Region-specific cellular and molecular basis of liver regeneration after acute pericentral injury

Liver injuries often occur in a zonated manner. However, detailed regenerative responses to such zonal injuries at cellular and molecular levels remain largely elusive. By using a fate-mapping strain, Cyp2e1-DreER, to elucidate liver regeneration after acute pericentral injury, we found that pericentral regeneration is primarily compensated by the expansion of remaining pericentral hepatocytes, and secondarily by expansion of periportal hepatocytes. Employing single-cell RNA sequencing, spatial transcriptomics, immunostaining, and in vivo functional assays, we demonstrated that the upregulated expression of the mTOR/4E-BP1 axis and lactate dehydrogenase A in hepatocytes contributes to pericentral regeneration, while activation of transforming growth factor β (TGF-β1) signaling in the damaged area mediates fibrotic responses and inhibits hepatocyte proliferation. Inhibiting the pericentral accumulation of monocytes and monocyte-derived macrophages through an Arg-Gly-Asp (RGD) peptide-based strategy attenuates these cell-derived TGF-β1 signalings, thus improving pericentral regeneration. Our study provides integrated and high-resolution spatiotemporal insights into the cellular and molecular basis of pericentral regeneration.

Creating a semi-opened micro-cavity ovary through sacrificial microspheres as an in vitro model for discovering the potential effect of ovarian toxic agents

The bio-engineered ovary is an essential technology for treating female infertility. Especially the development of relevant in vitro models could be a critical step in a drug study. Herein, we develop a semi-opened culturing system (SOCS) strategy that maintains a 3D structure of follicles during the culture. Based on the SOCS, we further developed micro-cavity ovary (MCO) with mouse follicles by the microsphere-templated technique, where sacrificial gelatin microspheres were mixed with photo-crosslinkable gelatin methacryloyl (GelMA) to engineer a micro-cavity niche for follicle growth. The semi-opened MCO could support the follicle growing to the antral stage, secreting hormones, and ovulating cumulus-oocyte complex out of the MCO without extra manipulation. The MCO-ovulated oocyte exhibits a highly similar transcriptome to the in vivo counterpart (correlation of 0.97) and can be fertilized. Moreover, we found that a high ROS level could affect the cumulus expansion, which may result in anovulation disorder. The damage could be rescued by melatonin, but the end of cumulus expansion was 3h earlier than anticipation, validating that MCO has the potential for investigating ovarian toxic agents in vitro. We provide a novel approach for building an in vitro ovarian model to recapitulate ovarian functions and test chemical toxicity, suggesting it has the potential for clinical research in the future.

Single-cell and spatially resolved transcriptomics for liver biology

Single-cell transcriptomics enables the identification of rare cell types and the inference of state transitions, whereas spatially resolved transcriptomics allows the quantification of cells and genes in the context of tissues. The recent progress in these new technologies is improving our understanding of the cell landscape and its roles in diseases. Here, we review key biological insights into liver homeostasis, development, regeneration, chronic liver disease, and cancer obtained from single-cell and spatially resolved transcriptomics. We highlight recent progress in the liver cell atlas that characterizes the comprehensive cellular composition; diversity and function; the spatial architecture such as liver zonation, cell communication, and proximity; the cell identity conversion and cell-specific alterations that are associated with liver pathology; and new therapeutic targets. We further discuss outstanding challenges, advanced experimental technologies, and computational methods that help to address these challenges.

TIST: Transcriptome and Histopathological Image Integrative Analysis for Spatial Transcriptomics

Sequencing-based spatial transcriptomics (ST) is an emerging technology to study in situ gene expression patterns at the whole-genome scale. Currently, ST data analysis is still complicated by high technical noises and low resolution. In addition to the transcriptomic data, matched histopathological images are usually generated for the same tissue sample along the ST experiment. The matched high-resolution histopathological images provide complementary cellular phenotypical information, providing an opportunity to mitigate the noises in ST data. We present a novel ST data analysis method called transcriptome and histopathological image integrative analysis for ST (TIST), which enables the identification of spatial clusters (SCs) and the enhancement of spatial gene expression patterns by integrative analysis of matched transcriptomic data and images. TIST devises a histopathological feature extraction method based on Markov random field (MRF) to learn the cellular features from histopathological images, and integrates them with the transcriptomic data and location information as a network, termed TIST-net. Based on TIST-net, SCs are identified by a random walk-based strategy, and gene expression patterns are enhanced by neighborhood smoothing. We benchmark TIST on both simulated datasets and 32 real samples against several state-of-the-art methods. Results show that TIST is robust to technical noises on multiple analysis tasks for sequencing-based ST data and can find interesting microstructures in different biological scenarios. TIST is available at http://lifeome.net/software/tist/ and https://ngdc.cncb.ac.cn/biocode/tools/BT007317.

POS0535 OUTCOMES IN PATIENTS WITH RHEUMATOID ARTHRITIS INITIATING THERAPY WITH ETANERCEPT, ADALIMUMAB, OR JANUS KINASE INHIBITORS

Background

Ongoing debate exists regarding the optimal sequence of tumor necrosis factor inhibitors and Janus kinase inhibitors (JAKis) in patients with rheumatoid arthritis (RA) as first-line biologic or targeted synthetic disease-modifying antirheumatic drug (b/tsDMARD) therapy following conventional therapies.

Objectives

To describe baseline characteristics, effectiveness, persistency, and treatment patterns among first-line b/tsDMARD-naive initiators of etanercept (ETN), adalimumab (ADA), or JAKis (tofacitinib, baricitinib, and upadacitinib).

Methods

Data on patients who initiated b/tsDMARD from 11/2012 to 6/2021 were obtained from the CorEvitas RA Registry, a prospective, multicenter, observational, disease-based registry. Patients ≥18 years with rheumatologist-diagnosed RA and 6- and/or 12-months’ (M) follow-up were included. We report descriptive statistics at baseline, persistency on therapy, escalation/de-escalation of therapy, details on patterns of drug switching, and effectiveness outcomes using regression models adjusted for baseline covariates (demographic/socioeconomic/lifestyle characteristics, comorbidities, medication history, disease activity, and patient-reported outcomes). Outcomes were evaluated at 6M and 12M follow-up.

Results

First-line initiators of ETN, ADA, and JAKis with baseline and follow-up visits were identified: 803, 984, and 361 patients at 6M, respectively; 589, 749, and 264 patients at 12M, respectively. Baseline characteristics were similar among ETN, ADA, and JAKi initiators with the exception of disease duration, which was longer among first-line JAKi initiators (mean, 8.6 y) versus ETN (5.9 y) and ADA (5.8 y) initiators. Unadjusted mean improvement in Clinical Disease Activity Index (CDAI) was generally similar between groups at 6M and 12M (Table 1). Adjusted effectiveness results were similar at 6M and 12M (Figure 1). At 6M, 68% of ETN, 69% of ADA, and 67% of JAKi initiators remained on the same therapy; at 12M, 53% of ETN, 57% of ADA, and 57% of JAKi initiators remained on the same therapy. The frequency of switching to another b/tsDMARD was similar across initiators.

Table 1.

Patient Description at Time of Initiation and Unadjusted Disease Activity Results

ETNADAJAKisAge, years54.4 (12.8)55.5 (12.1)60.9 (12.5)Female, n (%)666 (77)843 (76)303 (77)BMI, kg/m230.4 (7.6)31.3 (7.9)30.8 (7.6)Duration of RA, years5.9 (7.6)5.8 (7.3)8.6 (10.0)BL disease activitya CDAI19.9 (14.3)18.9 (12.7)18.8 (13.2) mHAQ0.5 (0.5)0.5 (0.5)0.5 (0.5) Patient painb48.0 (28.8)49.2 (28.5)45.2 (29.2)Disease activity decrease from BL at 6M CDAI6.9 (13.6)6.4 (12.1)4.7 (12.3) mHAQ0.1 (0.4)0.1 (0.4)0.1 (0.4) Patient painb9.7 (30.2)10.6 (28.4)8.9 (29.5)Disease activity decrease from BL at 12M CDAI7.4 (13.5)6.1 (13.0)5.1 (13.0) mHAQ0.1 (0.4)0.1 (0.4)0.1 (0.4) Patient painb8.8 (29.7)8.7 (30.1)7.5 (28.6)Achievement of LDAc, % 6M43.441.932.5 12M41.039.638.3

aBaseline for combined population with 6M and 12M follow-up. b(range: 0–100). cCDAI ≤10 among those with moderate or high disease activity at baseline.

Data are mean (SD) unless otherwise specified.

ADA, adalimumab; BL, baseline; CDAI, Clinical Disease Activity Index; ETN, etanercept; JAKis, Janus kinase inhibitors; LDA, low disease activity; M, months; mHAQ, modified Health Assessment Questionnaire; RA, rheumatoid arthritis; SD, standard deviation.

Conclusion

In this real-world study in patients initiating first-line b/tsDMARD therapy with ETN, ADA, or JAKis, we did not observe differences in clinical effectiveness/patient-reported outcomes and treatment persistency at 6M and12M after treatment initiation.

Acknowledgements

This study is sponsored by CorEvitas, LLC. CorEvitas has been supported through contracted subscriptions in the last two years by AbbVie, Amgen Inc., Arena, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Chugai, Eli Lilly and Company, Genentech, Gilead, GSK, Janssen, LEO, Novartis, Ortho Dermatologics, Pfizer Inc., Regeneron, Sanofi, Sun, and UCB. Writing support was funded by Amgen Inc. and provided by Su Cappello, PharmD, of Peloton Advantage, LLC, an OPEN Health company, and Julie Wang, DPM, of Amgen Inc.

Disclosure of Interests

Dimitrios A Pappas Shareholder of: Officer or Board Member for Corrona Research Foundation, Speakers bureau: Speaker/Honoraria for AbbVie, Novartis, Roche Hellas, Sanofi, Consultant of: Consultant for AbbVie, Roche Hellas; Advisor for Sanofi, Employee of: Employment by, ownership interest, and stock options in CorEvitas, LLC, Jacqueline O’Brien Employee of: Employment by CorEvitas, LLC., Lin Guo Employee of: Employment by CorEvitas, LLC., Ying Shan Employee of: Employment by CorEvitas, LLC., Joshua Baker Consultant of: Received consulting fees from Bristol Myers Squibb, Pfizer, CorEvitas LLC, and Burns-White, LLC., Greg Kricorian Shareholder of: Employment by and stock ownership in Amgen Inc., Employee of: Employment by and stock ownership in Amgen Inc., Scott Stryker Shareholder of: Employment by and stock ownership in Amgen Inc., Employee of: Employment by and stock ownership in Amgen Inc., David Collier Shareholder of: Employment by and stock ownership in Amgen Inc., Employee of: Employment by and stock ownership in Amgen Inc.

[Analysis of clinical phenotype and genotype of Chinese children with disorders of sex development]

Objective: To explore the heterogeneity and correlation of clinical phenotypes and genotypes in children with disorders of sex development (DSD). Methods: A retrospective study of 1 235 patients with clinically proposed DSD in 36 pediatric medical institutions across the country from January 2017 to May 2021. After capturing 277 DSD-related candidate genes, second-generation sequencing was performed to analyzed the heterogeneity and correlation combined with clinical phenotypes. Results: Among 1 235 children with clinically proposed DSD, 980 were males and 255 were females of social gender at the time of initial diagnosis with the age ranged from 1 day of age to 17.92 years. A total of 443 children with pathogenic variants were detected through molecular genetic studies, with a positive detection rate of 35.9%. The most common clinical phenotypes were micropenis (455 cases), hypospadias (321 cases), and cryptorchidism (172 cases) and common mutations detected were in SRD5A2 gene (80 cases), AR gene (53 cases) and CYP21A2 gene (44 cases). Among them, the SRD5A2 mutation is the most common in children with simple micropenis and simple hypospadias, while the AMH mutation is the most common in children with simple cryptorchidism. Conclusions: The SRD5A2 mutation is the most common genetic variant in Chinese children with DSD, and micropenis, cryptorchidism, and hypospadias are the most common clinical phenotypes. Molecular diagnosis can provide clues about the biological basis of DSD, and can also guide clinicians to perform specific clinical examinations. Target sequence capture probes and next-generation sequencing technology can provide effective and economical genetic diagnosis for children with DSD.

Highly Regional Genes: graph-based gene selection for single cell RNA-seq data

Gene selection is an indispensable step for analyzing noisy and high-dimensional single cell RNA-seq (scRNA-seq) data. Compared with the commonly used variance-based methods, by mimicking the human maker selection in the 2D visualization of cells, a new feature selection method called HRG (Highly Regional Genes) is proposed to find the informative genes which show regional expression patterns in the cell-cell similarity network. We mathematically find the optimal expression patterns which can maximize the proposed scoring function. In comparison with several unsupervised methods, HRG shows high accuracy and robustness, and can increase the performance of downstream cell clustering and gene correlation analysis. Also, it is applicable for selecting informative genes of sequencing-based spatial transcriptomic data.

JEBIN: analyzing gene co-expressions across multiple datasets by joint network embedding

The inference of gene co-expression associations is one of the fundamental tasks for large-scale transcriptomic data analysis. Due to the high dimensionality and high noises in transcriptomic data, it is difficult to infer stable gene co-expression associations from single dataset. Meta-analysis of multisource data can effectively tackle this problem. We proposed Joint Embedding of multiple BIpartite Networks (JEBIN) to learn the low-dimensional consensus representation for genes by integrating multiple expression datasets. JEBIN infers gene co-expression associations in a nonlinear and global similarity manner and can integrate datasets with different distributions in linear time complexity with the gene and total sample size. The effectiveness and scalability of JEBIN were verified by simulation experiments, and its superiority over the commonly used integration methods was proved by three indexes on real biological datasets. Then, JEBIN was applied to study the gene co-expression patterns of hepatocellular carcinoma (HCC) based on multiple expression datasets of HCC and adjacent normal tissues, and further on latest HCC single-cell RNA-seq data. Results show that gene co-expressions are highly different between bulk and single-cell datasets. Finally, many differentially co-expressed ligand-receptor pairs were discovered by comparing HCC with adjacent normal data, providing candidate HCC targets for abnormal cell-cell communications.

Comprehensive analysis of spatial architecture in primary liver cancer

Heterogeneity is the major challenge for cancer prevention and therapy. Here, we first constructed high-resolution spatial transcriptomes of primary liver cancers (PLCs) containing 84,823 spots within 21 tissues from seven patients. The progressive comparison of spatial tumor microenvironment (TME) characteristics from nontumor to leading-edge to tumor regions revealed that the tumor capsule potentially affects intratumor spatial cluster continuity, transcriptome diversity, and immune cell infiltration. Locally, we found that the bidirectional ligand-receptor interactions at the 100-μm-wide cluster-cluster boundary contribute to maintaining intratumor architecture and the PROM1⁺ and CD47⁺ cancer stem cell niches are related to TME remodeling and tumor metastasis. Last, we proposed a TLS-50 signature to accurately locate tertiary lymphoid structures (TLSs) spatially and unveiled that the distinct composition of TLSs is shaped by their distance to tumor cells. Our study provides previous unknown insights into the diverse tumor ecosystem of PLCs and has potential benefits for cancer intervention.

Photoluminescence and magnetism integrated multifunctional black phosphorus probes through controllable PO bond orbital hybridization

Biological probes with integrated photoluminescence and magnetism characteristics play a critical role in modern clinical diagnosis and surgical protocols combining fluorescence optical imaging (FOI) with magnetic resonance imaging (MRI) technology. However, traditional magnetic semiconductors can easily generate a spin splitting at the Fermi level and half-metallic electronic occupation, which will sharply reduce the radiation recombination efficiency of photogenerated carriers. To overcome this intrinsic contradiction, we propose a controllable oxidation strategy to introduce some particular PO bonds into black phosphorus nanosheets, in which the p orbital hybridization between P and O atoms not only provides some carrier recombination centers but also leads to a room-temperature spin polarization. As a result, the coexistence of photoluminescence and magnetism is realized in multifunctional black phosphorus probes with excellent biocompatibility. This work provides a new insight into integrating photoluminescence and magnetism together by intriguing atomic orbital hybridization.

Salvage mandibular reconstruction: multi-institutional analysis of 17 patients

Unsuccessful mandibular reconstruction occasionally occurs, leaving the patient with undesirable function and contours. In such cases, second- or third-time corrective operations are challenging. However, published studies on the complicated retreatment of such patients are scarce. A retrospective analysis covering the years 2015-2019 was conducted in three centers. All 17 patients included had undergone prior failed mandibular reconstructions in other institutions. Salvage secondary or tertiary reconstructive surgeries were attempted and the results are presented. Major factors for these failed reconstructions included exposed non-vascularized bone grafts (n = 7, 41.2%), flap loss (n = 4, 23.5%), exposed artificial joint (n = 3, 17.6%), skewed occlusion with deformity (n = 1, 5.9%), non-union (n = 1, 5.9%), and recurrence (n = 1, 5.9%). Fibula flaps were transferred in 15 patients, while iliac flaps were used in two patients for mandibular re-do reconstructions. Virtual surgical designs were conducted in nine (52.9%) patients, with navigation-guided approaches performed in three cases. Postoperative functions were relatively favorable in these complicated mandibular re-do reconstruction cases. Mandibular symmetry (mandibular length and height; P = 0.002) and condylar position (P < 0.001) were regained after these re-do attempts. Secondary or tertiary mandibular re-do reconstruction can still achieve good functional outcomes with appropriate preoperative selection and well-conceived designs, especially with the aid of virtual surgery and navigation.

AB0202 IMPROVEMENT IN CLINICAL DISEASE ACTIVITY AND PATIENT-REPORTED OUTCOMES AFTER 6 MONTHS OF TREATMENT WITH ABATACEPT, STRATIFIED BY LINE OF THERAPY, IN PATIENTS WITH RA: RESULTS FROM A LARGE, US, NATIONAL OBSERVATIONAL STUDY

Background:

RA is more responsive to treatment in the early stages of disease, and early treatment may lead to better long-term outcomes.1,2 Data on the effectiveness of specific drugs as first or later lines of therapy will help inform treatment sequencing.

Objectives:

Data from patients enrolled in the Corrona RA Registry were used to compare the effectiveness of abatacept across lines of therapy overall (primary cohort) and in a subset of patients who were anti-citrullinated protein antibody positive (ACPA+).

Methods:

Patients with RA who initiated abatacept (January 2006 to October 2020), had 6 months’ follow-up (within 4−9 months of starting abatacept), had baseline (BL) and follow-up CDAI scores available, and had BL CDAI >2.8 were included. Outcomes were compared for first-, second- and third or higher-line therapy: 0, 1 or ≥2 prior biologic DMARDs or Janus kinase inhibitors, respectively. Continuous outcomes included change from BL to 6 months in mean CDAI and patient-reported pain, fatigue, and HAQ. Binary outcomes included rate of achieving minimal clinically important difference (MCID) in CDAI or modified ACR20/50/70 at 6 months. Continuous and binary outcomes were analysed using multiple linear and logistic regression, respectively. The models included line of therapy, age, sex, disease duration, work status, SC nodules, history of hypertension and depression, BL CDAI, BL patient-reported pain and BL fatigue. Additional subgroup analyses were carried out in patients with moderate/high disease activity (CDAI >10) at BL.

Results:

In total, 2876 patients (2327 with BL CDAI >10; 890 ACPA+) were included; 442, 911, and 1523 patients initiated first-, second- or third/higher-line abatacept, respectively. Compared with patients on second/third/higher-line abatacept therapy, those on first-line abatacept were significantly older, had shorter disease duration, and had lower BL CDAI, pain and fatigue (all p<0.001). In adjusted analyses, patients receiving abatacept as earlier lines of therapy had significantly greater improvement from BL in mean CDAI and in patient-reported fatigue and HAQ (Table 1). There was no significant difference between lines of therapy in change in patient-reported pain. Patients receiving first-line abatacept had significantly higher odds of achieving a MCID in CDAI or modified ACR20/50/70 response (Figure 1). Similar patterns were seen when the sample was limited to patients with moderate/high disease activity or in patients who were ACPA+.

Conclusion:

There were significant differences in improvement in clinical disease activity and patient-reported outcomes across lines of therapy. Better treatment responses were observed with earlier lines of abatacept therapy in the overall population, in patients who were ACPA+ and in those with moderate/high BL disease activity.

References:

[1]Harrold LR, et al. Clin Rheumatol 2017;36:1215−1220.

[2]Monti S, et al. RMD Open 2015;1(Suppl 1):e000057.

Table 1.

Adjusted mean change in CDAI and patient-reported outcomes from BL to 6 months after initiation of abatacept by line of therapy (primary cohort)

Adjusted outcome, mean change (SE)First-line (n=440)Second-line (n=898)Third/higher-line (n=1515)p valueaCDAI−7.96 (0.33)−7.49 (0.27)−5.74 (0.19)<0.001Patient-reported pain (VAS 0–100)−9.43 (0.69)−7.98 (0.47)−7.70 (0.35)0.074Patient-reported fatigue (VAS 0–100)−7.49 (0.71)−5.87 (0.51)−4.81 (0.36)0.002Patient-reported HAQ−0.16 (0.01)−0.12 (0.01)−0.08 (0.01)<0.001

aEstimated by multiple linear regression model adjusted for age, sex, disease duration, work status, SC nodules, history of hypertension and depression, BL CDAI, BL patient-reported pain and BL fatigue (factors that were identified a priori based on clinical experience or that differed significantly by line of therapy); p values reflect ANOVA overall test of differences across lines of therapy.

VAS=visual analogue scale.

Acknowledgements:

Professional medical writing and editorial assistance was provided by Claire Line, PhD, at Caudex and was funded by Bristol Myers Squibb. The poster was a collaborative effort between Corrona and Bristol Myers Squibb, with financial support provided by Bristol Myers Squibb. This study was sponsored by Corrona, LLC. Corrona is supported through contracted subscriptions with multiple pharmaceutical companies.

Disclosure of Interests:

Leslie Harrold Consultant of: AbbVie, Bristol Myers Squibb, Genentech/Roche, Grant/research support from: Pfizer, Keith Wittstock Employee of: Bristol Myers Squibb, Sheila Kelly Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Sang Hee Park Employee of: Bristol Myers Squibb, Xue Han Employee of: Bristol Myers Squibb, Ying Shan: None declared, Carla Roberts-Toler: None declared, Nicole Middaugh: None declared, Vadim Khaychuk Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb

scCancer: a package for automated processing of single-cell RNA-seq data in cancer

Molecular heterogeneities and complex microenvironments bring great challenges for cancer diagnosis and treatment. Recent advances in single-cell RNA-sequencing (scRNA-seq) technology make it possible to study cancer cell heterogeneities and microenvironments at single-cell transcriptomic level. Here, we develop an R package named scCancer, which focuses on processing and analyzing scRNA-seq data for cancer research. Except basic data processing steps, this package takes several special considerations for cancer-specific features. Firstly, the package introduced comprehensive quality control metrics. Secondly, it used a data-driven machine learning algorithm to accurately identify major cancer microenvironment cell populations. Thirdly, it estimated a malignancy score to classify malignant (cancerous) and non-malignant cells. Then, it analyzed intra-tumor heterogeneities by key cellular phenotypes (such as cell cycle and stemness), gene signatures and cell-cell interactions. Besides, it provided multi-sample data integration analysis with different batch-effect correction strategies. Finally, user-friendly graphic reports were generated for all the analyses. By testing on 56 samples with 433 405 cells in total, we demonstrated its good performance. The package is available at: http://lifeome.net/software/sccancer/.

FRI0100 COMPARISON OF PATIENTS (PTS) WITH RHEUMATOID ARTHRITIS (RA) AMONG DISEASE ACTIVITY CATEGORIES AFTER 6 MONTHS OF TREATMENT WITH A TUMOUR NECROSIS FACTOR INHIBITOR (TNFI): RESULTS FROM THE CORRONA® RA REGISTRY

Background:

Targeting remission (REM) or low disease activity (LDA) is a widely accepted treatment strategy for RA. However, there are limited data on the proportion of pts who achieve these targets, or remain in moderate (MDA) or high disease activity (HDA) following advanced therapy.

Objectives:

To estimate the proportion of RA pts in disease activity states (REM, LDA, MDA, and HDA) who were biologic-naïve at initiation and had continuous treatment with a TNFi for 6–12 months in the Corrona RA registry.

Methods:

Eligible pts were aged ≥18 years, biologic-naïve, initiated TNFi treatment between January 1, 2010 and July 31, 2019, and had continuous use of a TNFi for 6–12 months. Disease activity was defined based on Clinical Disease Activity Index (CDAI) at the visit closest to 6-month follow-up: REM, ≤2.8; LDA, >2.8–10; MDA, >10–22; and HDA, >22. Disease characteristics, disease activity measures, and pt-reported outcomes (PROs) were reported at TNFi initiation and at the 6-month follow-up visit.

Results:

2586 biologic-naïve pts who initiated a TNFi and had continuous use for 6–12 months were included. At TNFi initiation, 167 (6%) were in REM, 479 (19%) had LDA, 907 (35%) had MDA, and 1033 (40%) had HDA. After 6–12 months of treatment, 563 (21.8%) were in REM, 923 (35.7%) had LDA, 674 (26.1%) had MDA, and 426 (16.5%) had HDA. Pts with HDA/MDA at 6–12 months were more likely to have a history of hypertension (32.7% HDA; 34.0% MDA; vs 23.6% REM) and had higher mean body mass index (BMI) (30.9 HDA; 31.1 MDA; vs 29.0 REM) at baseline compared with pts in REM. Disease activity measures and PROs were worse in pts with MDA and HDA vs LDA and REM after 6–12 months (Table). Pt Global Assessment was higher than Physician Global Assessment across all groups.

Conclusion:

While 57.4% of pts who initiated a TNFi experienced a favorable outcome, >40% required additional or alternative intervention to achieve REM/LDA. Pts who remained in MDA/HDA continued to have an inadequate response to TNFi (as measured by disease activity measures and PROs) after 6–12 months of treatment compared with those who achieved REM/LDA.

Table

Summary of disease activity measures and PROs in previously biologic-naïve pts at the 6–12-month follow-up visit, stratified by disease activity category at the 6–12-month follow-up visit

Characteristics at 6–12 months, mean (standard deviation)Disease activity category at 6–12 monthsREM (n=563)LDA (n=923)MDA (n=674)HDA (n=426)CDAI1.2 (0.8)6.2 (2.1)15.4 (3.4)32.7 (9.2)Tender joint count (28)0.1 (0.3)1.0 (1.3)4.3 (3.3)13.4 (7.0)Swollen joint count (28)0.1 (0.3)1.1 (1.6)4.0 (3.6)9.1 (5.9)C-reactive protein6.4 (22.7)7.0 (10.6)11.1 (19.9)12.6 (22.1)Modified health assessment questionnaire0.1 (0.2)0.3 (0.4)0.5 (0.5)0.8 (0.5)Pt global assessment6.6 (6.8)28.6 (20.9)43.7 (25.7)58.0 (22.7)Physician global assessment3.6 (4.3)12.1 (10.4)27.4 (15.9)44.9 (19.8)Pt pain assessment8.7 (11.0)30.3 (23.5)46.1 (27.0)59.9 (24.4)Pt fatigue assessment15.7 (19.2)34.5 (26.6)48.3 (28.0)59.4 (27.5)Morning stiffness (min)16.5 (36.5)55.4 (146.3)96.9 (197.5)143.6 (260.0)

Disclosure of Interests:

Joel M Kremer Shareholder of: May own stocks and opinions, Grant/research support from: Research and consulting fees from AbbVie Inc., Consultant of: AbbVie, Amgen, BMS, Genentech, Inc., Gilead, GSK, Lilly, Pfizer, Regeneron and Sanofi, Employee of: Corrona, LLC employee, Anne Winkler Consultant of: AbbVie, Pfizer, and Novratis, Speakers bureau: AbbVie, Janssen, Sanofi, Genentech, Celgene, Eli Lilly, and Novartis., Laura Anatale-Tardiff Employee of: Corrona, LLC employee, Robert McLean Employee of: Corrona, LLC, Ying Shan Employee of: Corrona, LLC employee, Page Moore Employee of: Corrona, LLC employee, Namita Tundia Shareholder of: May own stocks and options, Employee of: AbbVie employee, Jessica Suboticki Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., John Tesser Consultant of: Sanofi/Regeneron, Speakers bureau: Sanofi/Regeneron

P-type laser-doped WSe2/MoTe2 van der Waals heterostructure photodetector

Van der Waals heterostructures (vdWHs) based on two-dimensional (2D) materials are being studied extensively for their prospective applications in photodetectors. As the pristine WSe₂/MoTe₂ heterostructure is a type I (straddling gap) structure, it cannot be used as a photovoltaic device theoretically, although both WSe₂ and MoTe₂ have excellent photoelectric properties. The Fermi level of p-doped WSe₂ is close to its valence band. The p-doped WSe₂/MoTe₂ heterostructure can perform as a photovoltaic device because a built-in electric field appears at the interface between MoTe₂ and p-doped WSe₂. Here, a 633 nm laser was used for scanning the surface of WSe₂ in order to obtain the p-doped WSe₂. x-ray photoelectron spectroscopy (XPS) and electrical measurements verified that p-type doping in WSe₂ is produced through laser treatment. The p-type doping in WSe₂ includes substoichiometric WO_x and nonstoichiometric WSe_x. A photovoltaic device using p-doped WSe₂ and MoTe₂ was successfully fabricated. The band structure, light-matter reactions, and carrier-transport in the p-doped WSe₂/MoTe₂ heterojunction were analyzed. The results showed that this photodetector has an on/off ratio of ≈10⁴, dark current of ≈1 pA, and response time of 72 μs under the illumination of 633 nm laser at zero bias (V _ds = 0 V). The proposed p-doping method may provide a new approach to improve the performance of nanoscale optoelectronic devices.

MOTS-c accelerates bone fracture healing by stimulating osteogenesis of bone marrow mesenchymal stem cells via positively regulating FOXF1 to activate the TGF-β pathway

OBJECTIVE

To elucidate the function of MOTS-c in accelerating bone fracture healing by inducing BMSCs differentiation into osteoblasts, as well as its potential mechanism.

MATERIALS AND METHODS

Primary BMSCs were extracted from rats and induced for osteogenesis. The highest dose of MOTS-c that did not affect BMSCs proliferation was determined by CCK-8 assay. After 7-day osteogenesis, the relative levels of ALP, Bglap, and Runx2 in MOTS-c-treated BMSCs influenced by FOXF1 were examined. ALP staining and alizarin red S staining in BMSCs were performed as well. The interaction between FOXF1 and TGF-β was analyzed by ChIP assay. At last, rescue experiments were performed to uncover the role of FOXF1/TGF-β axis in MOTS-c-induced osteogenesis.

RESULTS

1 μM MOTS-c was the highest dose that did not affect BMSCs proliferation. MOTS-c treatment upregulated the relative levels of ALP, Bglap, and Runx2, and stimulated mineralization ability in BMSCs, which were attenuated by the silence of FOXF1. TGF-β was proved to interact with FOXF1, and its level was positively mediated by FOXF1. The silence of FOXF1 attenuated the accelerated osteogenesis and TGF-β upregulation in BMSCs because of MOTS-c induction, and these trends were further reversed by the overexpression of TGF-β.

CONCLUSIONS

MOTS-c treatment markedly induces osteogenesis in BMSCs. During MOTS-c-induced osteogenic progression, the upregulated FOXF1 triggers the activation of TGF-β pathway, thus accelerating bone fracture healing.

[Correlation between the expression of STOX1 in placenta of patients with early onset preeclampsia]

Objective: To investigate the relationship of STOX1expression and pathogenesis of early onset preeclampsia. Methods: 65 cases of preeclampsia women who delivered in Shanghai Pudong Hospital from October 2015 to June 2018, were recruited, which included 31 cases with early onset preeclampsia (early onset group, gestational week<34 weeks) and 34 patients with late onset preeclampsia (late onset group, gestational week ≥34 weeks). 34 cases women who received caesarean section because of pelvic structural deformities, breech presentation, macrosomia and social factors were included as the control group(gestational week ≥34 weeks) were selected as control group.The expression and localization of STOX1 mRNA and protein in placenta of three groups of maternal were evaluated by immunohistochemistry SP, RT-qPCR and Western blotting. Results: (1) The expression of STOX1 in placenta mainly distributed in the cytoplasm of placental syncytiotrophoblasts, cytotrophoblasts, vascular endothelial and mesenchymal cells, a few in the cell nucleus.The staining intensity of STOX1 in early onset group was significantly stronger than that in late onset group, the staining intensity of the late onset group was similar to that of the control group. The positive expression rates of STOX1protein in early onset group, late onset group and control group were 96.8%(30/31), 70.6%(24/34), 67.6%(23/34) respectively, which was higher in early onset group than that in late onset group(P=0.005). There was no statistical difference of STOX1 level between the late onset group and the control group(P=0.793). (2)Relative expression of STOX1 mRNA in early onset group, late onset group and control group were 0.054 3±0.003 5,0.037 5±0.000 7,0.035 2±0.000 4 respectively, which was significantly higher in early onset group than that in late onset group(P<0.05), while there was no statistical difference between the late onset group and the control group(P>0.05).(3)Relative expression level of STOX1 protein in early onset group, late onset group and control group were 0.78±0.04,0.59±0.020 and 0.54±0.018 respectively, which is higher in early onset group than that in late onset group(P<0.05). There was no statistical difference of STOX1 level between the late onset group and the control group(P>0.05). Conclusions: The pathogenesis of early onset and late onset preeclampsia may be different. Up-regulated expression of STOX1 in placenta may be associated with the pathogenesis of early onset preeclampsia.

[Expression and significance of STOX1 in villi and placenta at different stages of normal gestation]

Objective: To investigate the expression and significance of STOX1 in different stages of gestation villi and placenta. Methods: Totally 137 cases of normal villi and placenta of pregnant women were collected from the Department of Obstetrics of Shanghai Pudong Hospital from October 1(st) 2015 to February 28(th) 2018, including 64 cases of early pregnancy (early pregnancy group) which consists of 32 cases of 5-7(+6) weeks gestation (early pregnancy group A) and 32 cases of 8-11(+3) weeks gestation (early pregnancy group B), 28 cases of 14-26 weeks gestation(middle pregnancy group) and 45 cases of 37-41 weeks gestation (late pregnancy group). The expression and localization of STOX1 mRNA and protein in placenta were evaluated by RT-qPCR, Western blotting and immunohistochemistry. Results: (1)STOX1 was positively expressed in the cytotrophoblasts and syncytiotrophoblasts as well as interstitial and vascular endothelial cells of all groups. (2)STOX1 mRNA expression in each group was significantly different (P<0.05), the lowest was in the early pregnancy group A(0.007 8±0.000 4), which increased along with the progression of gestational age(P<0.05),and reached the highest level in the third trimester(0.064 4±0.001 3). (3)The protein level of STOX1 in different stages of normal pregnancy was 0.53±0.20 in early pregnancy group A;0.62±0.37 in early pregnancy group B;0.70±0.03 in middle pregnancy group and 0.81±0.04 in late pregnancy group respectively; which was positively related with the progression of gestational age (P<0.05). Conclusion: The expressions of STOX1 is gradually increasing along with the normal pregnancy progression, suggesting that it might be involved in proliferation, differentiation and infiltration and (or) apoptosis of trophoblast cells and the development of the placenta.

[Analysis of 17 cases underwent laparoscopic rectal cancer surgery with transanal natural orifice specimen extraction and resection]

Objective: To study the feasibility, safety and short-term efficacy of total laparoscopic rectal cancer surgery with transanal natural orifice specimen extraction and resection. Methods: From May 2014 to March 2016, 17 patients with rectal carcinoma were treated by total laparoscopic rectal cancer surgery with transanal natural orifice specimen extraction and resection. The clinical data of these patients was collected and retrospectively analyzed to assess the impact of the operation on postoperative recovery time and the incidence of complications. Results: All operations had been successfully accomplished without conversion to open surgery or conversional laparoscopic-assisted surgery . The median operative time was 105 minutes. The median blood loss was 35 ml. The median proximal and distal margin of tumor is 16 cm and 3.5 cm. The median number of lymph nodes harvest is 21, and the median first bowl movement is 43 hours. The hospitalization after operation is 8 days. No patient underwent abdomen hemorrhage or anastomotic leakage. Conclusion: Laparoscopic rectal cancer surgery with transanal natural orifice specimen extraction and resection appears to be feasible, safe and with promising efficacy for selected patients.

Abstract P4-06-09: Addition of a remote genetic counselor to the breast specialist's team improves clinical decision-making

Background: There is a shortage of trained genetic counselors (GC) and often long wait times for appointments, resulting in other specialists frequently ordering genetic testing. However, non-genetic specialists, including breast surgeons, find it difficult to stay current in genetics due to rapid advances in gene discovery, expanded panel offerings, and frequent changes to professional guidelines. We tested a novel model for hereditary cancer risk assessment where breast surgeons had “on demand” access to a remote laboratory-based genetic counselor for peer to peer consultation. In this study we sought to determine the impact this model has on breast surgeons' routinely ordering genetic testing including test identification, ordering patterns, and medical management.

Methods: An IRB approved multi-center prospective study involved 14 community-based breast cancer surgeons experienced with hereditary cancer risk assessment without a genetic counselor as part of their practice. Cases were all discussed with a remote Invitae GC to determine testing eligibility and selection. Physicians had the option to utilize remote GCs to discuss results or to refer to traditional genetic counseling services. Pre and post-test surveys were completed for each patient by the testing physician. To protect patient privacy, a unique case ID was used to link patient test data with identifying data.

Results: A total of 192 patients were evaluated with median age of 52. Risk assessment via BRCAPRO and the Hughes Risk model were performed on 98% of patients by the physicians. 65% of patients met NCCN guidelines for testing. Pathogenic mutations were found in 14% of patients. Breast surgeons changed their test selection 21% of the time after discussion with a GC. They called to discuss results in 47% of cases and medical management changes were incorporated in 15% of these cases based on discussion with a remote GC.

Conclusions: Remote GC provider support assisted physicians in facilitating customized test selection, aided in navigating challenging counseling cases, and impacted clinical management. This service may serve as a viable, effective model for 'on demand' genetic counseling support and may be a novel opportunity to expand genetic testing in a breast surgery setting.

Citation Format: Rosen B, O'Leary E, Shan Y, Pat W, Peter B. Addition of a remote genetic counselor to the breast specialist's team improves clinical decision-making [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-06-09.

eEF-2 kinase is a critical regulator of Warburg effect through controlling PP2A-A synthesis

Cancer cells predominantly metabolize glucose by glycolysis to produce energy in order to meet their metabolic requirement, a phenomenon known as Warburg effect. Although Warburg effect is considered a peculiarity critical for survival and proliferation of cancer cells, the regulatory mechanisms behind this phenomenon remain incompletely understood. We report here that eukaryotic elongation factor-2 kinase (eEF-2K), a negative regulator of protein synthesis, has a critical role in promoting glycolysis in cancer cells. We showed that deficiency in eEF-2K significantly reduced the uptake of glucose and decreased the productions of lactate and adenosine triphosphate in tumor cells and in the Ras-transformed mouse embryonic fibroblasts. We further demonstrated that the promotive effect of eEF-2K on glycolysis resulted from the kinase-mediated restriction of synthesis of the protein phosphatase 2A-A (PP2A-A), a key factor that facilitates the ubiquitin-proteasomal degradation of c-Myc protein, as knockdown of eEF-2K expression led to a significant increase in PP2A-A protein synthesis and remarkable downregulation of c-Myc and pyruvate kinase M2 isoform, the key glycolytic enzyme transcriptionally activated by c-Myc. In addition, depletion of eEF-2K reduced the ability of the transformed cells to proliferate and enhanced the sensitivity of tumor cells to chemotherapy both in vitro and in vivo. These results, which uncover a role of the eEF-2K-mediated control of PP2A-A in tumor cell glycolysis, provide new insights into the regulation of the Warburg effect.

Efficient oxygen electroreduction over ordered mesoporous Co–N-doped carbon derived from cobalt porphyrin

High-performance self-supported Co–N-doped carbon electrocatalyst for ORR with comparable activity to Pt/C in both acidic and alkaline media was prepared.

Lentivirus-mediated RNA interference of myostatin gene affects MyoD and Myf5 gene expression in duck embryonic myoblasts

The aim of this study was to construct lentivirus-mediated short hairpin RNA (shRNA) vectors targeting the duck MSTN gene and investigate whether these vectors can affect the development of duck primary cultured embryonic myoblasts. MSTN mRNA levels in the myoblasts were detected using quantitative real-time polymerase chain reaction (PCR), cell proliferation was assessed by MTT assays and cell differentiation was assayed by photography. MSTN mRNA levels in PLL3.7-MSTN-shRNA1, PLL3.7-MSTN-shRNA2 and PLL3.7-MSTN-shRNA3 lentivirus-mediated shRNA groups were reduced by 61.6%, 76.9% and 79.1%, respectively, compared to control cells. Down-regulation of MSTN in duck embryonic myoblasts stimulated cell proliferation and inhibited differentiation, accompanied by a greater than twofold down-regulation of MyoD expression and up-regulation of Myf5 expression. These results revealed that silencing of MSTN changes the development of duck embryonic myoblasts by regulating the expression level of MyoD and Myf5 genes.

Evaluation of improved γ-aminobutyric acid production in yogurt using Lactobacillus plantarum NDC75017

Most γ-aminobutyric acid (GABA)-producing microorganisms are lactic acid bacteria (LAB), but the yield of GABA is limited in most of these GABA-producing strains. In this study, the production of GABA was carried out by using Lactobacillus plantarum NDC75017, a strain screened from traditional fermented dairy products in China. Concentrations of substrate (l-monosodium glutamate, L-MSG) and coenzyme (pyridoxal-5-phosphate, PLP) of glutamate decarboxylase (GAD) and culture temperature were investigated to evaluate their effects on GABA yield of Lb. plantarum NDC75017. The results indicated that GABA production was related to GAD activity and biomass of Lb. plantarum NDC75017. Response surface methodology was used to optimize conditions of GABA production. The optimal factors for GABA production were L-MSG at 80 mM, PLP at 18 μM, and a culture temperature of 36 °C. Under these conditions, production of GABA was maximized at 314.56 mg/100 g. Addition of Lb. plantarum NDC75017 to a commercial starter culture led to higher GABA production in fermented yogurt. Flavor and texture of the prepared yogurt and the control yogurt did not differ significantly. Thus, Lb. plantarum NDC75017 has good potential for manufacture of GABA-enriched fermented milk products.

Combination of adenoviruses expressing melanoma differentiation-associated gene-7 and chemotherapeutic agents produces enhanced cytotoxicity on esophageal carcinoma

We examined the combinatory antitumor effects of adenoviruses expressing human mda-7/IL-24 gene (Ad-mda-7) and chemotherapeutic agents on nine kinds of human esophageal carcinoma cells. All the carcinoma cells expressed the melanoma differentiation-associated gene-7/interleukin-24 (MDA-7/IL-24) receptor complexes, IL-20R2 and either IL-20R1 or IL-22R1, and were susceptible to Ad-mda-7, whereas fibroblasts were positive only for IL-20R2 gene and resistant to Ad-mda-7-mediated cytotoxicity. Sensitivity of these esophageal carcinoma cells to Ad-mda-7 was however lower than that to Ad expressing the wild-type p53 gene. We thereby investigated a possible combination of Ad-mda-7 and anticancer agents and found that Ad-mda-7 with 5-fluorouracil (5-FU), cisplatin, mitomycin C or etoposide produced greater cytotoxic effects than those by Ad-mda-7 or the agent alone. Half-maximal inhibitory concentration values of the agents in respective cells were decreased by the combination with Ad-mda-7. Cell cycle analyses showed that Ad-mda-7 and 5-FU increased G2/M-phase and S-phase populations, respectively, and the combination augmented sub-G1 populations. Ad-mda-7-treated cells showed cleavages of caspase-8, -9 and -3 and poly (ADP-ribose) polymerase, but the cleavage levels were not different from those of the combination-treated cells. Ad-mda-7 treatments upregulated Akt phosphorylation but suppressed IκB-α levels, whereas 5-FU treatments induced phosphorylation of p53 and extracellular signal-regulated protein kinases 1 and 2. Molecular changes caused by the combination were similar to those by Ad-mda-7 treatments, but the Ad-mda-7-mediated upregulation of Akt phosphorylation decreased with the combination. These data collectively suggest that Ad-mda-7 induced apoptosis despite Akt activation and that the combinatory antitumor effects with 5-FU were produced partly by downregulating the Ad-mda-7-induced Akt activation.

Imbalance of different types of CD4(+) forkhead box protein 3 (FoxP3)(+) T cells in patients with new-onset systemic lupus erythematosus

The aim of this study was to examine the numbers of CD4(+) CD25(-) forkhead box protein 3 (FoxP3)(+) , CD4(+) CD25(+) FoxP3(+) and CD4(+) CXCR5(+) FoxP3(+) T cells in patients with new-onset systemic lupus erythematosus (SLE). The numbers of CD4(+) CD25(-) FoxP3(+) , CD4(+) CD25(+) FoxP3(+) and CD4(+) CXCR5(+) FoxP3(+) T cells and the concentrations of serum interleukin (IL)-10 in 23 patients and 20 healthy controls (HC) were measured. The potential correlations between CD4(+) FoxP3(+) T cells, serum IL-10 and clinical measures in SLE patients were analysed. In comparison with that in the HC, significantly reduced numbers of CD4(+) CD25(+) FoxP3(+) and CD4(+) CXCR5(+) FoxP3(+) T cells, but increased numbers of CD4(+) CD25(-) FoxP3(+) T cells, were detected, accompanied by significantly lower levels of serum IL-10 in the patients. Stratification analysis indicated the numbers of CD4(+) CD25(+) FoxP3(+) and CD4(+) CXCR5(+) FoxP3(+) T cells and serum IL-10 levels in the patients with seropositive anti-dsDNA were significantly less than that in those with seronegative anti-dsDNA. Treatment with the anti-SLE therapy, particularly with prednisone, leflunomide and methotrexate, significantly improved the imbalance of these types of FoxP3(+) T cells and increased the concentrations of serum IL-10 in the drug-responding patients. The numbers of CD4(+) CD25(+) FoxP3(+) T cells were correlated negatively with the values of SLE disease activity index (SLEDAI), whereas the numbers of CD4(+) CD25(-) FoxP3(+) T cells were correlated positively with the values of SLEDAI, erythrocyte sedimentation rate (ESR) and serum C3. In addition, the concentrations of serum IL-10 were correlated positively with the numbers of CD4(+) CD25(+) FoxP3(+) T cells, but negatively with the values of SLEDAI, serum C3, CRP and ESR in these patients. Our data indicate that the imbalance of different types of FoxP3(+) CD4(+) T cells may contribute to the development of SLE in Chinese patients.

High frequencies of activated B cells and T follicular helper cells are correlated with disease activity in patients with new-onset rheumatoid arthritis

This study aimed to examine the frequency of different subsets of circulating B and T follicular helper (Tfh) cells in patients with new-onset rheumatoid arthritis (RA) and following standard therapies. Twenty-five RA patients and 15 healthy controls (HC) were recruited for characterizing the frequency of CD27⁺, immunoglobulin (Ig)D⁺, CD86⁺, CD95⁺, Toll-like receptor (TLR)-9⁺ B cells and inducible T cell co-stimulator (ICOS) and programmed death 1 (PD-1)-positive Tfh cells and the level of serum interleukin (IL)-21. The potential correlation between the frequency of different subsets of B and Tfh cells and the values of clinical measures in RA patients was analysed. In comparison with HC, significantly higher percentages of circulating IgD⁺ CD27⁻ CD19⁺ naive B, CD86⁺ CD19⁺ and CD95⁺ CD19⁺ activated B, CD3⁺ CD4⁺ CXCR5⁺, CD3⁺ CD4⁺ CXCR5⁺ ICOS⁺, CD3⁺ CD4⁺ CXCR5⁺ PD-1⁺ and CD3⁺ CD4⁺ CXCR5⁺ ICOS⁺ PD-1⁺ Tfh cells but lower IgD⁺ CD27⁺ CD19⁺ preswitch memory B cells were detected, accompanied by significantly higher levels of serum IL-21 in the RA patients. Furthermore, the percentages of CD95⁺ B cells were correlated positively with the frequency of PD-1⁺ Tfh cells, but negatively with ICOS⁺ Tfh cells. The percentages of CD86⁺ B cells and ICOS⁺ Tfh cells were correlated positively with the values of disease activity score 28 (DAS28). Following the drug therapies for 1 month, the percentages of CD86⁺ B and PD-1⁺ Tfh cells were reduced significantly in the drug-responding patients. Our data suggest that activated B and Tfh cells may contribute to the pathogenesis of RA and the frequency of activated B and Tfh cells may be used as biomarkers for evaluating the therapeutic responses of individual patients with RA.

Piperlongumine induces autophagy by targeting p38 signaling

Piperlongumine (PL), a natural product isolated from the plant species Piper longum L., can selectively induce apoptotic cell death in cancer cells by targeting the stress response to reactive oxygen species (ROS). Here we show that PL induces cell death in the presence of benzyloxycarbonylvalyl-alanyl-aspartic acid (O-methyl)-fluoro-methylketone (zVAD-fmk), a pan-apoptotic inhibitor, and in the presence of necrostatin-1, a necrotic inhibitor. Instead PL-induced cell death can be suppressed by 3-methyladenine, an autophagy inhibitor, and substantially attenuated in cells lacking the autophagy-related 5 (Atg5) gene. We further show that PL enhances autophagy activity without blocking autophagy flux. Application of N-acetyl-cysteine, an antioxidant, markedly reduces PL-induced autophagy and cell death, suggesting an essential role for intracellular ROS in PL-induced autophagy. Furthermore, PL stimulates the activation of p38 protein kinase through ROS-induced stress response and p38 signaling is necessary for the action of PL as SB203580, a p38 inhibitor, or dominant-negative p38 can effectively reduce PL-mediated autophagy. Thus, we have characterized a new mechanism for PL-induced cell death through the ROS-p38 pathway. Our findings support the therapeutic potential of PL by triggering autophagic cell death.

Interaction of Sirt3 with OGG1 contributes to repair of mitochondrial DNA and protects from apoptotic cell death under oxidative stress

Sirtuin 3 (Sirt3), a major mitochondrial NAD(+)-dependent deacetylase, targets various mitochondrial proteins for lysine deacetylation and regulates important cellular functions such as energy metabolism, aging, and stress response. In this study, we identified the human 8-oxoguanine-DNA glycosylase 1 (OGG1), a DNA repair enzyme that excises 7,8-dihydro-8-oxoguanine (8-oxoG) from damaged genome, as a new target protein for Sirt3. We found that Sirt3 physically associated with OGG1 and deacetylated this DNA glycosylase and that deacetylation by Sirt3 prevented the degradation of the OGG1 protein and controlled its incision activity. We further showed that regulation of the acetylation and turnover of OGG1 by Sirt3 played a critical role in repairing mitochondrial DNA (mtDNA) damage, protecting mitochondrial integrity, and preventing apoptotic cell death under oxidative stress. We observed that following ionizing radiation, human tumor cells with silencing of Sirt3 expression exhibited deteriorated oxidative damage of mtDNA, as measured by the accumulation of 8-oxoG and 4977 common deletion, and showed more severe mitochondrial dysfunction and underwent greater apoptosis in comparison with the cells without silencing of Sirt3 expression. The results reported here not only reveal a new function and mechanism for Sirt3 in defending the mitochondrial genome against oxidative damage and protecting from the genotoxic stress-induced apoptotic cell death but also provide evidence supporting a new mtDNA repair pathway.