Spartin-mediated lipid transfer facilitates lipid droplet turnover.

Lipid droplets (LDs) are organelles critical for energy storage and membrane lipid homeostasis, whose number and size are carefully regulated in response to cellular conditions. The molecular mechanisms underlying lipid droplet biogenesis and degradation, however, are not well understood. The Troyer syndrome protein spartin (SPG20) supports LD delivery to autophagosomes for turnover via lipophagy. Here, we characterize spartin as a lipid transfer protein whose transfer ability is required for LD degradation. Spartin copurifies with phospholipids and neutral lipids from cells and transfers phospholipids in vitro via its senescence domain. A senescence domain truncation that impairs lipid transfer in vitro also impairs LD turnover in cells while not affecting spartin association with either LDs or autophagosomes, supporting that spartin's lipid transfer ability is physiologically relevant. Our data indicate a role for spartin-mediated lipid transfer in LD turnover.

Study on the growth mechanism of monolayer and few-layer hexagonal boron nitride films on copper foil.

During the process of synthesizing h-BN on Cu foil via chemical vapor deposition (CVD), low-pressure CVD (LPCVD) typically synthesizes monolayer h-BN films, whereas atmospheric pressure CVD (APCVD) yields few-layer h-BN films. Herein, a growth mechanism for monolayer and few-layer h-BN on Cu foil is proposed using first-principles calculations: Cu(111) passivated h-BN hinders the diffusion of B and N atoms at the subsurface of Cu(111), preventing sufficient transportation of B and N atoms to the existing h-BN layer, thereby leading to the formation of monolayer h-BN in LPCVD. For APCVD, the edges of h-BN are passivated by H, which decreases the barrier energy for the diffusion of B and N atoms on the Cu(111) subsurface, and B and N atoms can easily migrate from the subsurface of Cu(111) to its surface, resulting in the nucleation of h-BN between the existing h-BN and Cu(111), and leading to the formation of few-layer h-BN films. This work provides a theoretical basis at the atomic scale for further understanding the growth of monolayer and few-layer h-BN films on Cu foil.

Laparoscopically harvested omental flap for immediate breast reconstruction: a retrospective single-center study of 300 cases.

BACKGROUND: The laparoscopically harvested omental flap (LHOF) has been used in partial or total breast reconstruction, but most studies on LHOF were case reports or small case series. However, the clinical feasibility and oncological safety of LHOF in oncoplastic breast surgery remains controversial. This study reported our experience applying LHOF for immediate breast reconstruction. METHODS: Between June 2018 and March 2022, 300 patients underwent oncoplastic breast surgery using LHOF at our institution. Their clinicopathological data, complications, cosmetic outcomes, and oncologic outcomes were evaluated. RESULTS: All patients underwent total breast reconstruction using LHOF after nipple-sparing mastectomy. The median operation time was 230 min (ranging from 155 to 375 min). The median operation time for harvesting the omental flap was 55 min (ranging from 40 to 105 min). The success rate of the laparoscopically harvested pedicled omental flap was over 99.0%. Median blood loss was 70 ml, ranging from 40 to 150 ml. The volume of the flap was insufficient in 102 patients (34.0%). The overall complication rate was 12.3%. Subcutaneous fluid in the breast area (7%) was the most common reconstruction-associated complication, but most cases were relieved spontaneously. The incidence rate of omental flap necrosis was 3.3%. LHOF-associated complications occurred in two cases, including one case of incisional hernia and one case of vascular injury. Cosmetic outcomes were satisfactory in 95.1% of patients on a four-point scale by three-panel assessment and 97.2% using the BCCT.core software. Two local and one systemic recurrence were observed during a median follow-up period of 32 months. CONCLUSIONS: The LHOF for immediate breast reconstruction is a safe and feasible method that involves minimal donor-site morbidity, satisfactory cosmetic outcomes, and promising oncologic safety.

Travel Distance Between Participants in US Telemedicine Sessions With Estimates of Emissions Savings: Observational Study.

BACKGROUND: Digital health and telemedicine are potentially important strategies to decrease health care's environmental impact and contribution to climate change by reducing transportation-related air pollution and greenhouse gas emissions. However, we currently lack robust national estimates of emissions savings attributable to telemedicine. OBJECTIVE: This study aimed to (1) determine the travel distance between participants in US telemedicine sessions and (2) estimate the net reduction in carbon dioxide (CO2) emissions attributable to telemedicine in the United States, based on national observational data describing the geographical characteristics of telemedicine session participants. METHODS: We conducted a retrospective observational study of telemedicine sessions in the United States between January 1, 2022, and February 21, 2023, on the doxy.me platform. Using Google Distance Matrix, we determined the median travel distance between participating providers and patients for a proportional sample of sessions. Further, based on the best available public data, we estimated the total annual emissions costs and savings attributable to telemedicine in the United States. RESULTS: The median round trip travel distance between patients and providers was 49 (IQR 21-145) miles. The median CO2 emissions savings per telemedicine session was 20 (IQR 8-59) kg CO2). Accounting for the energy costs of telemedicine and US transportation patterns, among other factors, we estimate that the use of telemedicine in the United States during the years 2021-2022 resulted in approximate annual CO2 emissions savings of 1,443,800 metric tons. CONCLUSIONS: These estimates of travel distance and telemedicine-associated CO2 emissions costs and savings, based on national data, indicate that telemedicine may be an important strategy in reducing the health care sector's carbon footprint.

SEC14L3 plays a tumor-suppressive role in breast cancer through a Wnt/ß-catenin-related way.

Breast cancer, the most prevalent malignancy in women, is also the leading cause of cancer-related deaths in women worldwide. The activation of the Wnt pathway plays a pivotal role in the metastatic abilities of breast cancer. In this study, IL1F6, MRGPRX1, and SEC14L3 were significantly correlated to breast cancer patients'overall survival based on TCGA-BRCA dataset. Although IL1F6, MRGPRX1 and SEC14L3 high expression were associated with better survival in breast cancer patients, SEC14L3 had the biggest survival benefit for breast cancer; therefore, SEC14L3 was selected for the subsequent investigation. SEC14L3 mRNA expression and protein levels within breast cancer cell lines decreased compared with normal human breast epithelial cells. Overexpressing SEC14L3 in breast cancer cells inhibited the malignant phenotypes of cancer cells, including the capacity of cells to migrate and invade. SEC14L3 overexpression decreased the levels of mesenchymal markers, whereas SEC14L3 knockdown facilitated the malignant behaviors of breast cancer cells. SEC14L3 overexpression also inhibited Wnt/ß-catenin activation. The Wnt agonist strengthened the malignant phenotypes of breast cancer cells; moreover, the anti-tumor effects of SEC14L3 overexpression were partially attenuated by the Wnt agonist. Conclusively, SEC14L3, which is underexpressed in breast cancer cells and tissues, could play a tumor-suppressive role in a Wnt/ß-catenin-related way.

Spatial Distribution of Hateful Tweets Against Asians and Asian Americans During the COVID-19 Pandemic, November 2019 to May 2020.

Objectives. To illustrate the spatiotemporal distribution of geolocated tweets that contain anti-Asian hate language in the contiguous United States during the early phase of the COVID-19 pandemic. Methods. We used a data set of geolocated tweets that match with keywords reflecting COVID-19 and anti-Asian hate and identified geographical clusters using the space-time scan statistic with Bernoulli model. Results. Anti-Asian hate language surged between January and March 2020. We found clusters of hate across the contiguous United States. The strongest cluster consisted of a single county (Ross County, Ohio), where the proportion of hateful tweets was 312.13 times higher than for the rest of the country. Conclusions. Anti-Asian hate on Twitter exhibits a significantly clustered spatiotemporal distribution. Clusters vary in size, duration, strength, and location and are scattered across the entire contiguous United States. Public Health Implications. Our results can inform decision-makers in public health and safety for allocating resources for place-based preparedness and response for pandemic-induced racism as a public health threat. (Am J Public Health. 2022;112(4):646-649. https://doi.org/10.2105/AJPH.2021.306653.

Evidence of transgenerational effects on autism spectrum disorder using multigenerational space-time cluster detection.

BACKGROUND: Transgenerational epigenetic risks associated with complex health outcomes, such as autism spectrum disorder (ASD), have attracted increasing attention. Transgenerational environmental risk exposures with potential for epigenetic effects can be effectively identified using space-time clustering. Specifically applied to ancestors of individuals with disease outcomes, space-time clustering characterized for vulnerable developmental stages of growth can provide a measure of relative risk for disease outcomes in descendants. OBJECTIVES: (1) Identify space-time clusters of ancestors with a descendent with a clinical ASD diagnosis and matched controls. (2) Identify developmental windows of ancestors with the highest relative risk for ASD in descendants. (3) Identify how the relative risk may vary through the maternal or paternal line. METHODS: Family pedigrees linked to residential locations of ASD cases in Utah have been used to identify space-time clusters of ancestors. Control family pedigrees of none-cases based on age and sex have been matched to cases 2:1. The data have been categorized by maternal or paternal lineage at birth, childhood, and adolescence. A total of 3957 children, both parents, and maternal and paternal grandparents were identified. Bernoulli space-time binomial relative risk (RR) scan statistic was used to identify clusters. Monte Carlo simulation was used for statistical significance testing. RESULTS: Twenty statistically significant clusters were identified. Thirteen increased RR (> 1.0) space-time clusters were identified from the maternal and paternal lines at a p-value < 0.05. The paternal grandparents carry the greatest RR (2.86-2.96) during birth and childhood in the 1950's-1960, which represent the smallest size clusters, and occur in urban areas. Additionally, seven statistically significant clusters with RR < 1 were relatively large in area, covering more rural areas of the state. CONCLUSION: This study has identified statistically significant space-time clusters during critical developmental windows that are associated with ASD risk in descendants. The geographic space and time clusters family pedigrees with over 3 + generations, which we refer to as a person's geographic legacy, is a powerful tool for studying transgenerational effects that may be epigenetic in nature. Our novel use of space-time clustering can be applied to any disease where family pedigree data is available.

Using GIS to Understand the Influence of Hurricane Harvey on Spatial Access to Primary Care.

Hurricanes can have a significant impact on the functioning and capacity of healthcare systems. However, little work has been done to understand the extent to which hurricanes influence local residents' spatial access to healthcare. Our study evaluates the change in spatial access to primary care physicians (PCPs) between 2016 and 2018 (i.e., before and after Hurricane Harvey) in Harris County, Texas. We used an enhanced 2-step floating catchment area (E2SFCA) method to measure spatial access to PCPs at the census tract level. The results show that, despite an increased supply of PCPs across the county, most census tracts, especially those in the northern and eastern fringe areas, experienced decreased access during this period as measured by the spatial access ratio (SPAR). We explain this decline in SPAR by the shift in the spatial distribution of PCPs to the central areas of Harris County from the fringe areas after Harvey. We also examined the socio-demographic impact in the SPAR change and found little variation in change among different socio-demographic groups. Therefore, public health professionals and disaster managers may use our spatial access measure to highlight the geographic disparities in healthcare systems. In addition, we recommend considering other social and institutional dimensions of access, such as users' needs, preferences, resource capacity, mobility options, and quality of healthcare services, in building a resilient and inclusive post-hurricane healthcare system.

Characterization, expression, and function analysis of AKR1A1 gene from yellow catfish (Tachysurus fulvidraco).

Aldehyde reductase (AKR1A1) is a carbonyl detoxification protein in toxic aldehyde removal. In the present study, the full-length cDNA of yellow catfish AKR1A1 (TfAKR1A1) was cloned. As expected, yellow catfish AKR1A1 showed similarities with that of other species. Subsequently, prokaryotic expression vector was constructed and recombinant TfAKR1A1 (rTfAKR1A1) was successfully induced and purified. rTfAKR1A1 exhibited reductive activity to many aldehydes and ketones. To determine whether TfAKR1A1 could confer stress tolerance in vitro, the viability of control and TfAKR1A1 expression E. coli under abiotic stress was compared by spot assay. Results showed that the recombinant strain had better stress resistance under cadmium, hydrogen peroxide, and DL-glyceraldehyde stress. Then, effects of an intraperitoneal injection of rTfAKR1A1 protein on cadmium-induced oxidative stress were evaluated. Results displayed that TfAKR1A1 and Nrf2 expression levels were significantly decreased, CAT and SOD expression levels were significantly increased, BCL-2 and IL-10 expression levels were significantly increased, and caspase3a, NF-κB, and IL-1ß expression levels were significantly decreased in protein-injection group. Furthermore, oxidative stress indexes in livers under different protein injection doses were examined by ELISA. Results showed that CAT, SOD, and GSH-Px activities were upregulated, ROS and T-AOC contents were also improved, while MDA content was significantly decreased both in lower and middle dose injection groups. Finally, liver pathological section analysis was performed. Results displayed that liver injury degree in protein-injected groups was lower than that of PBS group under cadmium stress. These results suggested that TfAKR1A1 played important roles in response to cadmium stress in yellow catfish.

The Validity of MotionSense HRV in Estimating Sedentary Behavior and Physical Activity under Free-Living and Simulated Activity Settings.

MotionSense HRV is a wrist-worn accelerometery-based sensor that is paired with a smartphone and is thus capable of measuring the intensity, duration, and frequency of physical activity (PA). However, little information is available on the validity of the MotionSense HRV. Therefore, the purpose of this study was to assess the concurrent validity of the MotionSense HRV in estimating sedentary behavior (SED) and PA. A total of 20 healthy adults (age: 32.5 ± 15.1 years) wore the MotionSense HRV and ActiGraph GT9X accelerometer (GT9X) on their non-dominant wrist for seven consecutive days during free-living conditions. Raw acceleration data from the devices were summarized into average time (min/day) spent in SED and moderate-to-vigorous PA (MVPA). Additionally, using the Cosemed K5 indirect calorimetry system (K5) as a criterion measure, the validity of the MotionSense HRV was examined in simulated free-living conditions. Pearson correlations, mean absolute percent errors (MAPE), Bland-Altman (BA) plots, and equivalence tests were used to examine the validity of the MotionSense HRV against criterion measures. The correlations between the MotionSense HRV and GT9X were high and the MAPE were low for both the SED (r = 0.99, MAPE = 2.4%) and MVPA (r = 0.97, MAPE = 9.1%) estimates under free-living conditions. BA plots illustrated that there was no systematic bias between the MotionSense HRV and criterion measures. The estimates of SED and MVPA from the MotionSense HRV were significantly equivalent to those from the GT9X; the equivalence zones were set at 16.5% for SED and 29% for MVPA. The estimates of SED and PA from the MotionSense HRV were less comparable when compared with those from the K5. The MotionSense HRV yielded comparable estimates for SED and PA when compared with the GT9X accelerometer under free-living conditions. We confirmed the promising application of the MotionSense HRV for monitoring PA patterns for practical and research purposes.

Racial Disparities in Diabetes Management Outcomes: Evidence from a Remote Patient Monitoring Program for Type 2 Diabetic Patients.

Introduction: Despite growing documentation of the efficacy of telemedicine in diabetes management, racial disparities in telemedicine-facilitated diabetes management remain underexplored. This study examined disparities in diabetes management outcomes between black and white patients with type 2 diabetes (T2D) in a remote monitoring program. Methods: The analysis sample included 914 white T2D patients and 365 black T2D patients in Nebraska who completed a 3-month remote patient monitoring and coaching after hospital discharge from 2014 to 2017. Ordinary least squares regression was estimated to examine racial differences in hemoglobin A1c (HbA1c), and logistic regression was used to determine the odds of HbA1c > 9% at the end of the program, controlling for demographics, baseline health conditions, and patient activation and engagement with the program. Results: The proportion of white patients with HbA1c > 9% was reduced from 16% at the baseline to 7% at program completion, and the corresponding reduction among black patients was from 30% to 18%. After adjusting for the effects of baseline HbA1c and other covariates, the average HbA1c among black patients at the end of the program was 0.23 points higher than that among white patients (p < 0.01), and the adjusted odds of black patients having HbA1c > 9% was 1.68 times that of white patients (95% confidence interval [1.07-2.63]). Discussion: The remote patient monitoring and coaching program reduced the absolute gap between black and white T2D patients. However, substantial racial disparities in HbA1c still remained at the end of the program and warranted further research.

A multi-modal relative spatial access assessment approach to measure spatial accessibility to primary care providers.

Two-step floating catchment area (2SFCA) methods that account for multiple transportation modes provide more realistic accessibility representation than single-mode methods. However, the use of the impedance coefficient in an impedance function (e.g., Gaussian function) introduces uncertainty to 2SFCA results. This paper proposes an enhancement to the multi-modal 2SFCA methods through incorporating the concept of a spatial access ratio (SPAR) for spatial access measurement. SPAR is the ratio of a given place's access score to the mean of all access scores in the study area. An empirical study on spatial access to primary care physicians (PCPs) in the city of Albuquerque, NM, USA was conducted to evaluate the effectiveness of SPAR in addressing uncertainty introduced by the choice of the impedance coefficient in the classic Gaussian impedance function. We used ESRI StreetMap Premium and General Transit Specification Feed (GTFS) data to calculate the travel time to PCPs by car and bus. We first generated two spatial access scores-using different catchment sizes for car and bus, respectively-for each demanding population location: an accessibility score for car drivers and an accessibility score for bus riders. We then computed three corresponding spatial access ratios of the above scores for each population location. Sensitivity analysis results suggest that the spatial access scores vary significantly when using different impedance coefficients (p < 0.05); while SPAR remains stable (p = 1). Results from this paper suggest that a spatial access ratio can significantly reduce impedance coefficient-related uncertainties in multi-modal 2SFCA methods.

Breast Cancer Screening for Patients of Rural Accountable Care Organization Clinics: A Multi-Level Analysis of Barriers and Facilitators.

Not all women 50-74 years received biennial mammography and the situation is worse in rural areas. Accountable care organizations (ACO) emphasize coordinated care, use of electronic health system, and preventive quality measures and these practices may improve their patients' breast cancer screening rate. Using medical record data of 8,347 women patients aged 50-74 years from eight rural ACO clinics in Nebraska, this study examined patient-, provider-, and county-level barriers and facilitators for breast cancer screening. A generalized estimating equations model was used to account for the correlation among patients from the same provider and county. The multi-level logistic regression results suggest that uninsured non-Hispanic Black patients were less likely to meet the biennial mammography screening guideline. Patients whose preferred language being English, having a preventive visit in the past 12 months, having one or more chronic conditions were more likely to meet the biennial mammography screening guideline. Patients with a primary care provider (PCP) that was male, without a medical doctor degree were less likely to screen biennially. Patients with a PCP that reviewed performance report quarterly, or manually checked patients' mammography screening status during visits were more likely to screen biennially. Interestingly, patients whose PCP reported being reminded by a care coordination team were less likely to screen biennially. Patients living in counties with more PCPs were also more likely to screen biennially. The study findings suggest that efforts targeting individual and practice-level barriers could be most effective in improving mammography screening for these rural ACO patients.

The Association of Point-of-Sale E-cigarette Advertising with Socio-Demographic Characteristics of Neighborhoods.

Electronic cigarettes (e-cigarettes) marketing expenditure is skyrocketing in the United States. However, little is understood about the geographic and socio-demographic patterns of e-cigarette advertising. We examined the associations between point-of-sale (POS) e-cigarette advertising and neighborhood socio-demographic characteristics in the Omaha Metropolitan Area of Nebraska. In 2014, fieldworkers collected comprehensive POS e-cigarette advertising data from all stores that sell tobacco (n = 463) in the Omaha Metropolitan Area. We used Geographic Information Systems to map POS e-cigarette advertisement density for the entire study area. Linear regression was used to examine the association between socio-demographic factors and POS e-cigarette advertising density. E-cigarette advertising density exhibited an obviously uneven geographic pattern in Omaha. Higher level of POS e-cigarette advertising was significantly related to lower median household income, higher percentage of Hispanics, and higher percentage of young adults. However, after adjusting for covariates, only median household income remained significantly associated with POS e-cigarette advertising. We found geographic, socioeconomic, and racial and ethnic disparities in exposure to POS e-cigarette advertising in Omaha, Nebraska. Future studies are needed to understand how these disparities influence e-cigarette adoption by different social groups and how to use such information to inform e-cigarette prevention strategies.

A DNA Origami Mechanical Device for the Regulation of Microcosmic Structural Rigidity.

DNA origami makes it feasible to fabricate a tremendous number of DNA nanostructures with various geometries, dimensions, and functionalities. Moreover, an increasing amount of research on DNA nanostructures is focused on biological and biomedical applications. Here, the reversible regulation of microcosmic structural rigidity is accomplished using a DNA origami device in vitro. The designed DNA origami monomer is composed of an internal central axis and an external sliding tube. Due to the external tube sliding, the device transforms between flexible and rigid states. By transporting the device into the liposome, the conformational change of the origami device induces a structural change in the liposome. The results obtained demonstrate that the programmed DNA origami device can be applied to regulate the microcosmic structural rigidity of liposomes. Because microcosmic structural rigidity is important to cell proliferation and function, the results obtained potentially provide a foundation for the regulation of cell microcosmic structural rigidity using DNA nanostructures.

Solution-assisted ultrafast transfer of graphene-based thin films for solar cells and humidity sensors.

Vacuum filtration enables the fabrication of large-area graphene-based membranes (GBMs), possessing a smoother surface than that by spray, spin coating or drop casting. However, due to the strong interaction with substrates, the separation of thin GBMs from the filter is problematic. Conventional stamping separation/transfer of graphene oxide (GO) thin films requires another substrate and pressing for >10 h, which may damage the delicate structure of the transfer substrates. Other methods require GO to be reduced on filters before separation, thus limiting the reduction methods. Inspired by a coagulation bath that enables rapid formation of ultrastrong GO fibers, we present an ultrafast (<1 min) and solution-assisted strategy to fabricate smooth and freestanding GO films. The diverse interfacial energy of hydrogen bonds also demonstrates another reason for the successful separation. The film thickness ranges from 45 nm to several micrometers. When used as a composite of counter electrodes in dye sensitized solar cells, it showed higher (8.58%) power conversion efficiency than its spin-(7.71%) and spray-coated (8.07%) counterparts. It also showed promising performance in capacitive humidity sensors. The capacitance varied by three orders of magnitude in the range of the relative humidity of 15%-95%. Therefore the strategy realizes an ultrafast and high-quality film production which is suitable for various applications.

Neighbourhood exposure to point-of-sale price promotions for cigarettes is associated with financial stress among smokers: results from a population-based study.

AIM: To examine the association between neighbourhood exposure to point-of-sale (POS) cigarette price promotions and financial stress among smokers in a Midwestern metropolitan area in the USA. METHODS: Survey data from 888 smokers provided information on sociodemographic and smoking related variables. Financial stress was measured with the question: 'In the last six months, because of lack of money, was there a time when you were unable to buy food or pay any important bills on time, such as electricity, telephone, credit card, rent or your mortgage? (Yes/No).' Using audit data from 504 tobacco retailers, we estimated a score of POS price promotions for each respondent by summing the different types of promotion in each store in their neighbourhood, as defined by a 1-km roadway buffer. RESULTS: Adjusted results provided strong support for an association between higher scores of neighbourhood POS cigarette price promotions and a higher probability of financial stress (p=0.007). CONCLUSION: Exposure to POS cigarette price promotions is associated with financial stress. This finding, coupled with previous reports that smokers with financial stress are less likely to attempt to quit or succeed in quitting smoking, suggests that POS cigarette price promotions may act as an impediment to smoking cessation.

Point-of-Sale E-cigarette Advertising Among Tobacco Stores.

The marketing expenditure and sale of e-cigarettes increased sharply in the United States in recent years. However, little is known about neighborhood characteristics of point-of-sale (POS) e-cigarette advertising among tobacco stores. The purpose of this study was to examine socio-demographic characteristics of POS e-cigarette advertising among tobacco stores in the Omaha metropolitan area of Nebraska, USA. Between April and June 2014, trained fieldworkers completed marketing audits of all stores that sell tobacco (n = 463) in the Omaha metropolitan area and collected comprehensive e-cigarette advertising data of these stores. Based on the auditing information, we categorized tobacco stores based on e-cigarette advertising status. Logistic regression was used to examine the association between neighborhood socio-demographic factors and e-cigarette advertising among tobacco stores. 251 (54.2%) of the 463 tobacco stores had e-cigarette advertisements. We found that neighborhoods of stores with POS e-cigarette advertising had higher per capita income (p < 0.05), higher percentage of non-hispanic whites (p < 0.005), and higher percentage of individuals with high school education (p < 0.005) than neighborhoods of stores without POS e-cigarette advertising. There were negative associations between e-cigarette advertising and number of adolescents or number of middle/high school students. After adjusting for covariates, only percentage of non-Hispanic Whites remained a significant factor for e-cigarette advertising. POS e-cigarette advertising among tobacco stores is related with neighborhood socioeconomic and demographic characteristics. Future studies are needed to understand how these characteristics are related with e-cigarette purchasing and e-cigarette prevalence among social groups.

Plant Cell Wall-Penetrable, Redox-Responsive Silica Nanoprobe for the Imaging of Starvation-Induced Vesicle Trafficking.

Autophagy is a self-protection process against reactive oxygen species (ROS). The intracellular level of ROS increased when cells were cultured under nutrient starvation. Antioxidants such as glutathione and ascorbic acid play an important role in ROS removal. However, the cellular redox state in the autophagic pathway is still unclear. Herein, we developed a new redox-sensitive probe with a disulfide-linked silica scaffold to enable the sensing of the reduction environment in cell organelles. This redox-responsive silica nanoprobe (ReSiN) could penetrate the plant cell wall and release fluorescent molecules in response to redox states. By applying the ReSiN to tobacco BY-2 cells and tracing the distribution of fluorescence, we found a higher reducing potential in the central vacuole than in the autolysosomes. Upon cysteine protease inhibitor (E64-c) treatment in sucrose-free medium, the disulfide-silica structures of the ReSiNs were broken down in the vacuoles but were not degraded and were accumulated in the autolysosomes. These results reveal the feasibility of our nanoprobe for monitoring the endocytic and macroautophagic pathways. These pathways merge upstream of the central vacuole, which is the final destination of both pathways. In addition, different redox potentials were observed in the autophagic pathway. Finally, the expression of the autophagy-related protein (Atg8) fused with green fluorescence protein confirmed that the ReSiN treatment itself did not induce the autophagic pathway under normal physiological conditions, indicating the versatility of this nanoprobe in studying stimuli-triggered autophagy-related trafficking.