Integrating respiratory microbiome and host immune response through machine learning for respiratory tract infection diagnosis.

At present, the diagnosis of lower respiratory tract infections (LRTIs) is difficult, and there is an urgent need for better diagnostic methods. This study enrolled 136 patients from 2020 to 2021 and collected bronchoalveolar lavage fluid (BALF) specimens. We used metatranscriptome to analyze the lower respiratory tract microbiome (LRTM) and host immune response. The diversity of the LRTM in LRTIs significantly decreased, manifested by a decrease in the abundance of normal microbiota and an increase in the abundance of opportunistic pathogens. The upregulated differentially expressed genes (DEGs) in the LRTIs group were mainly enriched in infection immune response-related pathways. Klebsiella pneumoniae had the most significant increase in abundance in LRTIs, which was strongly correlated with host infection or inflammation genes TNFRSF1B, CSF3R, and IL6R. We combined LRTM and host transcriptome data to construct a machine-learning model with 12 screened features to discriminate LRTIs and non-LRTIs. The results showed that the model trained by Random Forest in the validate set had the best performance (ROC AUC: 0.937, 95% CI: 0.832-1). The independent external dataset showed an accuracy of 76.5% for this model. This study suggests that the model integrating LRTM and host transcriptome data can be an effective tool for LRTIs diagnosis.

Enhancing lower respiratory tract infection diagnosis: implementation and clinical assessment of multiplex PCR-based and hybrid capture-based targeted next-generation sequencing.

BACKGROUND: Shotgun metagenomic next-generation sequencing (mNGS) is widely used to detect pathogens in bronchoalveolar lavage fluid (BALF). However, mNGS is complex and expensive. This study explored the feasibility of targeted next-generation sequencing (tNGS) in distinguishing lower respiratory tract infections in clinical practice. METHODS: We used 229 retrospective BALF samples to establish thresholds and diagnostic values in a prospective cohort of 251 patients. After target pathogen selection, primer and probe design, optimization experiments, and bioinformatics analysis, multiplex PCR-based tNGS (mp-tNGS) and hybrid capture-based tNGS (hc-tNGS), targeting 198 and 3060 pathogens (DNA and RNA co-detection workflow) were established and performed. FINDINGS: mp-tNGS and hc-tNGS took 10.3 and 16 h, respectively, with low sequencing data sizes of 0.1 M and 1 M reads, and test costs reduced to a quarter and half of mNGS. The LoDs of mp-tNGS and hc-tNGS were 50-450 CFU/mL. mp-tNGS and hc-tNGS were highly accurate, with 86.5% and 87.3% (vs. 85.5% for mNGS) sensitivities and 90.0% and 88.0% (vs. 92.1% for mNGS) specificities. tNGS detection rates for casual pathogens were 84.3% and 89.5% (vs. 88.5% for mNGS), significantly higher than conventional microbiological tests (P < 0.001). In seven samples, tNGS detected Pneumocystis jirovecii, a fungus not detected by mNGS. Whereas mNGS detected six samples with filamentous fungi (Rhizopus oryzae, Aureobasidium pullulans, Aspergillus niger complex, etc.) which missed by tNGS. The anaerobic bacteria as pathogen in eight samples was failed to detect by mp-tNGS. INTERPRETATION: tNGS may offer a new, broad-spectrum, rapid, accurate and cost-effective approach to diagnosing respiratory infections. FUNDING: National Natural Science Foundation of China (81625014 and 82202535).

A vascular endothelial growth factor-loaded chitosanhyaluronic acid hydrogel scaffold enhances the therapeutic effect of adipose-derived stem cells in the context of stroke.

Adipose-derived stem cell, one type of mesenchymal stem cells, is a promising approach in treating ischemia-reperfusion injury caused by occlusion of the middle cerebral artery. However, its application has been limited by the complexities of the ischemic microenvironment. Hydrogel scaffolds, which are composed of hyaluronic acid and chitosan, exhibit excellent biocompatibility and biodegradability, making them promising candidates as cell carriers. Vascular endothelial growth factor is a crucial regulatory factor for stem cells. Both hyaluronic acid and chitosan have the potential to make the microenvironment more hospitable to transplanted stem cells, thereby enhancing the therapeutic effect of mesenchymal stem cell transplantation in the context of stroke. Here, we found that vascular endothelial growth factor significantly improved the activity and paracrine function of adipose-derived stem cells. Subsequently, we developed a chitosan-hyaluronic acid hydrogel scaffold that incorporated vascular endothelial growth factor and first injected the scaffold into an animal model of cerebral ischemia-reperfusion injury. When loaded with adipose-derived stem cells, this vascular endothelial growth factor-loaded scaffold markedly reduced neuronal apoptosis caused by oxygen-glucose deprivation/reoxygenation and substantially restored mitochondrial membrane potential and axon morphology. Further in vivo experiments revealed that this vascular endothelial growth factor-loaded hydrogel scaffold facilitated the transplantation of adipose-derived stem cells, leading to a reduction in infarct volume and neuronal apoptosis in a rat model of stroke induced by transient middle cerebral artery occlusion. It also helped maintain mitochondrial integrity and axonal morphology, greatly improving rat motor function and angiogenesis. Therefore, utilizing a hydrogel scaffold loaded with vascular endothelial growth factor as a stem cell delivery system can mitigate the adverse effects of ischemic microenvironment on transplanted stem cells and enhance the therapeutic effect of stem cells in the context of stroke.

Amine-Borane-Mediated, Nickel/Photoredox-Catalyzed Cross-Electrophile Coupling between Alkyl and Aryl Bromides.

Nickel/photoredox catalysis has emerged as a powerful platform for exploring nontraditional and challenging cross-couplings. Herein, a metallaphotoredox catalytic protocol has been developed on the basis of a tertiary amine-ligated boryl radical-induced halogen atom transfer process under blue-light irradiation. A wide variety of aryl and heteroaryl bromides featuring different functional groups and pharmaceutical moieties were facilely coupled to rapidly install C(sp3)-enriched aromatic scaffolds. The compatibility of Lewis base-ligated borane with nickel catalysis was well exemplified to extend the chemical space for Ni-catalyzed cross-electrophile coupling.

PathoTracker: an online analytical metagenomic platform for Klebsiella pneumoniae feature identification and outbreak alerting.

Clinical metagenomics (CMg) Nanopore sequencing can facilitate infectious disease diagnosis. In China, sub-lineages ST11-KL64 and ST11-KL47 Carbapenem-resistant Klebsiella pneumoniae (CRKP) are widely prevalent. We propose PathoTracker, a specially compiled database and arranged method for strain feature identification in CMg samples and CRKP traceability. A database targeting high-prevalence horizontal gene transfer in CRKP strains and a ST11-only database for distinguishing two sub-lineages in China were created. To make the database user-friendly, facilitate immediate downstream strain feature identification from raw Nanopore metagenomic data, and avoid the need for phylogenetic analysis from scratch, we developed data analysis methods. The methods included pre-performed phylogenetic analysis, gene-isolate-cluster index and multilevel pan-genome database and reduced storage space by 10-fold and random-access memory by 52-fold compared with normal methods. PathoTracker can provide accurate and fast strain-level analysis for CMg data after 1 h Nanopore sequencing, allowing early warning of outbreaks. A user-friendly page ( http://PathoTracker.pku.edu.cn/ ) was developed to facilitate online analysis, including strain-level feature, species identifications and phylogenetic analyses. PathoTracker proposed in this study will aid in the downstream analysis of CMg.

Fluidized bed photobioreactor based on diatomite powder and high light intensity improved microalgae harvesting, nutrient removal and lipid accumulation: Performance and microscopic mechanism.

Cultivation of microalgae using anaerobic digestate is a gain-win strategy for algal biomass production and achieving environmental benefits. However, the low biomass concentration and high harvest cost of the conventional suspended microalgae culture system are troublesome issues. In this study, a novel fluidized bed photobioreactor (FBPBR) based on diatomite powder was constructed for cultivating Scenedesmus quadricauda and treating diluted anaerobic digestate. The optimized diatomite carrier dosage of 750 mg/L increased microalgal biomass concentration to 1.58 g/L compared to suspended microalgae without carrier (0.99 g/L). When the light intensity was increased from 100 to 200 µmol/m2/s, the microalgal biomass in the FBPBR increased to 1.84 g/L and the settling efficiency increased to 93.58 %. This was due to the 1.60-fold enhancement of extracellular polymeric substance (EPS) secretion and changes in EPS properties. The increase in hydrophobic functional groups of EPS under high light intensity, coupled with the reconstitution of protein secondary structure, facilitated the initial attachment of algae to diatomite and the thickening of microalgal biofilm. Moreover, transcriptomic analysis demonstrated that diatomite promoted antioxidant defense and photosynthesis in S. quadricauda cells, alleviating the adverse effect of anaerobic digestate stress. The diatomite addition and elevated light intensity contributed to the highest lipid content (60.37 %), which was owing to the upregulated genes encoding fatty acid and triacylglycerol synthesis under the stress of localized nutrient starvation in the inner layer of microalgae biofilms. Furthermore, the regulation of phosphorus metabolism and NH4+-N assimilation improved nutrient removal (93.24 % and 96.86 % for NH4+-N and TP removal). This work will provide guidance for the development of FBPBR based on diatomite powder.

Effect of konjac glucomannan-based preservation pads on quality changes in refrigerated large yellow croaker (Pseudosciaena crocea).

The purpose of this study was to evaluate the preservation effects of konjac glucomannan (KGM)/oregano essential oil (OEO) Pickering emulsion-based pads (K/OPE pads) on large yellow croaker (Pseudosciaena crocea) fillets stored at 4 °C. The K/OPE pads were fabricated using a freeze-drying technique. The homogeneous distribution of the OEO Pickering emulsions in the KGM matrix was observed using scanning electron microscopy. Fourier transform infrared spectroscopy confirmed that the OEO emulsions were encapsulated in the KGM and there was hydrogen bonding interaction between them. Compared with the KGM pads, the K/OPE pad groups demonstrated enhanced antioxidant and antimicrobial properties. When the content of OPE was increased from 20 % to 40 %, the antioxidant performance of the K/OPE pads increased from 48.09 % ± 0.03 % to 86.65 % ± 0.02 % and the inhibition range of Escherichia coli and Staphylococcus aureus increased to 13.84 ± 0.81 and 16.87 ± 1.53 mm, respectively. At the same time, K/OPE pads were more effective in inhibiting the formation of total volatile alkaline nitrogen and the production of thiobarbituric acid-reactive substances, thereby helping in reducing water loss and maintaining the muscle tissue structure of fish fillets for a longer storage time. Consequently, these K/OPE40 pads extended the shelf life of the fish fillets by an additional 4 days and delayed spoilage during refrigerated storage. The findings suggest that the K/OPE pads can effectively safeguard the quality of refrigerated large yellow croaker fillets, presenting their potential as an active packaging material in the fish preservation industry.

Clinical Impact of Plasma Metagenomic Next-Generation Sequencing on Infection Diagnosis and Antimicrobial Therapy in Immunocompromised Patients.

BACKGROUND: Clinical impact of plasma metagenomic next-generation sequencing (mNGS) on infection diagnosis and antimicrobial therapy in immunocompromised patients with suspected infection remains unclear. METHODS: Between March and December 2022, 424 cases with fever, infection history, mechanical ventilation, or imaging abnormalities underwent plasma mNGS testing at a single center. Eleven patients have received solid organ transplantation, and the remaining patients were categorised into febrile neutropenia (FN), non-neutropenia (NN), and non-haematologic disease (NTHD) groups based on immunosuppression severity. The diagnostic rate of infection and the utilisation of antimicrobial agents based on mNGS were assessed. RESULTS: The use of mNGS significantly improved the diagnostic rates for fungi in the FN (56.1%, P = 0.003) and NN (58.8%, P = 0.008) groups versus the NHD group (33.3%). Positive impacts associated with therapy were significantly greater than negative impacts across all three groups (all P < 0.001), and the utilisation of escalation therapy was significantly more frequent in the FN group than in the NN groups (P = 0.006). Over 70% of cases with negative mNGS results across the three groups underwent de-escalation therapy, with >1/3 being discontinued, preventing antimicrobial overuse. CONCLUSIONS: Plasma mNGS has a clinically confirmed positive impact in immunocompromised patients with neutropenia, improving the diagnosis of fungal infections and antimicrobial therapy.

A case report of the metagenomic next-generation sequencing for timely diagnosis of a traveler with nonspecific febrile Q fever.

Q fever is a worldwide distribution disease caused by Coxiella burnetii（C. burnetii）, an obligate intracellular, Gram-negative acidophilic bacterium belonging to γ-proteobacterium. Most patients present with acute Q-fever accompanied by atypical flu-like symptoms, with only 1%-5% of cases may develop into persistent and focally infected foci, mainly manifest as endocarditis, osteomyelitis and prosthetic arthritis. In this case, the patient experienced an unexplained and uninterrupted fever up to 39.2 °C for a week, accompanied by chills and headaches, as well as abnormal liver function. The laboratory reported negative results for blood culture and respiratory-associated pathogens, however, the metagenomic next-generation sequencing (mNGS) reported that detection of 20 sequence reads of C. burnetii in the patient's peripheral blood. In addition, the patient had traveled to Sri Lanka, Iraq and Saudi Arabia before illness. In clinical, the treatment regimen was adjusted from empirically intravenous moxifloxacin 400 mg a day for 1 week to continuously oral minocyline 100 mg twice daily for 2 weeks. The patient was in good health without any adverse sequelae during outpatient visitation and the phone calls follow-up. In conclusion, the mNGS does provide an early and timely diagnostic basis for rare and difficult to culture pathogens, which contributes to the success of clinical anti-infection.

The plasma viral communities associate with clinical profiles in a large-scale haematological patients cohort.

BACKGROUND: Haematological patients exhibit immune system abnormalities that make them susceptible to viral infections. Understanding the relationship between the virome in the blood plasma of haematological patients and their clinical characteristic is crucial for disease management. We aimed to explore the presence of viral pathogens and identify close associations between viral infections and various clinical features. RESULTS: A total of 21 DNA viruses and 6 RNA viruses from 12 virus families were identified from 1383 patients. Patients with haematological diseases exhibited significantly higher diversity, prevalence, and co-detection rates of viral pathogens. During fever episodes, pathogen detection was notably higher, with Epstein-Barr virus (EBV) and Mucorales infections being the most probable culprits for fever symptoms in non-haematological patients. The detection rate of torque teno virus (TTV) significantly increases in haematological patients after transplantation and during primary lung infections. Additionally, TTV-positive patients demonstrate significantly higher absolute neutrophil counts, while C-reactive protein and procalcitonin levels are notably lower. Furthermore, TTV, cytomegalovirus, and parvovirus B19 (B19V) were found to be more prevalent in non-neutropenic patients, while non-viral pathogenic infections, such as Gram-negative bacteria and Mucorales, were more common in neutropenic patients. Pegivirus C (HPgV-C) infection often occurred post-transplantation, regardless of neutropenia. Additionally, some viruses such as TTV, B19V, EBV, and HPgV-C showed preferences for age and seasonal infections. CONCLUSIONS: Analysis of the plasma virome revealed the susceptibility of haematological patients to plasma viral infections at specific disease stages, along with the occurrence of mixed infections with non-viral pathogens. Close associations were observed between the plasma virome and various clinical characteristics, as well as clinical detection parameters. Understanding plasma virome aids in auxiliary clinical diagnosis and treatment, enabling early prevention to reduce infection rates in patients and improve their quality of life. Video Abstract.

Mechanisms of enhancing MgO for stabilization/solidification of Pb-contaminated red clay through CO2 sequestration.

Pb-contaminated soil poses significant environmental and health risks as well as soil stability issues. Research on sandy soils highlights CO2-enhanced reactive MgO as a promising solution for improving the solidification of Pb-contaminated soils. However, carbonation effects can differ markedly between soil types owing to varying soil properties. In this study, we evaluated the effects of CO2-enhanced reactive MgO on the engineering and environmental characteristics of Pb-contaminated red clay and explored its mechanism of carbonation solidification. The results showed that CO2-enhanced reactive MgO increased the strength of Pb-contaminated red clay to over 3 MPa within 1 h, which was approximately 25 times the strength of untreated soil (0.2 MPa) and significantly higher than that of reactive MgO-treated, uncarbonated soil (0.8 MPa). The pH of the carbonated soil (9-10) facilitated Pb2+ immobilization, and the increase over the initial parameter elevated the electrical conductivity value. Moreover, CO2-enhanced reactive MgO reduced the Pb2+ leaching concentration to below 0.1 mg/L, even at high Pb concentrations (10,000 mg/kg). Pb2+ transformed into lead carbonates during the carbonation process, with the hydrated magnesium carbonates forming a dense internal structure. This solidification mechanism included chemical precipitation, physical adsorption, and encapsulation. Notably, the carbonation time should be controlled within 1 h to prevent soil expansion. Together, these findings support the potential of CO2-enhanced reactive MgO for efficient and low-carbon application in the solidification of Pb-contaminated red clay.

Investigation of the Rapid Emergence of Colistin Resistance in a Newborn Infected with KPC-2-Producing Hypervirulent Carbapenem-Resistant Klebsiella pneumoniae.

OBJECTIVES: Hypervirulent carbapenem-resistant Klebsiella pneumoniae (hv-CRKp) poses a significant threat to public health. This study reports an infection related to hv-CRKp in a premature infant and reveals its colistin resistance and evolutionary mechanisms within the host. METHODS: Three KPC-producing CRKp strains were isolated from a patient with sepsis and CRKp osteoarthritis who had been receiving colistin antimicrobial therapy. The minimum inhibitory concentrations (MICs) of ceftazidime, ceftazidime-avibactam (CAZ-AVI), meropenem, imipenem, tigecycline, amikacin, minocycline, sulfamethoxazole/trimethoprim, ciprofloxacin, levofloxacin, aztreonam, cefepime, cefoperazone/sulbactam, piperacillin/tazobactam, and colistin were determined using the microbroth dilution method. The whole-genome sequencing analysis was conducted to determine the sequence types (STs), virulence genes, and antibiotic resistance genes of the three CRKp strains. RESULTS: Whole-genome sequencing revealed that all three CRKp strains belonged to the ST11 clone and carried a plasmid encoding blaKPC-2. The three strains all possessed the iucABCDiutA virulence cluster, peg-344 gene, and rmpA/rmpA2 genes, defining them as hv-CRKp. Further experiments and whole-genome analysis revealed that a strain of K. pneuomniae had developed resistance to colistin. The mechanism found to be responsible for colistin resistance was a deletion mutation of approximately 9000 bp including the mgrB gene. CONCLUSION: This study characterizes colistin resistance of the ST11 clone hv-CRKp during colistin treatment and its rapid evolution within the host.

Patients' Preferences for Adjuvant Osimertinib in Non-Small-Cell Lung Cancer After Complete Surgical Resection: What Makes It Worth It to Patients?

BACKGROUND: The ADAURA trial confirmed adjuvant Osimertinib's efficacy in EGFR-mutated Non-small-cell lung cancer (NSCLC), yet the limited mature overall survival (OS) data at approval poses a challenge. This study explores patient preferences in the absence of complete OS information, hypothesizing that disease-free survival (DFS) benefit alone may influence adjuvant Osimertinib pursuit. METHODS: At Roswell Park Comprehensive Cancer Center (Jan-Dec 2021), patients assessed for adjuvant therapy received a survey probing OS and DFS preferences. Scenarios were (a) minimum OS justifying Osimertinib, (b) minimum DFS improvement justifying 3-years of adjuvant Osimertinib, (c) minimum 5-year DFS percent change, and (d) minimum OS justifying copay changes. Results were analyzed. RESULTS: Of 524 NSCLC patients, 51 participated. Scenario 1 saw 56% requiring a 12-month OS benefit for Osimertinib justification. In scenario 2, 72% deemed a 12-month DFS benefit sufficient. Scenario 3 revealed 31% opting out despite a 10% OS increase. Scenario 4 showed varied willingness to pay, with 33% unwilling to any shoulder copayment even with a 10-year OS benefit. CONCLUSION: This study explores patient preferences without complete OS data, revealing diverse thresholds. Factors include employment, education, and willingness to pay. Findings underscore shared decision-making importance. Limitations include sample size, potential biases, and regional focus; larger cohorts are needed for validation.

Tracking intra-species and inter-genus transmission of KPC through global plasmids mining.

Klebsiella pneumoniae carbapenemase (KPC) poses a major public health risk. Understanding its transmission dynamics requires examining the epidemiological features of related plasmids. Our study compiled 15,660 blaKPC-positive isolates globally over the past two decades. We found extensive diversity in the genetic background of KPC, with 23 Tn4401-related and 341 non-Tn4401 variants across 163 plasmid types in 14 genera. Intra-K. pneumoniae and cross-genus KPC transmission patterns varied across four distinct periods. In the initial periods, plasmids with narrow host ranges gradually established a survival advantage. In later periods, broad-host-range plasmids became crucial for cross-genera transmission. In total, 61 intra-K. pneumoniae and 66 cross-genus transmission units have been detected. Furthermore, phylogenetic reconstruction dated the origin of KPC transmission back to 1991 and revealed frequent exchanges across countries. Our research highlights the frequent and transient spread events of KPC mediated by plasmids across multiple genera and offers theoretical support for high-risk plasmid monitoring.

Boosting Volatile fatty acids (VFAs) production in fermentation microorganisms through genes expression control: Unraveling the role of iron homeostasis transcription factors.

Iron (Fe0, Fe (II), and Fe (III)) has been previously documented to upregulate the expression of key genes, enhancing the production of volatile fatty acids (VFAs) to achieve waste/wastewater resource recovery. However, the precise mechanism by why iron influences gene expression remains unclear. This study applied iron-assisted fermentation systems to explore the behind enhancing mechanism by constructing regulon networks among genes, microbes, and transcription factors. In iron-conditioned systems, a significant enhancement in VFAs production and upregulation of genes expression (1.19-3.92 folds) related to organic conversion and the electron transfer chain was observed. Besides, gene co-expression network and Procrustes analysis identified ten hub transcription factors (e.g., arsR, crp, iscR, perR) and their major contributors (genus) (e.g., Paludibacter, Acinetobacter, Tolumonas). Further analysis suggested that most of hub transcription factors were implicated in iron homeostasis regulation, which speculated that the induced iron homeostasis transcription factors probably effectively regulated the expression of genes encoding enzymes involving in VFAs production and electron transfer of functional microbes, in the case of Paludibacter, Acinetobacter, and Tolumonas while regulating the iron homeostasis, resulting in the efficient production of VFAs in iron-conditioned systems. This study might contribute to an enhanced understanding of the underlying genetic mechanisms by why iron influences gene expression regulation of microbes, which also provides a genetic theoretical basis for improving system VFAs production and resource recovery.

SIRT3 facilitates mitochondrial structural repair and functional recovery in rats after ischemic stroke by promoting OPA1 expression and activity.

BACKGROUND: Optical atrophy 1 (OPA1), a protein accountable for mitochondrial fusion, facilitates the restoration of mitochondrial structure and function following cerebral ischemia/reperfusion (I/R) injury. The OPA1-conferred mitochondrial protection involves its expression and activity, which can be improved by SIRT3 in non-cerebral ischemia. Nevertheless, it remains obscure whether SIRT3 enhances the expression and activity of OPA1 after cerebral I/R injury. METHODS: Mature male Sprague Dawley rats were intracranially injected with adeno-associated viral-Sirtuin-3(AAV-SIRT3) and AAV-sh_OPA1, followed by a 90-min temporary blockage of the middle cerebral artery and subsequent restoration of blood flow. Cultured cortical neurons of rats were transfected with LV-SIRT3 or LV-sh_OPA1 before a 2-h oxygen-glucose deprivation and reoxygenation. The rats and neurons were subsequently treated with a selective OPA1 activity inhibitor (MYLS22). The interaction between SIRT3 and OPA1 was assessed by molecular dynamics simulation technology and co-immunoprecipitation. The expression, function, and specific protective mechanism of SIRT3 were examined by various analyses. RESULTS: SIRT3 interacted with OPA1 in the rat cerebral cortex before and after cerebral I/R. After cerebral I/R damage, SIRT3 upregulation increased the OPA1 expression, which enhanced deacetylation and OPA1 activity, thus alleviating cerebral infarct volume, neuronal apoptosis, oxidative pressure, and impairment in mitochondrial energy production; SIRT3 upregulation also improved neuromotor performance, repaired mitochondrial ultrastructure and membrane composition, and promoted the mitochondrial biogenesis. These neuroprotective effects were partly reversed by OPA1 expression interference and OPA1 activity inhibitor MYLS22. CONCLUSION: In rats, SIRT3 enhances the expression and activity of OPA1, facilitating the repair of mitochondrial structure and functional recovery following cerebral I/R injury. These findings highlight that regulating SIRT3 may be a promising therapeutic strategy for ischemic stroke.

Iodine(III)-Mediated Trifluoroacetylation of a C(sp2)-H or C(sp)-H Bond with Masked Trifluoroacyl Reagents.

A novel strategy for incorporating a trifluoroacetyl functionality into a range of structurally varied unsaturated bonds was developed by using PhI(OCOMe)2 as an oxidant with a masked trifluoroacyl reagent as a trifluoroacetyl radical precursor. The oxidative decarboxylation of the masked trifluoroacyl precursor followed by a tandem radical process provides versatile access to 5-exo-trig cyclization of N-arylacrylamides, direct C(sp2)-H trifluoroacetylation of quinolines, isoquinoline, 2H-indazole, and quinoxalin-2(1H)-ones, and C(sp)-H trifluoroacetylation of alkynes. This protocol is characterized by mild reaction conditions, operational simplicity, and broad functional group compatibility.

SIRT1 restores mitochondrial structure and function in rats by activating SIRT3 after cerebral ischemia/reperfusion injury.

Mitochondrial dysfunction contributes to cerebral ischemia-reperfusion (CI/R) injury, which can be ameliorated by Sirtuin-3 (SIRT3). Under stress conditions, the SIRT3-promoted mitochondrial functional recovery depends on both its activity and expression. However, the approach to enhance SIRT3 activity after CI/R injury remains unelucidated. In this study, Sprague-Dawley (SD) rats were intracranially injected with either adeno-associated viral Sirtuin-1 (AAV-SIRT1) or AAV-sh_SIRT1 before undergoing transient middle cerebral artery occlusion (tMCAO). Primary cortical neurons were cultured and transfected with lentiviral SIRT1 (LV-SIRT1) and LV-sh_SIRT1 respectively before oxygen-glucose deprivation/reoxygenation (OGD/R). Afterwards, rats and neurons were respectively treated with a selective SIRT3 inhibitor, 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP). The expression, function, and related mechanism of SIRT1 were investigated by Western Blot, flow cytometry, immunofluorescence staining, etc. After CI/R injury, SIRT1 expression decreased in vivo and in vitro. The simulation and immune-analyses reported strong interaction between SIRT1 and SIRT3 in the cerebral mitochondria before and after CI/R. SIRT1 overexpression enhanced SIRT3 activity by increasing the deacetylation of SIRT3, which ameliorated CI/R-induced cerebral infarction, neuronal apoptosis, oxidative stress, neurological and motor dysfunction, and mitochondrial respiratory chain dysfunction, promoted mitochondrial biogenesis, and retained mitochondrial integrity and mitochondrial morphology. Meanwhile, SIRT1 overexpression alleviated OGD/R-induced neuronal death and mitochondrial bioenergetic deficits. These effects were reversed by AAV-sh_SIRT1 and the neuroprotective effects of SIRT1 were partially offset by 3-TYP. These results suggest that SIRT1 restores the structure and function of mitochondria by activating SIRT3, offering neuroprotection against CI/R injury, which signifies a potential approach for the clinical management of cerebral ischemia.