eligible studies. Two reviewers independently screened the studies for relevance, extracted data, and quality. We compared the effect of the ratio of on-scene ALS-trained personnel >50 % to those with a ratio ≤50 % among prehospital personnel on the clinical outcomes of OHCA patients. The primary outcome was survival-to-discharge and secondary outcomes were any return of spontaneous circulation (ROSC), sustained ROSC (≥2 h), and favourable neurological outcome at discharge (cerebral performance category scores: 1 or 2). Pooled odds ratios (ORs) were calculated, and the certainty of evidence was assessed. RESULTS: From 10,864 references, we identified four non-randomised studies, including 16,475 patients. Two studies were performed in Japan and two in Taiwan. There were significant differences in survival-to-discharge (OR: 1.24, 95 % confidence interval [CI]: 1.07-1.44, I2: 7 %), any ROSC (OR:1.22, 95 % CI: 1.04-1.43, I2: 74 %) and sustained ROSC (OR: 1.39, 95 % CI: 1.16-1.65, I2: 40 %), but insignificant differences in favourable neurological outcome at discharge. The overall certainty of evidence was rated as very low for all outcomes. CONCLUSION: Prehospital ALS care with a ratio of on-scene ALS-trained personnel >50 % could improve OHCA patient outcomes than crew ratios ≤50 %. Further studies are required to reach a robust conclusion.

Home Dust Mites Promote MUC5AC Hyper-Expression by Modulating the sNASP/TRAF6 Axis in the Airway Epithelium.

House dust mites (HDMs) are a common source of respiratory allergens responsible for allergic asthma and innate immune responses in human diseases. Since HDMs are critical factors in the triggering of allergen-induced airway mucosa from allergic asthma, we aimed to investigate the mechanisms of Toll-like receptors (TLR) in the signaling of the HDM extract that is involved in mucus hypersecretion and airway inflammation through the engagement of innate immunity. Previously, we reported that the somatic nuclear autoantigenic sperm protein (sNASP)/tumor necrosis factor receptor-associated factor 6 (TRAF6) axis controls the initiation of TLRs to maintain the homeostasis of the innate immune response. The present study showed that the HDM extract stimulated the biogenesis of Mucin 5AC (MUC5AC) in bronchial epithelial cells via the TLR2/4 signaling pathway involving MyD88 and TRAF6. Specifically, sNASP binds to TRAF6 in unstimulated bronchial epithelial cells to prevent the activation of TRAF6-depenedent kinases. Upon on HDMs' stimulation, sNASP is phosphorylated, leading to the activation of TRAF6 downstream of the p38 MAPK and NF-κB signaling pathways. Further, NASP-knockdown enhanced TRAF6 signaling and MUC5AC biogenesis. In the HDM-induced mouse asthma model, we found that the HDM extract promoted airway hyperresponsiveness (AHR), MUC5AC, and allergen-specific IgE production as well as IL-5 and IL-13 for recruiting inflammatory cells. Treatment with the PEP-NASP peptide, a selective TRAF6-blocking peptide, ameliorated HDM-induced asthma in mice. In conclusion, this study indicated that the sNASP/TRAF6 axis plays a regulatory role in asthma by modulating mucus overproduction, and the PEP-NASP peptide might be a potential target for asthma treatment.

Characterization of the Oxazinomycin Biosynthetic Pathway Revealing the Key Role of a Nonheme Iron-Dependent Mono-oxygenase.

Oxazinomycin is a C-nucleoside natural product with antibacterial and antitumor activities. In addition to the characteristic C-glycosidic linkage shared with other C-nucleosides, oxazinomycin also features a structurally unusual 1,3-oxazine moiety, the biosynthesis of which had previously been unknown. Herein, complete in vitro reconstitution of the oxazinomycin biosynthetic pathway is described. Construction of the C-glycosidic bond between ribose 5-phosphate and an oxygen-labile pyridine heterocycle is catalyzed by the C-glycosidase OzmB and involves formation of an enzyme-substrate Schiff base intermediate. The DUF4243 family protein OzmD is shown to catalyze oxygen insertion and rearrangement of the pyridine C-nucleoside intermediate to generate the 1,3-oxazine moiety along with the elimination of cyanide. Spectroscopic analysis and mutagenesis studies indicate that OzmD is a novel nonheme iron-dependent enzyme in which the catalytic iron center is likely coordinated by four histidine residues. These results provide the first example of 1,3-oxazine biosynthesis catalyzed by an unprecedented iron-dependent mono-oxygenase.

A functional circuit formed by the autonomic nerves and myofibroblasts controls mammalian alveolar formation for gas exchange.

Alveolar formation increases the surface area for gas exchange. A molecular understanding of alveologenesis remains incomplete. Here, we show that the autonomic nerve and alveolar myofibroblast form a functional unit in mice. Myofibroblasts secrete neurotrophins to promote neurite extension/survival, whereas neurotransmitters released from autonomic terminals are necessary for myofibroblast proliferation and migration, a key step in alveologenesis. This establishes a functional link between autonomic innervation and alveolar formation. We also discover that planar cell polarity (PCP) signaling employs a Wnt-Fz/Ror-Vangl cascade to regulate the cytoskeleton and neurotransmitter trafficking/release from the terminals of autonomic nerves. This represents a new aspect of PCP signaling in conferring cellular properties. Together, these studies offer molecular insight into how autonomic activity controls alveolar formation. Our work also illustrates the fundamental principle of how two tissues (e.g., nerves and lungs) interact to build alveoli at the organismal level.

Allopregnanolone suppresses glioblastoma survival through decreasing DPYSL3 and S100A11 expression.

Allopregnanolone (allo) is a physiological regulator of neuronal activity that treats multiple neurological disorders. Allo penetrates the blood-brain barrier with very high efficiency, implying that allo can treat CNS-related diseases, including glioblastoma (GBM), which always recurs after standard therapy. Hence, this study aimed to determine whether allo has a therapeutic effect on GBM. We found that allo enhanced temozolomide (TMZ)-suppressed cell survival and proliferation of TMZ-resistant cells. In particular, allo enhanced TMZ-inhibited cell migration and TMZ-induced apoptosis. Additionally, allo strongly induced DNA damage characterized by γH2Ax. Furthermore, quantitative proteomic analysis, iTRAQ, showed that allo significantly decreased the levels of DPYSL3, S100A11, and S100A4, reflecting the poor prognosis of patients with GBM confirmed by differential gene expression and survival analysis. Moreover, single-cell RNA-Seq revealed that S100A11, expressed in malignant cells, oligodendrocytes, and macrophages, was significantly associated with immune cell infiltration. Furthermore, overexpression of DPYSL3 or S100A11 prevented allo-induced cell death. In conclusion, allo suppresses GBM cell survival by decreasing DPYSL3/S100A11 expression and inducing DNA damage.

Estradiol-mediated inhibition of Sp1 decreases miR-3194-5p expression to enhance CD44 expression during lung cancer progression.

BACKGROUND: Sp1, an important transcription factor, is involved in the progression of various cancers. Our previous studies have indicated that Sp1 levels are increased in the early stage of lung cancer progression but decrease during the late stage, leading to poor prognosis. In addition, estrogen has been shown to be involved in lung cancer progression. According to previous studies, Sp1 can interact with the estrogen receptor (ER) to coregulate gene expression. The role of interaction between Sp1 and ER in lung cancer progression is still unknown and will be clarified in this study. METHODS: The clinical relevance between Sp1 levels and survival rates in young women with lung cancer was studied by immunohistochemistry. We validated the sex dependence of lung cancer progression in EGFRL858R-induced lung cancer mice. Wound healing assays, chamber assays and sphere formation assays in A549 cells, Taxol-induced drug-resistant A549 (A549-T24) and estradiol (E2)-treated A549 (E2-A549) cells were performed to investigate the roles of Taxol and E2 in lung cancer progression. Luciferase reporter assays, immunoblot and q-PCR were performed to evaluate the interaction between Sp1, microRNAs and CD44. Tail vein-injected xenograft experiments were performed to study lung metastasis. Samples obtained from lung cancer patients were used to study the mRNA level of CD44 by q-PCR and the protein levels of Sp1 and CD44 by immunoblot and immunohistochemistry. RESULTS: In this study, we found that Sp1 expression was decreased in premenopausal women with late-stage lung cancer, resulting in a poor prognosis. Tumor formation was more substantial in female EGFRL858R mice than in male mice and ovariectomized female mice, indicating that E2 might be involved in the poor prognosis of lung cancer. We herein report that Sp1 negatively regulates metastasis and cancer stemness in E2-A549 and A549-T24 cells. Furthermore, E2 increases the mRNA and protein levels of RING finger protein 4 (RNF4), which is the E3-ligase of Sp1, and thereby decreases Sp1 levels by promoting Sp1 degradation. Sp1 can be recruited to the promoter of miR-3194-5p, and positively regulate its expression. Furthermore, there was a strong inverse correlation between Sp1 and CD44 levels in clinical lung cancer specimens. Sp1 inhibited CD44 expression by increasing the expression of miR-3194-5p, miR-218-5p, miR-193-5p, miR-182-5p and miR-135-5p, ultimately resulting in lung cancer malignancy. CONCLUSION: Premenopausal women with lung cancer and decreased Sp1 levels have a poor prognosis. E2 increases RNF4 expression to repress Sp1 levels in premenopausal women with lung cancer, thus decreasing the expression of several miRNAs that can target CD44 and ultimately leading to cancer malignancy.

Identification of a Pyrrole Intermediate Which Undergoes C-Glycosidation and Autoxidation to Yield the Final Product in Showdomycin Biosynthesis.

Showdomycin is a C-nucleoside bearing an electrophilic maleimide base. Herein, the biosynthetic pathway of showdomycin is presented. The initial stages of the pathway involve non-ribosomal peptide synthetase (NRPS) mediated assembly of a 2-amino-1H-pyrrole-5-carboxylic acid intermediate. This intermediate is prone to air oxidation whereupon it undergoes oxidative decarboxylation to yield an imine of maleimide, which in turn yields the maleimide upon acidification. It is also shown that this pyrrole intermediate serves as the substrate for the C-glycosidase SdmA in the pathway. After coupling with ribose 5-phosphate, the resulting C-nucleoside undergoes a similar sequence of oxidation, decarboxylation and deamination to afford showdomcyin after exposure to air. These results suggest that showdomycin could be an artifact due to aerobic isolation; however, the autoxidation may also serve to convert an otherwise inert product of the biosynthetic pathway to an electrophilic C-nucleotide thereby endowing showdomycin with its observed bioactivities.

USP24 promotes drug resistance during cancer therapy.

Drug resistance has remained an important issue in the treatment and prevention of various diseases, including cancer. Herein, we found that USP24 not only repressed DNA-damage repair (DDR) activity by decreasing Rad51 expression to cause the tumor genomic instability and cancer stemness, but also increased the levels of the ATP-binding cassette (ABC) transporters P-gp, ABCG2, and ezrin to enhance the pumping out of Taxol from cancer cells, thus resulted in drug resistance during cancer therapy. A novel USP24 inhibitor, NCI677397, was screened for specific inhibiting the catalytic activity of USP24. This inhibitor was identified to suppress drug resistance via decreasing genomic instability, cancer stemness, and the pumping out of drugs from cancer cells. Understanding the role and molecular mechanisms of USP24 in drug resistance will be beneficial for the future development of a novel USP24 inhibitor. Our studies provide a new insight of USP24 inhibitor for clinically implication of blocking drug resistance during chemotherapy.

USP24 stabilizes bromodomain containing proteins to promote lung cancer malignancy.

Bromodomain (BRD)-containing proteins are important for chromatin remodeling to regulate gene expression. In this study, we found that the deubiquitinase USP24 interacted with BRD through its C-terminus increased the levels of most BRD-containing proteins through increasing their protein stability by the removal of ubiquitin from Lys391/Lys400 of the BRD. In addition, we found that USP24 and BRG1 could regulate each other through regulating the protein stability and the transcriptional activity, respectively, of the other, suggesting that the levels of USP24 and BRG1 are regulated to form a positive feedback loop in cancer progression. Loss of the interaction motif of USP24 eliminated the ability of USP24 to stabilize BRD-containing proteins and abolished the effect of USP24 on cancer progression, including its inhibition of cancer cell proliferation and promotion of cancer cell migration, suggesting that the interaction between USP24 and the BRD is important for USP24-mediated effects on cancer progression. The targeting of BRD-containing proteins has been developed as a strategy for cancer therapy. Based on our study, targeting USP24 to inhibit the levels of BRD-containing proteins may inhibit cancer progression.

Studies of lincosamide formation complete the biosynthetic pathway for lincomycin A.

The structure of lincomycin A consists of the unusual eight-carbon thiosugar core methyllincosamide (MTL) decorated with a pendent N-methylprolinyl moiety. Previous studies on MTL biosynthesis have suggested GDP-ᴅ-erythro-α-ᴅ-gluco-octose and GDP-ᴅ-α-ᴅ-lincosamide as key intermediates in the pathway. However, the enzyme-catalyzed reactions resulting in the conversion of GDP-ᴅ-erythro-α-ᴅ-gluco-octose to GDP-ᴅ-α-ᴅ-lincosamide have not yet been elucidated. Herein, a biosynthetic subpathway involving the activities of four enzymes-LmbM, LmbL, CcbZ, and CcbS (the LmbZ and LmbS equivalents in the closely related celesticetin pathway)-is reported. These enzymes catalyze the previously unknown biosynthetic steps including 6-epimerization, 6,8-dehydration, 4-epimerization, and 6-transamination that convert GDP-ᴅ-erythro-α-ᴅ-gluco-octose to GDP-ᴅ-α-ᴅ-lincosamide. Identification of these reactions completes the description of the entire lincomycin biosynthetic pathway. This work is significant since it not only resolves the missing link in octose core assembly of a thiosugar-containing natural product but also showcases the sophistication in catalytic logic of enzymes involved in carbohydrate transformations.

Effects of real-time feedback on cardiopulmonary resuscitation quality on outcomes in adult patients with cardiac arrest: A systematic review and meta-analysis.

AIM: To investigate the relationship between the implementation of real-time audiovisual cardiopulmonary resuscitation (CPR) feedback devices with cardiac arrest patient outcomes, such as return of spontaneous circulation (ROSC), short-term survival, and neurological outcome. METHODS: We systematically searched PubMed, Embase, and the Cochrane CENTRAL from inception date until April 30, 2020, for eligible randomized and nonrandomized studies. Pooled odds ratio (OR) for each binary outcome was calculated using R system. The primary patient outcome was ROSC. The secondary outcomes were short-term survival and favorable neurological outcomes (cerebral performance category scores: 1 or 2). RESULTS: We identified 11 studies (8 nonrandomized and 3 randomized studies) including 4851 patients. Seven studies documented patients with out-of-hospital cardiac arrest and four studies documented patients with in-hospital cardiac arrest. The pooled results did not confirm the effectiveness of CPR feedback device, possibly because of the high heterogeneity in ROSC (OR: 1.42, 95% CI: 1.03-1.94, I2: 80%, tau2: 0.1875, heterogeneity test p <  0.01) and survival-to-discharge (OR: 1.27, 95% CI: 0.74-2.18, I2: 86%, tau2: 0.4048, heterogeneity test p <  0.01). The subgroup analysis results revealed that heterogeneity was due to the types of devices used. Patient outcomes were more favorable in studies investigating portable devices than in studies investigating automated external defibrillator (AED)-associated devices. CONCLUSIONS: Whether real-time CPR feedback devices can improve patient outcomes (ROSC and short-term survival) depend on the type of device used. Portable devices led to better outcomes than did AED-associated devices. Future studies comparing different types of devices are required to reach robust conclusion. PROTOCOL REGISTRATION: Prospero registration ID CRD42020155388.

Characterization of the coformycin biosynthetic gene cluster in Streptomyces kaniharaensis.

Coformycin and pentostatin are structurally related N-nucleoside inhibitors of adenosine deaminase characterized by an unusual 1,3-diazepine nucleobase. Herein, the cof gene cluster responsible for coformycin biosynthesis is identified. Reconstitution of the coformycin biosynthetic pathway in vitro demonstrates that it overlaps significantly with the early stages of l-histidine biosynthesis. Committed entry into the coformycin pathway takes place via conversion of a shared branch point intermediate to 8-ketocoformycin-[Formula: see text]-monophosphate catalyzed by CofB, which is a homolog of succinylaminoimidazolecarboxamide ribotide (SAICAR) synthetase. This reaction appears to proceed via a Dieckmann cyclization and a retro-aldol elimination, releasing ammonia and D-erythronate-4-phosphate as coproducts. Completion of coformycin biosynthesis involves reduction and dephosphorylation of the CofB product, with the former reaction being catalyzed by the NADPH-dependent dehydrogenase CofA. CofB also shows activation by adenosine triphosphate (ATP) despite the reaction requiring neither a phosphorylated nor an adenylated intermediate. This may serve to help regulate metabolic partitioning between the l-histidine and coformycin pathways.