Icariin inhibits chondrocyte ferroptosis and alleviates osteoarthritis by enhancing the SLC7A11/GPX4 signaling

BACKGROUND

Chondrocyte ferroptosis plays a critical role in the pathogenesis of osteoarthritis (OA), regulated by the SLC7A11/GPX4 signaling pathway. Icariin (ICA), a flavonoid glycoside, exhibits strong anti-inflammatory and antioxidant activities. This study investigated whether ICA could modulate the SLC7A11/GPX4 signaling to inhibit chondrocyte ferroptosis and alleviate OA.

PURPOSE

The objective was to explore the impact of ICA on chondrocyte ferroptosis in OA and its modulation of the SLC7A11/GPX4 signaling pathway.

METHODS

The anti-ferroptosis effects of ICA were evaluated in an interleukin-1β (IL-1β)-treated SW1353 cell model, using Ferrostatin-1 (Fer-1) and Erastin (Era) as ferroptosis inhibitor and inducer, respectively, along with GPX4 knockdown via lentivirus-based shRNA. Additionally, the therapeutic efficacy of ICA on OA-related articular cartilage damage was assessed in rats through histopathology and immunohistochemistry (IHC).

RESULTS

IL-1β treatment upregulated the expression of OA-associated matrix metalloproteinases (MMP3 and MMP1), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-5), and increased intracellular ROS, lipid ROS, and MDA levels while downregulating collagen II and SOX9 expression in SW1353 cells. ICA treatment countered the IL-1β-induced upregulation of MMPs and ADAMTS-5, restored collagen II and SOX9 expression, and reduced intracellular ROS, lipid ROS, and MDA levels. Furthermore, IL-1β upregulated P53 but downregulated SLC7A11 and GPX4 expression in SW1353 cells, effects that were mitigated by ICA or Fer-1 treatment. Significantly, ICA also alleviated Era-induced ferroptosis, whereas it had no effect on GPX4-silenced SW1353 cells. In vivo, ICA treatment reduced articular cartilage damage in OA rats by partially restoring collagen II and GPX4 expression, inhibiting cartilage extracellular matrix (ECM) degradation and chondrocyte ferroptosis.

CONCLUSION

ICA treatment mitigated chondrocyte ferroptosis and articular cartilage damage by enhancing the SLC7A11/GPX4 signaling, suggesting its potential as a therapeutic agent for OA interventions.

POS0541 PREDICTORS OF REMISSION IN RHEUMATOID ARTHRITIS PATIENTS TREATED WITH UPADACITINIB OR ADALIMUMAB IN THE SELECT-COMPARE PHASE 3 STUDY: CLINICAL STATUS AT WEEK 12, BUT NOT STANDARD LABORATORY MEASURES, PROVIDES THE BEST CURRENT PREDICTOR OF REMISSION AT WEEK 26

Background

Upadacitinib (UPA, 15 mg QD), an oral JAK1 selective inhibitor, showed greater efficacy compared to adalimumab (ADA, 40 mg EOW) at week 12 in patients with active rheumatoid arthritis (RA) on background methotrexate (MTX) in the SELECT-COMPARE phase 3 study1. Treatment with UPA compared to ADA resulted in a larger proportion of patients reaching CDAI Remission (REM) at week 26 (23% vs. 14%, p-value ≤ 0.001). Because remission is the goal in managing RA, it is of clinical relevance to identify early during the treatment course who might be able to achieve this state. It has been reported that early response to therapy with UPA was associated with achieving CDAI REM at week 262. In parallel, it has been reported that reduction in monocyte can predict DAS28-ESR REM in RA patients treated with anti-TNF therapy3. However, the relative predictive values of clinical and standard laboratory measures have not been compared side-by-side.

Objectives

To determine post-hoc the relative predictive values of selected clinical and standard laboratory measures collected at week 12 for identifying RA patients who will be in CDAI REM at week 26 upon treatment with UPA or ADA.

Methods

Clinical (CDAI, SDAI, and DAS28-CRP) and laboratory data (CRP, ESR, CBC with differential, and Lipids) for all available patients enrolled in the SELECT-COMPARE phase 3 study were included in this post-hoc analysis (UPA: n =623 [CDAI REM at wk26 = 23.8%]; ADA: n = 316 [CDAI REM at wk 26 = 14.2%]). Patients who switched treatment between weeks 14 and 22 due to not reaching at least 20% improvement in tender and swollen joints were classified as non-responders for CDAI REM at week 26. The predictive value of clinical and laboratory endpoints recorded at week 12 for determining CDAI REM status at week 26 was assessed by univariate logistic regression. We report the performance of each model as ROC AUC with a cutoff of 0.75 for meaningful predictive value.

Results

For both patients treated with UPA and those treated with ADA, clinical disease activity status measures (CDAI, SDAI, and DAS28-CRP) and relative change in disease activity measures (Percent Change [PCHG] in CDAI, PCHG in DAS28-CRP, and PCHG in SDAI) at week 12 resulted in the highest predictive performance for determining CDAI REM status at week 26 (Figure 1). In contrast, none of the selected standard laboratory measures (CRP, ESR, CBC with differential, and Lipids) reached a meaningful predictive value (ROC AUC < 0.75). Of note, cell numbers and changes in cell numbers (including Neutrophils Lymphocytes, Basophils, Eosinophils, and Monocytes) at week 12 had no meaningful predictive value for determining CDAI REM at week 26.

Figure 1.

Univariate Logistic Models to Predict CDAI REM at Week 26 in Active RA Patients who had an Inadequate Response to MTX: ROC Analysis AUC.

Legend: All evaluated parameters were recorded at Week 12; CHG = Change from Baseline to Week 12; PCHG = Percent Change from Baseline to Week 12

Conclusion

This analysis suggests that standard laboratory measures (CRP, ESR, CBC with differential, and Cholesterol) at week 12 do not represent useful predictors for REM at week 26 in csDMARD-IR RA patients. In particular, blood cell numbers and the changes in these measures at week 12 do not provide additional predictive value in our analyses, contrasting with the results from Amarnani and colleagues3. Hence, clinical disease activity levels and changes in these measures at week 12 remain adequate predictors of CDAI REM at week 26. Still, the absolute predictive performance of clinical measures remains suboptimal, highlighting the need to dedicate continued efforts to identify and validate improved predictors of long-term REM in RA.

References

[1]Fleischmann, R. et al. Arth Rheumatol71, 1788-1800 (2019).

[2]Kavanaugh, A. et al. J Clin Rheumatol27, S81-S81 (2021).

[3]Amarnani, R. et al. Ann Rheum Dis80, 448-449 (2021).

Acknowledgements

AbbVie, Inc was the study sponsor, contributed to the study design, data collection, analysis & interpretation, and writing, reviewing, and approval of the final version.

Disclosure of Interests

Thierry Sornasse Shareholder of: AbbVie, Employee of: AbbVie, Fang Cai Shareholder of: AbbVie, Employee of: AbbVie, Feng Hong Shareholder of: AbbVie, Employee of: AbbVie, Samuel Anyanwu Shareholder of: AbbVie, Employee of: AbbVie, In-Ho Song Shareholder of: AbbVie, Employee of: AbbVie, Marwan Bukhari Speakers bureau: Bristol-Myers Squib, UCB celltech, Roche/Chugai, Pfizer, Abbvie, Merck, Mennarini, Sanofi-aventis, Eli-Lilly, Janssen, Amgen, Novartis and Gilead, Paid instructor for: honoraria from educational groups revalidaid and TREG consultants.

POS0692 RHEUMATOID ARTHRITIS PATIENTS WHO SWITCHED TREATMENT FROM ADALIMUMAB TO UPADACITINIB DEMONSTRATE A ROBUST REDUCTION OF INFLAMMATION-RELATED BIOMARKERS: PROTEOMICS ANALYSIS FROM THE SELECT-COMPARE PHASE 3 STUDY

Background

Upadacitinib 15 mg QD (UPA), an oral JAK inhibitor, showed greater efficacy compared to adalimumab (ADA) in patients (pts) with active rheumatoid arthritis (RA) on background MTX at wk 12 of the SELECT-COMPARE phase 3 study1. A subset of pts switched treatment (ADA to UPA [23.5%] and UPA to ADA [19.2%]) due to non-response (NR) to the initial therapy. A higher proportion of pts rescued from ADA to UPA achieved CDAI ≤10 (LDA) post-switch (47%) vs pts rescued from UPA to ADA through 24 wks (36%)2.

Objectives

To explore the biological mechanisms associated with the differential clinical response in RA pts who switched treatment due to NR to initial ADA or UPA therapy in comparison to pts who continued treatment based on response (R) to the initial therapy.

Methods

We included a random subset of pts (100 pts each from the originally randomized treatment groups [UPA, n=651; ADA, n=327]). NR was defined as <20% improvement in TJC or SJC at wks 14–24 compared to baseline (BL) and R as achieving these improvements. The levels of 181 inflammation-related protein biomarkers (BM) were analyzed using the Olink platform at BL, wks 2, 8, and 26. Contrasts between relative BM levels were assessed using a repeated measure mixed linear model, and correlations between BM levels and DAS28-CRP were computed using Pearson’s method.

Results

In this patient subset, 40% of ADA NR who switched to UPA achieved CDAI LDA at wk 26 vs 17% of UPA NR who switched to ADA. Proteomics analysis identified 42 BMs that showed significant differential modulation between R and NR prior to switch (BL to wk 8) or after switch (wks 8–26) (Table 1). Ten BMs (CCL7, CCL8, CHI3L1, CSF1, IL6, MMP1, SLAMF1, TNFRSF9, TNFSF14, and VEGFA) were differentially modulated between ADA R and NR and were significantly decreased after switching to UPA (wk 26). The levels of these 10 BMs were similar between UPA R and NR through wk 8, except for CHI3L1, and MMP1, SLAMF1, and TNFSF14 increased after switching to ADA (wk 26). Another group of 13 BMs (CCL13, CCL19, CCL23, FGF21, IL18, IL10RA, IL18BP, IL1R1, IL2RA, MMP3, TNFSF11, TNFSF13B, TNFRSF1A) had similar levels between ADA R and NR through wk 8 and were significantly decreased after switching to UPA (wk 26). The levels of these 13 BMs were similar between UPA R and NR, except for FGF21, and the levels of CCL13, CCL19, CCL23, IL10RA, IL1R1, IL2RA, and TNFSF11 increased after switching to ADA (wk 26). Notably, the BL levels of CCL7, CCL23, CHI3L1, CSF1, IL2RA, IL6, MMP1, MMP3, and VEGFA were correlated with DAS28-CRP at BL, suggesting a potential relationship of these BMs in the pathobiology of RA. Among the remaining BMs, the levels of CCL3, CCL4, CX3CL1, EPCAM, and FLT3LG were similar between UPA R and NR and decreased after switching to ADA (wk 26).

Table 1.

Classification of Selected Protein BMs

BL to Week 14: ADABL to Week 14: UPAR / NR (n = 79 / 21)R / NR (n = 84 / 16)BM Wk 8BM Wk 8NR>RNR=RNR<RNR>RNR=RNR <RADA → UPA WEEK 8 - 26BM ↓CCL7, CCL8, CHI3L1, CSF1, IL6, MMP1, SLAMF1, TNFRSF9, TNFSF14, VEGFACCL13, CCL19, CCL23, FGF21, IL18, IL10RA, IL18BP, IL1R1, IL2RA, MMP3, TNFSF11, TNFSF13B, TNFRSF1AUPA → ADA WEEK 8 - 26CCL3, CCL4, CX3CL1, EPCAM, FLT3LGBM ↔CCL3, CCL4, CXCL8, CXCL9, CXCL10, CXCL16, IL17ACCL11, CCL25, CDCP1, CX3CL1, FABP4, FLT3LG, IL12B, KITLG, MMP10, SPP1CDCP1, CHI3L1CCL7, CCL8, CSF1, CXCL8, CXCL9, CXCL10, IL6, IL17A, IL18BP, MMP3, TNFRSF9, TNFSF13B, TNFRSF1A, VEGFACCL11, CXCL16, FABP4, FGF21, KITLG, MMP10, PON3BM ↑EPCAMPON3IL12BCCL13, CCL19, CCL23, IL10RA, IL1R1, IL2RA, MMP1, SLAMF1, SPP1, TNFSF11, TNFSF14

Conclusion

We propose that switching to UPA from ADA NR leads to more favorable clinical improvement that is paralleled by a more profound immune modulation than switching to ADA from UPA NR, consistent with the broader mechanistic inhibition achieved by JAK-associated signaling pathway inhibition compared with discrete TNF-signaling inhibition.

References

[1]Fleischmann R. et al. Arthritis Rheumatol 2019; 71:1788–1800.

[2]Fleischmann R. et al. Ann Rheum Dis 2021; 80:432–9.

Acknowledgements

AbbVie and the authors thank the patients, study sites, and investigators who participated in these clinical trials. AbbVie funded these studies and participated in the study design, research, analysis, data collection, interpretation of data, reviewing, and approval of the publication. All authors had access to relevant data and participated in the drafting, review, and approval of this publication. No honoraria or payments were made for authorship. Medical writing support was provided by Matthew Eckwahl, PhD, of AbbVie.

Disclosure of Interests

Thierry Sornasse Shareholder of: AbbVie, Employee of: AbbVie, Fang Cai Shareholder of: AbbVie, Employee of: AbbVie, Heidi Camp Shareholder of: AbbVie, Employee of: AbbVie, In-Ho Song Shareholder of: AbbVie, Employee of: AbbVie, Iain McInnes Consultant of: AbbVie, Astra Zeneca, BMS, Lilly, Amgen, Causeway, Oxford Biodynamics, Novartis, Janssen, Pfizer, Boerhinger, and UCB, Grant/research support from: AbbVie, Astra Zeneca, BMS, Lilly, Amgen, Causeway, Oxford Biodynamics, Novartis, Janssen, Pfizer, Boerhinger, and UCB

OP0024 DIFFERENTIATION BETWEEN IL-6 AND IL-17 PATHWAY INHIBITION IN RELATIONSHIP WITH CLINICAL OUTCOMES IN NON-BIOLOGICAL DMARD-IR AND BIOLOGICAL DMARD-IR PSORIATIC ARTHRITIS PATIENTS TREATED WITH UPADACITINIB IN SELECT-PsA 1 AND SELECT-PsA 2 STUDIES

Background

The differential contribution of IL-6 and IL-17 pathways to the pathogenesis of psoriatic arthritis (PsA) is not fully understood. Upadacitinib (UPA), an oral JAK inhibitor, was more effective than placebo (PBO) in improving key clinical manifestations of PsA in two global phase 3 trials, SELECT-PsA 1 (non-biological DMARD-IR, nbDMARD-IR) and SELECT-PsA 2 (biological DMARD-IR, bDMARD-IR).1,2 Targeted proteomic analysis suggested that UPA modulates multiple biological pathways in innate and adaptive immune systems via direct and indirect inhibition of key regulators, including IL-6 and IL-17 pathways, with a possible shift from Th1 predominance in nbDMARD-IR PsA to a more Th17 bias in bDMARD-IR PsA.3

Objectives

We assessed the relationship between IL-6 and IL-17 pathway modulation and different clinical outcomes after UPA treatment in nbDMARD-IR and bDMARD-IR PsA patients.

Methods

A subset of patients was randomly selected from SELECT-PsA 1 (n=74 of UPA 15 mg QD, n=74 of PBO) and PsA 2 studies (n=90 of UPA 15 mg QD, n=81 of PBO). Serum levels of IL-6, IL-17A, IL-17F, and beta-defensin 2 (BD2) proteins were measured at baseline, week 2, and week 12 by validated immunoassays. The quantitative cytokine measurements were transformed as log10, and PASI score was transformed as log10 (x+1) prior to analysis. A Repeated Measure Mixed Linear Model was used to compare UPA versus PBO treatment effects in overall selected patients and between responders and non-responders defined by PASDAS score ≤ 3.6 (Minimal Disease Activity, MDA)4 and PASI75 at week 12, respectively. The relationships between cytokines and clinical outcomes (PASI and DAS28-CRP) were assessed by Pearson’s correlation at baseline and after treatment.

Results

In nbDMARD-IR PsA patients, baseline IL-17A, IL-17F, and BD2 levels correlated with each other and with PASI, while IL-6 appeared independent from the IL-17 pathway and correlated with DAS28-CRP. At week 12, UPA treatment significantly decreased IL-6 and BD2. The decrease of IL-6 was more pronounced in PASDAS MDA responders and correlated with DAS28-CRP improvement, but the decrease of BD2 was significant in PASI75 responders and correlated with PASI improvement. In contrast, IL-17A and IL-17F were not significantly changed after UPA treatment, neither correlated with clinical outcomes at week 12.

In bDMARD-IR PsA patients, baseline IL-17A level was significantly elevated compared to nbDMARD-IR patients but weakly correlated with other cytokines and show no correlation with PASI. At week 12, the reduction of IL-6 after UPA treatment was not different between responders and non-responders (PASDAS MDA or PASI75) and did not correlate with DAS28-CRP improvement, while the reduction of BD2 remained significant in PASI75 responders and correlated with PASI improvement. Further, UPA treatment significantly reduced IL-17A in PASDAS MDA responders and IL-17F in PASI75 responders compared to non-responders, respectively. The reduction of IL-17F correlated with PASI improvement at week 12.

Conclusion

IL-6 and IL-17 pathway inhibition after UPA treatment showed different profiles in relationship with clinical outcomes in nbDMARD-IR versus bDMARD-IR PsA patients. IL-6 decrease was more pronounced in nbDMARD-IR PsA patients and associated with joint manifestation improvement, while IL-17A and IL-17F decreases were only observed in bDMARD-IR PsA patients and associated with psoriasis improvement. BD2, a biomarker of Th17-associated skin pathology, significantly decreased after UPA treatment in both nbDMARD-IR and bDMARD-IR PsA studies, which likely contributed to UPA effects on psoriasis improvement in a broad range of PsA patients.

References

[1]McInnes IB, et al. N Engl J Med 2021;384:1227-39.

[2]Mease PJ, et al. Ann Rheum Dis 2020;80:312-20.

[3]Sornasse T, et al. Ann Rheum Dis 2021;80:433.

[4]Salaffi F, et al. Biomed Res Int 2014;2014:528105.

Acknowledgements

AbbVie, Inc., in collaboration with the authors, contributed to the study design, data collection and analysis, interpretation of the results, and preparation, review and approval of the final version. No honoraria or payments were made for authorship.

Disclosure of Interests

Fang Cai Shareholder of: AbbVie, Employee of: AbbVie, Thierry Sornasse Shareholder of: AbbVie, Employee of: AbbVie, Melanie Ruzek Shareholder of: AbbVie, Employee of: AbbVie, Yuni Fang Shareholder of: AbbVie, Employee of: AbbVie, Koji Kato Shareholder of: AbbVie, Employee of: AbbVie, Peter Wung Shareholder of: AbbVie, Employee of: AbbVie, Iain McInnes Consultant of: AbbVie, AstraZeneca, BMS, Lilly, Amgen, Causeway, Oxford Biodynamics, Novartis, Janssen, Pfizer, Boehringer, and UCB, Grant/research support from: AbbVie, AstraZeneca, BMS, Lilly, Amgen, Causeway, Oxford Biodynamics, Novartis, Janssen, Pfizer, Boehringer, and UCB.

[Methylation of p16 gene and reduced expression of p16 protein in insulinoma associated with clinicopathological features]

Objective: To study the alterations of p16 gene and its expression in insulinoma and to correlate the findings with clinicopathological characteristics. Methods: Expression of p16 protein was detected in 72 insulinomas and 49 para-tumoral or normal pancreatic tissues by immunohistochemical staining. Genomic DNA was isolated from 32 tumor tissue and 17 paired pancreatic tissues and bisulfite-modified. Promoter methylation status of p16 gene was detected in 32 tumor tissue and 17 paired pancreatic tissues by methylation specific PCR. The findings were correlated with the clinicopathological features. Results: There were 30 males and 42 females in all 72 patients, aged (46.5±14.0) years. Loss or reduced expression of p16 protein was found in 42 of 72 insulinomas (58.3%) while loss or reduced expression of p16 was seen in only 34.7% (17/49) of para-tumoral or normal pancreatic tissues (χ²=6.52, P=0.011). Promoter methylation of p16 gene was found in 13 of 32 insulinomas (40.6%) and only 2 of 17 (11.8%) para-tumoral tissues (χ²=4.35, P=0.037). The expression of p16 protein in insulinoma was not associated with clinicopathological features such as gender, age, tumor size and tumor grade. Conclusions: Loss or reduced expression of p16 protein was found in insulinomas, and associated with p16 gene promoter methylation.

Emerging salt marshes as a source of Trichoderma arenarium sp. nov. and other fungal bioeffectors for biosaline agriculture

AIMS

Sustainable agriculture requires effective and safe biofertilizers and biofungicides with low environmental impact. Natural ecosystems that closely resemble the conditions of biosaline agriculture may present a reservoir for fungal strains that can be used as novel bioeffectors.

METHODS AND RESULTS

We isolated a library of fungi from the rhizosphere of three natural halotolerant plants grown in the emerging tidal salt marshes on the south-east coast of China. DNA barcoding of 116 isolates based on the rRNA ITS1 and 2 and other markers (tef1 or rpb2) revealed 38 fungal species, including plant pathogenic (41%), saprotrophic (24%) and mycoparasitic (28%) taxa. The mycoparasitic fungi were mainly species from the hypocrealean genus Trichoderma, including at least four novel phylotypes. Two of them, representing the taxa Trichoderma arenarium sp. nov. (described here) and T. asperelloides, showed antagonistic activity against five phytopathogenic fungi, and significant growth promotion on tomato seedlings under the conditions of saline agriculture.

CONCLUSIONS

Trichoderma spp. of salt marshes play the role of natural biological control in young soil ecosystems with a putatively premature microbiome.

SIGNIFICANCE AND IMPACT OF THE STUDY

The saline soil microbiome is a rich source of halotolerant bioeffectors that can be used in biosaline agriculture.

Serum Cytokine Analysis Reveals Predictors of Progression from Chronic Hepatitis B to Liver Cirrhosis

Hepatitis B virus (HBV) infection is more likely to develop into chronic and persistent infection in China, which is the main cause of chronic liver disease. We examined the cytokine profiles of chronic hepatitis B (CHB) and CHB-caused liver cirrhosis (LC) to look for the predictor of progression from CHB to LC. Serum samples of 15 healthy controls (HC), 15 CHB patients and 15 LC patients were collected to detect the profiles of 48 cytokines by multiplex biometric ELISA-based immunoassay. Partial least squares discriminant analysis (PLS-DA) and random forest were used to analyse significant cytokines, which were further validated by ELISA using an independent cohort of 60 CHB patients, 60 LC patients and 35 HC samples. There were 18 differentially expressed cytokines of CHB and LC. Three cytokines were identified by PLS-DA and random forest, including interleukin (IL)-9, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-2 receptor subunit α (IL-2Rα), which displayed significant changes in serum levels. Differentially expressed cytokine networks between HC, CHB and LC also indicated particular cytokine co-expression network patterns of CHB and LC. The receiver-operator characteristic (ROC) analysis demonstrated that IL-9, GM-CSF, IL-2Rα and their logistic regression panel are potential predictors that significantly differentiate CHB from LC (P < 0.001) and CHB from Child class A LC (P < 0.001). The three cytokines and the panel showed significant correlation with the Child-Pugh score. IL-9, GM-CSF, IL-2Rα and their logistic panel may be predictors for monitoring the progression of CHB to LC.

ST8SIA1 inhibition sensitizes triple negative breast cancer to chemotherapy via suppressing Wnt/β-catenin and FAK/Akt/mTOR

BACKGROUND

Chemoresistance is the major cause of therapeutic failure in triple negative breast cancer (TNBC). In this work, we investigated the molecular mechanism for the development of TNBC chemoresistance.

METHODS

mRNA and protein levels of ST8SIA1 were analyzed in chemosensitive and chemoresistant TNBC cells and tissues. Proliferation and survival assays were performed to determine the role of ST8SIA1 in TNBC chemoresistance.

RESULTS

We found that ST8SIA1 mRNA and protein levels were increased in multiple TNBC cell lines after prolonged exposure to chemotherapeutic drugs. Consistently, retrospective study demonstrated that the majority of TNBC patients who developed chemoresistance displayed upregulation of ST8SIA1. We further found that chemoresistant TNBC cells were more sensitive than chemosensitive cells to ST8SIA1 inhibition in decreasing growth and viability. Consistently, ST8SIA1 inhibition augmented the efficacy of chemotherapy in TNBC cells. Mechanism studies demonstrated that ST8SIA1 inhibition led to suppression of FAK/Akt/mTOR and Wnt/β-catenin signalling pathways.

CONCLUSIONS

These findings provide an explanation for the heterogeneity of chemotherapy responses across TNBC individuals and reveal the supportive roles of ST8SIA1in TNBC chemoresistance.

Identification and characterisation of a novel FT orthologous gene in London plane with a distinct expression response to environmental stimuli compared to PaFT

FLOWERING LOCUS T (FT) is a key integrator of environmental signals and internal cues, and codes for florigen-like activity which regulates the transition from vegetative to reproductive growth in flowering plants. Unlike annual plants, perennial tree species undergo several years of vegetative growth prior to the transition to the reproductive stage, as characterised by the ability to form flower buds. Thereafter, trees in temperate regions typically display an annual growth cycle involving distinct vegetative growth, flowering and dormancy stages. In London plane (Platanus acerifolia Willd.), a FT-like gene has previously been identified. Here, we report the isolation of a novel FT orthologous gene, PaFTL, and investigate the functions of PaFT and PaFTL through the analysis of expression profiles and transgenic phenotypes. PaFT displayed the highest levels of expression during tree dormancy, and similarly elevated expression levels were seen under conditions of low temperature and short days (LT/SD). In contrast, PaFTL transcripts were up-regulated during the floral transition phase, the early stages of inflorescence development and throughout the main flowering period, whereas expression levels were low and variable during dormancy and in response to LT/SD treatments. Ectopic expression of 35s::PaFTL in tobacco produced a phenotype similar to that with PaFT, namely, advanced floral initiation. Overall, the results suggest that PaFT and PaFTL have both conserved and diverse functions in floral initiation, floral development and dormancy regulation.

Genome-wide association analysis of residual feed intake in Junmu No. 1 White pigs

Residual feed intake (RFI) is a measure of feed efficiency. Pigs with low RFI have reduced feed costs without compromising their growth. For marker-assisted selection, it is helpful to identify genes or genetic markers associated with RFI in animals with improved feed efficiency at an early age. Using Illumina's PorcineSNP60 BeadChip, we performed a pilot genome-wide association study of 217 Junmu No. 1 white male pigs phenotyped for RFI. Two-step and one-step methods were used separately to identify associated SNPs. Both methods obtained similar results. Twelve SNPs were identified as significantly associated with RFI at a Bonferroni adjusted P-level < 9.7 × 10^-7 , and 204 were found to have suggestive (moderately significant) association with RFI at P < 5 × 10^-5 . NMBR, KCTD16, ASGR1, PRKCQ, PITRM1, TIAM1 and RND3 were identified as candidate genes for RFI.

Hypoxia regulates sumoylation pathways in intervertebral disc cells: implications for hypoxic adaptations

OBJECTIVE

To explore the hypoxic regulation of sumoylation pathways and cell viability in nucleus pulposus (NP) and annulus fibrosus (AF) cells.

DESIGN

Expression of small ubiquitin-like modifier (SUMO) molecules, SUMO E1 activating enzymes SAE1 and SAE2, SUMO E2 conjugating enzyme UBC9, and de-sumoylation enzyme sentrin/SUMO-specific proteases (SENP)1 was immunolocalized in rat intervertebral disc (IVD) cells. NP and AF cells were cultured in hypoxia and cell viability was evaluated by quantifying cell proliferation, cellular senescence, apoptosis, and cell cycle distribution. Hypoxic regulation of sumoylation pathways was studied by analyzing the transcription and expression of SUMO molecules and sumoylation enzymes. Loss of function study using SENP1 siRNA was performed to investigate the regulatory role of sumoylation on the function of hypoxia inducible factor 1α (HIF-1α) and the hypoxic tolerance of IVD cells.

RESULTS

Sumoylation pathways were expressed in IVD cells and localized predominantly in nuclei. Both NP and AF cells maintained viability under hypoxia and upregulated the expression of SENP1. In NP cells hypoxia transiently increased the expression of SUMO-1, SUMO-2/3, SAE2, and UBC9, whereas SUMO-1 was elevated while SUMO-2/3, SAE1, SAE2, and UBC9 were reduced by low oxygen tensions in AF cells. Although downregulation of SENP1 decreased the transcriptional activity of HIF-1α, the viability of disc cells showed no significant loss under hypoxia.

CONCLUSIONS

NP and AF cells equally tolerate oxygen deficiency, but differently regulate the sumoylation pathways under hypoxia. The distinct sumoylation dynamics may help extend our understanding of the cell-specific regulation of the molecular basis that promotes cell survival in the hypoxic IVD.

Aging and age related stresses: a senescence mechanism of intervertebral disc degeneration

Intervertebral disc (IVD) degeneration is a complicated process that involves both age-related change and tissue damage caused by multiple stresses. In a degenerative IVD, cellular senescence accumulates and is associated with reduced proliferation, compromised self-repair, increased inflammatory response, and enhanced catabolic metabolism. In this review, we decipher the senescence mechanism of IVD degeneration (IVDD) by interpreting how aging coordinates with age-related, microenvironment-derived stresses in promoting disc cell senescence and accelerating IVDD. After chronic and prolonged replication, cell senescence may occur as a natural part of the disc aging process, but can potentially be accelerated by growth factor deficiency, oxidative accumulation, and inflammatory irritation. While acute disc injury, excessive mechanical overloading, diabetes, and chronic tobacco smoking contribute to the amplification of senescence-inducing stresses, the avascular nature of IVD impairs the immune-clearance of the senescent disc cells, which accumulate in cell clusters, demonstrate inflammatory and catabolic phenotypes, deteriorate disc microenvironment, and accelerate IVDD. Anti-senescence strategies, including telomerase transduction, supply of growth factors, and blocking cell cycle inhibitors, have been shown to be feasible in rescuing disc cells from early senescence, but their efficiency for disc regeneration requires more in vivo validations. Guidelines dedicated to avoiding or alleviating senescence-inducing stresses might decelerate cellular senescence and benefit patients with IVD degenerative diseases.

Abstract P6-05-12: Prognosis of subtypes of the mucinous breast carcinoma in Chinese women: A population-based study of 32-year experience (1983-2014)

Background: The heterogeneous nature of the mucinous breast cancer (MBC), with its subtypes of pure (PMBC) and mixed carcinoma (MMBC), calls for more precise individualized prognosis assessment. PMBC showed favorable prognosis in both Chinese and Caucasian women, with nodal status and TNM stage as the prognostic predictors [PMID: 18026874, 22451233]. However, few studies had investigated tumor biology and prognosis of MMBC in Chinese population, especially with respect to the different co-existing cancer components.

Methods: From January 1983 to December 2014, 197 consecutive MBC patients, including 117 PMBC and 80 MMBC, received breast cancer surgery in Peking Union Medical College Hospital. The clinicopathological characteristics, treatment choice, disease-free survival (DFS) and overall survival (OS) were compared both between PMBC vs MMBC, and among subgroups of MMBC according to the mixed entities, including 24 women with ductal caricinoma in situ (DCIS) and 45 with IDC. Univariate and Cox multivariate analyses were performed to identify the prognostic factors.

Results: The 197 MBC comprised 1.9% of contemporary 10,192 breast cancer (BC). Compared to PMBC, MMBC had significantly more lymph node metastasis (p=0.038), Her2 positivity (p=0.036), high Ki-67 index (defined as &gt;20%, p=0.026) and anti-Her2 targeted therapy (p=0.006). All these differences remained significant when the comparison were performed among PMBC, MBC+DCIS and MBC+IDC, and additional significant difference were identified in tumor size (p=0.036), pTNM stage (p=0.003) and chemotherapy (p=0.003). However, no significant difference was found in DFS or OS between any two subtypes/subgroups of MBC, including PMBC, MMBC, MBC+DCIS and MBC+IDC.

Table 1. Comparison of survival outcomes among PMBC, MBC+DCIS and MBC+IDC§SurvivalPMBC (N=117, Median, range, and Mean±SD)MBC+DCIS (N=24, Median, range, and Mean±SD)MBC+IDC (N=45, Median, range, and Mean±SD)P-ValueDFS (months)43 (1-233), 52.7±45.227 (1-84), 34.3±25.326 (1-113), 33.1±26.60.187OS (months)46 (1-312), 56.9±51.827 (1-84), 34.4±25.326 (1-113), 34.8±28.70.628§ Kaplan-Meier survival curves would be displayed in the poster

High Ki-67 index (p=0.046) appeared to be the significant DFS related prognostic factor for PMBC, whereas estrogen receptor (ER) status (univariate p=0.000, multivariate p=0.062) and immunophenotype (luminal, her2, or triple-negative, univariate p=0.000, multivariate p=0.079) might be the potential DFS predictors for MMBC. None of the above-mentioned clinicopathological factors could serve as OS predictors for MBC.

Conclusion: This population-based study showed that there were significant difference in nodal status, Ki-67, Her2 positivity and targeted therapy between PMBC and MMBC, and furthermore in tumor size, stage and chemotherapy among PMBC and subgroups of MMBC such as MBC+DCIS and MBC+IDC. However, survival outcomes were similar between these clinical entities and subgroups, suggesting the intra-tumoral heterogeneity might not interfere with survival outcomes of MBC in Chinese woman. High Ki-67 index was identified as the significant DFS related prognostic factor for PMBC, whereas ER status and immunophenotype as the potential DFS predictors for MMBC.

Citation Format: Yao R, Pan B, Sun Q, Zhou Y, Mao F, Lin Y, Guan J, Wang X, Zhang Y, Zhang X, Shen S, Zhong Y, Xu Y, Shi J, Zhu Q, Cai F, Liang Z. Prognosis of subtypes of the mucinous breast carcinoma in Chinese women: A population-based study of 32-year experience (1983-2014). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-05-12.

Abstract P3-07-47: Comprehensive profiling of metaplastic breast carcinoma reveals frequent over-expression of PD-L1

Background: Metaplastic breast carcinoma (MBC) is a rare subtype of breast carcinoma less responsive to conventional chemotherapy relative to usual breast carcinomas (UBCs) such as ductal and lobular subtype. In molecular terms MBC usually clusters with triple negative breast cancer (TNBC), but MBCs portray a worse prognosis in comparison to TNBCs. Published studies investigating MBCs for specific biomarkers of therapy response are rare and limited by the methodological approaches.

Methods: This study included 132 patients with 38 histologically confirmed MBCs and 94 UBCs. Amongst the 94 UBCSs, 44 were estrogen receptor positive, 33 were triple negative and 17 were HER2 positive. Direct sequencing analysis was performed on genomic DNA isolated from formalin-fixed paraffin-embedded tissue (FFPE) using the Illumina MiSeq Next Generation Sequencing platform (NGS). Immunohistochemistry for PD-L1 (SP142, Spring Bioscience), PD-1 (NAT105, Ventana) and EGFR (31G7, Life Technologies) was performed using automated procedures. Additionally, mutation analysis for EGFRvIII was performed on RNA extracted from FFPE tissue.

Results: At the genomic level, numerous cases of MBC had multiple genomic alterations with the most frequent genetic mutation in TP53 gene (14/24), similar to the TNBC controls (17/33). BRCA1 mutations were detected in 2/10 cases. Potentially actionable mutations were rare and included PIK3CA gene. Importantly, PD-L1 expression on cancer cells was detected in significantly higher proportion of MBCs (37%) than in the UBC cohort (6%) or TNBC control (14%) (p=3.7x10-5 and p=0.03, respectively). PD-1 positive tumors infiltrating lymphocytes (TILS) varied greatly in MBC (0 to &gt;50/mm2). Over-expression of EGFR was frequent in MBCs (62%); however no mutations in the gene including EGFRvIII were detected.

Conclusion: Comprehensive profiling of a large cohort of this rare carcinoma highlighted predominance of TP53 mutations, wild type EGFR gene expression, a distinct increase in proportion of PD-L1 expression in carcinoma cells, and PD-1 expression in TILS. The latter properties can be exploited in clinical trials utilizing immune check point inhibitors.

Citation Format: Gatalica Z, Joneja U, Ghazalpour A, Swensen J, Feldman R, Cai F, Chen W, Xiao N, Reddy S, Palazzo J. Comprehensive profiling of metaplastic breast carcinoma reveals frequent over-expression of PD-L1. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-47.

Brief Exercises Affect Gene Expression in Circulating Monocytes

We aimed to give a systematic hypothesis on the functions of exercise on circulating monocytes by identifying a discrete set of genes in circulating monocytes that were altered by exercise. The microarray expression profile of GSE51835 was downloaded from gene expression omnibus (GEO) database for the identification of differentially expressed genes (DEGs) using limma and affy packages in R language. Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed for DEGs, followed by the construction of co-expression network and protein-protein interaction (PPI) network. The top 10 nodes in PPI network were screened, and subnetwork was constructed for the key genes identification. Totally, 35 DEGs, including 2 upregulated genes and 33 downregulated genes, were identified. The enriched GO terms were mainly linked to immune response and defence response, and the enriched KEGG pathways were mainly associated with natural killer cell-mediated cytotoxicity and graft-versus-host disease. Dual-specificity phosphatase 2 (DUSP2) was identified as a key node in the co-expression network. In the PPI network, CD247 module (CD247), chemokine (C-X-C motif) receptor 4 (CXCR4), granzyme B (GZMB) and perforin 1 (PRF1) were identified as key nodes. An important interaction, GZMB/PRF1, was detected. Five key genes, including DUSP2, CD247, CXCR4, GZMB and PRF1, and an interaction of GZMB/PRF1, were significant factors in the immune processes of circulating monocytes, which might be regulated by brief exercises, leading to the enhancement of immune function.

Molecular cloning and functional characterization of a glutathione S-transferase involved in both anthocyanin and proanthocyanidin accumulation in Camelina sativa (Brassicaceae)

Recently, we found that the Arabidopsis TT19 protein, a glutathione S-transferase, has two functional domains that influence both anthocyanin and proanthocyanidin accumulation. To further understand the function of this protein in the other species, we cloned a cDNA encoding a glutathione S-transferase (namely CMGSTF12) from Camelina sativa, an oil crop that has received renewed interest due to its biofuel value and high omega-3 levels. Southern blot analysis demonstrated one copy of CMGSTF12 in C. sativa. Transformation of the Arabidopsis loss-of-function tt19-1 mutant with CMGSTF12 cDNA complemented accumulation of anthocyanin in vegetative tissues and resulted in the wild-type level of proanthocyanidin (both extractable and unextractable) in seeds. No obvious flavonoid accumulation changes were detected in the transgenic seeds, indicating that CMGSTF12 may only involve the lower flavonoid pathway, further proving that the TT19 protein controls accumulation of unextractable proanthocyanidin.

'Green'-synthesized near-infrared PbS quantum dots with silica-PEG dual-layer coating: ultrastable and biocompatible optical probes for in vivo animal imaging

In this paper, PbS semiconductor quantum dots (QDs) with near-infrared (NIR) photoluminescence were synthesized in oleic acid and paraffin liquid mixture by using an easily handled and 'green' approach. Surface functionalization of the QDs was accomplished with a silica and polyethylene glycol (PEG) phospholipid dual-layer coating and the excellent chemical stability of the nanoparticles is demonstrated. We then successfully applied the ultrastable PbS QDs to in vivo sentinel lymph node (SLN) mapping of mice. Histological analyses were also carried out to ensure that the intravenously injected nanoparticles did not produce any toxicity to the organism of mice. These experimental results suggested that our ultrastable NIR PbS QDs can serve as biocompatible and efficient probes for in vivo optical bioimaging and has great potentials for disease diagnosis and clinical therapies in the future.

Protective effect of Puerarin on β-amyloid-induced neurotoxicity in rat hippocampal neurons

Puerarin (CAS Number 3681-99-0), a major isoflavone glycoside purified from Pueraria lobata, was reported to possess antioxidative and estrogen-like biological activities. Recent studies showed that puerarin protects different cell types from damage caused by a variety of toxic stimuli. In the present study, we investigated the neuroprotective effect of puerarin against Aβ25-35-induced neurotoxicity in cultured hippocampal neurons, as well as the underlying mechanism(s). Following exposure of cells to Aβ25-35, cell survival and glutathione peroxidase (GSH-Px) and catalase (CAT) activities were reduced while production of reactive oxygen species (ROS) was increased. Preincubation of the cells with puerarin prior to Aβ25-35 exposure increased cell survival and GSH-Px and CAT activities and decreased ROS production. It was previously shown that overactivation of glycogen synthase kinase-3β (GSK-3β) is implicated in Aβ-induced cell death. In this study, Aβ25-35 treatment is found to increase GSK-3β activity and pretreatment with puerarin preventesAβ-induced activation of GSK-3β based on Western blot analysis. In addition, puerarin is shown to activate protein kinase B (PKB)/Akt, an important upstream kinase of GSK-3β, possibly promoting subsequent GSK-3β inhibition. Our data suggest that puerarin attenuates cell death induced by Aβ25-35 via various mechanisms, which might be beneficial for the treatment of Alzheimer's disease.

Effect of casein phosphopeptide-amorphous calcium phosphate added to acidic beverages on enamel erosion in vitro

BACKGROUND

To investigate, in vitro, the effect on enamel erosion of the addition of 0.2% w/v casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) to four commercially-available soft drinks, two of which were carbonated.

METHODS

Enamel specimens (n=27) were sectioned from sound extracted human third molar teeth and polished to a mirror finish. Exposed enamel windows of 1 mm2 were created by painting the surface with acid-resistant nail varnish. Four citric flavoured soft drinks (pH range 2.2 to 2.4) and distilled deionized water (DDW) were tested. Each drink was tested with and without 0.2% CPP-ACP w/v. The specimens were placed into 50 mL of solution at 37 °C for 30 minutes, rinsed and varnish removed. The samples were profiled with a white light profilometer and erosive depths recorded.

RESULTS

All soft drinks tested caused enamel erosion but adding 0.2% w/v CPP-ACP significantly reduced (p<.05) erosive depth in all test solutions in comparison with the solutions without CPP-ACP. The erosive depths for all solutions with 0.2% CPP-ACP did not differ significantly from those of DDW.

CONCLUSIONS

Adding CPP-ACP at 0.2% w/v significantly decreased the erosivity of all four soft drinks. The erosivity of the soft drinks with 0.2% CPP-ACP added did not differ significantly from that of distilled water.

New Approaches to Enhanced Remineralization of Tooth Enamel

Dental caries is a highly prevalent diet-related disease and is a major public health problem. A goal of modern dentistry is to manage non-cavitated caries lesions non-invasively through remineralization in an attempt to prevent disease progression and improve aesthetics, strength, and function. Remineralization is defined as the process whereby calcium and phosphate ions are supplied from a source external to the tooth to promote ion deposition into crystal voids in demineralized enamel, to produce net mineral gain. Recently, a range of novel calcium-phosphate-based remineralization delivery systems has been developed for clinical application. These delivery systems include crystalline, unstabilized amorphous, or stabilized amorphous formulations of calcium phosphate. These systems are reviewed, and the technology with the most scientific evidence to support its clinical use is the remineralizing system utilizing casein phosphopeptides to stabilize and deliver bioavailable calcium, phosphate, and fluoride ions. The recent clinical evidence for this technology is presented and the mechanism of action discussed. Biomimetic approaches to stabilization of bioavailable calcium, phosphate, and fluoride ions and the localization of these ions to non-cavitated caries lesions for controlled remineralization show promise for the non-invasive management of dental caries.

Effect of synthetic cannabinoid HU210 on memory deficits and neuropathology in Alzheimer's disease mouse model

Cannabinoids have been shown to increase neurogenesis in adult brain, as well as protect neurons from excitotoxicity, calcium influx, inflammation, and ischemia. Recent studies have shown that synthetic cannabinoids can alleviate water maze impairments in rats treated with intracranial amyloid beta protein (Abeta); however it is unknown whether this effect is due to the cannabinoids' anti-inflammatory properties or whether it affects Abeta processing. Here we investigate whether cannabinoids have any effect on Alzheimer's disease in vivo. We found that HU210, a potent synthetic cannabinoid, did not improve water maze performance or a contextual fear conditioning task in an APP23/PS45 double transgenic mouse model of AD. HU210 had no effect on APP processing and Abeta generation, as well as neuritic plaque formation in the brains of AD transgenic mice. Our study showed that synthetic cannabinoid HU210 had no beneficial effects on AD neuropathology and behavioral deficits of AD model mice, which advises caution of such drug's application in AD therapies.

Protein degradation by the proteasome is required for synaptic tagging and the heterosynaptic stabilization of hippocampal late-phase long-term potentiation

Activity-dependent regulation of synaptic efficacy is believed to underlie learning and memory formation. Here we show that protein degradation by the proteasome is required for the induction of the protein synthesis-dependent late-phase of long-term potentiation (late-LTP) but not for its maintenance. Proteasome activity was also key to the polarity of heterosynaptic interactions between synapses expressing synaptic plasticity and newly activated synapses. In fact, proteasome activity was required for the consolidation of an otherwise transient potentiation (early-LTP) into late-LTP by strong tetanization of a separate afferent pathway both in the "weak-before-strong" and in the "strong-before-weak" two-pathway paradigms [Frey and Morris (1997) Nature 385:533-536; Frey and Morris (1998) Neuropharmacology 37:545-552], suggesting that proteasome activity plays a role in the synaptic tagging and capture of plasticity-related proteins at stimulated synapses. Additionally, proteasome inhibition abrogated immunity against heterosynaptic depotentiation of an established late-LTP when applied during weak tetanic stimulation in the "strong-before-weak" two-pathway paradigm. Such a heterosynaptic destabilizing effect of proteasome inhibition was abolished by concomitant inhibition of N-methyl-d-aspartate (NMDA) receptors, suggesting that it is an active process. Together, these results indicate that the proteasome plays important roles in the establishment of late-LTP and in the preservation of potentiated synapses when a subsequent synaptic plasticity is induced within the same neuronal population.

Prokaryotic expression of a novel mouse pro-apoptosis protein PNAS-4 and application of its polyclonal antibodies

Mouse PNAS-4 (mPNAS-4) has 96% identity with human PNAS-4 (hPNAS-4) in primary sequence and has been reported to be involved in the apoptotic response to DNA damage. However, there have been no studies reported of the biological functions of mPNAS-4. In studies conducted by our group (unpublished data), it was interesting to note that overexpression of mPNAS-4 promoted apoptotic death in Lewis lung carcinoma cells (LL2) and colon carcinoma cells (CT26) of mice both in vitro and in vivo. In our studies, mPNAS-4 was cloned into the pGEX-6P-1 vector with GST tag at N-terminal in Escherichia coli strain BL21(DE3). The soluble and insoluble expression of recombinant protein mPNAS-4 (rmPNAS-4) was temperature-dependent. The majority of rmPNAS-4 was insoluble at 37 degrees C, while it was almost exclusively expressed in soluble form at 20 degrees C. The soluble rmPNAS-4 was purified by one-step affinity purification, using a glutathione Sepharose 4B column. The rmPNAS-4 protein was further identified by electrospray ionization-mass spectrometry analysis. The search parameters of the parent and fragment mass error tolerance were set at 0.1 and 0.05 kDa, respectively, and the sequence coverage of search result was 28%. The purified rmPNAS-4 was further used as immunogen to raise polyclonal antibodies in New Zealand white rabbit, which were suitable to detect both the recombinant and the endogenous mPNAS-4 in mouse brain tissue and LL2 cells after immunoblotting and/or immunostaining. The purified rmPNAS-4 and our prepared anti-mPNAS-4 polyclonal antibodies may provide useful tools for future biological function studies for mPNAS.

Hypothalamic preproghrelin gene expression is repressed by insulin via both PI3-K/Akt and ERK1/2 MAPK pathways in immortalized, hypothalamic neurons

The gut peptide ghrelin is expressed within neurons of the hypothalamus. Using a hypothalamic cell line, mHypoE-38 neurons, the effect of insulin on preproghrelin gene expression was assayed. These cells contain neuron-specific markers, preproghrelin and the insulin receptor. We determined that insulin has direct effects on preproghrelin gene expression. Insulin (10 nM) stimulated protein kinase B (Akt) and extracellular signal-regulated kinase 1 and 2 (ERK1/2) phosphorylation from 5 to 60 min and 5 min, respectively, and led to repression of preproghrelin gene expression at 2 h. Pharmacological inhibitors to phosphoinositide-3-kinase (PI3-K; LY294002) and MEK (PD98059) demonstrated that basal ghrelin gene expression is regulated by the PI3-K pathway and requires the mitogen-activated protein kinase pathway for insulin-stimulated preproghrelin repression. These results demonstrate that insulin has a direct effect on hypothalamic neurons to decrease preproghrelin gene expression through classic insulin pathways.

Fluoride and casein phosphopeptide-amorphous calcium phosphate

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) slows the progression of caries and remineralizes enamel subsurface lesions. The aim of this study was to determine the ability of CPP-ACP to increase the incorporation of fluoride into plaque and to promote enamel remineralization in situ. Randomized, double-blind, cross-over studies involved mouthrinses and dentifrices containing CPP-ACP and fluoride. The mouthrinses were used for 60 sec, three times/day for 5 days, and supragingival plaque was collected and analyzed for F. The dentifrices were rinsed as a water slurry for 60 sec four times/day for 14 days in an in situ model. The addition of 2% CPP-ACP to the 450-ppm-F mouthrinse significantly increased the incorporation of fluoride into plaque. The dentifrice containing 2% CPP-ACP produced a level of remineralization similar to that achieved with a dentifrice containing 2800 ppm F. The dentifrice containing 2% CPP-ACP plus 1100 ppm F was superior to all other formulations.

Remineralization of enamel subsurface lesions in situ by sugar-free lozenges containing casein phosphopeptideamorphous calcium phosphate

BACKGROUND

The anticariogenic potential of casein phosphopeptide-amorphous calcium phosphate nanocomplexes (CPP-ACP) has been demonstrated using laboratory, animal and human in situ caries models. The aim of this study was to determine the effect of CPP-ACP incorporation into a sugar-free lozenge (pressed mint tablet) on enamel remineralization in a human in situ model.

METHODS

The study utilized a double-blind, randomized, cross-over design with four treatments: (i) a lozenge containing 56.4mg (3 per cent w/w) CPP-ACP; (ii) a lozenge containing 18.8mg (1 per cent w/w) CPP-ACP; (iii) a lozenge not containing CPP-ACP; and (iv) a no lozenge nil-treatment control. Ten subjects wore removable palatal appliances with four, human-enamel, half-slab insets containing subsurface lesions. Lozenges were consumed, without chewing, four times per day for 14 days duration. After each treatment period the enamel slabs were removed, paired with their respective demineralized control, embedded, sectioned and subjected to microradiography and computer-assisted densitometric image analysis to determine the level of remineralization.

RESULTS

The incorporation of CPP-ACP into the lozenge significantly increased enamel subsurface lesion remineralization with 18.8 and 56.4mg of CPP-ACP increasing remineralization by 78 and 176 per cent respectively, relative to the control sugarfree lozenge.

CONCLUSION

This study demonstrates that lozenges are a suitable vehicle for the delivery of CPP-ACP to promote enamel remineralization.

Effect of addition of citric acid and casein phosphopeptide-amorphous calcium phosphate to a sugar-free chewing gum on enamel remineralization in situ

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) has been shown to remineralize enamel subsurface lesions in situ. The aim of this study was to investigate the effects of CPP-ACP in a fruit-flavoured sugar-free chewing gum containing citric acid on enamel remineralization, and acid resistance of the remineralized enamel, using an in situ remineralization model. The study utilized a double-blind, randomized, crossover design with three treatments: (i) sugar-free gum (2 pellets) containing 20 mg citric acid and 18.8 mg CPP-ACP, (ii) sugar-free gum containing 20 mg citric acid alone, (iii) sugar-free gum not containing CPP-ACP or citric acid. Ten subjects were instructed to wear removable palatal appliances, with 4 half-slab insets of human enamel containing demineralized subsurface lesions and to chew gum (2 pellets) for 20 min 4 times per day for 14 days. At the completion of each treatment the enamel half-slabs were removed and half of the remineralized lesion treated with demineralization buffer for 16 h in vitro. The enamel slabs (remineralized, acid-challenged and control) were then embedded, sectioned and subjected to microradiography to determine the level of remineralization. Chewing with gum containing citric acid and CPP-ACP resulted in significantly higher remineralization (13.0 +/- 2.2%) than chewing with either gum containing no CPP-ACP or citric acid (9.4 +/- 1.2%) or gum containing citric acid alone (2.6 +/- 1.3%). The acid challenge of the remineralized lesions showed that the level of mineral after acid challenge was significantly greater for the lesions exposed to the gum containing CPP-ACP.

Modulation of the oxidative stress and nuclear factor kappaB activation by theaflavin 3,3'-gallate in the rats exposed to cerebral ischemia-reperfusion

The major pathobiological mechanisms of IR injury include excitotoxicity, oxidative stress, and inflammation. TF3, a major constituent of black tea, possesses biological functions such as anti-oxidative and anti-inflammatory activities. The purpose of this study was to verify the neuronal protective potential of TF3 and its mechanisms against cerebral IR injury in rats. TF3 administration (10 and 20 mg.kg-1) ameliorated the infarct volume. TF3 also decreased the content of MDA and NO. TF3 significantly increased the activity of SOD and GSH-Px, which were reduced by IR injury. Administration of TF3 decreased mRNA and protein expression of COX-2 and iNOS. DNA binding and Western blotting revealed an increase in NF-kappaB activation and IkappaB depletion in IR brain tissue. Pretreatment with TF3 markedly inhibited IRinduced increase in nuclear localization of NF-kappaB, and preserved IkappaB in the cytoplasm. The results show that TF3 exerts protective effects against cerebral IR injury by reducing oxidative stress and modulating the NF-kappaB activation.

An improved mechanical technique for assisted hatching

BACKGROUND

Varied clinical outcomes of assisted hatching (AH) have been reported. We attempt to investigate whether the size of the zona opening created by AH is adequate for blastocyst hatching, and, if not, set up a new method to improve it.

METHODS

A new AH technique, long zona dissection (LZD), was established, and experiments were performed to compare the effects of different sizes of zona opening on complete hatching of blastocysts in mouse and human embryos in vitro.

RESULTS

The LZD technique can create a long zona slit on early embryos, even blastocysts, with the slit size beyond two-thirds of zona diameter. Compared with three-dimensional partial zona dissection, LZD can significantly enhance the hatching speed and the rate of complete hatching of mouse blastocysts (93.9%). All (100%) human blastocysts completely hatched following LZD; however, when the slit size after AH was about two-fifths of zona diameter, more of the larger inner cell masses (ICM) became trapped by the zona opening during hatching than the smaller ICM (53.3 versus 12.5%, P = 0.01).

CONCLUSIONS

Zona opening of moderate size following AH is inadequate for the completion of blastocyst hatching in vitro; in some cases, however, it can be significantly improved by LZD.

Acid resistance of enamel subsurface lesions remineralized by a sugar-free chewing gum containing casein phosphopeptide-amorphous calcium phosphate

The aim of this clinical study was to investigate the acid resistance of enamel lesions remineralized in situ by a sugar-free chewing gum containing casein phosphopeptide-amorphous calcium phosphate nanocomplexes (CPP-ACP: Recaldent). The study utilized a double-blind, randomized, crossover design with two treatments: (i) sugar-free gum containing 18.8 mg of CPP-ACP, and (ii) sugar-free gum not containing CPP-ACP as control. Subjects wore removable palatal appliances with insets of human enamel containing demineralized subsurface lesions and chewed the gum for 20 min 4 times per day for 14 days. After each treatment the enamel slabs were removed and half of each lesion challenged with acid in vitro for 8 or 16 h. The level of remineralization was determined using microradiography. The gum containing CPP-ACP produced approximately twice the level of remineralization as the control sugar-free gum. The 8- and 16-hour acid challenge of the lesions remineralized with the control gum resulted in 65.4 and 88.0% reductions, respectively, of deposited mineral, while for the CPP-ACP-remineralized lesions the corresponding reductions were 30.5 and 41.8%. The acid challenge after in situ remineralization for both control and CPP-ACP-treated lesions resulted in demineralization underneath the remineralized zone, indicating that the remineralized mineral was more resistant to subsequent acid challenge. The results show that sugar-free gum containing CPP-ACP is superior to an equivalent gum not containing CPP-ACP in remineralization of enamel subsurface lesions in situ with mineral that is more resistant to subsequent acid challenge.

Confirmation and refinement of a genetic locus for disseminated superficial actinic porokeratosis (DSAP1) at 12q23.2-24.1

BACKGROUND

Our previous study has identified two loci for disseminated superficial actinic porokeratosis (DSAP), but the genes responsible are still unknown.

OBJECTIVES

To narrow down the candidate regions and to assess candidate genes.

METHODS

A genome-wide scan and linkage analysis were carried out in a newly collected five-generation Chinese family with DSAP. In addition, six candidate genes were screened for possible DSAP-associated mutations.

RESULTS

DSAP in this family was associated with chromosome 12q. Fine mapping and haplotype construction refined the DSAP1 locus to a 4.4-cM interval. No disease-associated mutation was detected in CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 or KIAA0789 genes.

CONCLUSIONS

The DSAP1 locus was localized to a 4.4-cM interval at chromosome 12q23.2-24.1. CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 and KIAA0789 genes were not associated with DSAP1.