Effect of Oregon grape root extracts on P-glycoprotein mediated transport in in vitro cell lines

Purpose: This study aims to investigate the potential of Oregon grape root extracts to modulate the activity of P-glycoprotein. Methods: We performed 3H-CsA or 3H-digoxin transport experiments in the absence or presence of two sources of Oregon grape root extracts (E1 and E2), berberine or berbamine in Caco-2 and MDCKII-MDR1 cells. In addition, real time quantitative polymerase chain reaction (RT-PCR) was performed in Caco-2 and LS-180 cells to investigate the mechanism of modulating P-glycoprotein. Results: Our results showed that in Caco-2 cells, Oregon grape root extracts (E1 and E2) (0.1-1 mg/mL) inhibited the efflux of CsA and digoxin in a dose-dependent manner. However, 0.05 mg/mL E1 significantly increased the absorption of digoxin. Ten µM berberine and 30 µM berbamine significantly reduced the efflux of CsA, while no measurable effect of berberine was observed with digoxin. In the MDCKII-MDR1 cells, 10 µM berberine and 30 µM berbamine inhibited the efflux of CsA and digoxin. Lastly, in real time RT-PCR study, Oregon grape root extract (0.1 mg/mL) up-regulated mRNA levels of human MDR1 in Caco-2 and LS-180 cells at 24 h. Conclusion: Our study showed that Oregon grape root extracts modulated P-glycoprotein, thereby may affect the bioavailability of drugs that are substrates of P-glycoprotein.

Partial SAA patients benefit from delayed response of IST

Introduction

Severe aplastic anemia(SAA)is a severe disease characterized by immune-mediated bone marrow failure and pancytopenia. Immunosuppressive therapy (ATG plus CsA, IST) is the standard treatment for patients who are not suitable for allogeneic hematopoietic stem cell transplantation (allo-HSCT). Some patients have a delayed response after 6 months of ATG, and unnecessary to be given secondary ATG or allo-HSCT. We attempted to distinguish patients who may get potential delayed response from those who were really not responsive to IST.

Methods

We collected data from 45 SAA patients who were assessed no-response to IST at 6 months after rATG and failed to receive secondary ATG or allo-HSCT.

Results

CsA plus eltrombopag (EPAG) group has an extra 75% response rate while CsA maintenance group has an extra 44% response rate at 12 months. ATG was applied within 30 days after diagnosis, ATG dosage was suffificient (ATG/lymphocyte ≥2), and absolute reticulocyte count (ARC) was ≥30×109 /L at 6 months, indicated patients could get delayed response and benefifit from CsA maintenance. Addition of EPAG could give an even better response. Otherwise, secondary ATG or allo-HSCT treatment were recommended to be given immediately.

Clinical Trial Registration

https://www.chictr.org.cn/searchproj.aspx, identifier ChiCTR2300067615.

De novo donor-specific antibodies in belatacept-treated vs cyclosporine-treated kidney-transplant recipients: Post hoc analyses of the randomized phase III BENEFIT and BENEFIT-EXT studies

Donor-specific antibodies (DSAs) are associated with an increased risk of antibody-mediated rejection and graft failure. In BENEFIT and BENEFIT-EXT, kidney-transplant recipients were randomized to receive belatacept more intense (MI)-based, belatacept less intense (LI)-based, or cyclosporine-based immunosuppression for up to 7 years (84 months). The presence/absence of HLA-specific antibodies was determined at baseline, at months 6, 12, 24, 36, 48, 60, and 84, and at the time of clinically suspected episodes of acute rejection, using solid-phase flow-cytometry screening. Samples from anti-HLA-positive patients were further tested with a single-antigen bead assay to determine antibody specificities, presence/absence of DSAs, and mean fluorescence intensity (MFI) of any DSAs present. In BENEFIT, de novo DSAs developed in 1.4%, 3.5%, and 12.1% of belatacept MI-treated, belatacept LI-treated, and cyclosporine-treated patients, respectively. The corresponding values in BENEFIT-EXT were 3.8%, 1.1%, and 11.2%. Per Kaplan-Meier analysis, de novo DSA incidence was significantly lower in belatacept-treated vs cyclosporine-treated patients over 7 years in both studies (P < .01). In patients who developed de novo DSAs, belatacept-based immunosuppression was associated with numerically lower MFI vs cyclosporine-based immunosuppression. Although derived post hoc, these data suggest that belatacept-based immunosuppression suppresses de novo DSA development more effectively than cyclosporine-based immunosuppression.

Mitochondrial permeability transition pore in inflammatory apoptosis of human conjunctival epithelial cells and T cells: effect of cyclosporin A

PURPOSE

To investigate the role of mitochondrial permeability transition pore (MPTP) and effect of cyclosporin A (CsA) on inflammatory apoptosis of human conjunctival epithelial cells (IOBA-NHC) and T cells.

METHODS

IOBA-NHC and Jurkat cells were stimulated with IFNγ, TNFα, αFas, or PMA/αCD3, in the presence or absence of CsA. MPTP was determined using the calcein-cobalt technique. Mitochondrial membrane potential (ΔΨm) was measured with JC-1. Apoptosis was quantified by Annexin V/PI staining. Apoptosis mediators were evaluated by flow cytometry or Western blot.

RESULTS

In IOBA-NHC, TNFα, and IFNγ induced MPTP opening, ΔΨm loss, and increased cell apoptosis. This was accompanied by upregulation of Fas/FasL; Bax; and caspase-3, -8, and -9 activation. Addition of CsA prevented IOBA-NHC from cell death by blocking MPTP opening, ΔΨm loss, Fas/FasL, and caspase activation. In PMA/αCD3-activated Jurkat T cells, MPTP opening and ΔΨm loss were increased along with cell apoptosis and upregulated Fas/FasL/caspase expressions. CsA further promoted T-cell apoptosis, ΔΨm loss, and upregulation of Fas/FasL/caspase.

CONCLUSIONS

Inflammation induces aberrant MPTP opening, resulting in an increased apoptosis in conjunctival epithelial cells. CsA protected IOBA-NHC from cell death by blocking both intrinsic and extrinsic apoptosis pathways. CsA promoted T-cell apoptosis via upregulating Fas/FasL and caspase activities with a minimal effect on MPTP. The findings suggest that the differential effect of CsA on T cells versus ocular surface resident epithelial cells may contribute to its therapeutic efficacy in treating ocular inflammation such as dry eye disease.