Irisin in thyroid diseases.

Irisin, a hormone-like adipo-myokine, has garnered considerable attention in recent years for its potential impact in metabolic diseases. Its physiological effects are similar to those of thyroid hormones, prompting numerous investigations into potential correlations and interactions between irisin and thyroid function through various in vitro and animal experiments. However, existing studies suggest that the relationship between irisin and thyroid diseases is highly complex and multifaceted. In this paper, we have summarized the research results on serum irisin and thyroid function, providing an overview of advancements and constraints in current research on irisin and thyroid hormones. The aim is to offer insights and directions for future clinical trials in this field.

CRISPR-Mediated Viral Gene Knockout to Investigate Viral Evasion of Antiviral Innate Immunity.

The innate immune system relies on a variety of pathogen recognition receptors (PRRs) as the first line of defense against pathogenic invasions. Viruses have evolved multiple strategies to evade the host immune system through coevolution with hosts. The CRISPR-Cas system is an adaptive immune system in bacteria or archaea that defends against viral reinvasion by targeting nucleic acids for cleavage. Based on the characteristics of Cas proteins and their variants, the CRISPR-Cas system has been developed into a versatile gene-editing tool capable of gene knockout or knock-in operations to achieve genetic variations in organisms. It is now widely used in the study of viral immune evasion mechanisms. This chapter will introduce the use of the CRISPR-Cas9 system for editing herpes simplex virus 1 (HSV-1) genes to explore the mechanisms by which HSV-1 evades host innate immunity and the experimental procedures involved.

CRISPR-Mediated Library Screening of Gene-Knockout Cell Lines for Investigating Antiviral Innate Immunity.

The application of CRISPR-mediated library screening has fundamentally transformed functional genomics by revealing the complexity of virus-host interactions. This protocol describes the use of CRISPR-mediated library screening to identify key functional genes regulating the innate immune response to PEDV infection. We detail a step-by-step process, starting from the design and construction of a customized CRISPR knockout library targeting genes involved in innate immunity to the effective delivery of these constructs into cells using lentiviral vectors. Subsequently, we outline the process of identifying functional genes postviral attack, including the use of next-generation sequencing (NGS), to analyze and identify knockout cells that exhibit altered responses to infection. This integrated approach provides researchers in immunology and virology with a resource and a robust framework for uncovering the genetic basis of host-pathogen interactions and the arsenal of the innate immune system against viral invasions.

CRISPR-Mediated Construction of Gene-Knockout Mice for Investigating Antiviral Innate Immunity.

With the rapid development of CRISPR-Cas9 technology, gene editing has become a powerful tool for studying gene function. Specifically, in the study of the mechanisms by which natural immune responses combat viral infections, gene knockout mouse models have provided an indispensable platform. This article describes a detailed protocol for constructing gene knockout mice using the CRISPR-Cas9 system. This field focuses on the design of single-guide RNAs (sgRNAs) targeting the antiviral immune gene cGAS, embryo microinjection, and screening and verification of gene editing outcomes. Furthermore, this study provides methods for using cGAS gene knockout mice to analyze the role of specific genes in natural immune responses. Through this protocol, researchers can efficiently generate specific gene knockout mouse models, which not only helps in understanding the functions of the immune system but also offers a powerful experimental tool for exploring the mechanisms of antiviral innate immunity.

Mass Spectrometry-Based Direct Sequencing of tRNAs De Novo and Quantitative Mapping of Multiple RNA Modifications.

Despite the extensive use of next-generation sequencing (NGS) of RNA, simultaneous direct sequencing and quantitative mapping of multiple RNA nucleotide modifications remains challenging. Mass spectrometry (MS)-based sequencing can directly sequence all RNA modifications without being limited to specific ones, but it requires a perfect MS ladder that few tRNAs can provide. Here, we describe an MS ladder complementation sequencing approach (MLC-Seq) that circumvents the perfect ladder requirement, allowing de novo MS sequencing of full-length heterogeneous cellular tRNAs with multiple nucleotide modifications at single-nucleotide precision. Unlike NGS-based methods, which lose RNA modification information, MLC-Seq preserves RNA sequence diversity and modification information, revealing new detailed stoichiometric tRNA modification profiles and their changes upon treatment with the dealkylating enzyme AlkB. It can also be combined with reference sequences to provide quantitative analysis of diverse tRNAs and modifications in total tRNA samples. MLC-Seq enables systematic, quantitative, and site-specific mapping of RNA modifications, revealing the truly complete informational content of tRNA.

CAFs-derived TIAM1 Promotes OSCC Cell Growth and Metastasis by Regulating ZEB2.

Previous studies have suggested that cancer-associated fibroblasts (CAFs) within the tumor microenvironment are a critical factor in tumorigenesis and tumor development. However, the regulatory mechanisms of CAFs on oral squamous cell carcinoma (OSCC) are poorly defined. A CAF-conditioned medium (CAF-CM) was collected and applied to culture OSCC cells. Then, cell viability, proliferation, migration, and invasion were evaluated using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Transwell, and scratch healing assays. T-Lymphoma Invasion and Metastasis 1 (TIAM1), zinc finger E-box-binding homeobox 2 (ZEB2), E-cadherin, and increased N-cadherin protein levels were determined using western blot. TIAM1 and ZEB2 mRNA levels were measured using real-time quantitative polymerase chain reaction (RT-qPCR). Their interaction was analyzed using Co-immunoprecipitation (Co-IP) assay. SCC25 cells with or without (TIAM1-silencing) CAFs were subcutaneously inoculated in nude mice to assess the effect of TIAM1 in CAFs on OSCC tumor growth in vivo. CAFs expedited OSCC cell proliferation, migration, invasion, and EMT. TIAM1 and ZEB2 expression were upregulated in OSCC patients and OSCC cells, and the TIAM1 level was much higher in CAFs than in OSCC cells. Furthermore, TIAM1 knockdown in CAFs might partly abolish the promotion of CAFs on OSCC cell development, implying that TIAM1 might be secreted by CAFs into the culture medium to exert its effects inside OSCCs. TIAM1 might increase ZEB2 expression, and ZEB2 upregulation might partly reverse the repression of TIAM1 silencing in CAFs on OSCC cell malignant behaviors. In vivo studies confirmed that CAFs accelerated OSCC tumor growth, these effects were partially counteracted by TIAM1 downregulation. Overall, TIAM1 secreted by CAFs could expedite OSCC cell growth and metastasis by regulating ZEB2, providing a promising therapeutic target for OSCC treatment.

An expanded odorant-binding protein mediates host cue detection in the parasitic wasp Baryscapus dioryctriae basis of the chromosome-level genome assembly analysis.

BACKGROUND: Baryscapus dioryctriae (Chalcidodea: Eulophidae) is a parasitic wasp that parasitizes the pupae of many Pyralidae members and has been used as a biological control agent against Dioryctria pests of pinecones. RESULTS: This B. dioryctriae assembly has a genome size of 485.5 Mb with a contig N50 of 2.17 Mb, and scaffolds were assembled onto six chromosomes using Hi-C analysis, significantly increasing the scaffold N50 to 91.17 Mb, with more than 96.13% of the assembled bases located on chromosomes, and an analysis revealed that 94.73% of the BUSCO gene set. A total of 54.82% (279.27 Mb) of the assembly was composed of repetitive sequences and 24,778 protein-coding genes were identified. Comparative genomic analysis demonstrated that the chemosensory perception, genetic material synthesis, and immune response pathways were primarily enriched in the expanded genes. Moreover, the functional characteristics of an odorant-binding protein (BdioOBP45) with ovipositor-biased expression identified from the expanded olfactory gene families were investigated by the fluorescence competitive binding and RNAi assays, revealing that BdioOBP45 primarily binds to the D. abietella-induced volatile compounds, suggesting that this expanded OBP is likely involved in locating female wasp hosts and highlighting a direction for future research. CONCLUSIONS: Taken together, this work not only provides new genomic sequences for the Hymenoptera systematics, but also the high-quality chromosome-level genome of B. dioryctriae offers a valuable foundation for studying the molecular, evolutionary, and parasitic processes of parasitic wasps.

Proteasomes safeguard the plant stress granule homeostasis.

In this issue of Molecular Cell, Xie et al.1 revealed that the proteasome is a constitutive component of plant stress granules (SGs), and that enhanced proteolytic activity is essential for efficient SG disassembly and plant survival during the stress response.

Paternal hypercholesterolemia elicits sex-specific exacerbation of atherosclerosis in offspring.

Emerging studies suggest that various parental exposures affect offspring cardiovascular health, yet the specific mechanisms, particularly the influence of paternal cardiovascular disease (CVD) risk factors on offspring cardiovascular health, remain elusive. The present study explores how paternal hypercholesterolemia affects offspring atherosclerosis development using the LDL receptor-deficient (LDLR-/-) mouse model. We found that paternal high-cholesterol diet feeding led to significantly increased atherosclerosis in F1 female, but not male, LDLR-/- offspring. Transcriptomic analysis highlighted that paternal hypercholesterolemia stimulated proatherogenic genes, including Ccn1 and Ccn2, in the intima of female offspring. Sperm small noncoding RNAs (sncRNAs), particularly transfer RNA-derived (tRNA-derived) small RNAs (tsRNAs) and rRNA-derived small RNAs (rsRNAs), contribute to the intergenerational transmission of paternally acquired metabolic phenotypes. Using a newly developed PANDORA-Seq method, we identified that high-cholesterol feeding elicited changes in sperm tsRNA/rsRNA profiles that were undetectable by traditional RNA-Seq, and these altered sperm sncRNAs were potentially key factors mediating paternal hypercholesterolemia-elicited atherogenesis in offspring. Interestingly, high-cholesterol feeding altered sncRNA biogenesis-related gene expression in the epididymis but not testis of LDLR-/- sires; this may have led to the modified sperm sncRNA landscape. Our results underscore the sex-specific intergenerational effect of paternal hypercholesterolemia on offspring cardiovascular health and contribute to the understanding of chronic disease etiology originating from parental exposures.

miR-137: a potential therapeutic target for lung cancer.

Lung cancer is a prevalent malignancy and the leading cause of cancer-related deaths, posing a significant threat to human health. Despite advancements in treatment, the prognosis for lung cancer patients remains poor due to late diagnosis, cancer recurrence, and drug resistance. Epigenetic research, particularly in microRNAs, has introduced a new avenue for cancer prevention and treatment. MicroRNAs, including miR-137, play a vital role in tumor development by regulating various cellular processes. MiR-137 has garnered attention for its tumor-suppressive properties, with studies showing its potential in inhibiting cancer progression. In lung cancer, miR-137 is of particular interest, with numerous reports exploring its role and mechanisms. A comprehensive review is necessary to consolidate current evidence. This review highlights recent studies on miR-137 in lung cancer, covering cell proliferation, migration, apoptosis, drug resistance, and therapy, emphasizing its potential as a biomarker and therapeutic target for lung cancer treatment and prognosis.

Genome-wide investigation of the TIFY transcription factors in alfalfa (Medicago sativa L.): identification, analysis, and expression.

BACKGROUND: Alfalfa (Medicago sativa L.) is an essential leguminous forage with high nutrition and strong adaptability. The TIFY family is a plant-specific transcription factor identified in many plants. However, few reports have been reported on the phylogenetic analysis and gene expression profiling of TIFY family genes in alfalfa. RESULT: A total of 84 TIFY genes belonging to 4 categories were identified in alfalfa, including 58 MsJAZs, 18 MsZMLs, 4 MsTIFYs and 4 MsPPDs, respectively. qRT-PCR data from 8 genes in different tissues revealed that most MsTIFY genes were highly expressed in roots. The expression of MsTIFY14 was up-regulated after different times in both thrips-resistant and susceptible alfalfa after thrips feeding, and the expression of the remaining MsTIFYs had a strong correlation with the time of thrips feeding. Different abiotic stresses, including drought, salt, and cold, could induce or inhibit the expression of MsTIFY genes to varying degrees. In addition, the eight genes were all significantly up-regulated by JA and/or SA. Interestingly, MsTIFY77 was induced considerably by all the biotic, abiotic, or plant hormones (JA or SA) except ABA. CONCLUSION: Our study identified members of the TIFY gene family in alfalfa and analyzed their structures and possible functions. It laid the foundation for further research on the molecular functions of TIFYs in alfalfa.

Microvesicles derived from mesenchymal stem cells inhibit acute respiratory distress syndrome-related pulmonary fibrosis in mouse partly through hepatocyte growth factor.

BACKGROUND: Pulmonary fibrosis is one of the main reasons for the high mortality rate among acute respiratory distress syndrome (ARDS) patients. Mesenchymal stromal cell-derived microvesicles (MSC-MVs) have been shown to exert antifibrotic effects in lung diseases. AIM: To investigate the effects and mechanisms of MSC-MVs on pulmonary fibrosis in ARDS mouse models. METHODS: MSC-MVs with low hepatocyte growth factor (HGF) expression (siHGF-MSC-MVs) were obtained via lentivirus transfection and used to establish the ARDS pulmonary fibrosis mouse model. Following intubation, respiratory mechanics-related indicators were measured via an experimental small animal lung function tester. Homing of MSC-MVs in lung tissues was investigated by near-infrared live imaging. Immunohistochemical, western blotting, ELISA and other methods were used to detect expression of pulmonary fibrosis-related proteins and to compare effects on pulmonary fibrosis and fibrosis-related indicators. RESULTS: The MSC-MVs gradually migrated and homed to damaged lung tissues in the ARDS model mice. Treatment with MSC-MVs significantly reduced lung injury and pulmonary fibrosis scores. However, low expression of HGF (siHGF-MSC-MVs) significantly inhibited the effects of MSC-MVs (P < 0.05). Compared with the ARDS pulmonary fibrosis group, the MSC-MVs group exhibited suppressed expression of type I collagen antigen, type III collagen antigen, and the proteins transforming growth factor-ß and α-smooth muscle actin, whereas the siHGF-MVs group exhibited significantly increased expression of these proteins. In addition, pulmonary compliance and the pressure of oxygen/oxygen inhalation ratio were significantly lower in the MSC-MVs group, and the effects of the MSC-MVs were significantly inhibited by low HGF expression (all P < 0.05). CONCLUSION: MSC-MVs improved lung ventilation functions and inhibited pulmonary fibrosis in ARDS mice partly via HGF mRNA transfer.

Systemic Immune-Inflammation Indices Could Be Additional Predictive Markers for Cesarean Scar Pregnancy.

PROBLEM: Cesarean scar pregnancy (CSP) is characterized by a gestational sac fully or partially implanted in the scar from a previous cesarean section. Systemic immune-inflammation indices (SIIs) have recently been discussed as additional diagnostic markers in placenta accreta and preeclampsia. CSP shares a similar pathogenesis with these diseases, suggesting that assessing the SIIs and neutrophil-to-lymphocyte ratio (NLR) could enhance additional predictability in diagnosing CSP. METHOD OF STUDY: In this study, we analyzed the complete blood counts between 264 women who were confirmed with CSP by ultrasound and 295 women who underwent elective termination. RESULTS: The mean counts of total white cells and neutrophils were significantly higher, whereas the counts of monocytes, lymphocytes, and platelets were significantly lower in the CSP group compared to the control group (p < 0.001). Additionally, the SII, systemic inflammation response index (SIRI), or NLR was significantly higher in the CSP group compared to the control group (p < 0.0001). Given the limited effect of SII and SIRI on the increased risk of developing CSP, the optimal cut-off value for NLR in predicting CSP was 2.87 (area under the curve [AUC] 0.656, 68% sensitivity). The optimal cut-off value for NLR in predicting type 2 CSP was 2.91 (AUC 0.690, 71% sensitivity). CONCLUSIONS: Although ultrasound or magnetic resonance imaging images are a gold standard for visualizing the gestational sac's location in the diagnosis of CSP, assessing peripheral blood tests is cost-effective, and NLR may provide additional diagnosis value for CSP.

Increased GluK1 Subunit Receptors in Corticostriatal Projection from the Anterior Cingulate Cortex Contributed to Seizure-Like Activities.

The corticostriatal connection plays a crucial role in cognitive, emotional, and motor control. However, the specific roles and synaptic transmissions of corticostriatal connection are less studied, especially the corticostriatal transmission from the anterior cingulate cortex (ACC). Here, a direct glutamatergic excitatory synaptic transmission in the corticostriatal projection from the ACC is found. Kainate receptors (KAR)-mediated synaptic transmission is increased in this corticostriatal connection both in vitro and in vivo seizure-like activities. GluK1 containing KARs and downstream calcium-stimulated adenylyl cyclase subtype 1 (AC1) are involved in the upregulation of KARs following seizure-like activities. Inhibiting the activities of ACC or its corticostriatal connection significantly attenuated pentylenetetrazole (PTZ)-induced seizure. Additionally, injection of GluK1 receptor antagonist UBP310 or the AC1 inhibitor NB001 both show antiepileptic effects. The studies provide direct evidence that KARs are involved in seizure activity in the corticostriatal connection and the KAR-AC1 signaling pathway is a potential novel antiepileptic strategy.

Dimeric Small Molecule Acceptors via Terminal-End Connections: Effect of Flexible Linker Length on Photovoltaic Performance.

The dimerization of small molecule acceptors (SMAs) holds significant potential by combining the advantages of both SMAs and polymer acceptors in realizing high power conversion efficiency (PCE) and operational stability in organic solar cells (OSCs). However, advancements in the selection and innovation of dimeric linkers are still challenging in enhancing their performance. In this study, three new dimeric acceptors, namely DY-Ar-4, DY-Ar-5, and DY-Ar-6 are synthesized, by linking two Y-series SMA subunits via an "end-to-end" strategy using flexible spacers (octyl, decyl, and dodecyl, respectively). The influence of spacer lengths on device performance is systematically investigated. The results indicate that DY-Ar-5 exhibits more compact and ordered packing, leading to an optimal morphology. OSCs based on PM6: DY-Ar-5 achieves a maximum PCE of 15.76%, attributes to enhance and balance carrier mobility, and reduce carrier recombination. This dimerization strategy using suitable non-conjugated linking units provides a rational principle for designing high-performance non-fullerene acceptors.

Reprogramming macrophage metabolism following myocardial infarction: A neglected piece of a therapeutic opportunity.

Given the global prevalence of myocardial infarction (MI) as the leading cause of mortality, there is an urgent need to devise novel strategies that target reducing infarct size, accelerating cardiac tissue repair, and preventing detrimental left ventricular (LV) remodeling. Macrophages, as a predominant type of innate immune cells, undergo metabolic reprogramming following MI, resulting in alterations in function and phenotype that significantly impact the progression of MI size and LV remodeling. This article aimed to delineate the characteristics of macrophage metabolites during reprogramming in MI and elucidate their targets and functions in cardioprotection. Furthermore, we summarize the currently proposed regulatory mechanisms of macrophage metabolic reprogramming and identify the regulators derived from endogenous products and natural small molecules. Finally, we discussed the challenges of macrophage metabolic reprogramming in the treatment of MI, with the goal of inspiring further fundamental and clinical research into reprogramming macrophage metabolism and validating its potential therapeutic targets for MI.

Influential factors of adherence to inhalation drug therapy in patients with stable chronic obstructive pulmonary disease.

OBJECTIVE: This study aimed to investigate the influential factors of adherence to inhalation drug therapy (IDT) in patients with stable chronic obstructive pulmonary disease (COPD). METHODS: A total of 243 patients with stable COPD who visited the chronic disease clinic of the respiratory department of our hospital between April 2022 and October 2022 were selected as participants using the convenience sampling method. Relevant information about all participants was collected by questionnaire for investigation, including basic information, clinical characteristics, inhaled drug names, situational awareness, dose and frequency. RESULTS: Univariate analysis revealed positive correlations between the following factors: (1) the total score of drug adherence and the total scores of the COPD knowledge questionnaire (COPD-Q), social support, subjective support, objective support and support utilisation, (2) the total score of dosage adherence and the total scores of COPD-Q, objective support and support utilisation and (3) the total score of technical standardisation and the total scores of social support, subjective support and objective support (p < 0.05). Multifactorial analysis showed that COPD health literacy, number of acute exacerbations in the past year and social support factors collectively accounted for 37.4% of the variable of patient adherence to IDT, as did COPD health literacy, modified Medical Research Council (mMRC) grading, duration of COPD, utilisation of support and marital status collectively account for 47.4% of the variable of patient dosage adherence. The goodness-of-fit of age, mMRC grading, social support, mode of residence, number of acute exacerbations in the past year and literacy to the patients' inhalation technical standardisation in the model was 47.4%. CONCLUSION: Dose adherence was predominantly influenced by COPD health literacy, mMRC grading, duration of COPD, utilisation of support and marital status. Inhalation technical standardisation was substantially limited by age, mMRC grading, social support, mode of residence, number of acute exacerbations in the past year and literacy.

Strategies of invasive snail Pomacea canaliculata during hibernation in rice fields of south China: effects of body size, sex, and soil depth.

BACKGROUND: The invasive freshwater snail Pomacea canaliculata is an agricultural pest with a certain level of tolerance to abiotic stress. After the harvest of late rice, the snails usually burrow themselves into the soil surface layers to overwinter and pose a renewed threat to rice production in the following year. Revealing the response of snails to environmental stresses is crucial for developing countermeasures to control their damage and spread. RESULTS: In this study, we conducted a 120-day in situ experiment during the winter to investigate the survival and physiological changes of hibernating snails in 0-5 and 5-10 cm soil depths, aiming to explore their overwintering strategies. Our results showed that 73.61%, 87.50%, and 90.28% of male, female, and juvenile snails survived after hibernation for 120 days in 0-10 cm soil depth, respectively. The differences in survival rates based on sex and size of snails potentially reflect the countermeasures of snails to rapidly reproduce after hibernation. Simultaneously, the hibernating snails exhibited the ability to maintain a certain level of body weight. During this period, the snails increased their antioxidant enzyme activities to cope with oxidative stress, and enhanced their lipid storage. The hibernation survival of snails was not significantly affected by different soil depths, indicating that they have the potential to hibernate into deeper soils. Furthermore, snails were capable of increasing their contents of bound water and glycerol to cope with sudden cold spells during hibernation. CONCLUSION: Our findings emphasize the adaptive changes of P. canaliculata snails overwintering in paddy soils. In future studies, the vulnerabilities of P. canaliculata during hibernation (e.g. shell characteristics, nutrient reserves, and dehydration tolerance, etc.,) should be investigated to develop effective control methods for this period. © 2024 Society of Chemical Industry.

Soil organic carbon estimation using remote sensing data-driven machine learning.

Soil organic carbon (SOC) is a crucial component of the global carbon cycle, playing a significant role in ecosystem health and carbon balance. In this study, we focused on assessing the surface SOC content in Shandong Province based on land use types, and explored its spatial distribution pattern and influencing factors. Machine learning methods including random forest (RF), extreme gradient boosting (XGBoost), and support vector machine (SVM) were employed to estimate the surface SOC content in Shandong Province using diverse data sources like sample data, remote sensing data, socio-economic data, soil texture data, topographic data, and meteorological data. The results revealed that the SOC content in Shandong Province was 8.78 g/kg, exhibiting significant variation across different regions. Comparing the model error and correlation coefficient, the XGBoost model showed the highest prediction accuracy, with a coefficient of determination (R²) of 0.7548, root mean square error (RMSE) of 7.6792, and relative percentage difference (RPD) of 1.1311. Elevation and Clay exhibited the highest explanatory power in clarifying the surface SOC content in Shandong Province, contributing 21.74% and 13.47%, respectively. The spatial distribution analysis revealed that SOC content was higher in forest-covered mountainous regions compared to cropland-covered plains and coastal areas. In conclusion, these findings offer valuable scientific insights for land use planning and SOC conservation.

Safety assessment of coronary arteries during left bundle branch area pacing.

BACKGROUND: This study aimed to assess the safety of left bundle branch area pacing (LBBAP) by measuring the distance from the tip of the electrode to the nearby coronary artery with a nine-partition grid method. METHODS: From January 2019 to October 2020, patients who underwent LBBAP and postoperative coronary angiography in the Second Affiliated Hospital of Nanchang University were included in the study. The patients' fluoroscopic images of LBBAP and coronary angiography were collected and analyzed. Changes in the ST­T segment in the electrocardiogram (ECG), serum troponin, and myocardial enzyme profiles were observed before and after the LBBAP procedure. RESULTS: A total of 50 patients were included in this study, of whom 46 patients underwent implantation with a pacemaker and 4 patients received an implantable cardioverter defibrillator (ICD). The pacing electrodes were confined to the posterior-middle (PM), median (M), Posterior inferior (PI), and middle inferior (MI) positions of the two-dimensional nine-square grid or in the junction area of the above positions, and were concentrated in the rectangle formed by the line of the center points of the four positions. The average vertical distances from the electrode tip to the left anterior descending branch artery (LAD), posterior descending branches (PD) and the left posterior ventricular branches (PL) were 19.69 ± 8.72 mm, 26.09 ± 8.02 mm, and 21.11 ± 7.86 mm, respectively; the minimum was 5.28 mm, 9.51 mm, and 8.69 mm, respectively. Coronary angiography in all patients showed no significant injury to the ventricular septal branch; however, we observed elevated serum troponin and changes in ST­T segment in ECG. CONCLUSION: The study demonstrates that pacing electrodes in LBBAP can be safely implanted over a wide range. Coronary arteries are likely to be safe when the pacing electrodes are located within the rectangle formed by the line connecting the PM, M, PI, and MI zone centroids. The left bundle branch can be quickly captured and the safety of the coronary artery can be improved by locating the electrode in the posterior-mid zone. The potential risk of injury to the LAD from the electrode is greater compared with the PD.