Metformin promotes anti-tumor immunity in STK11 mutant NSCLC through AXIN1-dependent upregulation of multiple nucleotide metabolites

Background:Metformin has pleiotropic effects beyond glucose reduction,including tumor inhibition and immune regulation.It enhanced the anti-tumor effects of programmed cell death protein 1(PD-1)inhibitors in serine/threonine kinase 11(STK11)mutant non-small cell lung cancer(NSCLC)through an axis inhibition protein 1(AXIN1)-dependent manner.However,the alterations of tumor metabolism and metabolites upon metformin administration remain unclear.Methods:We performed untargeted metabolomics using liquid chromatography(LC)-mass spectrometry(MS)/MS system and conducted cell experiments to verify the results of bioinformatics analysis.Results:According to the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway database,most metabolites were annotated into metabolism,including nucleotide metabolism.Next,the differentially expressed metabolites in H460(refers to H460 cells),H460_met(refers to metformin-treated H460 cells),and H460_KO_met(refers to metformin-treated Axin1-/-H460 cells)were distributed into six clusters based on expression patterns.The clusters with a reversed expression pattern upon metformin treatment were selected for further analysis.We screened out metabolic pathways through KEGG pathway enrichment analysis and found that multiple nucleotide metabolites enriched in this pathway were upregulated.Furthermore,these metabolites enhanced the cytotoxicity of activated T cells on H460 cells in vitro and can activate the stimulator of the interferon genes(STING)pathway independently of AXIN1.Conclusion:Relying on AXIN1,metformin upregulated multiple nucleotide metabolites which promoted STING signaling and the killing of activated T cells in STK11 mutant NSCLC,indicating a potential immunotherapeutic strategy for STK11 mutant NSCLC.

An online survey of non-compressible torso hemorrhage:training is needed

Hemorrhage is the leading cause of combat deaths,which is a primary lesson learned from modern warfare.[1]If temporary hemostasis is not available,the mortality of non-compressible torso hemorrhage(NCTH),a potentially preventable death(PPD),is as high as 85.5%.[2]

Sepsis-induced immunosuppression:mechanisms,diagnosis and current treatment options

Sepsis is a common complication of combat injuries and trauma,and is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection.It is also one of the significant causes of death and increased health care costs in modern intensive care units.The use of antibiotics,fluid resuscitation,and organ support therapy have limited prognostic impact in patients with sepsis.Although its pathophysiology remains elusive,immunosuppression is now recognized as one of the major causes of septic death.Sepsis-induced immunosuppression is resulted from disruption of immune homeostasis.It is characterized by the release of antiinflammatory cytokines,abnormal death of immune effector cells,hyperproliferation of immune suppressor cells,and expression of immune checkpoints.By targeting immunosuppression,especially with immune checkpoint inhibitors,preclinical studies have demonstrated the reversal of immunocyte dysfunctions and established host resistance.Here,we comprehensively discuss recent findings on the mechanisms,regulation and biomarkers of sepsis-induced immunosuppression and highlight their implications for developing effective strategies to treat patients with septic shock.

The anatomical,electrophysiological and histological observations of muscle contraction units in rabbits:a new perspective on nerve injury and regeneration

In the conventional view a muscle is composed of intermediate structures before its further division into microscopic muscle fibers.Our experiments in mice have confirmed this intermediate structure is composed of the lamella cluster formed by motor endplates,the innervating nerve branches and the corresponding muscle fibers,which can be viewed as an independent structural and functional unit.In this study,we verified the presence of these muscle construction units in rabbits.The results showed that the muscular branch of the femoral nerve sent out 4–6 nerve branches into the quadriceps and the tibial nerve sent out 4–7 nerve branches into the gastrocnemius.When each nerve branch of the femoral nerve was stimulated from the most lateral to the medial,the contraction of the lateral muscle,intermediate muscle and medial muscle of the quadriceps could be induced by electrically stimulating at least one nerve branch.When stimulating each nerve branch of the tibial nerve from the lateral to the medial,the muscle contraction of the lateral muscle 1,lateral muscle 2,lateral muscle 3 and medial muscle of the gastrocnemius could be induced by electrically stimulating at least one nerve branch.Electrical stimulation of each nerve branch resulted in different electromyographical waves recorded in different muscle subgroups.Hematoxylin-eosin staining showed most of the nerve branches around the neuromuscular junctions consisted of one individual neural tract,a few consisted of two or more neural tracts.The muscles of the lower limb in the rabbit can be subdivided into different muscle subgroups,each innervated by different nerve branches,thereby allowing much more complex muscle activities than traditionally stated.Together,the nerve branches and the innervated muscle subgroups can be viewed as an independent structural and functional unit.This study was approved by the Animal Ethics Committee of Peking University People’s Hospital(approval No.2019 PHE027)on October 20,2019.

Mechanism of calcium hydroxide inhibiting methicillin resistant Staphylococcus aureus

Objective:To investigate the inhibitory effect of calcium hydroxide on methicillin-resistant Staphylococcus aureus and the related inhibition mechanism.Methods:To determine the minimum inhibitory concentration of calcium hydroxide using microplate dilution method;to compare the effects of calcium hydroxide at 8MIC,MIC,1/4MIC and 0 concentrations on MRSA using growth curve method;to determine the effects of calcium hydroxide on the cell membrane of methicillin-resistant Staphylococcus aureus using calcium xanthophyll and propidium iodide fluorescence staining The effect of calcium hydroxide on the morphology of methicillin-resistant Staphylococcus aureus was observed by scanning electron microscopy;the inhibition mechanism of calcium hydroxide on MRSA was investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis of protein bands.Results:The MIC of calcium hydroxide on MRSA was 3.125 mg/mL;the fluorescence intensity showed significant changes after co-culture of calcium hydroxide with bacteria;MRSA appeared to be significantly crumpled and broken in the presence of calcium hydroxide;the SDS-PAGE experimental bands indicated that the protein inside the bacteria decreased accordingly with the increase of calcium hydroxide concentration.Conclusion:Calcium hydroxide has a significant inhibitory effect on the growth of MRSA,and its bactericidal mechanism may be related to the destruction of bacterial body structure.

Preparation and characterization of hemihydrate calcium sulfate-calcium hydroxide composite bone repair materials

Objective:To prepare a bone repair material with certain mechanical strength and biological activity,this paper used calcium sulfate hemihydrate(CSH)powder compounded with calcium hydroxide(Ca(OH)2)powder to prepare a bone repair scaffold material for physicochemical property characterization and testing.Methods:The physical and chemical properties and characterization of the dried and cured bone repair materials were determined by Fourier infrared spectroscopy(FT-IR),X-ray diffraction(XRD),and scanning electron microscopy;Universal material testing machine to determine the mechanical and mechanical strength of composite materials.Results:XRD showed that the structure of the composite material phase at 5%concentration was calcium sulfate hemihydrate and calcium hydroxide after hydration.The FT-IR and XRD analyses were consistent.Scanning electron microscopy(SEM)results showed that calcium hydroxide was uniformly dispersed in the hemihydrate calcium sulfate material.0%,1%,5%,and 10%specimen groups had compressive strengths of 3.86±3.1,5.27±1.28,8.22±0.96,and 14.4±3.28 MPa.10%addition of calcium hydroxide significantly improved the mechanical strength of the composites,but also reduced the the porosity of the material.Conclusion:With the addition of calcium hydroxide,the CSH-Ca(OH)2 composite was improved in terms of mechanical material and is expected to be a new type of bone repair material.

A case report of Vibrio vulnificus infection in the lower limbs by sea fish stabbing and literature review

Objective: To summarize and analyze the clinical treatment experience of Vibrio vulnificus sepsis and improve the success rate of treatment. Methods: The clinical data of a patient with vibrio vulnificus sepsis admitted to the Department of Critical Care Medicine, the First Affiliated Hospital of Hainan Medical College in October 2019 were analyzed. Summarize the experience of treatment and compare with other literatures to analyze the most reasonable clinical treatment of vibrio vulnificus sepsis. Results: The patient was acutely ill, the disease progressed rapidly, fever, soft tissue swelling and pain, necrosis, ulceration and pus, systemic multiple organ failure, family members finally gave up treatment, microbiology culture prompted: Vibrio parahaemolyticus. Conclusions: Early intervention, blood purification, debridement, removal of infection sources and inflammatory mediators can improve the survival rate of patients with Vibrio vulnificus infection. Due to the high mortality rate, clinicians should pay attention to it.

Risk factors and predictive model of cerebral edema after road traffic accidents-related traumatic brain injury

Purpose:Cerebral edema(CE)is the main secondary injury following traumatic brain injury(TBI)caused by road traffic accidents(RTAs).It is challenging to be predicted timely.In this study,we aimed to develop a prediction model for CE by identifying its risk factors and comparing the timing of edema occurrence in TBI patients with varying levels of injuries.Methods:This case-control study included 218 patients with TBI caused by RTAs.The cohort was divided into CE and non-CE groups,according to CT results within 7 days.Demographic data,imaging data,and clinical data were collected and analyzed.Quantitative variables that follow normal distribution were presented as mean±standard deviation,those that do not follow normal distribution were presented as median(Q1,Q3).Categorical variables were expressed as percentages.The Chi-square test and logistic regression analysis were used to identify risk factors for CE.Logistic curve fitting was performed to predict the time to secondary CE in TBI patients with different levels of injuries.The efficacy of the model was evaluated using the receiver operator characteristic curve.Results:According to the study,almost half(47.3%)of the patients were found to have CE.The risk factors associated with CE were bilateral frontal lobe contusion,unilateral frontal lobe contusion,cerebral contusion,subarachnoid hemorrhage,and abbreviated injury scale(AIS).The odds ratio values for these factors were 7.27(95%confidence interval(CI):2.08-25.42,p=0.002),2.85(95%CI:1.11-7.31,p=0.030),2.62(95%CI:1.12-6.13,p=0.027),2.44(95%CI:1.25-4.76,p=0.009),and 1.5(95%CI:1.10-2.04,p=0.009),respectively.We also observed that patients with mild/moderate TBI(AIS≤3)had a 50%probability of developing CE 19.7 h after injury(χ^(2)=13.82,adjusted R2=0.51),while patients with severe TBI(AIS>3)developed CE after 12.5 h(χ^(2)=18.48,adjusted R2=0.54).Finally,we conducted a receiver operator characteristic curve analysis of CE time,which showed an area under the curve of 0.744 and 0.672 for severe and mild/moderate TBI,respectively.Conclusion:Our study found that the onset of CE in individuals with TBI resulting from RTAs was correlated with the severity of the injury.Specifically,those with more severe injuries experienced an earlier onset of CE.These findings suggest that there is a critical time window for clinical intervention in cases of CE secondary to TBI.

Need for standardized evidence-based in trauma care report

Since medical science is a kind of empirical discipline,the mainpurposes of biomedical journals are to publish the up-to-dateconvincing clinical investigations from medical personnel,and torecommend thefindings to more clinical practitioners.These pub-lications are often presented by form of case report,case-controlstudy,cohort study,retrospective study,prospective study,andeven meta-analysis,etc.

Blast injuries with contrasting outcomes treated by military surgery strategies:A case report

The treatment strategy for blast injuries is closely linked to the clinical outcome of blast injury casualties.However,the application of military surgery experience to blast injuries caused by production safety accidents is relatively uncommon.In this study,the authors present 2 cases of blast injuries caused by one gas explosion,both cases involved individuals of the same age and gender and experienced similar degree of injury.The authors highlight the importance of using a military surgery treatment strategy,specifically emphasizing the need to understand the concept of damage control and disposal.It is recommended that relevant training in this area should be strengthened to improve the clinical treatment of such injuries.This study provides a valuable reference for healthcare professionals dealing with blast injuries.

Discovering deaminases using AlphaFold2:a strategy to search for tool proteins for gene editing

A recent study by Huang et al.published in Cell reported the application of AlphaFold2 to forecast the structures of deaminase proteins and cluster them based on structural similarity,creating a truncated Sdd that can be used as a cytosine base editor(CBE)to be integrated into a single adeno-associated virus(AAV)1 This ground-breaking study aided by the artificial intelligence system would largely broaden the utility of tool proteins for gene editing.

Sensory neurons: unveiling the symphony of wound healing

In a recent paper published in Nature,Lu et al.reveal a pivotal role of Nav1.8+nociceptor-released neuropeptide calcitonin generelated peptide(CGRP)in modulating the activities of myeloid cells during skin and muscle injury repair.This study demonstrated the significant impact of sensory neurons on injuryinduced inflammation and wound healing.

Total body water percentage and 3rd space water are novel risk factors for training-related lower extremity muscle injuries in young males

Purpose:To identify the risk factors for training-related lower extremity muscle injuries in young males by a non-invasive method of body composition analysis.Methods:A total of 282 healthy young male volunteers aged 18-20 years participated in this cohort study.Injury location,degree,and injury rate were adjusted by a questionnaire based on the overuse injury assessment methods used in epidemiological studies of sports injuries.The occurrence of training injuries is monitored and diagnosed by physicians and treated accordingly.The body composition was measured using the BodyStat QuadScan 4000 multifrequency Bio-impedance system at 5,50,100 and 200 kHz to obtain 4 impedance values.The Shapiro-Wilk test was used to check whether the data conformed to a normal distribution.Data of normal distribution were shown as mean±SD and analyzed by t-test,while those of non-normal distribution were shown as median(Q1,Q3)and analyzed by Wilcoxon rank sum test.The receiver operator characteristic curve and logistic regression analysis were performed to investigate risk factors for developing training-related lower extremity injuries and accuracy.Results:Among the 282 subjects,78(27.7%)developed training injuries.Lower extremity training injuries revealed the highest incidence,accounting for 23.4%(66 cases).These patients showed higher percentages of lean body mass(p=0.001),total body water(TBW,p=0.006),extracellular water(p=0.020)and intracellular water(p=0.010)as well as a larger ratio of basal metabolic rate/total weight(p=0.006),compared with those without lower extremity muscle injuries.On the contrary,the percentage of body fat(p=0.001)and body fat mass index(p=0.002)were lower.Logistic regression analysis showed that TBW percentage>65.35%(p=0.050,odds ratio=3.114)and 3rd space water>0.95%(p=0.045,odds ratio=2.342)were independent risk factors for lower extremity muscle injuries.Conclusion:TBW percentage and 3rd space water measured with bio-impedance method are potential risk factors for predicting the incidence of lower extremity muscle injuries in young males following training.

Bitter receptor TAS2R138 facilitates lipid droplet degradation in neutrophils during Pseudomonas aeruginosa infection

Bitter receptors function primarily in sensing taste,but may also have other functions,such as detecting pathogenic organisms due to their agile response to foreign objects.The mouse taste receptor type-2 member 138(TAS2R138)is a member of the G-protein-coupled bitter receptor family,which is not only found in the tongue and nasal cavity,but also widely distributed in other organs,such as the respiratory tract,gut,and lungs.Despite its diverse functions,the role of TAS2R138 in host defense against bacterial infection is largely unknown.Here,we show that TAS2R138 facilitates the degradation of lipid droplets(LDs)in neutrophils during Pseudomonas aeruginosa infection through competitive binding with PPARG(peroxisome proliferator-activated receptor gamma)antagonist:A/-(3-oxododecanoyl)-L-homoserine lactone(AHL-12),which coincidently is a virulence-bound signal produced by this bacterium(P.aeruginosa).The released PPARG then migrates from nuclei to the cytoplasm to accelerate the degradation of LDs by binding PLIN2(perilipin-2).Subsequently,the TAS2R138-AHL-12 complex targets LDs to augment their degradation,and thereby facilitating the clearance of AHL-12 in neutrophils to maintain homeostasis in the local environment.These findings reveal a crucial role for TAS2R138 in neutrophil-mediated host immunity against P.aeruginosa infection.

Applications and challenges of CRISPR-Cas gene-editing to disease treatment in clinics

Clustered regularly interspaced short palindromic repeats(CRISPR)-associated systems(Cas)are efficient tools for targeting specific genes for laboratory research,agricultural engineering,biotechnology,and human disease treatment.Cas9,by far the most extensively used gene-editing nuclease,has shown great promise for the treatment of hereditary diseases,viral infection,cancers,and so on.Recent reports have revealed that some other types of CRISPR-Cas systems may also have surprising potential to join the fray as gene-editing tools for various applications.Despite the rapid progress in basic research and clinical tests,some underlying problems present continuous,significant challenges,such as editing efficiency,relative difficulty in delivery,off-target effects,immunogenicity,etc.This article summarizes the applications of CRISPR-Cas from bench to bedside and highlights the current obstacles that may limit the usage of CRISPR-Cas systems as gene-editing toolkits in precision medicine and offer some viewpoints that may help to tackle these challenges and facilitate technical development.CRISPR-Cas systems,as a powerful gene-editing approach,will offer great hopes in clinical treatments for many individuals with currently incurable diseases.

PDGFR kinase inhibitor protects against septic death via regulation of BTLA

Sepsis,defined as life-threatening organ failure caused by a dysregulated host response to severe infection,is a major cause of death among intensive care unit patients.Therapies targeting on immunomodulatory is a new research field in sepsis treatment.B-and T-lymphocyte attenuator(BTLA)is an inhibitory costimulatory factor molecule of B and T lymphocytes.Studies have shown that elevated expression of BTLA in lymphocytes can reduce mortality in sepsis,but its regulatory compounds and the underlying mechanism remains to be elucidated.Here,we show that treatment with CP-673451 significantly decreases mortality of septic mouse.CP-673451 is a PDGFR kinase inhibitor which can promote the expression of BTLA,inhibit the release of chemokines such as CXCL13,and reduce first the chemotaxis of B cells to the peripheral blood and vital organs.CP-673451 also inhibits both the release of cytokines and chemokines such as IL-1β,IL-6,IL-10,TNF-α,CCL1,CCL2 and CCL7 and reduces both the chemotactic ability of T cells.This suggests that CP-673451 may prevent septic death by inhibiting lymphocyte chemotaxis and alleviating“cytokine storm”.In conclusion,our study provides a new therapeutic target and an effective compound for sepsis treatment.

Electrotaxis of alveolar epithelial cells in direct-current electric fields

Purpose:This study aims to elucidate the electrotaxis response of alveolar epithelial cells(AECs)in direct-current electric fields(EFs),explore the impact of EFs on the cell fate of AECs,and lay the foundation for future exploitation of EFs for the treatment of acute lung injury.Methods:AECs were extracted from rat lung tissues using magnetic-activated cell sorting.To elucidate the electrotaxis responses of AECs,different voltages of EFs(0,50,100,and 200 mV/mm)were applied to two types of AECs,respectively.Cell migrations were recorded and trajectories were pooled to better demonstrate cellular activities through graphs.Cell directionality was calculated as the cosine value of the angle formed by the EF vector and cell migration.To further demonstrate the impact of EFs on the pulmonary tissue,the human bronchial epithelial cells transformed with Ad12-SV402B(BEAS-2B cells)were obtained and experimented under the same conditions as AECs.To determine the influence on cell fate,cells underwent electric stimulation were collected to perform Western blot analysis.Results:The successful separation and culturing of AECs were confirmed through immunofluorescence staining.Compared with the control,AECs in EFs demonstrated a significant directionality in a voltage-dependent way.In general,type I alveolar epithelial cells migrated faster than type II alveolar epithelial cells,and under EFs,these two types of cells exhibited different response threshold.For type II alveolar epithelial cells,only EFs at 200 mV/mm resulted a significant difference to the velocity,whereas for,EFs at both 100 mV/mm and 200 mV/mm gave rise to a significant difference.Western blotting suggested that EFs led to an increased expression of a AKT and myeloid leukemia 1 and a decreased expression of Bcl-2-associated X protein and Bcl-2-like protein 11.Conclusion:EFs could guide and accelerate the directional migration of AECs and exert antiapoptotic effects,which indicated that EFs are important biophysical signals in the re-epithelialization of alveolar epithelium in lung injury.

CRISPR base editor treats premature-aging syndrome

A recent paper published in Nature by Koblan et al.reported the use of CRISPR-mediated adenine base editor(ABE)to repair mutations of the Hutchinson-Gilford progeria syndrome(HGPS or progeria),attenuate symptoms,and extend lifespan of mice(Fig.1),representing a major advance in design of treatments for human accelerated-ageing disorders and potentially other genetic diseases.

CRISPR-mediated RNA base editing:a promising strategy to rescue deafness

A recent study published in Science Translational Medicine by Xiao et al.reported the use of mini dCas13X-based adenosine base editor(mxABE)to correct a mutant transcript and rescued the auditory function of an autosomal dominant hearing loss disease(Fig.1).

Fossicking for microbial defense system:novel antiviral immunity

A recent paper in Science by Gao et al.extended a comprehensive comparative genomics approach to identify new antiviral systems in prokaryotes for combating invading phages.1 These defense systems manifest a variety of host defense mechanisms by utilizing enzymatic activities including reverse transcriptases,adenosine deaminases of RNA editing,and retroms(Fig.1).Some of these antiviral systems not only enrich our understanding the phage-bacterial interaction but also represent a versatile,powerful tool for biomedical research and biotechnological applications.