Role of interferon alpha-inducible protein 6 in modulating the proliferation, apoptosis and senescence of oesophageal squamous cell carcinoma cells.

Oesophageal cancer is one of the most malignant tumors worldwide. Dysfunction of interferon alpha-inducible protein 6 (IFI6) has been implicated in numerous human diseases, including cancer. We performed the study to investigate the function and potential molecular pathways of IFI6 in oesophageal squamous cell carcinoma (ESCC) cells. IFI6 expression was analysed using databases-derived data and paraffin-embedded tissue samples. CCK-8-based analyses and EdU staining, colony formation, ß-galactosidase staining and Annexin V/PI double-staining assays were used to determine the influence of IFI6 on cell growth, senescence and apoptosis. Tumor growth in vivo was investigated in mouse xenograft models. RNA sequencing (RNA-seq) was performed to identify the transcripts and pathways affected by IFI6. The results showed that IFI6 expression was elevated in ESCC and correlated with poor clinical prognosis (P<0.05). IFI6 was overexpressed and silenced in TE-1 and TE-10 cells using lentiviruses. Upregulation of IFI6 promoted cell growth both in vitro and in vivo, whereas downregulation induced opposite effects. IFI6 overexpression inhibited cell senescence and apoptosis but did not influence cell cycle progression, while IFI6 downregulation increased cell senescence and apoptosis. RNA-seq revealed that 3 mRNAs (EPHA5, CLIP1 and GTF2F2) were consistently associated with both IFI6 overexpression and silencing. IFI6 appeared to modulate TE-1 cells via complex mechanisms. In conclusion, IFI6 plays a positive role in the proliferation of ESCC cells both in vitro and in vivo, which could be a novel therapeutic target for treating ESCC.

[Clinical and genetic characteristics of 9 rare cases with coexistence of dual genetic diagnoses].

Objective: To analyze the clinical and genetic characteristics of pediatric patients with dual genetic diagnoses (DGD). Methods: Clinical and genetic data of pediatric patients with DGD from January 2021 to February 2022 in Peking University First Hospital were collected and analyzed retrospectively. Results: Among the 9 children, 6 were boys and 3 were girls. The age of last visit or follow-up was 5.0 (2.7,6.8) years. The main clinical manifestations included motor retardation, mental retardation, multiple malformations, and skeletal deformity. Cases 1-4 were all all boys, showed myopathic gait, poor running and jumping, and significantly increased level of serum creatine kinase. Disease-causing variations in Duchenne muscular dystrophy (DMD) gene were confirmed by genetic testing. The 4 children were diagnosed with DMD or Becker muscular dystrophy combined with a second genetic disease, including hypertrophic osteoarthropathy, spinal muscular atrophy, fragile X syndrome, and cerebral cavernous malformations type 3, respectively. Cases 5-9 were clinically and genetically diagnosed as COL9A1 gene-related multiple epiphyseal dysplasia type 6 combined with NF1 gene-related neurofibromatosis type 1, COL6A3 gene-related Bethlem myopathy with WNT1 gene-related osteogenesis imperfecta type XV, Turner syndrome (45, X0/46, XX chimera) with TH gene-related Segawa syndrome, Chromosome 22q11.2 microduplication syndrome with DYNC1H1 gene-related autosomal dominant lower extremity-predominant spinal muscular atrophy-1, and ANKRD11 gene-related KBG syndrome combined with IRF2BPL gene-related neurodevelopmental disorder with regression, abnormal movement, language loss and epilepsy. DMD was the most common, and there were 6 autosomal dominant diseases caused by de novo heterozygous pathogenic variations. Conclusions: Pediatric patients with coexistence of double genetic diagnoses show complex phenotypes. When the clinical manifestations and progression are not fully consistent with the diagnosed rare genetic disease, a second rare genetic disease should be considered, and autosomal dominant diseases caused by de novo heterozygous pathogenic variation should be paid attention to. Trio-based whole-exome sequencing combining a variety of molecular genetic tests would be helpful for precise diagnosis.

[Advances in research of interchangeable immunization with live attenuated Japanese encephalitis vaccines and inactivated vaccines].

Japanese encephalitis (JE) virus is the leading cause of vaccine-preventable encephalitis in Asia and the Western Pacific, which mainly invades central nervous system. Vaccination is the most important strategy to prevent JE. Currently, both live attenuated Japanese encephalitis vaccines (JE-L) and inactivated vaccines (JE-I) are in use. Due to the supply of vaccines and the personal choice of recipients, there will be a demand for interchangeable immunization of these two vaccines. However, relevant research is limited. By reviewing domestic and foreign research evidence, this article summarizes the current situation of the interchangeable use of JE-L and JE-I, and makes recommendations when the interchangeable immunization is in urgent need, so as to provide reference for practical vaccination and policymaking in China.

[Evaluating the real-world vaccine effectiveness using a regression discontinuity design].

Estimating the actual real-world effectiveness of the vaccine is an essential part of the post-marketing evaluation. This regression discontinuity design (RDD) using observational data is designed to quantify the effect of an intervention when eligibility for the intervention is based on a defined cutoff as age, making it suited to estimate vaccine effects. This approach can avoid the high cost and ethical issues; overcome difficulties in the organization and practice process in randomized controlled trials, which leads to a higher level of causal inference evidence and more realistic results. Here, we describe key features of RDD in general, and then specific scenarios, with examples, to illustrate that RDD are an essential tool for advancing our understanding of vaccine effects.

Total bone mineral density is inversely associated with stroke: a family osteoporosis cohort study in rural China.

BACKGROUND: The relationship of osteoporosis and stroke is still not fully clarified. Apart from the well-known risk factors for stroke, bone mineral density (BMD) has gained more interest in recent years. AIM: To further elucidate the relationship between BMD and stroke risk, a prospective cohort study in the Chinese rural population was conducted. DESIGN: Retrospective analysis of a family osteoporosis cohort. METHODS: Our subjects were selected from an osteoporosis cohort conducted in Anqing, China. All participants underwent a questionnaire assessment, clinical examinations and laboratory assessments. During the follow-up period, the number of people who had a stroke was recorded. Generalized estimating equation regression analysis was performed to determine the significance of the association between BMD and stroke. RESULTS: A total of 17868 people were included. A two-way interaction test of sex and BMD on stroke was significant (P = 0.002). There was a significant difference in BMD and stroke morbidity in the male group (P = 0.003). When BMD was assessed as quartiles and the lowest quartile was used as reference, a significantly lower risk for stroke was observed in Q2-4. Notably, no significant difference was observed in female participants with adjusted odds ratio (P > 0.05). The P-value for interaction was calculated. The body mass index (P = 0.014) and waist-to-hip ratio (P = 0.027) were found to be significantly associated with BMD and stroke risk in female participants. CONCLUSIONS: In Chinese rural areas, total BMD may negatively correlated with stroke, especially in men.

[A comparative analysis of the efficacy of Advance(®) medial pivot prosthesis knee arthroplasty with posterior cruciate ligament retention or substituting based on propensity score matching].

Objective: To compare the clinical outcome of posterior cruciate ligament (PCL) retention type and PCL substituting type using Advance(®) Medial Pivot (AMP) inner-axis knee prosthesis. Methods: A retrospective analysis was conducted on the cases of total knee arthroplasty (TKA) with AMP prosthesis in the Affiliated Hospital of Qingdao University from January 2011 to September 2016. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), American Knee Society Knee Score (KSS) clinical scores, KSS functional scores and knee-joint range of motion (ROM) before and after TKA, and Forgotten Joint Scores (FJS) after TKA were collected. The matching group was obtained by 1∶1 propensity score matching (PSM). Results: Complete scoring data were obtained in 47 knees of CR group and 1 059 knees of CS group, there were statistical differences in age, sex, body mass index, preoperative WOMAC score, preoperative KSS function score and ROM between the two groups (all P<0.05), except preoperative KSS clinical score (25±4 and 24±7, respectively, t=0.82, P=0.41). With the PSM matching, 37 knees in CR group and 37 knees in CS group were obtained. No significant differences in preoperative indexes were found between the matching groups (all P>0.05). The WOMAC, KSS clinical scores, KSS functional scores and ROM after TKA in each matching group were all much better than those before TKA (all P<0.05); no statistical differences existed in WOMAC, KSS clinical scores, KSS functional scores, ROM and FJS after TKA between the matching groups (all P>0.05). One PCL injury was found in CR matching group after TKA. Incidence of complications in the CR matching group (8.1%) was higher than that in the CS matching group (2.7%), but there was no statistical difference (χ(2)=1.04, P=0.31). Conclusions: When using AMP prosthesis, both CR insert and CS insert can obtain good clinical results in TKA. The potential risk of PCL injury and other complications after CR TKA makes it necessary for surgeons to carefully select an appropriate type of prosthesis.

Efficient electrochemical generation of ferrate(VI) by iron coil anode imposed with square alternating current and treatment of antibiotics.

Anode passivation is still a main challenge for the electrochemical generation of ferrate(VI, Fe(VI)), leading to the reduction of Fe(VI) production efficiency. In this study, cyclic voltammetry, scanning electronic microscopy, and electrochemical impedance spectroscopy were used to select better anode electrode configurations (iron wire, iron gauze, and iron coil). The results indicate that iron coil had the least degree of passivation. Different imposed current waveforms during the electrochemical generation of Fe(VI) were also investigated, and the iron coil imposed with square alternating current (AC) wave can mitigate the anode passivation, resulting in higher Fe(VI) production efficiency. The optimum conditions for the electrochemical generation of Fe(VI) were evaluated and the optimum temperature (40 ℃), current density (10 mA/cm2), AC cycle period (15 s) and electrolyte concentrations (14 M NaOH) were identified. As a result, 0.12 mol/L Fe(VI) concentration and over 50% of current efficiency can be achieved after 3 h electrolysis. The generated Fe(VI) solution was further applied to oxidize doxycycline(DOX) and sulfadiazine(SDZ) as typical antibiotics. Over 80% of DOX can be removed at a Fe(VI) to DOX molar ratio of 5:1 (pH = 4-9), whilst a higher Fe(VI) to SDZ molar ratio of 20:1 (pH = 7) was needed to obtain 75% SDZ removal.

Analyses of microRNA166 gene structure, expression, and function during the early stage of somatic embryogenesis in Dimocarpus longan Lour.

MicroRNA166 (miR166) contributes to post-transcriptional regulation by binding the mRNAs of HD-ZIP III genes, which affects plant growth and development. The structural characteristics, expression, and functions of miR166 genes during the early somatic embryogenesis stage in Dimocarpus longan remain unknown. We isolated the transcripts of pri-miR166 S78 with two transcription initiation sites (TSSs) and pri-miR166 S338 with one TSS. These sequences contain potential smORFs and encode different miRNA peptides (miPEPs). Additionally, their promoters contain cis-acting elements responsive to diverse stimuli. The pre-miR166 S78 and pre-miR166 S338 expression levels were up-regulated in response to 2,4-D, abscisic acid, and ethylene. Although the expression patterns induced by hormones were similar, there were differences in the extent of the response, with pre-miR166 S338 more responsive than pre-miR166 S78. Thus, miRNA transcription and maturation are not simply linearly correlated. Moreover, pre-miR166 S78 and pre-miR166 S338 expression levels were down-regulated, whereas ATHB15 (target gene) expression was up-regulated, from the longan embryonic callus to the globular embryo stages. These results are indicative of a negative regulatory relationship between miR166 and ATHB15 during the early somatic embryogenesis stage in longan. At the same stages, miR166a.2-agomir, miR166a.2-antagomir, and miPEP166 S338 increased or decreased the expression of miR166a.2 and ATHB15, but with no consistent patterns or linear synchronization, from which we've found some reasons for it.

Krebs von den Lungen-6 associated with chest high-resolution CT score in evaluation severity of patients with interstitial lung disease.

AIMS: The purpose of this prospective, single-center study was to measure the value of Krebs von den Lungen-6 (KL-6), a kind of transmembrane mucoprotein, in diagnosing interstitial lung disease (ILD) and in assessing the severity of ILD. METHODS: We enrolled 184 patients and 30 healthy controls. Ninety-eight patients were diagnosed with ILD, 47 with pneumonia, 19 with non-small cell lung cancer without ILD (NSCLC/non-ILD) and 20 with other lung diseases. Serum KL-6 levels, CT scores of high-resolution computerised tomography (HRCT) and pulmonary function in ILD patients were assessed. RESULTS: The mean value of serum KL-6 in patients with ILD, pneumonia, NSCLC/non-ILD, other lung diseases and healthy controls were 1000.67±882.73U/ml, 234.11±91.02U/ml, 269.95±149.23U/ml, 234.85±83.51U/ml and 189.03±55.50U/ml, respectively. Serum KL-6 levels of patients with ILD were significantly higher than that of other groups (P<0.000). The level of serum KL-6 in patients with pneumonia, NSCLC/non-ILD and other lung diseases was also statistically higher than healthy controls (P<0.05). When the cut-off value was 312U/ml, the sensitivity and specificity of KL-6 for the diagnosis of ILD was 84.7% and 85.3% respectively (AUC: 0.936, 95% CI: 0.906-0.965). The serum KL-6 levels in patients with ILD were significantly positively correlated with the CT scores (r=0.539, P=0.000) and negatively correlated with DLCO (r=-0.513, P=0.000). CONCLUSION: Serum KL-6 might be useful in the diagnosis of ILD, especially in the hard-to-diagnose cases, with high sensitivity and specificity. Furthermore, KL-6 might be a valuable marker for evaluation of ILD severity.

EGFL7 silencing inactivates the Notch signaling pathway; enhancing cell apoptosis and suppressing cell proliferation in human cutaneous melanoma.

Melanoma is the main cause of death in patients with skin cancer. While the pathogenesis of cutaneous melanoma is poorly understood, increasing evidence shows that epidermal growth factor (EGF) may be involved. Herein, we tested the hypothesis that down-regulation of EGFL7 inhibits development and progression of human cutaneous melanoma (CM). Initially, we performed immunohistochemical analysis of EGFL7 in 130 specimens and the findings indicated that EGFL7 was highly expressed in CM. The expressions of EGFL7 and Notch signaling pathway-related genes in CM were then measured by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot assay. In order to assess biological functions of EGFL7 in CM we up-regulated or down-regulated endogenous EGFL7 using EGFL7-OE or shRNA against EGFL7 in the A375 CM cell line. To better understand the pivotal role of Notch signaling pathway in CM, we blocked this pathway in A375 cells by inhibitor treatment. Finally, tumor xenograft in nude mice was performed to test the in vivo tumorigenesis of the transfected A375 cells. While EGFL7 activated the Notch signaling pathway in CM, gain- and loss-of-function studies established that decreased EGFL7 inhibited cell proliferation and promoted apoptosis in A375 cells. Moreover, down-regulated EGFL7 suppressed in vivo tumorigenesis. Most importantly, we determined that down-regulating EGFL7 inhibited CM development by suppressing the Notch signaling pathway. The combined findings define potential roles of decreased EGFL7 as inhibitors of CM development by suppressing the Notch signaling pathway, and EGFL7 may therefore be a novel therapeutic target in cutaneous melanoma patients.

[Preparation of chaperone-antigen peptide vaccine derived from human gastric cancer stem cells and its immune function].

Objective: To explore the method of extracting chaperone antigen peptide complexes from gastric cancer stem cells and its immune function. Methods: Gastric cancer stem cells and gastric cancer cells were screened by low temperature ultrasonic lysis. After salting out and dialysis, the lysate supernatant was processed with SDS-PAGE to analyze the expression of chaperone antigen peptide complexes, and then was separated and purified with CNBr-activated SepharoseTM 4B. Reverse high pressure liquid chromatography (HPLC), SDS-PAGE and Western blotting were used to analyze the purity and nature of the acquired albumen. Lymphocyte proliferation assay and lymphocytotoxicity assay were used to ditermine the immunological activity of the chaperone-antigen peptide complexes. Results: The chaperone antigen peptide complexes of gastric cancer stem cells were prepared and identified successfully, of which the main components were the antigen peptides of HSP60, HSP70, HSP90 and HSP110. 0.75 µg and 1.00 µg HSP70-antigen peptide and 1.00 µg HSP90-antigen peptide activated lymphocytes significantly. Their A(490) values were 0.26±0.03, 0.45±0.05 and 0.32±0.04, respectively, while the corresponding doses of HSP60-antigen peptide and HSP110-antigen peptide did not activate lymphocytes. The killing rates of 1.00 µg HSP70-antigen peptide and 1.00 µg HSP70 were (45.0±2.0)% and (16.0±2.0)%, respectively, showing a significant difference (P=0.012). Similarly, the killing rates of 1.00 µg HSP90-antigen peptide and 1.00 µg HSP90 were (36.0±5.0)% and (13.0±4.0)%, respectively, also showing a significant difference (P=0.048). Conclusions: The amount of chaperone antigen peptide complexes in gastric cancer cells is extremely low, but it is obviously increased in gastric cancer stem cells. After purification, the chaperone antigen peptide complexes with high purity can be prepared. The extracted chaperone antigen peptide complexes have stronger immunogenicity, and can be used to make tumor vaccine in vitro, which may have a good application value in the targeted therapy of gastric cancer.

Reversal of cisplatin resistance in non-small cell lung cancer stem cells by Taxus chinensis var.

Drug resistance in cells is a major impedance to successful treatment of lung cancer. Taxus chinensis var. inhibits the growth of tumor cells and promotes the synthesis of interleukins 1 and 2 and tumor necrosis factor, enhancing immune function. In this study, T. chinensis var.-induced cell death was analyzed in lung cancer cells (H460) enriched for stem cell growth in a defined serum-free medium. Taxus-treated stem cells were also analyzed for Rhodamine 123 (Rh-123) expression by flow cytometry, and used as a standard functional indicator of MDR. The molecular basis of T. chinensis var.-mediated drug resistance was established by real-time PCR analysis of ABCC1, ABCB1, and lung resistance-related protein (LRP) mRNA, and western blot analysis of MRP1, MDR1, and LRP. Our results revealed that stem cells treated with higher doses of T. chinensis var. showed significantly lower growth inhibition rates than did H460 cells (P < 0.05). The growth of stem and H460 cells treated with a combination of T. chinensis var. and cisplatin was also significantly inhibited (P < 0.05). Rh-123 was significantly accumulated in the intracellular region and showed delayed efflux in stem cells treated with T. chinensis var. (P < 0.05), compared to those treated with verapamil. T. chinensis var.-treated stem cells showed significant downregulation of the ABCC1, ABCB1, and LRP mRNA and MRP1, MDR1, and LRP (P < 0.05) compared to H460 cells. Thus, T. chinensis var.-mediated downregulation of MRP1, MDR1, and LRP might contribute to the reversal of drug resistance in non-small cell lung cancer stem cells.

[The expression of beta-tubulin gene in myelodysplastic syndrome evoluting to leukemia].

OBJECTIVE: Based on our previous established cohort of myelodysplastic syndrome (MDS), we investigated the potential effect of beta-tubulin(TUBB) gene in the transformation of MDS into acute leukemia. METHODS: From our nested case-control study cohort of MDS patients, we chose 11 paired transformed and non-transformed MDS patients. TUBB gene expression was tested by quantitative real-time PCR. TUBB-siRNA transfection was used to down-regulate TUBB gene expression in SKM-1 cell line. The function of TUBB gene in SKM-1 cell line was evaluated by cell proliferation, soft agar clone formation and electron microscope. RESULTS: TUBB gene expression in MDS patients in transformed group were significantly higher than that in control group (2.91±0.41 vs 0.90±0.23, P<0.01). After TUBB-siRNA transfection, A450/630nm of SKM-1 cells at 24 h, 48 h and 72 h were 0.299±0.045, 0.526±0.034 and 0.652±0.035, respectively, which were significantly decreased than those in negative-siRNA group(0.438±0.074, 0.858±0.064 and 0.974±0.044)(P<0.05). Soft agar clone formation in TUBB-siRNA group was (7.0±0.2)%, which was significantly reduced than that of negative-siRNA group (25.0±0.2)% (P<0.01). Electron microscope showed significant apoptotic signs in TUBB-siRNA group, including vacuoles in cytoplasm and karyorrhexis. CONCLUSION: Our results indicate that TUBB gene may play a role in the transformation of MDS into acute leukemia by affecting the proliferation of malignant clones.

[Spatial analysis and prediction of severe fever with thrombocytopenia syndrome in Zhejiang province, 2011-2015].

Objective: To understand the distribution of the severe fever with thrombocytopenia syndrome (SFTS) in Zhejiang province, and predict the incidence and the probability of SFTS outbreak. Methods: Based on the cases of SFTS from 2011-2015, software ArcGIS 10.0 was used to analyze the spatial distribution, Moran's I and Getis-Ord Gi were used to analyze the spatial autocorrelation. The incidence trend was explored by trend surface analysis, and the prediction was made by Kriging interpolation. Results: The incidence of SFTS increased and the distribution expanded in Zhejiang from 2011 to 2015, the seasonal and the demographic characteristics of SFTS were similar to the previous research; there were regional clustering of the cases (P<0.001); a downward trend was observed from northeast to southwest in terms of incidence of SFTS; the second-order disjunctive Kriging interpolation based on circular model and the indicator Kriging interpolation based on exponential model had higher prediction accuracy, the probabilities of outbreak in Anji, Daishan and Tiantai were high, the prediction deviation of inland was less than that of edge area. Conclusion: The prediction of SFTS by Kriging interpolation had high accuracy, the incidence of SFTS was higher and the distribution of SFTS was larger than the results of surveillance, the risk areas for epidemic were Anji, Daishan, Ninghai,Tiantai, Sanmen and Linhai.

Association of Resting Heart Rate with Infrarenal Aortic Diameter: A Cross Sectional Study in Chinese Hypertensive Adults.

OBJECTIVE: Elevated resting heart rate (RHR) has been shown to be a risk marker for cardiovascular disease. Results from studies on the effects of RHR in large arteries are limited to the functional changes of those arteries, while the association between RHR and aortic diameter remains largely understudied. METHODS: This was a cross sectional study of hypertensive Chinese adults from rural areas. The maximum infrarenal aortic diameter (maxIAD) from renal arteries to the iliac bifurcation was obtained by ultrasound. MaxIADs in different RHR groups were compared in males and females separately because of the significant differences between sexes. Multiple regression analysis was used to determinate the correlation between RHR and maxIAD. Further interactions between three factors (BMI, smoking, and anti-hypertensive regimens) and RHR for maxIAD were examined using subgroup analysis. RESULTS: 19,200 subjects were enrolled in the study, with an average age of 64.8±7.4 years and 61.6% females. Only 22 cases (0.11%) were detected with AAA, with males (n = 17) presenting a higher AAA incidence than females (n = 5). In subjects ≥65 years, there were 18 (0.19%) AAA, and 15 (83.3%) had a history of smoking. In the total subjects, the mean maxIAD ranged from 15.7±2.1 mm to 15.2±2.2 mm as RHR changed from the lowest quartile to the highest (≥84 bpm) in males, with a similar tendency observed in females. The correlation coefficient of RHR on maxIAD was -0.17 in males and -0.12 in females. Further subgroup analysis revealed that smoking exaggerated the correlation between RHR and maxIAD, but only in females. CONCLUSIONS: A low AAA incidence was observed in this hypertensive Chinese population. There was a negative association between RHR and maxIAD, potentially exaggerated by smoking, especially in females.

Clinical and epidemiological survey and analysis of the first case of human infection with avian influenza A(H7N9) virus in Hangzhou, China.

To investigate and report on the clinical and epidemiological characteristics of the first case of human infection with avian influenza A(H7N9) virus in Hangzhou, China. A field epidemiological survey was used to study the first case in Hangzhou. The patient was a 39-year-old male chef with a history of exposure to a farm product market and to poultry prior to the onset of disease on 15 March 2013. He had diarrhea, chills, pyrexia, and intermittent cough with freshly red foamy bloody sputum early in his disease. His fever > 39 °C continued for a week with rapid progression. Computed tomography findings showed extensive bilateral consolidation, followed by multiorgan failure. The patient died on the morning of 27 March. His infection was eventually confirmed 1 week later on 3 April. Flu-like symptoms including fever and cough were found in 46 of his 138 close contacts. This was the first case of human infection with avian influenza A(H7N9) virus in Hangzhou. None of the close contacts had onset of the disease. The case patient's condition progressed rapidly. The source of infection might be his exposure to the farm product market, but the mode of exposure remains unclear.

Three-dimensional structure of Bax-mediated pores in membrane bilayers.

B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax) is a member of the Bcl-2 protein family having a pivotal role in triggering cell commitment to apoptosis. Bax is latent and monomeric in the cytosol but transforms into its lethal, mitochondria-embedded oligomeric form in response to cell stress, leading to the release of apoptogenic factors such as cytochrome C. Here, we dissected the structural correlates of Bax membrane insertion while oligomerization is halted. This strategy was enabled through the use of nanometer-scale phospholipid bilayer islands (nanodiscs) the size of which restricts the reconstituted system to single Bax-molecule activity. Using this minimal reconstituted system, we captured structural correlates that precede Bax homo-oligomerization elucidating previously inaccessible steps of the core molecular mechanism by which Bcl-2 family proteins regulate membrane permeabilization. We observe that, in the presence of BH3 interacting domain death agonist (Bid) BH3 peptide, Bax monomers induce the formation of ~3.5-nm diameter pores and significantly distort the phospholipid bilayer. These pores are compatible with promoting release of ions as well as proteinaceous components, suggesting that membrane-integrated Bax monomers in the presence of Bid BH3 peptides are key functional units for the activation of the cell demolition machinery.