Multivalent Proteins Rapidly and Reversibly Phase-Separate upon Osmotic Cell Volume Change

Processing bodies (PBs) and stress granules (SGs) are prominent examples of subcellular, membraneless compartments that are observed under physiological and stress conditions, respectively. We observe that the trimeric PB protein DCP1A rapidly (within ∼10 s) phase-separates in mammalian cells during hyperosmotic stress and dissolves upon isosmotic rescue (over ∼100 s) with minimal effect on cell viability even after multiple cycles of osmotic perturbation. Strikingly, this rapid intracellular hyperosmotic phase separation (HOPS) correlates with the degree of cell volume compression, distinct from SG assembly, and is exhibited broadly by homo-multimeric (valency ≥ 2) proteins across several cell types. Notably, HOPS sequesters pre-mRNA cleavage factor components from actively transcribing genomic loci, providing a mechanism for hyperosmolarity-induced global impairment of transcription termination. Our data suggest that the multimeric proteome rapidly responds to changes in hydration and molecular crowding, revealing an unexpected mode of globally programmed phase separation and sequestration.

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

[The role of large-scale testing platform in the prevention and control of the COVID-19 pandemic: an empirical study based on a novel numerical model]

Objective: China adopted an unprecedented province-scale quarantine since January 23rd 2020, after the novel coronavirus (COVID-19) broke out in Wuhan in December 2019. Responding to the challenge of limited testing capacity, large-scale (>20 000 tests per day) standardized and fully-automated laboratory (Huo-Yan) was built as an ad-hoc measure. There is so far no empirical data or mathematical model to reveal the impact of the testing capacity improvement since quarantine. Methods: Based on the suspected case data released by the Health Commission of Hubei Province and the daily testing data of Huo-Yan Laboratory, the impact of detection capabilities on the realization of "clearing" and "clearing the day" of supected cases was simulated by establishing a novel non-linear and competitive compartments differential model. Results: Without the establishment of Huo-Yan, the suspected cases would increase by 47% to 33 700, the corresponding cost of quarantine would be doubled, the turning point of the increment of suspected cases and the achievement of "daily settlement" (all newly discovered suspected cases are diagnosed according to the nucleic acid testing result) would be delayed for a whole week and 11 days. If the Huo-Yan Laboratory could ran at its full capacity, the number of suspected cases could start to decrease at least a week earlier, the peak of suspected cases would be reduced by at least 44%, and the quarantine cost could be reduced by more than 72%. Ideally, if a daily testing capacity of 10 500 tests was achieved immediately after the Hubei lockdown, "daily settlement" for all suspected cases could be achieved. Conclusions: Large-scale, standardized clinical testing platform, with nucleic acid testing, high-throughput sequencing, and immunoprotein assessment capabilities, need to be implemented simultaneously in order to maximize the effect of quarantine and minimize the duration and cost of the quarantine. Such infrastructure, for both common times and emergencies, is of great significance for the early prevention and control of infectious diseases.

Glutamine Synthetase Promotes Radiation Resistance via Facilitating Nucleotide Metabolism and Subsequent DNA Damage Repair

Radiation resistance is a critical problem in radiotherapy for cancer. Radiation kills tumor cells mainly through causing DNA damage. Thus, efficiency of DNA damage repair is one of the most important factors that limits radiotherapy efficacy. Glutamine physiologically functions to generate protein and nucleotides. Here, we study the impact of glutamine metabolism on cancer therapeutic responses, in particular under irradiation-induced stress. We show that radiation-resistant cells possessed low glycolysis, mitochondrial respiration, and TCA cycle but high glutamine anabolism. Transcriptome analyses revealed that glutamine synthetase (GS), an enzyme catalyzing glutamate and ammonia to glutamine, was responsible for the metabolic alteration. ChIP and luciferase reporter assays revealed that GS could be transcriptionally regulated by STAT5. Knockdown of GS delayed DNA repair, weakened nucleotide metabolism, and enhanced radiosensitivity both in vitro and in vivo. Our data show that GS links glutamine metabolism to radiotherapy response through fueling nucleotide synthesis and accelerating DNA repair.

Abstract 5679: Androgen receptor degraders overcome common resistance mechanisms developed during prostate cancer treatment

Background: Androgen receptor (AR) signaling is critical for prostate development and homeostasis as well as for the initiation and progression of prostate cancer (PCa). Indeed, the clinical development of second-generation AR antagonists, including enzalutamide, has confirmed that AR remains a key oncogene in castration-resistant prostate cancer (CRPC). Furthermore, response to enzalutamide is temporary and incremental, and PCa cells that develop resistance to AR-targeted therapy usually maintain AR expression. Therefore, with the hypothesis that AR protein is still active even during castration- and enzalutamide-resistant states, we employed the proteolysis targeting chimera (PROTAC) strategy to build compounds that targeted the AR through proteasomal degradation. We developed an optimized functional molecule, ARD-61, that targets enzalutamide-resistant and AR splice variant (including AR-V7, which lacks the ligand binding domain) overexpressing cells in vitro and in vivo.

Methods/Results: To characterize ARD-61, we performed western blotting, qRT-PCR, growth assays, xenograft studies, as well as proteomic and RNA-sequencing analyses. Additionally, to investigate the sensitivity of AR splice variants to ARD-61, we created CRISPR-Cas9 mediated stable AR-V7 overexpression in LNCaP cells. ARD-61 functions to rapidly and specifically degrade AR protein, and thus decreases downstream AR signaling in a wide variety (e.g. enzalutamide sensitive, AR-mutated, enzalutamide resistant) of AR-positive cell lines and tumor xenografts. Enzalutamide-sensitive and -resistant cell lines were similarly sensitive to ARD-61 in vivo and in vitro. CRISPR-induced endogenous overexpression of AR-V7 had no effect on the sensitivity of cells to ARD-61 or enzalutamide.

Conclusions: Our data reveal the necessity of full-length AR in all Pca stages. Despite continued AR-antagonization, enzalutamide-resistant cell lines require full-length AR for sustained survival. Further, AR-variant overexpression, previously shown to promote resistance to AR-targeted therapies, still required AR protein with an intact ligand-binding domain to maintain growth in our models. Our data illustrate the importance of continued targeting of AR in advanced Pca, as well as demonstrate the efficacy of ARD-61. Ultimately, through its clinical translation, we anticipate the development of ARD-61 to be a therapeutic advance for patients with the metastatic CRPC.

Citation Format: Steven Kregel, Chao Wang, Xin Han, Lanbo Xiao, Ester Fernandez-Salas, Pushpinder Bawa, Brooke L. McCollum, Kari Wilder-Romans, Ingrid J. Apel, Xuhong Cao, Corey Speers, Shaomeng Wang, Arul M. Chinnaiyan. Androgen receptor degraders overcome common resistance mechanisms developed during prostate cancer treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5679.

Abstract 1278: Elucidating the mechanistic role of ERG in prostate cancer

Introduction: The transcription factor ERG is important for the development of angiogenesis, blood vessel integrity, and maintenance of hematopoietic stem cells. However, aberrant overexpression of ERG has been shown to be associated with various cancers. For example, ERG is recurrently involved in a translocation with TMPRSS2, which shifts it under AR regulation, and is thus subjected to overexpression in about 50% of prostate cancers in Caucasian males. While the clinical prognostic value of the TMPRSS2:ERG fusion is still debated, mechanistic studies of ERG-positive prostate cancers have demonstrated that ERG promotes cell invasion and metastasis. However, the molecular and cellular mechanisms of oncogenic ERG function in prostate cancer remain largely unclear.

Methods/Results: To more comprehensively study the molecular and phenotypic roles of the TMPRSS2:ERG fusion product in prostate cancer, we developed an inducible ERG overexpression model in multiple cell lines as well as a CRISPR-Cas9-mediated TMPRSS2:ERG fusion translocation model. Using these models, we first performed RNA-seq and observed that ERG overexpression induced a global transcriptional program that increased the expression of genes related to epithelial-mesenchymal transition and decreased the expression of genes related to cell-cycle promotion. Further, using Boyden Chamber Assays as well as IncuCyte, we showed that overexpression of ERG promoted cell invasion but suppressed cell proliferation. We then used flow cytometric analysis to show that cells overexpressing ERG undergo a prolonged S phase. Interestingly, ERG antagonization through peptidomimetic inhibition partially rescued the proliferation rates of these ERG-overexpressing cells. Finally, using genome-wide CRISPR/Cas9 screening and NGS of the integrated sgRNA expression cassettes in the inducible ERG model, we identified panels of genes mediating ERG functions.

Discussion: Unlike oncogenic kinases such as BCR-ABL in Chronic Myeloid Leukemia, transcription factors such as ERG have been more challenging to directly target in cancer. Thus, elucidation of the mechanisms of ERG-mediated transcriptional reprogramming, ERG binding partners, as well as the regulation of ERG, may result in the development of new strategies to target ERG by selectively antagonizing ERG oncogenic functions. Using our models, we are able to gain a better understanding of the role of ERG in cancer development and progression and thus provide insight for the development of new strategies for the prevention, detection, and treatment of prostate cancer.

Citation Format: Caleb Cheng, Lanbo Xiao, Jean Tien, Cynthia Wang, Jesse Cheng, Eileen Shiau, Xiaoju Wang, Arul M. Chinnaiyan. Elucidating the mechanistic role of ERG in prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1278.

Assessment of knee extensor and flexor function using isokinetic test in COPD: impact on exercise capacity

OBJECTIVE: To quantify the relationship between strength and endurance of knee extensor and flexor and exercise capacity in patients with chronic obstructive pulmonary disease (COPD).METHODS: A total of 108 patients with stable COPD (age: 65 years, IQR25-75: 59-72) were enrolled in this cross-sectional study. Knee extensor and flexor function was evaluated using the isokinetic test, and the parameters attained were considered as independent variables. Exercise capacity was evaluated using 6-minute walking test (6MWT) and 30-second sit-to-stand test (30s SST), and the results were considered as dependent variables. The association between lower-limb muscle function and exercise capacity was assessed using multiple regression analysis.RESULTS: The patients mostly had moderate-to-severe airflow obstruction with a post-bronchodilator forced expiratory volume in 1 second (FEV₁) of 57.87 ± 17.71% predicted. In multiple regression analysis, flexor total work (TW), extensor endurance ratio (ER), age and FEV₁%pred were significantly associated with 6MWT (adjusted R² = 0.455, P < 0.001). Flexor TW and age were significantly associated with 30s SST (adjusted R² = 0.355, P < 0.001).CONCLUSION: Knee endurance has a significant relationship with exercise capacity, and knee flexor endurance seems to be an important factor contributing to exercise capacity in COPD patients.

[Influencing factors on smoking cessation among outpatients from the National Central Subsidy Smoking Cessation Clinic Project, in 2015-2018]

Objective: To evaluate the effect of smoking cessation project run by the Central Subsidy Smoking Cessation Clinic and to explore the related influencing factors on smoking cessation, in order to improve related services and provide better guidance to these smoking cessation clinics. Methods: Practitioners who had been trained to run smoking cessation projects were recruited to conduct face-to-face interview with the smokers. Questionnaires were completed to provide information on related psychological, social and behavioral issues. In these clinics, medications were provided to the patients by the health care takers in the clinic. One month after the first visit, smoking cessation rate (self-reported, 7-day point prevalence abstinence rate at 30-day follow-up) was counted. Results: The overall smoking cessation rate (self-reported, 7-day point prevalence abstinence rate at 30-day follow-up) appeared as 34.1%. Results from the multivariate logistic regression showed that patients over the age of 60 were the ones most likely to quit smoking. Smokers who showed higher possibility of quitting would include those: not on the daily base, intend to quit within 30 days, with other diseases, or taking varenicline and bupropion. Factors as unemployment, longer history of smoking, bigger quantity of cigarettes consumption per day, dependence on nicotine and urgency on taking up the first cigarette in the early morning etc., were related to the less likelihood of giving up smoking. However, histories of cessation did not seem to affect the possibility of quitting. Conclusions: Data from self-reported 7-day point prevalence abstinence at 30-day follow-up study showed that the smoking cessation intervention programs run by the central subsidy smoking cessation clinic project had been effectively implemented. Advocacy on quit smoking at early stage seemed to have better outcomes, thus should be called for. Since medications as varenicline tartrate and bupropion hydrochloride can increase the possibility of stop smoking, we would suggest that all the hospitals which are with smoking cessation clinics be equipped with these medicines. Professional assistance provided by practitioners is of key importance to help overcome the withdrawal symptoms during the periods of cessation, on these smokers.

Characterization of carbapenem-resistant Klebsiella pneumoniae in a tertiary hospital in Fuzhou, China

Aims

The emergence of carbapenem‐resistant Klebsiella pneumoniae (CRKP) strains has led to increased mortality and morbidity rates. Tigecycline, a new class of broad‐spectrum glycyl‐tetracycline antibiotics, has been used to target multi‐ and pan‐drug‐resistant bacterial infections. This study aimed to assess the molecular characteristics of CRKP in a tertiary hospital, and its susceptibility to tigecycline, to create a reference for hospital infection control and clinical drug use.

Methods and Results

We retrieved patient clinical information and CRKP characterization from medical records and detected the MIC of tigecycline using the micro‐broth dilution method. Multi‐locus sequence typing was performed, and antibiotic resistance genes associated with CRKP were detected by qPCR. A total of 166 CRKP strains were detected in the sputum, urine and blood among intensive care unit patients (average age, 69·6 years). The most infrequently observed resistance genes were amikacin resistance genes, followed by tobramycin resistance genes. KPC‐2, CTX‐M9 and CTX‐M1 were the most frequently detected resistance genes.

Conclusions

No strain was resistant to tigecycline (MIC ≥ 8 µg ml⁻¹). Twenty‐four sequence types were identified, with ST11 being the most common type.

Significance and Impact of the Study

Clinicians and infection control experts should be aware of CRKP prevalence to facilitate clinical treatment and improve nosocomial infection control.

Noninvasive identification of lineage-specific circular RNA for ER-positive breast cancer

3543

Background: Non-invasive testing in plasma using RNA biomarkers has been limited by exoribonuclease-mediated degradation of RNA. Circular RNA (circRNA) are covalently closed RNA structures that resist this degradation due to their circular structure. Therefore circRNA are more stable than their linear counterparts. CircRNA are formed by alternative backsplicing of the 3’ end of a downstream exon to the 5’ end of an upstream exon. Here, we propose a novel method for non-invasive identification of circRNA and demonstrate circularized forms of several lineage and cancer specific targets for estrogen receptor-positive breast cancer. Methods: Capture RNA sequencing on cancer tissue was previously performed to determine the relative expression of potential circRNA isoforms in breast cancer patients. These isoforms as well as those predicted by intron length were screened using a quantitative PCR-based assay on ER-positive breast cancer cells. RNA extracted from breast cancer cells are exposed to ribonuclease R to demonstrate stability of circRNA. CircRNA derived from targets with known universal expression are used as positive controls as well as for analysis on plasma. Results: We identify the circRNA isoforms with highest expression for five genes, including ESR1, that are differentially expressed in ER-positive breast cancer compared to other cancers and normal breast tissue. We determine that the circRNA corresponding to all five targets is specifically expressed in breast cancer cell lines with at least 1000-fold higher expression than in non-ER positive breast cancer cell lines. We demonstrate that the highest expressing circRNA isoforms are resistant to degradation by ribonuclease R, whereas corresponding linear mRNA is susceptible. We also demonstrate the presence and stability of positive control circRNA in plasma from patients without cancer. Conclusions: CircRNA are promising biomarkers for early non-invasive detection of cancer due to their stability in plasma. This assay reliably detects ER-positive breast cancer specific circRNA, and exoribonuclease resistance has been validated. Application of this diagnostic assay to plasma from breast cancer patients is underway.

Identification of a potential target for treatment of squamous cell carcinoma of the tongue: follistatin

Squamous cell carcinoma (SCC) of the tongue is the most common oral cancer and is prone to develop regional lymph nodes and distant metastases. Reliable and stable therapeutic targets can improve the curative effect and reduce toxic side effects caused by traditional treatments such as surgery, radiotherapy, and chemotherapy. We have analysed three sets of series of functional gene expression of SCC of the tongue from gene expression omnibus (GEO) datasets, and 154 common differentially expressed genes (DEG) between SCC of the tongue and the corresponding normal tissues were screened. Further bioinformatics research that was based on the data from the Cancer genome atlas, Gene ontology, and the Kyoto encyclopaedia of genes and genomes indicated that the increased expression of follistatin might be correlated with a poor prognosis in these patients. By assay of colony formation, reverse transcription polymerase chain reaction (RT-PCR), western blotting, immunohistochemical staining, and lentivirus transfection, we confirmed that downregulation of follistatin inhibited the proliferation of SCC cells in the tongue.

Androgen receptor degraders overcome common resistance mechanisms developed during prostate cancer treatment

Androgen receptor (AR) antagonists, such as enzalutamide, have had a major impact on the treatment of metastatic castration-resistant prostate cancer (CRPC). However, even with the advent of AR antagonist therapies, patients continue to develop resistance, and new strategies to combat continued AR signalling are needed. Here, we develop AR degraders using PROteolysis TArgeting Chimeric (PROTAC) technology in order to determine whether depletion of AR protein can overcome mechanisms of resistance commonly associated with current AR-targeting therapies. ARD-61 is the most potent of the AR degraders and effectively induces on-target AR degradation with a mechanism consistent with the PROTAC design. Compared to clinically-approved AR antagonists, administration of ARD-61 in vitro and in vivo results in more potent anti-proliferative, pro-apoptotic effects and attenuation of downstream AR target gene expression in prostate cancer cells. Importantly, we demonstrate that ARD-61 functions in enzalutamide-resistant model systems, characterized by diverse proposed mechanisms of resistance that include AR amplification/overexpression, AR mutation, and expression of AR splice variants, such as AR-V7. While AR degraders are unable to bind and degrade AR-V7, they continue to inhibit tumor cell growth in models overexpressing AR-V7. To further explore this, we developed several isogenic prostate cell line models in which AR-V7 is highly expressed, which also failed to influence the cell inhibitory effects of AR degraders, suggesting that AR-V7 is not a functional resistance mechanism for AR antagonism. These data provide compelling evidence that full-length AR remains a prominent oncogenic driver of prostate cancers which have developed resistance to AR antagonists and highlight the clinical potential of AR degraders for treatment of CRPC.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present our current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals for the third (O3), fourth (O4) and fifth observing (O5) runs, including the planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study the capability of the network to determine the sky location of the source for gravitational-wave signals from the inspiral of binary systems of compact objects, that is binary neutron star, neutron star-black hole, and binary black hole systems. The ability to localize the sources is given as a sky-area probability, luminosity distance, and comoving volume. The median sky localization area (90% credible region) is expected to be a few hundreds of square degrees for all types of binary systems during O3 with the Advanced LIGO and Virgo (HLV) network. The median sky localization area will improve to a few tens of square degrees during O4 with the Advanced LIGO, Virgo, and KAGRA (HLVK) network. During O3, the median localization volume (90% credible region) is expected to be on the order of 10 5 , 10 6 , 10 7 Mpc 3 for binary neutron star, neutron star-black hole, and binary black hole systems, respectively. The localization volume in O4 is expected to be about a factor two smaller than in O3. We predict a detection count of 1 - 1 + 12 ( 10 - 10 + 52 ) for binary neutron star mergers, of 0 - 0 + 19 ( 1 - 1 + 91 ) for neutron star-black hole mergers, and 17 - 11 + 22 ( 79 - 44 + 89 ) for binary black hole mergers in a one-calendar-year observing run of the HLV network during O3 (HLVK network during O4). We evaluate sensitivity and localization expectations for unmodeled signal searches, including the search for intermediate mass black hole binary mergers.

MicroRNA-19a-3p suppresses invasion and metastasis of prostate cancer via inhibiting SOX4

OBJECTIVE

To explore the role of microRNA-19a-3p in regulating invasion, metastasis and EMT (epithelial mesenchymal transition) of prostate cancer (PCa) cells, as well as its underlying mechanism.

MATERIALS AND METHODS

MicroRNA-19a-3p mimic and negative control plasmid were first constructed. After transfection of microRNA-19a-3p mimic or negative control in DU145 cells, expression levels of microRNA-19a-3p and SOX4 were detected by quantitative Real-time-polymerase chain reaction (qRT-PCR) and Western blot. The regulatory effects of microRNA-19a-3p on migration and invasion of DU145 cells were detected by wound healing assay and transwell assay, respectively. Protein levels of matrix metalloproteinase-2 (MMP2), matrix metalloproteinase-9 (MMP9), N-cadherin, Vimentin, alpha-smooth muscle actin (α-SMA) and E-cadherin in DU145 cells transfected with microRNA-19a-3p mimic or negative control were detected by Western blot.

RESULTS

Overexpression of microRNA-19a-3p inhibited protein level of SOX4 in DU145 cells. The migration and invasion of DU145 cells were inhibited after transfection of microRNA-19a-3p mimic. Protein levels of MMP2, MMP9, N-cadherin, Vimentin and α-SMA were downregulated, whereas E-cadherin was upregulated after microRNA-19a-3p overexpression.

CONCLUSIONS

MicroRNA-19a-3p inhibits migration, invasion and EMT of PCa cells via inhibiting SOX4.

Quantum-Enhanced Advanced LIGO Detectors in the Era of Gravitational-Wave Astronomy

The Laser Interferometer Gravitational Wave Observatory (LIGO) has been directly detecting gravitational waves from compact binary mergers since 2015. We report on the first use of squeezed vacuum states in the direct measurement of gravitational waves with the Advanced LIGO H1 and L1 detectors. This achievement is the culmination of decades of research to implement squeezed states in gravitational-wave detectors. During the ongoing O3 observation run, squeezed states are improving the sensitivity of the LIGO interferometers to signals above 50 Hz by up to 3 dB, thereby increasing the expected detection rate by 40% (H1) and 50% (L1).

Exosomes derived from bone marrow mesenchymal stem cells improve osteoporosis through promoting osteoblast proliferation via MAPK pathway

OBJECTIVE

Osteoporosis is the most common bone metabolic disease. Exosome exerts a crucial role in the development of multiple diseases. The aim of the study was to investigate the role of exosome derived from bone marrow mesenchymal stem cells (MSCs) in osteoporosis and its underlying mechanism.

MATERIALS AND METHODS

MSCs were first isolated from rat bone marrow. After the surface antigen of MSCs was identified by flow cytometry, MSCs-derived exosomes (MSC-Exo) was extracted. The osteogenic and lipid differentiation abilities of BMSCs were determined by alizarin red staining and oil red staining, respectively. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to detect the mRNA expressions of genes. Cell counting kit-8 (CCK-8) assay was used to detect the viability of hFOB 1.19 cells. Western blot was used to measure expressions of the specific surface markers in exosomes and the MAPK pathway-related proteins in hFOB 1.19 cells. Moreover, cell cycle of hFOB 1.19 was detected by flow cytometry.

RESULTS

We observed a positive identification of surface antigens in MSCs, which presented good multidirectional differentiation ability. The isolated MSC-Exo exhibited typical morphology and particle size of exosomes, and the detection of specific surface labeled protein was positive under an electron microscope. After co-culture of MSC-Exo and osteoblast cell line hFOB 1.19, we found that MSC-Exo could promote the proliferation of hFOB 1.19 cells. Moreover, mRNA and protein expressions of GLUT3 in cells were increased, and the cell cycle was also promoted. The expressions of related proteins in the MAPK signaling pathway were found to be promoted. Rescue experiments demonstrated that MSC-Exo could promote the growth and cell cycle of hFOB 1.19, which were reversed by p-JNK knockdown.

CONCLUSIONS

MSC-derived exosomes improve osteoporosis by promoting the proliferation of osteoblasts via MAPK pathway.

Diagnostic value of various noninvasive indexes in the diagnosis of chronic hepatic fibrosis

OBJECTIVE

Hepatic fibrosis is a repair response to chronic liver injury. This study evaluated the diagnostic value of various noninvasive indicators for hepatic fibrosis in patients with chronic liver disease.

PATIENTS AND METHODS

95 patients with liver biopsy were enrolled in this study. Routine clinical and laboratory examinations were collected, including age, sex, blood routine, biochemistry, serum fibrosis, and FibroTouch. APRI and FIB4 scores were calculated. The patients were grouped according to liver pathological staging to analyze the correlation between the fibrosis with serum fibrosis, APRI, FIB4 score, and FibroTouch. The receiver operator characteristics of S2, S3, and S4 were analyzed to calculate the area under the curve (AUC).

RESULTS

No statistical difference was found on age, ALT, AST, GGT, BMI, TG, CHOL, and Glu (p > 0.05). Liver stiffness measurement (LSM), APRI, FIB4, PCIII, CIV, LN, and HA exhibited statistical significance (p < 0.05). Further correlation analysis showed that PCIII, IV-C, LN, APRI, LSM, and FIB4 were positively correlated with the stage of hepatic fibrosis (p < 0.05). ROC curve analysis demonstrated that LSM and FIB4 revealed good predictions of various stages of fibrosis in chronic liver disease with AUC greater than 0.7. The AUC of LSM in the diagnosis of liver cirrhosis (S4) reached 0.908. Its accuracy was influenced by liver inflammation.

CONCLUSIONS

The LSM value in FibroTouch showed high coincidence rate with hepatic fibrosis staging. It is a valuable noninvasive method for assessing the progression of hepatic fibrosis in chronic liver disease.

Autophagy attenuates the oxidative stress-induced apoptosis of Mc3T3-E1 osteoblasts

OBJECTIVE

The oxidative stress-induced osteoblast apoptosis plays an important role in the pathological process of osteoporosis, but the roles of autophagy in oxidative stress and apoptosis of osteoblasts remain unclear. This study aimed to observe the role of autophagy in oxidative stress injury of osteoblasts and the relationship between autophagy and apoptosis.

MATERIALS AND METHODS

Mc3T3-E1 cells were stimulated with different concentrations (0.1, 0.5, and 1 mM) of hydrogen peroxide. The cell viability was detected via cell counting kit 8 (CCK8) at different time points (0, 2, 6, 8, and 12 h), the apoptosis was detected via Western blotting and flow cytometry, and the autophagy was detected via macrophage-derived chemokine (MDC) and transmission electron microscope. The changes in expression of autophagy-associated protein, Beclin1, and LC3II/I ratio, were detected via Western blotting. Moreover, the intracellular reactive oxygen species (ROS) level and extracellular superoxide dismutase (SOD) level were observed using the autophagy regulators, rapamycin (Rap) and 3-methyladenine (3-MA), so as to clarify the interaction between autophagy and cellular oxidation.

RESULTS

Hydrogen peroxide-induced apoptosis and autophagy of osteoblasts were in dose- and time-dependent manners; the hydrogen peroxide inhibitors could inhibit the autophagy level, and autophagy inhibitor (3-MA) could significantly enhance the hydrogen peroxide-induced ROS level and apoptosis rate in cells. Besides, Western blotting confirmed that the cleaved caspase-3 and cleaved poly adenosine diphosphate ribose polymerase (PARP) proteins were increased. The autophagy inducer (Rap) partially inhibited the hydrogen peroxide-induced oxidative stress and apoptosis.

CONCLUSIONS

Autophagy inhibits the oxidative stress-mediated apoptosis of osteoblasts, which is a potential target for the osteoporosis treatment.

Probiotics maintain intestinal secretory immunoglobulin A levels in healthy formula-fed infants: a randomised, double-blind, placebo-controlled study

Formula-fed infants are more susceptible to infectious diseases because they lack the maternal immune factors transferred from breast milk, while their own immune system is still immature. As timely probiotic administration was suggested to promote immune system development in formula-fed infants, this study aimed at assessing the safety and the effects of a probiotic supplement (Bifidobacterium infantis R0033, Bifidobacterium bifidum R0071, and Lactobacillus helveticus R0052) on mucosal immune competence and digestive function in formula-fed infants. Healthy infants (3.5-6 months old) were randomised to receive either probiotic- (n=66) or placebo-supplemented (n=66) formula once a day for four weeks. In the probiotics group, faecal secretory immunoglobulin A (SIgA) levels remained similar between visit 2 (baseline; V2) and visit 3 (end-of-treatment; V3), but decreased in the placebo group. Changes in SIgA levels following treatment (log₁₀ΔV3-V2 [95%CI]) between the probiotic and placebo groups were statistically significant (23 ng/dl [-57;102] and -137 ng/dl [-212;-62], respectively (P=0.0044; ANCOVA)). While log₁₀ΔV3-V2 [95%CI] for salivary SIgA levels increased in both groups, this trend was more pronounced in the probiotics than in the placebo group with an increase of 123 ng/dl [9;236] and 37 ng/dL [-72;147], respectively (P=0.2829; ANCOVA). The weekly average number of stools/day was significantly higher in the probiotics group compared to placebo during the last week of treatment for the per protocol population. There was no difference in microbiota composition or anthropometric parameters between groups. No serious adverse event was reported, and all adverse events were mild and unrelated to the product or study. Our results show that formula-fed infants receiving probiotics maintained higher faecal SIgA levels at the end of the four-week treatment period, suggesting a positive effect of probiotics on SIgA production. This study demonstrates the safety of this probiotic formulation in infants. Formula-fed infants may benefit from probiotics supplementation to sustain the development of mucosal immunity.

[An analysis on incidence of HIV-1 epidemics among men who have sex with men in Sichuan Province during 2011-2015]

The assay was used in HIV/AIDS surveillance sentinel sites to identify recent HIV-1 infection, to estimate HIV-1 incidence and understand the epidemic trends among men who have sex with men during 2011-2015. During 2011-2015, the HIV-1 incidence of men who have sex with men was 5.16%(95%CI: 4.65%-5.66%) in Sichuan Province. According to<Pilot study on classification criteria of AIDS epidemic in China>, a total of 9 cities had been divided into two type of regions: the first type(the proportion of live HIV/AIDS accounts for more than 0.1% of the permanent population, and the number of live HIV/AIDS has reached 500 cases and above) and the second type(the proportion of live HIV/AIDS accounts for 0.03% to 0.100% of the permanent population, and the number of live HIV/AIDS has reached 100-500 cases). During 2011-2015, the HIV-1 incidence of the second type was 4.24% (95%CI: 3.72%-4.76%). The HIV-1 incidence of men who have sex with men was at a high level. The spread of HIV-1 to the second region was possible.