O-302 Lower expression of AHCY is associated with increased miscarriage risk

Study question

Are alterations in the transcript levels of genes from the methionine cycle associated with maternal associated miscarriage risk?

Summary answer

Lower expression of AHCY is associated with a greater number of prior pregnancy losses

What is known already

Around 15% of pregnancies end in miscarriage, and the risk of recurrence increases with each pregnancy loss. Aberrant differentiation (decidualization) of endometrial stromal cells into specialised decidual cells to accommodate implantation is a key maternal factor for miscarriage risk.

Our previous work identified secretory changes in cysteine and methionine metabolites upon decidualization. The methionine cycle contributes to vital cellular functions, including producing methionine for proliferation, regulating cell differentiation, and S-adenosylmethionine (SAM) production. SAM is required for protein, RNA and DNA methylation, thereby influencing pathways at the metabolic, epigenetic, and proteomic levels. AHCY clears S-adenosylhomocysteine (SAH), reducing its inhibition of methylation.

Study design, size, duration

Endometrial biopsies (n = 250) were collected during the luteal phase (LH + 6-11). Patients were grouped based on their miscarriage history. Accordingly, expression of genes from the methionine cycle were quantified using RT-qPCR.

Participants/materials, setting, methods

Endometrial biopsies were obtained, with written informed consent, from women attending the Implantation Clinic at University Hospitals Coventry and Warwickshire NHS Trust, following transvaginal ultrasounds to exclude uterine pathology. Isolated RNA was converted into cDNA. Expression of AHCY, AMD1, BHMT2, CBS, MAT2A, MAT2B, and MTR were normalised to L19. Statistical analysis was performed in Graphpad Prism; with significance accepted at p < 0.05. AHCY was silenced in an endometrial cell line to determine its effect on decidualization.

Main results and the role of chance

This study reports a distinct reduction in expression of methionine cycle genes (MAT2A, AHCY, AMD1, MTR, BHMT2) in the late-luteal phase of the cycle consistent with a reduction in proliferation.

By plotting percentile graphs based on the statistical distribution in gene expression for each day of the luteal phase, comparisons have been made between groups.

AHCY expression is significantly reduced in patients with increasing number of prior miscarriages, particularly between 0-2 and 5+ previous miscarriages (p = 0.0334). Neither patient age nor BMI are a factor in this reduced expression.

In contrast, there is a stromal specific increase in AHCY upon decidualization in vitro, suggesting it is required in the decidua. Silencing AHCY in an endometrial cell line significantly reduces PRL expression upon decidualization. Reduction in AHCY may lead to a decreased “methylation potential” as SAH cannot be cleared. SAH accumulation inhibits methylation, and limits SAM production, thus compounding its effect.

Decreased methylation potential could prevent differentiation of the stromal compartment, resulting in lower levels of PRL, and altering decidual timing. Therefore, an embryo may implant into a tissue primed for disintegration, resulting a miscarriage.

In summary, AHCY may contribute to aberrant decidualization augmenting the risk of miscarriage.

Limitations, reasons for caution

Results are based on endometrial biopsies from an implantation clinic, therefore studies into biopsies from women with normal reproductive histories should also be analysed. Further functional studies are needed to ascertain the mechanism of action of AHCY in miscarriage.

Wider implications of the findings

This study identified that a decrease in AHCY in whole endometrial tissue is associated with increased risk of miscarriage. Further, silencing AHCY perturbed decidual marker expression. Thus, AHCY may act as a biomarker for atypical decidualization, and the clearance of SAH may be a potential treatment.

Trial registration number

N/A

[Applications of the NDR and DIAL models for risk prediction on cardiovascular disease in patients with type 2 diabetes in Ningbo]

Objective: To validate the performance of cardiovascular risk prediction models based on the Sweden National Diabetes Register (NDR) and Diabetes Lifetime-perspective prediction (DIAL) model for assessing risks of 5-year and 10-year cardiovascular disease (CVD) among Chinese patients with type 2 diabetes. Methods: Based on the Chinese Electronic Health Records Research in Yinzhou study, 83 503 patients with type 2 diabetes aged 30-75 years without a history of CVD at baseline were included from January 1, 2010 to December 31, 2020. Recalibrated NDR model was used to estimate 5-year risk, while the recalibrated DIAL model was used to predict 5-year and 10-year risks. The competing events adjusted Kaplan-Meier analysis was used to obtain the observed cardiovascular events. Discrimination C statistics evaluated model accuracy, calibration χ² value, and calibration plots. Results: Through a median follow-up of 7.0 years, 7 326 cardiovascular events, and 2 937 non-vascular deaths were identified among a total of 83 503 subjects. The recalibrated NDR model overestimated 5-year risk by 39.4% in men and 8.6% in women, whereas the overestimation for the recalibrated DIAL model was 14.6% in men and 50.1% in women. The DIAL model had a better discriminative ability (C-statistic=0.681, 95%CI: 0.672-0.690) than NDR model (C-statistic=0.667, 95%CI: 0.657-0.677) in 5-year risk prediction for men, and the models had a similar ability for women (C-statistic=0.699, 95%CI: 0.690-0.708 for NDR and C-statistic=0.698, 95%CI: 0.689-0.706 for DIAL). The prediction accuracy of the DIAL model was improved in the 10-year risk, with the underestimation being 1.6% for men and the overestimation being 12.8% for women. Conclusions: Both recalibrated NDR and DIAL models overestimated 5-year cardiovascular risk in Chinese patients with type 2 diabetes, while the higher overestimation was shown using the DIAL model. However, the improvement was found in predicting 10-year CVD risk using the DIAL model, which suggested the value of lifetime risk prediction and indicated the need for research on the lifetime risk prediction model for cardiovascular risk assessment in Chinese patients with type 2 diabetes.

POS1002 DIAGNOSTIC DELAY AND ITS ASSOCIATED FACTORS IN CHINESE AXIAL SPONDYLOARTHRITIS: A RETROSPECTIVE STUDY

Background

Few data on the prolonged diagnosis and its associated factors in Chinese axial spondyloarthritis (axSpA) is available.

Objectives

To delineate the landscape of diagnostic delay in Chinese axSpA, investigate its associated factors and explore its potential impact on medication modalities.

Methods

A total of 1,295 patients fulfilling the ASAS classification criteria were obtained. Demographic and clinical data were collected through predesigned questionnaires and available medical records. Logistic regression analyses in univariate and multivariable model were performed, using the median of diagnostic delay as cut-off point for group classification. Differences between early and late diagnosed group were subsequently compared by the Pearson chi-square test or Mann-Whitney U test.

Results

The median (IQR) diagnostic delay in Chinese axSpA was 3.0 (1.0~7.0) years and 24.8% of them reported a history of misdiagnosis. Older age at onset (OR=0.97, P<0.001) and higher education attainment (P=0.001) were correlated with early diagnosis of axSpA, whereas coming from less developed areas (P=0.002), a history of peripheral arthritis at the time of diagnosis (OR=1.58, P=0.002) and history of misdiagnosis (OR=1.98, P<0.001) increased the risk of diagnostic delay. Medication modalities were similar between two groups, but the proportion with no medication ever and percentage without regular medication in recent 3 months were higher in the late diagnosed group than early group (26.5% vs. 20.7%, P=0.02; 34.7% vs. 28.6%, P=0.02).

Conclusion

Our findings depicted a detailed spectrum of diagnostic delay in Chinese axSpA, verified five associated factors and pinpointed a remarkable treatment delay even after diagnosis, especially in late diagnosis group.

References

[1]Masson Behar V, Dougados M, Etcheto A, Kreis S, Fabre S, Hudry C, et al. Diagnostic delay in axial spondyloarthritis: A cross-sectional study of 432 patients. Joint bone spine. 2017;84(4):467-71.

Figure 1.

Cumulative distribution of age at onset and age at diagnosis in Chinese axSpA

(A) the entire group. (B) stratified by early and late diagnosed group. (C) stratified by education level (college, middle school, secondary school). (D) stratified by history of peripheral arthritis when diagnosed. (E) stratified by history of misdiagnoses when diagnosed. (F) stratified by native place, as statistical significance was found between eastern coastal and western China, only these two groups were presented.

Disclosure of Interests

None declared

LncRNA ABHD11-AS1 promotes tumor progression in papillary thyroid carcinoma by regulating EPS15L1/EGFR signaling pathway

OBJECTIVES

lncRNA ABHD11 antisense RNA 1 (ABHD11-AS1) acts as an oncogene involved in papillary thyroid carcinoma (PTC) occurrence and progression. ABHD11-AS1 exerts biologic functions by some miRNAs and proteins to regulate multiple targets. Identification of novel mechanism of ABHD11-AS1 could be helpful in therapeutic targeting for PTC treatment.

METHODS

Differentially expressed lncRNAs were selected from TCGA database. qRT-PCR analysis was applied to examine the expression of ABHD11-AS1 in PTC cell lines and tissues. The relationship of ABHD11-AS1 expression and clinicopathological features was analyzed by Kaplan-Meier analysis. Two PTC cell lines (TPC-1 and KTC-1) were transfected with pcDNA 3.1, pcDNA3.1-ABHD11-AS1, si-NC and si-ABHD11-AS1, respectively, to verify the ABHD11-AS1 oncogene-regulating capacity to promote tumor progression. The cell metastasis and proliferation had been evaluated both in vitro and in vivo.

RESULTS

High expression of ABHD11-AS1 was found in PTC tissues (P < 0.01), which was significantly correlated with lymph node metastasis (P < 0.05). ABHD11-AS1 overexpression noticeably promoted cell proliferation, migration, and invasion capabilities, which were obviously decreased upon ABHD11-AS1 knockdown. ABHD11-AS1 positively regulated EGFR/EPS15L1 pathway, as EGFR, EPS15L1, STAT3, and p-STAT3 were activated.

CONCLUSION

ABHD11-AS1 promotes tumor progression in PTC by regulating EPS15L1/EGFR pathway.

[Time to initial diagnosis of imported malaria and its influencing factors in Jiangsu Province]

OBJECTIVE

To investigate the health-seeking behaviors of imported malaria cases after returning to China, and to investigate the factors affecting the time to initial diagnosis, so as to provide the scientific evidence for early identification of imported malaria cases and prevention of severe cases development and secondary transmission.

METHODS

The individual demographic features, and the disease onset and the time to initial diagnosis of imported malaria cases in Jiangsu Province in 2019 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China. The characteristics of health-seeking behaviors and epidemiological features of imported malaria cases were descriptively analyzed, and the factors affecting the time to initial diagnosis of imported malaria cases after returning to China were identified using multivariate logistic regression analysis.

RESULTS

A total of 244 imported malaria cases were reported in Jiangsu Province in 2019, and the time to initial diagnosis of the cases were 1-12 days, with mean time of (1.53 ± 1.65) days, with median time of one day. The highest number of malaria cases seeking healthcare services were found on the day of developing primary symptoms (76 cases, 31.1%), followed by on the second day (68 cases, 27.9%), on the third day (46 cases, 18.9%), and 54 cases (22.1%) received initial diagnosis 3 days following presence of primary symptoms, including 3 cases with initial diagnosis at more than one week. High proportions of imported malaria cases with a delay in the time to initial diagnosis were seen in migrant workers who returned to China in January (14 cases, 5.7%) and December (13 cases, 5.3%) and those aged between 41 and 50 years (32 cases, 13.1%). Multivariate logistic regression analysis showed relative short time to initial diagnosis among imported malaria cases returning to China on March [odds ratio (OR) = 0.16, P = 0.03, 95% confidence interval (CI): (0.03, 0.85)] and those with a history of overseas malaria parasite infections [OR = 0.36, P = 0.001, 95% CI: (0.19, 0.67)].

CONCLUSIONS

Timely health-seeking behaviors should be improved among imported malaria cases in Jiangsu Province, patients with a history of overseas malaria infections require faster health-seeking activities.

Mucoadhesive Nucleoside-Based Hydrogel Delays Oral Leukoplakia Canceration

Some oral squamous cell carcinomas (OSCCs) originate from preexisting oral potentially malignant disorders (OPMDs). Oral leukoplakia (OLK) is the most common and typical OPMD in the clinic, so treatment for it is essential to reduce OSCC incidence. Local chemotherapy is an option other than surgery considering the superficial site of OLK. However, there are no standardized drugs applied to OLK, and traditionally used chemotherapeutic drugs revealed limited efficacy for lack of adhesion. Hence, there is a growing demand to prepare new agents that combine mucoadhesion with an anti-OLK effect. Here, an isoguanosine-tannic acid (isoG-TA) supramolecular hydrogel via dynamic borate esters was successfully fabricated based on isoG and TA. Previously reported guanosine-TA (G-TA) hydrogel was also explored for an anti-OLK effect. Both gels not only exhibited ideal adhesive properties but also integrated anti-OLK activities in one system. In vitro cell viability indicated that isoG and TA inhibited the proliferation of dysplastic oral keratinocytes (DOKs). The in vivo OLK model evidence revealed that both gels showed potential to prevent OLK canceration. In addition, the probable anti-DOK mechanisms of isoG and TA were investigated. The results indicated that isoG could bind to adenosine kinase (ADK) and then affected the mammalian target of rapamycin (mTOR) pathway to inhibit DOK proliferation. TA could significantly and continuously reduce reactive oxygen species (ROS) in DOKs through its antioxidant effect. ROS plays an important role in the progression of cell cycle. We proved that the low level of ROS may inhibit DOK proliferation by inducing G₀/G₁ arrest in the cell cycle. Altogether, this study innovatively fabricated an isoG-TA hydrogel with ideal adhesion, and both isoG and TA showed in vitro inhibition of DOKs. Moreover, both isoG-TA and G-TA hydrogels possessed potential in delaying the malignant transformation of OLK, and the G-TA hydrogel showed a better statistical effect, providing an effective strategy for controlling OLK.

[Effect and influence factors of cardiopulmonary resuscitation in children with congenital heart disease in pediatric intensive care unit]

Objective: To investigate the prognostic factors of children with congenital heart disease (CHD) who had undergone cardiopulmonary resuscitation (CPR) in pediatric intensive care unit (PICU) in China. Methods: From November 2017 to October 2018, this retrospective multi-center study was conducted in 11 hospitals in China. It contained data from 281 cases who had undergone CPR and all of the subjects were divided into CHD group and non-CHD group. The general condition, duration of CPR, epinephrine doses during resuscitation, recovery of spontaneous circulation (ROSC), discharge survival rate and pediatric cerebral performance category in viable children at discharge were compared. According to whether malignant arrhythmia is the direct cause of cardiopulmonary arrest or not, children in CHD and non-CHD groups were divided into 2 subgroups: arrhythmia and non-arrhythmia, and the ROSC and survival rate to discharge were compared. Data in both groups were analyzed by t-test, chi-square analysis or ANOVA, and logistic regression were used to analyze the prognostic factors for ROSC and survival to discharge after cardiac arrest (CA). Results: The incidence of CA in PICU was 3.2% (372/11 588), and the implementation rate of CPR was 75.5% (281/372). There were 144 males and 137 females with median age of 32.8 (5.6, 42.7) months in all 281 CPA cases who received CPR. CHD group had 56 cases while non-CHD had 225 cases, with the percentage of 19.9% (56/281) and 80.1% (225/281) respectively. The proportion of female in CHD group was 60.7% (34/56) which was higher than that in non-CHD group (45.8%, 103/225) (χ²=4.00, P=0.045). There were no differences in ROSC and rate of survival to discharge between the two groups (P>0.05). The ROSC rate of children with arthythmid in CHD group was 70.0% (28/40), higher than 6/16 for non-arrhythmic children (χ²=5.06, P=0.024). At discharge, the pediatric cerebral performance category scores (1-3 scores) of CHD and non-CHD child were 50.9% (26/51) and 44.9% (92/205) respectively. Logistic regression analysis indicated that the independent prognostic factors of ROSC and survival to discharge in children with CHD were CPR duration (odds ratio (OR)=0.95, 0.97; 95%CI: 0.92~0.97, 0.95~0.99; both P<0.05) and epinephrine dosage (OR=0.87 and 0.79, 95%CI: 0.76-1.00 and 0.69-0.89, respectively; both P<0.05). Conclusions: There is no difference between CHD and non-CHD children in ROSC and survival rate of survival to discharge was low. The epinephrine dosage and the duration of CPR are related to the ROSC and survival to discharge of children with CHD.

Dynamical diffraction of high-energy electrons investigated by focal series momentum-resolved scanning transmission electron microscopy at atomic resolution

We report a study of scattering dynamics in crystals employing momentum-resolved scanning transmission electron microscopy under varying illumination conditions. As we perform successive changes of the probe focus, multiple real-space signals are obtained in dependence of the shape of the incident electron wave. With support from extensive simulations, each signal is shown to be characterised by an optimum focus for which the contrast is maximum and which differs among different signals. For instance, a systematic focus mismatch is found between images formed by high-angle scattering, being sensitive to thickness and chemical composition, and the first moment in diffraction space, being sensitive to electric fields. It follows that a single recording at one specific probe focus is usually insufficient to characterise materials comprehensively. Most importantly, we demonstrate in experiment and simulation that the second moment μ20+μ02=〈p2〉 of the diffracted intensity exhibits a contrast maximum when the electron probe is focused at the top and bottom faces of the specimen, making the presented concept attractive for measuring local topography. Given the versatility of 〈p2〉, we furthermore present a detailed study of its large-angle convergence both analytically using the Mott scattering approach, and by dynamical simulations using the multislice algorithm including thermal diffuse scattering. Both approaches are in very good agreement and yield logarithmic divergence with increasing scattering angle.

Optical Imaging in the Diagnosis of OPMDs Malignant Transformation

Oral potentially malignant disorders (OPMDs) are a heterogeneous group of oral lesions with a variable risk of malignant transformation to oral squamous cell carcinoma. The current OPMDs malignant transformation screening depends on conventional oral examination (COE) and is confirmed by biopsy and histologic examination. However, early malignant lesions with subtle mucosal changes are easily unnoticed by COE based on visual inspection and palpation. Optical techniques have been used to determine the biological structure, composition, and function of cells and tissues noninvasively by analyzing the changes in their optical properties. The oral epithelium and stroma undergo persistent structural, functional, and biochemical alterations during malignant transformation, leading to variations in optical tissue properties; optical techniques are thus powerful tools for detecting OPMDs malignant transformation. The optical imaging methods already used to detect OPMDs malignant transformation in vivo include autofluorescence imaging, narrowband imaging, confocal reflectance microscopy, and optical coherence tomography. They exhibit advantages over COE in detecting biochemical or morphologic changes at the molecular or cellular level in vivo; however, limitations also exist. This article comprehensively reviews the various real-time in vivo optical imaging methods used in the adjunctive diagnosis of OPMDs malignant transformation. We focus on the principles of these techniques, review their clinical application, and compare and summarize their advantages and disadvantages. Finally, we conclude with a discussion of current challenges and future directions of this field.

[Changing trend of incidence and mortality of stomach cancer during 2010-2016 in Henan Province, China]

Objective: To estimate stomach cancer incidence and mortality in Henan, 2016 and analyze the trend of stomach cancer incidence and mortality from 2010 to 2016. Methods: Stomach cancer related data in 2016 was extracted from Henan cancer registration and follow-up system. All data were qualified in validity, reliability and completeness according to the Guideline on Cancer Registration in China and International Agency for Research on Cancer (IARC/IACR). The incidence and mortality of stomach cancer were estimated by areas, gender and age based on the quality data and the registered population data of Henan province in 2016. The epidemic trend of stomach cancer was also been evaluated based on the age-standardized incidence and mortality by Chinese population (ASR China) from 2010 to 2016. Results: In 2016, the estimated incident cases of stomach cancer were 44 311. The incidence was 41.07/100 000, ASR China was 30.17/100 000, ASR by world population (ASR world) was 30.36/100 000, and the cumulative incidence rate was 3.84%. The incidences of male and female were 55.65/100 000 and 25.35/100 000, respectively. Meanwhile, 32 927 people died of stomach cancer in Henan. The mortality was 30.52/100 000, ASR China was 21.45/100 000, ASR world was 21.54/100 000, and the cumulative mortality was 2.53%. From 2010 to 2016, both the ASR China for incidence and mortality of stomach cancer in Henan showed a steady downward trend. In rural, the ASR China for incidence and mortality decreased rapidly, while the stable trend was observed in urban. Nevertheless, the incidence and mortality of stomach cancer in rural were still higher than those in urban. Conclusions: The incidence and mortality of stomach cancer in Henan province showed steadily declining trend from 2010 to 2016, and the geographical distribution difference between rural and urban areas was gradually narrowing. However, the disease burden was still high in 2016.

[Changing trend of incidence and mortality of esophageal cancer during 2010-2016 in Henan Province, China]

Objective: To estimate the incidence and mortality of esophageal cancer in 2016 and their changing trend during 2010-2016 according to the cancer registration data in Henan province. Methods: The data quality including completeness, validity, and reliability of local registries which submitted the cancer registration data of 2016 were assessed according to the criteria of Guideline on Cancer Registration in China and IARC/IACR. Esophageal cancer cases (ICD10: C15) were extracted from the database, and the incidence and mortality stratified by gender, age, and areas (urban/rural) were calculated, the incidence and mortality of provincial cancer were estimated combined with provincial population data. China's 2000 census population and Segi's population were used to calculate the age-standardized rate. Joinpoint model was used to estimate the changing trend of age standardized incidence and mortality along with the calendar year. Results: Approximately 40.10 thousand new esophageal cancer cases were diagnosed in Henan in 2016, accounting for 13.46% of all new cancer cases, and it ranked the third among cancer of all sites. The crude incidence of esophageal cancer was 37.21/100 000 with an age-standardized incidence rate by China standard population (ASIRC) of 26.74/100 000 and an age-standardized incidence rate by world standard population (ASIRW) of 27.12/100 000. The incidence of esophageal cancer in males was higher than that in females, with the ASIRC of 34.53/100 000 and 19.19/100 000, respectively. It was higher in rural areas than that in urban areas, with the ASIRC of 28.13/100 000 and 20.90/100 000, respectively. About 29.30 thousand deaths of esophageal cancer in Henan in 2016, accounting for 15.61% of all cancer deaths in Henan, which ranked the third among cancer of all sites. The crude mortality rate was 27.14/100 000 with an age-standardized mortality rate by China standard population (ASMRC) of 18.74/100 000 and an age-standardized mortality rate by world standard population (ASMRW) of 18.78/100 000. The mortality in males was higher than that in females, with the ASMRC of 24.78/100 000 and 13.12/100 000, respectively. It was also higher in rural areas than that in urban areas, with the ASMRC of 19.48/100 000 and 15.73/100 000, respectively. The ASIRC and ASMRC were declining with annual percent change (APC) of 3.12% (APC=-3.12%; 95%CI: -5.30%, -0.90%; P=0.015) and 2.47% (APC=-2.47%; 95%CI: -4.70%, -0.20%; P=0.039) during 2010-2016. However, the significant declining trend was only observed in rural areas in Henan, and the changing trend was same between males and females. Conclusions: The incidence and mortality of esophageal cancer are declining since 2010, however, the disease burden remains large in Henan. Therefore, comprehensive prevention and control efforts should be strengthened according to its epidemic characteristics and risk factors.

[MicroRNA-132 promotes atherosclerosis by inducing mitochondrial oxidative stressmediated ferroptosis]

OBJECTIVE

To explore the expression of microRNA-132 (miR-132) and its potential role in the development of atherosclerosis (AS).

METHODS

Thirty AS samples and 30 samples of normal peripheral vessels were collected from atherosclerotic patients undergoing peripheral angiostomy in our hospital for detecting the expression level of miR-132 using RT-qPCR. The expression of miR-132 in human umbilical vein endothelial cells (HUVEC) was up-regulated by liposome transfection, and intracellular reactive oxygen species (ROS), localization relationship between ROS and mitochondria, functional changes of mitochondrial reactive oxygen superoxide species (mtROS), mitochondrial membrane potential (MMP) and opening of mitochondrial permeability transition pore (mPTP) were analyzed by flow cytometry and laser confocal microscopy. The activity of mitochondrial redox respiratory chain complex (type I, II, III, IV and V) in HUVECs was detected using ELISA, and the expression levels of key iron death proteins were detected with Western blotting.

RESULTS

RT-qPCR results showed that miR-132 was significantly up-regulated in atherosclerotic plaques compared with normal vascular samples (P < 0.001). Compared with control HUVECs, HUVECs overexpressing miR-132 showed a significantly increased level of intracellular ROS (P < 0.001), and most of ROS was colocalized with mitochondria. HUVECs overexpressing miR-132 also showed significantly decreased MMP (P < 0.001) and obviously increased mtROS (P < 0.001) and opening of mPTP (P < 0.001), which led to mitochondrial REDOX respiratory chain stress disorder. The key iron death protein GPX4 was significantly down-regulated and the oxidized protein NOX4 was significantly increased in miR-132-overexpressing HUVECs (P < 0.001).

CONCLUSION

MiR-132 promotes atherosclerosis by inducing mitochondrial oxidative stress-mediated ferroptosis, which may serve as a promising therapeutic target for AS.

Mitochondria-targeted and FRET-based fluorescent probe for the imaging of endogenous SO2 in living cells

Sulfur dioxide (SO₂) is an important signal molecule in living systems, and plays a wide range of physiological functions. Real-time and in situ detection of the dynamic balance of SO₂ in mitochondria is of great significance to in-depth study its biological roles. Herein, we have developed a mitochondria-targeted fluorescent probe Nap-L based on the FRET mechanism to detect SO₂ in living cells. The probe Nap-L employed naphthalimide and positively charged benzopyridine as the donor and acceptor in the FRET system, and emitted green and red fluorescence under excitation. In respond to SO₂, the nucleophilic addition of bisulfite to benzopyridine and then interrupted the FRET process from naphthalimide to benzopyridine fluorophore, thereby triggering an obvious change in the fluorescence ratio. The probe Nap-L showed high selectivity to SO₂ over the biothiols (Hcy, GSH, Cys) and other biologically related species. Biological experiments suggested that the probe Nap-L mainly distributed in mitochondria, and can be successfully used to detect mitochondrial endogenous SO₂ in living cells.