Blockade of hypoxia-induced CXCR4 with AMD3100 inhibits production of OA-associated catabolic mediators IL-1β and MMP-13

Binding of the chemokine stromal cell-derived factor-1 (SDF-1) to its receptor C-X-C chemokine receptor type 4 (CXCR4) results in receptor activation and the subsequent release of matrix metalloproteinases (MMPs) that contribute to osteoarthritis (OA) cartilage degradation. As hypoxia is a defining feature of the chondrocyte microenvironment, the present study investigated the possible mechanism through which SDF‑1 induces cartilage degradation under hypoxic conditions. To do this, OA chondrocyte cultures and patient tissue explants pretreated with the CXCR4 inhibitor, AMD3100 were incubated with SDF‑1. It was identified that hypoxic conditions significantly elevated the expression of CXCR4 in osteoarthritic chondrocytes relative to normoxic conditions. Furthermore, SDF‑1 elevated MMP‑13 mRNA levels and proteinase activity. It also elevated the mRNA and protein levels of runt‑related transcription factor 2, and induced the release of glycosaminoglycans and the inflammatory cytokine, interleukin‑1β. By contrast, such changes did not occur to an appreciable degree in cells that were pretreated with AMD3100. The results of the present study demonstrate that even under hypoxic conditions, where CXCR4 expression is significantly elevated in chondrocytes, AMD3100 effectively blocks this receptor and protects chondrocytes from OA‑induced catabolism, suggesting that the successful inhibition of CXCR4 may be an effective approach for OA treatment.

[Comparison of anterolateral minithoracotomy versus partial upper hemisternotomy in aortic valve replacement]

OBJECTIVE

To compare the results of aortic valve replacement through anterolateral minithoracotomy (RT) and partial upper hemisternotomy (PS) approaches.

METHODS

This was a retrospective, observational, cohort study of collected data on 297 patients undergoing isolated primary aortic valve replacement between July 2009 and March 2016 at Department of Cardiovascular Surgery, Zhongshan Hospital, Fudan University. There were 174 male and 123 female patients, aging from 15 to 73 years with a mean age of (51±13) years. Of these, 132 were performed through right RT and 165 through PS. Outcomes of the two groups were compared by t test, t' test, rank-sum test and χ(2) test, respectively.

RESULTS

The overall in-hospital mortality was 1.7% (5/297), with no difference between the 2 groups (3.0%, 4/132 vs. 0.6%, 1/165, P=0.175 ). Patients in the RT group had longer cardiopulmonary bypass ((92±27) minutes vs. (76±18) minutes, t'=5.848, P=0.000)and crossclamping ((56±21) minutes vs. (43±12) minutes, t'=6.333, P=0.000)times. Three patients in the RT group and two patients required intraoperative conversion. Patients by way of RT was associated with a lower incidence of blood transfusions (20.4% vs. 39.4%, χ(2)=12.303, P=0.001) and less drainage (250 (307) ml vs. 570 (370) ml, Z=8.161, P=0.000). In addition, patients in RT group had a shorter postoperative length of stay (5(4) days vs. 9(10) days, Z=4.548, P=0.000).

CONCLUSIONS

Aortic valve replacement via RT and PS are both safe and feasible. The approach through PS is associated with better exposure, more extensive indication for surgery, and more suitable to heart centers which intend to carry out miminally invasive aortic valve replacement. While, for an experienced surgeon, the approach through right RT is worthy of clinical selective application for patients concern more about good cosmetic result, and patients have faster recovery by avoid sternotomy through RT approach.

[Transcatheter aortic valve replacement: the new era, new opportunity and new challenge of cardiac surgery]

Conventional surgical aortic valve replacement is still the current "gold standard" in treatment of aortic valve disease, but part of the high-risk elder patients couldn't tolerate the surgical trauma. Now those people could receive timely and effective treatment with the application of transcatheter aortic valve replacement, and the related guidelines have been published in recent years. With its wide use in recent 10 years, different implantation systems, such as SAPIEN, CoreValve, Lotus, ACURATE neo, have been gradually improved and provened in several large clinical trials. Transfemoral, transapical and transaortic approaches are approved for the access and used according to different indications. Bleeding, vascular events, Ⅲ grade atrioventricular block, coronary obstruction, valve malpositioning, valve degeneration are the major complications for this skill, but would be overcome with the improvement of the system. The transcather aortic valve replacement brings not only the opportunity to develop new treatment protocols, but the challenge for cardiac surgeons to learn new skills to control.

Intratumoral and Intertumoral Genomic Heterogeneity of Multifocal Localized Prostate Cancer Impacts Molecular Classifications and Genomic Prognosticators

BACKGROUND

Next-generation sequencing is revealing genomic heterogeneity in localized prostate cancer (CaP). Incomplete sampling of CaP multiclonality has limited the implications for molecular subtyping, stratification, and systemic treatment.

OBJECTIVE

To determine the impact of genomic and transcriptomic diversity within and among intraprostatic CaP foci on CaP molecular taxonomy, predictors of progression, and actionable therapeutic targets.

DESIGN, SETTING, AND PARTICIPANTS

Four consecutive patients with clinically localized National Comprehensive Cancer Network intermediate- or high-risk CaP who did not receive neoadjuvant therapy underwent radical prostatectomy at Roswell Park Cancer Institute in June-July 2014. Presurgical information on CaP content and a customized tissue procurement procedure were used to isolate nonmicroscopic and noncontiguous CaP foci in radical prostatectomy specimens. Three cores were obtained from the index lesion and one core from smaller lesions. RNA and DNA were extracted simultaneously from 26 cores with ≥90% CaP content and analyzed using whole-exome sequencing, single-nucleotide polymorphism arrays, and RNA sequencing.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Somatic mutations, copy number alternations, gene expression, gene fusions, and phylogeny were defined. The impact of genomic alterations on CaP molecular classification, gene sets measured in Oncotype DX, Prolaris, and Decipher assays, and androgen receptor activity among CaP cores was determined.

RESULTS AND LIMITATIONS

There was considerable variability in genomic alterations among CaP cores, and between RNA- and DNA-based platforms. Heterogeneity was found in molecular grouping of individual CaP foci and the activity of gene sets underlying the assays for risk stratification and androgen receptor activity, and was validated in independent genomic data sets. Determination of the implications for clinical decision-making requires follow-up studies.

CONCLUSIONS

Genomic make-up varies widely among CaP foci, so care should be taken when making treatment decisions based on a single biopsy or index lesions.

PATIENT SUMMARY

We examined the molecular composition of individual cancers in a patient's prostate. We found a lot of genetic diversity among these cancers, and concluded that information from a single cancer biopsy is not sufficient to guide treatment decisions.

Abstract LB-156: Delineating the pathological roles and molecular functions of histone methyltransferase G9a in hepatocellular carcinoma

Liver cancer, primarily hepatocellular carcinoma (HCC), is the third leading cause of cancer mortality worldwide. In HCC, epigenetic changes including aberrant DNA methylations and histone modifications occur far more frequently than genetic alternations. However, the underlying mechanism and specific gene targets are still unknown. Using RNA-Sequencing, we identified Euchromatic histone-lysine N-methyltransferase 2 (EHMT2/G9a) as one the most significantly deregulated epigenetic regulatory genes in human HCC. G9a is a SET domain containing histone methyltransferase specific for histone H3 lysine 9 methylation. However, little is known about the functional roles of G9a in human HCC. Herein, we showed that G9a expression was frequently up-regulated in primary HCC. Up-regulation of G9a was significantly associated with multiple clinicopathological features related to HCC metastasis. We demonstrated that the frequent G9a up-regulation in HCC was attributed to the G9a gene copy number gain. In addition, we identified miR-1 as a novel post-transcriptional regulator of G9a. Loss of miR-1 significantly contributed to G9a up-regulation in human HCC. Functionally, stable knockdown (by lenti-viral based shRNA) and genetic knock-out of G9a (by CRISPR/Cas9 gene editing system) significantly suppressed HCC cell proliferation, migration and colony formation. We also demonstrated that G9a specific inhibitors, UNC0638 and BIX01294, could effectively inhibit HCC cell growth. By utilizing nude mice model, we showed that depletion of G9a drastically inhibited in vivo tumorigenicity of HCC cells. Mechanistically, we found that up-regulation of G9a epigenetically silence the expression of tumor suppressive gene RARRES3 to promote HCC tumorigenicity and metastasis. In summary, our finding suggested that up-regulation of G9a contributed to the liver carcinogenesis and could be a therapeutic target for HCC treatment.

Citation Format: Lei Wei, Felice Ho-Ching Tsang, Sandy Leung-Kuen Au, Joyce Lee, Carmen Wong, Irene Oi-Lin Ng, Chun-Ming Wong. Delineating the pathological roles and molecular functions of histone methyltransferase G9a in hepatocellular carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-156.

Neural activity of orbitofrontal cortex contributes to control of waiting

The willingness to wait for delayed reward and information is of fundamental importance for deliberative behaviors. The orbitofrontal cortex (OFC) is thought to be a core component of the neural circuitry underlying the capacity to control waiting. However, the neural correlates of active waiting and the causal role of the OFC in the control of waiting still remain largely unknown. Here, we trained rats to perform a waiting task (waiting for a pseudorandom time to obtain the water reward), and recorded neuronal ensembles in the OFC throughout the task. We observed that subset OFC neurons exhibited ramping activities throughout the waiting process. Receiver operating characteristic analysis showed that neural activities during the waiting period even predicted the trial outcomes (patient vs. impatient) on a trial-by-trial basis. Furthermore, optogenetic activation of the OFC during the waiting period improved the waiting performance, but did not influence rats' movement to obtain the reward. Taken together, these findings reveal that the neural activity in the OFC contributes to the control of waiting.

Smc5/6 Mediated Sumoylation of the Sgs1-Top3-Rmi1 Complex Promotes Removal of Recombination Intermediates

Timely removal of DNA recombination intermediates is critical for genome stability. The DNA helicase-topoisomerase complex, Sgs1-Top3-Rmi1 (STR), is the major pathway for processing these intermediates to generate conservative products. However, the mechanisms that promote STR-mediated functions remain to be defined. Here we show that Sgs1 binds to poly-SUMO chains and associates with the Smc5/6 SUMO E3 complex in yeast. Moreover, these interactions contribute to the sumoylation of Sgs1, Top3, and Rmi1 upon the generation of recombination structures. We show that reduced STR sumoylation leads to accumulation of recombination structures, and impaired growth in conditions when these structures arise frequently, highlighting the importance of STR sumoylation. Mechanistically, sumoylation promotes STR inter-subunit interactions and accumulation at DNA repair centers. These findings expand the roles of sumoylation and Smc5/6 in genome maintenance by demonstrating that they foster STR functions in the removal of recombination intermediates.

Paediatric liver re-transplantation after primary partial liver graft transplantation: a report of four cases

OBJECTIVE

To discuss rules of anatomic shifting of the porta hepatis structures of the original graft and dissection techniques for the portal vein (pull-out technique) in pediatric liver re-transplantation.

METHOD

We summarized four cases of paediatric liver re-transplantation. The main donor type is partial liver graft especially using the left lateral lobe.

RESULT

In paediatric liver re-transplantation, gross morphological changes were observed in the liver, and the spatial position of the porta hepatis structures was shifted clockwise (with the anastomosis of the hepatic vein as the origin). Preoperative three-dimensional imaging showed that segment 3 of the liver graft increased in a compensatory manner. The pull-out technique could expose the surgical field without dissection and separation, and reduce the technical difficulty of identifying and dissociating the anatomical structures.

CONCLUSION

Changes in the spatial location and structure of the liver portal anatomy increase the difficulties and risks of surgery. We can reduce the difficulty of surgical anatomy, and the risk of bleeding and injury and increase the safety of paediatric liver re-transplantation by evaluation and the application of special techniques.

GAS5 modulated autophagy is a mechanism modulating cisplatin sensitivity in NSCLC cells

OBJECTIVE

In this study, we investigated the association between lncRNA GAS5 and cisplatin (DDP) resistance in NSCLC and further studied the regulative effect of GAS5 on autophagy and DDP resistance.

PATIENTS AND METHODS

GAS5 expression in cancerous and adjacent normal tissues from 15 NSCLC patients received neoadjuvant chemotherapy and the following surgery were measured using qRT-PCR analysis. GAS5 gain-and-loss study was performed using A549 and A549/DDP cells as an in-vitro model to investigate the effect of GAS5 on autophagy and cisplatin sensitivity.

RESULTS

NSCLC tissues had a substantially lower expression of GAS5 than adjacent normal tissues. The NSCLC tissues from patients with progressive disease (PD) had even lower GAS5 expression. GAS5 knockdown increased DDP IC50 of A549 cells, while GAS5 overexpression decreased DDP IC50 of A549/DDP cells. A549/DDP cells had significantly higher basal autophagy than A549 cells. GAS5 knockdown resulted in decreased autophagy in A549 cells, while GAS5 overexpression led to increased autophagy in A549/DDP cells. Treatment with 3-MA, an autophagy inhibitor, significantly decreased DDP IC50 and promoted DDP-induced cell apoptosis in A549 cells. In addition, 3-MA also partly reversed the effect of GAS5 knockdown. In A549/DDP cells, GAS5 showed the similar effect as 3-MA in reducing DPP IC50 and promoting DDP-induced apoptosis and also presented synergic effect with 3-MA.

CONCLUSIONS

GAS5 downregulation is associated with cisplatin resistance in NSCLC. GAS5 can inhibit autophagy and therefore enhance cisplatin sensitivity in NSCLC cells.

The distribution of MNS hybrid glycophorins with Mur antigen expression in Chinese donors including identification of a novel GYP.Bun allele

BACKGROUND AND OBJECTIVES

MNS hybrid glycophorins are identified by characteristic antigen profiles. One of these is the Mur antigen, which is expressed on red cell hybrid glycophorins of several phenotypes of the 'Miltenberger' series found predominantly in East Asian population. The aim of this study was to investigate the distribution of Mur-positive hybrid glycophorins and clarify the genetic basis in the donors from southern China.

MATERIALS AND METHODS

Blood samples from 528 donors were collected for Mur antigen serological typing. Sequencing of GYPB pseudoexon 3 and MNS phenotyping were conducted in Mur-positive samples. The multiplex ligation-dependent probe amplification (MLPA) was used to confirm the zygosity of the GYP.Mur allele and determine the MNSs genotype. The expression of Mur antigen was evaluated by flow cytometry.

RESULTS

Fifty-one Mur-positive samples were identified by serological testing. Sequencing analysis showed 50 donors (50/528, 9.5%) with the GYP.Mur allele (48 heterozygotes and two homozygotes), which were confirmed by the MLPA genotyping analysis, and one donor (1/528, 0.19%) with a novel GYP.Bun allele. Flow cytometry analysis revealed higher Mur antigen expression on GP.Mur (Mi.III) homozygotes than heterozygotes. For the GYP.Mur homozygotes, an incorrect 'N' positive typing with anti-N lectin was obtained.

CONCLUSION

GP.Mur (Mi.III) is the main Mur-positive hybrid glycophorin in Guangzhou donors. The dosage effect of Mur antigen observed provides a basis for selecting the homozygous GP.Mur RBCs as the reagent cells to avoid neglecting weak antibodies. A separate GYP.Bun lineage found in the southern China provides evidence for further complexity in the MNS system.

Sodium butyrate-induced apoptosis and ultrastructural changes in MCF-7 breast cancer cells

This study investigated the effects of sodium butyrate (NaB) on Michigan Cancer Foundation-7 (MCF-7) breast cancer cells and analyzed the relevant mechanism. Here, we demonstrated that a certain concentration of NaB effectively induced MCF-7 cell apoptosis. Cell counting kit-8 (CCK-8) assay was used to detect cell viability and the apoptosis rate. Western blotting was used to detect changes in the Bcl-2 expression level. We observed cell shape changes with microscopy. Immunofluorescence revealed some apoptotic nuclei. Electron microscopy revealed thick nucleoli, chromatin margination, reduced mitochondria, and dramatic vacuoles. Collectively, our findings elucidated the morphological mechanism by which NaB changed the ultrastructure of MCF-7 cells.

Cyclic Equibiaxial Tensile Strain Alters Gene Expression of Chondrocytes via Histone Deacetylase 4 Shuttling

Objectives

This paper aims to investigate whether equibiaxial tensile strain alters chondrocyte gene expression via controlling subcellular localization of histone deacetylase 4 (HDAC4).

Materials and Methods

Murine chondrocytes transfected with GFP-HDAC4 were subjected to 3 h cyclic equibiaxial tensile strain (CTS, 6% strain at 0.25 Hz) by a Flexcell^® FX-5000^™ Tension System. Fluorescence microscope and western blot were used to observe subcellular location of HDAC4. The gene expression was analyzed by real-time RT-PCR. The concentration of Glycosaminoglycans in culture medium was quantified by bimethylmethylene blue dye; Collagen II protein was evaluated by western blot. Cells phenotype was identified by immunohistochemistry. Cell viability was evaluated by live-dead cell detect kit. Okadaic acid, an inhibitor of HDAC4 nuclear relocation, was used to further validate whether HDAC4 nuclear relocation plays a role in gene expression in response to tension stimulation.

Results

87.5% of HDAC4 was located in the cytoplasm in chondrocytes under no loading condition, but it was relocated to the nucleus after CTS. RT-PCR analysis showed that levels of mRNA for aggrecan, collagen II, LK1 and SOX9 were all increased in chondrocytes subjected to CTS as compared to no loading control chondrocytes; in contrast, the levels of type X collagen, MMP-13, IHH and Runx2 gene expression were decreased in the chondrocytes subjected to CTS as compared to control chondrocytes. Meanwhile, CTS contributed to elevation of glycosaminoglycans and collagen II protein, but did not change collagen I production. When Okadaic acid blocked HDAC4 relocation from the cytoplasm to nucleus, the changes of the chondrocytes induced by CTS were abrogated. There was no chondrocyte dead detected in this study in response to CTS.

Conclusions

CTS is able to induce HDAC4 relocation from cytoplasm to nucleus. Thus, CTS alters chondrocytes gene expression in association with the relocation of HDAC4 induced by CTS.

Whole-genome sequencing of a malignant granular cell tumor with metabolic response to pazopanib

Granular cell tumors are an uncommon soft tissue neoplasm. Malignant granular cell tumors comprise <2% of all granular cell tumors, are associated with aggressive behavior and poor clinical outcome, and are poorly understood in terms of tumor etiology and systematic treatment. Because of its rarity, the genetic basis of malignant granular cell tumor remains unknown. We performed whole-genome sequencing of one malignant granular cell tumor with metabolic response to pazopanib. This tumor exhibited a very low mutation rate and an overall stable genome with local complex rearrangements. The mutation signature was dominated by C>T transitions, particularly when immediately preceded by a 5' G. A loss-of-function mutation was detected in a newly recognized tumor suppressor candidate, BRD7. No mutations were found in known targets of pazopanib. However, we identified a receptor tyrosine kinase pathway mutation in GFRA2 that warrants further evaluation. To the best of our knowledge, this is only the second reported case of a malignant granular cell tumor exhibiting a response to pazopanib, and the first whole-genome sequencing of this uncommon tumor type. The findings provide insight into the genetic basis of malignant granular cell tumors and identify potential targets for further investigation.

Stretchable Binary Fresnel Lens for Focus Tuning

This paper presents a tuneable binary amplitude Fresnel lens produced by wafer-level microfabrication. The Fresnel lens is fabricated by encapsulating lithographically defined vertically aligned carbon nanotube (CNT) bundles inside a polydimethyl-siloxane (PDMS) layer. The composite lens material combines the excellent optical absorption properties of the CNT with the transparency and stretchability of the PDMS. By stretching the elastomeric composite in radial direction, the lens focal length is tuned. Good focusing response is demonstrated and a large focus change (≥24%) was achieved by stretching lenses up to 11.4%.

The critical role of IL-6 in the pathogenesis of Takayasu arteritis

OBJECTIVES

To investigate T cell subsets and immune cytokine profiles in untreated Takayasu arteritis (TAK) patients and the underlying immunopathological mechanism.

METHODS

We enrolled 50 untreated TAK patients and 40 age-matched controls (20 healthy controls, 20 untreated SLE patients). Enzyme-linked immunosorbent assays (ELISAs) were used to define cytokine profiles in all patients, and flow cytometry was performed for 9 TAK patients and 12 healthy controls. Hematoxylin and eosin (Handamp;E) staining and immunohistochemistry (IHC) were performed in aortic tissues of 9 TAK and 9 atherosclerosis patients; clinical data were also collected.

RESULTS

Circulating CD4(+) T cells were more frequent in TAK patients (p<0.05). Frequencies of Th1, Th2, and Th17 cells were higher, whereas Treg cells were reduced in TAK. Significantly higher levels of IL-6 and lower levels of IFN-γ, IL-4, and IL-17 were detected in TAK patients (p<0.05). By H & E staining, thickened vascular walls with proliferation of collagen fibre were observed in most patients. Inflammatory sites with infiltrating macrophages, lymphocytes, and neutrophils were located in adventitia. IHC revealed T cells (mainly CD4(+) T cells) in vascular lesions. Additionally, IL-6 was positive throughout the vascular wall in most specimens, whereas IFN-γ, IL-12, and IL-17 were detected in inflammatory sites of active patients. IL-6 levels were positively related to ESR, CRP, and Kerr scores (p<0.05).

CONCLUSIONS

Significantly increased levels of IL-6 were detected in peripheral blood and aortic tissues of untreated patients. IL-6 might be a sensitive biomarker to assess disease activity and could be critical in the immunopathogenesis of TAK.

Predicting Periodontitis at State and Local Levels in the United States

The objective of the study was to estimate the prevalence of periodontitis at state and local levels across the United States by using a novel, small area estimation (SAE) method. Extended multilevel regression and poststratification analyses were used to estimate the prevalence of periodontitis among adults aged 30 to 79 y at state, county, congressional district, and census tract levels by using periodontal data from the National Health and Nutrition Examination Survey (NHANES) 2009-2012, population counts from the 2010 US census, and smoking status estimates from the Behavioral Risk Factor Surveillance System in 2012. The SAE method used age, race, gender, smoking, and poverty variables to estimate the prevalence of periodontitis as defined by the Centers for Disease Control and Prevention/American Academy of Periodontology case definitions at the census block levels and aggregated to larger administrative and geographic areas of interest. Model-based SAEs were validated against national estimates directly from NHANES 2009-2012. Estimated prevalence of periodontitis ranged from 37.7% in Utah to 52.8% in New Mexico among the states (mean, 45.1%; median, 44.9%) and from 33.7% to 68% among counties (mean, 46.6%; median, 45.9%). Severe periodontitis ranged from 7.27% in New Hampshire to 10.26% in Louisiana among the states (mean, 8.9%; median, 8.8%) and from 5.2% to 17.9% among counties (mean, 9.2%; median, 8.8%). Overall, the predicted prevalence of periodontitis was highest for southeastern and southwestern states and for geographic areas in the Southeast along the Mississippi Delta, as well as along the US and Mexico border. Aggregated model-based SAEs were consistent with national prevalence estimates from NHANES 2009-2012. This study is the first-ever estimation of periodontitis prevalence at state and local levels in the United States, and this modeling approach complements public health surveillance efforts to identify areas with a high burden of periodontitis.

The Role of miRNAs in Cartilage Homeostasis

Osteoarthritis (OA) is an age-related disease with poorly understood pathogenesis. Recent studies have demonstrated that miRNA might play a key role in OA initiation and development. We reviewed recent publications and elucidated the connection between miRNA and OA cartilage anabolic and catabolic signals, including four signaling pathways: TGF-β/Smads and BMPs signaling, associated with cartilage anabolism; and MAPK and NF-KB signaling, associated with cartilage catabolism. We also explored the relationships with MMP, ADAMTS and NOS (NitricOxide Synthases) families, as well as with the catabolic cytokines IL-1 and TNF-α. The potential role of miRNAs in biological processes such as cartilage degeneration, chondrocyte proliferation, and differentiation is discussed. Collective evidence indicates that miRNAs play a critical role in cartilage degeneration. These findings will aid in understanding the molecular network that governs articular cartilage homeostasis and in to elucidate the role of miRNA in the pathogenesis of OA.

Compression regulates gene expression of chondrocytes through HDAC4 nuclear relocation via PP2A-dependent HDAC4 dephosphorylation

Biomechanics plays a critical role in the modulation of chondrocyte function. The mechanisms by which mechanical loading is transduced into intracellular signals that regulate chondrocyte gene expression remain largely unknown. Histone deacetylase 4 (HDAC4) is specifically expressed in chondrocytes. Mice lacking HDAC4 display chondrocyte hypertrophy, ectopic and premature ossification, and die early during the perinatal period. HDAC4 has a remarkable ability to translocate between the cell's cytoplasm and nucleus. It has been established that subcellular relocation of HDAC4 plays a critical role in chondrocyte differentiation and proliferation. However, it remains unclear whether subcellular relocation of HDAC4 in chondrocytes can be induced by mechanical loading. In this study, we first report that compressive loading induces HDAC4 relocation from the cytoplasm to the nucleus of chondrocytes via stimulation of Ser/Thr-phosphoprotein phosphatases 2A (PP2A) activity, which results in dephosphorylation of HDAC4. Dephosphorylated HDAC4 relocates to the nucleus to achieve transcriptional repression of Runx2 and regulates chondrocyte gene expression in response to compression. Our results elucidate the mechanism by which mechanical compression regulates chondrocyte gene expression through HDAC4 relocation from the cell's cytoplasm to the nucleus via PP2A-dependent HDAC4 dephosphorylation.

Novel HIV-1 Non-nucleoside Reverse Transcriptase Inhibitor Agents: Optimization of Diarylanilines with High Potency against Wild-Type and Rilpivirine-Resistant E138K Mutant Virus

Three series (6, 13, and 14) of new diarylaniline (DAAN) analogues were designed, synthesized, and evaluated for anti-HIV potency, especially against the E138K viral strain with a major mutation conferring resistance to the new-generation non-nucleoside reverse transcriptase inhibitor drug rilpivirine (1b). Promising new compounds were then assessed for physicochemical and associated pharmaceutical properties, including aqueous solubility, log P value, and metabolic stability, as well as predicted lipophilic parameters of ligand efficiency, ligand lipophilic efficiency, and ligand efficiency-dependent lipophilicity indices, which are associated with ADME property profiles. Compounds 6a, 14c, and 14d showed high potency against the 1b-resistant E138K mutated viral strain as well as good balance between anti-HIV-1 activity and desirable druglike properties. From the perspective of optimizing future NNRTI compounds as clinical trial candidates, computational modeling results provided valuable information about how the R(1) group might provide greater efficacy against the E138K mutant.

Dopamine Agonists Exert Nurr1-inducing Effect in Peripheral Blood Mononuclear Cells of Patients with Parkinson's Disease

Background:

Nurr1 plays an essential role in the development, survival, and function maintenance of midbrain dopaminergic (DA) neurons, and it is a potential target for Parkinson's disease (PD). Nurr1 mRNA can be detected in peripheral blood mononuclear cells (PBMCs), but whether there is any association of altered Nurr1 expression in PBMC with the disease and DA drug treatments remains elusive. This study aimed to measure the Nurr1 mRNA level in PBMC and evaluate the effect of Nurr1 expression by DA agents in vivo and in vitro.

Methods:

The mRNA levels of Nurr1 in PBMC of four subgroups of 362 PD patients and 193 healthy controls (HCs) using real-time polymerase chain reaction were measured. The nonparametric Mann-Whitney U-test and Kruskal-Wallis test were performed to evaluate the differences between PD and HC, as well as the subgroups of PD. Multivariate linear regression analysis was used to evaluate the independent association of Nurr1 expression with Hoehn and Yahr scale, age, and drug treatments. Besides, the Nurr1 expression in cultured PBMC was measured to determine whether DA agonist pramipexole affects its mRNA level.

Results:

The relative Nurr1 mRNA levels in DA agonists treated subgroup were significant higher than those in recent-onset cases without any anti-PD treatments (de novo) (P < 0.001) and HC groups (P < 0.010), respectively. Furthermore, the increase in Nurr1 mRNA expression was seen in DA agonist and L-dopa group. Multivariate linear regression showed DA agonists, L-dopa, and DA agonists were independent predictors correlated with Nurr1 mRNA expression level in PBMC. In vitro, in the cultured PBMC treated with 10 μmol/L pramipexole, the Nurr1 mRNA levels were significantly increased by 99.61%, 71.75%, 73.16% in 2, 4, and 8 h, respectively (P < 0.001).

Conclusions:

DA agonists can induce Nurr1 expression in PBMC, and such effect may contribute to DA agonists-mediated neuroprotection on DA neurons.