Curcumin potentiates the fungicidal effect of dodecanol by inhibiting drug efflux in wild-type budding yeast

Drug resistance commonly occurs when treating immunocompromised patients who have fungal infections. Curcumin, is a compound isolated from Curcuma longa, has been reported to inhibit drug efflux in several human cell lines and nonpathogenic budding yeast Saccharomyces cerevisiae cells that overexpresses the ATP-binding cassette (ABC) transporters S. cerevisiae Pdr5p and pathogenic Candida albicans Cdr1p and Cdr2p. The aim of this study was to examine the effects of curcumin on multidrug resistance in a wild-type strain of the budding yeast with an intrinsic expression system of multidrug efflux-related genes. The antifungal activity of dodecanol alone was temporary against S. cerevisiae; however, restoration of cell viability was completely inhibited when the cells were co-treated with dodecanol and curcumin. Furthermore, restriction of rhodamine 6G (R6G) efflux from the cells and intracellular accumulation of R6G were observed with curcumin treatment. Reverse transcription-polymerase chain reaction analysis revealed that curcumin reduced the dodecanol-induced overexpression of the ABC transporter-related genes PDR1, PDR3 and PDR5 to their control levels in untreated cells. Curcumin can directly restrict the glucose-induced drug efflux and inhibits the expression of the ABC transporter gene PDR5, and can thereby inhibit the efflux of dodecanol from S. cerevisiae cells. Curcumin is effective in potentiating the efficacy of antifungal drugs via its effects on ABC transporters. SIGNIFICANCE AND IMPACT OF THE STUDY: Drug resistance is common in immunocompromised patients with fungal infections. Curcumin, isolated from Curcuma longa, inhibits drug efflux in nonpathogenic budding yeast Saccharomyces cerevisiae cells overexpressing ABC transporters S. cerevisiae Pdr5p and pathogenic Candida albicans Cdr1p and Cdr2p. We examined the effects of curcumin on multidrug resistance in a wild-type strain of the budding yeast with an intrinsic expression system of multidrug efflux-related genes. Curcumin directly inhibited drug efflux and also suppressed the PDR5 expression, thereby enhancing the antifungal effects. Thus, curcumin potentially promotes the efficacy of antifungals via its effects on ABC transporters in wild-type fungal strains.

Transcriptional activities of two newly identified Haemaphysalis longicornis tick-derived promoter regions in the Ixodes scapularis tick cell line (ISE6)

Ticks are obligate haematophagous ectoparasites considered to be second to mosquitoes as vectors of human diseases and the most important vector for animals. Despite efforts to control tick infestations, they remain a serious health problem. Gene manipulation has been established in mosquitoes and led to the control of mosquito populations and of mosquito-borne pathogens. Therefore, gene manipulation could be useful for controlling ticks and tick-borne pathogens. To investigate effective gene expression vectors for ticks, the promoter activities of commercial plasmids were evaluated in a tick cell line (ISE6). Dual luciferase assays revealed that pmirGLO, the human phosphoglycerate kinase promoter contained plasmid vector, showed the highest activity in ISE6 cells amongst the tested plasmids. Moreover, we identified the promoter regions of the Haemaphysalis longicornis actin (HlAct) and the intracellular ferritin (HlFer1) genes. To construct a more effective expression vector for ticks, these promoter regions were inserted into pmirGLO (pmirGLO-HlAct pro and pmirGLO-HlFer1 pro). The pmirGLO-HlAct pro vector showed significantly higher promoter activity than pmirGLO, whereas the pmirGLO-HlFer1 pro vector demonstrated significantly lower promoter activity than pmirGLO in ISE6 cells. The HlAct promoter region may have high promoter activity in ISE6 cells. The results of the present study provide useful information for the development of a genetic modification system in ticks.

Prognostic impact of interhospital variation in adjuvant chemotherapy for patients with Stage II/III colorectal cancer: a nationwide study

AIM

Clinical guidelines recommend adjuvant chemotherapy for high-risk patients with Stage II-III colorectal cancer. However, chemotherapeutic administration rates differ significantly between hospitals. We assessed the prognostic benefit of adjuvant chemotherapy in patients with Stage IIb/c colorectal cancer, and the prognostic impact of interhospital variations in the administration of adjuvant chemotherapy for Stage II-III colorectal cancer.

METHOD

We conducted a multicentre, retrospective study of 17 757 patients with Stage II-III colorectal cancer treated between 1997 and 2008 in 23 hospitals in Japan. Hospitals were classified as high-rate (rate > 42.8%) or low-rate (rate ≤ 42.8%), chemotherapy prescribing clinics.

RESULTS

The 5-year overall survival (OS) of patients with Stage II-III colorectal cancer receiving adjuvant chemotherapy was significantly higher than for those not receiving adjuvant chemotherapy (85.7% vs 79.2%, P < 0.01 and 79.9% vs 72.5%, P < 0.01, respectively). For patients with Stage II disease, adjuvant chemotherapy was an independent factor for longer OS (P < 0.01, hazard ratio = 0.71). Both adjuvant chemotherapy and high-rate hospital independently improved OS for patients with Stage III colorectal cancer (both P < 0.01; hazard ratio = 0.68 and 0.87, respectively).

CONCLUSION

Significant prognostic benefit was found for patients with Stage IIb/c colorectal cancer who received adjuvant chemotherapy, with patients who were treated in hospitals with high adjuvant chemotherapy rates demonstrating better prognoses.

Intraperitoneal injection of the SIRT1 activator SRT1720 attenuates the progression of experimental osteoarthritis in mice

Objectives

This study aimed to examine the effects of SRT1720, a potent SIRT1 activator, on osteoarthritis (OA) progression using an experimental OA model.

Methods

Osteoarthritis was surgically induced by destabilization of the medial meniscus in eight-week-old C57BL/6 male mice. SRT1720 was administered intraperitoneally twice a week after surgery. Osteoarthritis progression was evaluated histologically using the Osteoarthritis Research Society International (OARSI) score at four, eight, 12 and 16 weeks. The expression of SIRT1, matrix metalloproteinase 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5), cleaved caspase-3, PARP p85, and acetylated nuclear factor (NF)-κB p65 in cartilage was examined by immunohistochemistry. Synovitis was also evaluated histologically. Primary mouse epiphyseal chondrocytes were treated with SRT1720 in the presence or absence of interleukin 1 beta (IL-1β), and gene expression changes were examined by real-time polymerase chain reaction (PCR).

Results

The OARSI score was significantly lower in mice treated with SRT1720 than in control mice at eight and 12 weeks associated with the decreased size of osteophytes at four and eight weeks. The delayed OA progression in the mice treated with SRT1720 was also associated with increased SIRT1-positive chondrocytes and decreased MMP-13-, ADAMTS-5-, cleaved caspase-3-, PARP p85-, and acetylated NF-κB p65-positive chondrocytes and decreased synovitis at four and eight weeks. SRT1720 treatment partially rescued the decreases in collagen type II alpha 1 (COL2A1) and aggrecan caused by IL-1β, while also reducing the induction of MMP-13 by IL-1β in vitro.

Conclusion

The intraperitoneal injection of SRT1720 attenuated experimental OA progression in mice, indicating that SRT1720 could be a new therapeutic approach for OA.Cite this article: K. Nishida, T. Matsushita, K. Takayama, T. Tanaka, N. Miyaji, K. Ibaraki, D. Araki, N. Kanzaki, T. Matsumoto, R. Kuroda. Intraperitoneal injection of the SIRT1 activator SRT1720 attenuates the progression of experimental osteoarthritis in mice. Bone Joint Res 2018;7:252-262. DOI: 10.1302/2046-3758.73.BJR-2017-0227.R1.

First Direct Mass Measurements of Nuclides around Z=100 with a Multireflection Time-of-Flight Mass Spectrograph

The masses of ^{246}Es, ^{251}Fm, and the transfermium nuclei ^{249-252}Md and ^{254}No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed N=152 neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of ^{246}Es and ^{249,250,252}Md were measured for the first time. Using the masses of ^{249,250}Md as anchor points for α decay chains, the masses of heavier nuclei, up to ^{261}Bh and ^{266}Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter δ_{2n} derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N=152 neutron shell closure for Md and Lr.

Study of termination of postprandial gastric contractions in humans, dogs and Suncus murinus: role of motilin- and ghrelin-induced strong contraction

AIM

Stomach contractions show two types of specific patterns in many species, that is migrating motor contraction (MMC) and postprandial contractions (PPCs), in the fasting and fed states respectively. We found gastric PPCs terminated with migrating strong contractions in humans, dogs and suncus. In this study, we reveal the detailed characteristics and physiological implications of these strong contractions of PPC.

METHODS

Human, suncus and canine gastric contractions were recorded with a motility-monitoring ingestible capsule and a strain-gauge force transducer. The response of motilin and ghrelin and its receptor antagonist on the contractions were studied by using free-moving suncus.

RESULTS

Strong gastric contractions were observed at the end of a PPC in human, dog and suncus models, and we tentatively designated this contraction to be a postprandial giant contraction (PPGC). In the suncus, the PPGC showed the same property as those of a phase III contraction of MMC (PIII-MMC) in the duration, motility index and response to motilin or ghrelin antagonist administration. Ghrelin antagonist administration in the latter half of the PPC (LH-PPC) attenuated gastric contraction prolonged the duration of occurrence of PPGC, as found in PII-MMC.

CONCLUSION

It is thought that the first half of the PPC changed to PII-MMC and then terminated with PIII-MMC, suggesting that PPC consists of a digestive phase (the first half of the PPC) and a discharge phase (LH-PPC) and that LH-PPC is coincident with MMC. In this study, we propose a new approach for the understanding of postprandial contractions.