Orcinol gentiobioside inhibits RANKL-induced osteoclastogenesis by promoting apoptosis and suppressing autophagy via the JNK1 signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Osteoporosis (OP) is a metabolic disorder characterized by disrupted osteoclastic bone resorption and osteoblastic bone formation. Curculigo orchioides Gaertn has a long history of application in traditional Chinese and Indian medicine for treating OP. Orcinol gentiobioside (OGB) is a principal active constituent derived from Curculigo orchioides Gaertn and has been shown to have anti-OP activity. However, the therapeutic efficacy and mechanism of OGB in modulating osteoclastic bone resorption remain undefined.

AIM OF THE STUDY

To evaluate the effect of OGB on the formation, differentiation and function of osteoclasts derived from bone marrow macrophages (BMMs), and further elucidate the underlying action mechanism of OGB in OP.

MATERIALS AND METHODS

Osteoclasts derived from BMMs were utilized to evaluate the effect of OGB on osteoclast formation, differentiation and bone resorption. Tartrate-resistant acid phosphatase (TRAP) staining and activity assays were conducted to denote the activity of osteoclasts. Osteoclast-related genes and proteins were determined by RT-PCR and Western blotting assays. The formation of the F-actin ring was observed by confocal laser microscopy, and bone resorption pits were observed by inverted microscopy. The target of OGB in osteoclasts was predicted by using molecular docking and further verified by Cellular Thermal Shift Assay (CETSA) and reversal effects of the target activator. The apoptosis of osteoclasts was analyzed by flow cytometry, and autophagic flux in osteoclasts was determined by confocal laser microscopy.

RESULTS

OGB inhibited osteoclast formation and differentiation, osteoclast-related genes and proteins expression, F-actin ring formation, and bone resorption activity. Molecular docking and CETSA analysis demonstrated that OGB exhibited good affinity for c-Jun N-terminal Kinase 1 (JNK1). In addition, OGB induced apoptosis and inhibited autophagy in osteoclasts, and the JNK agonist anisomycin reversed the increase in apoptosis and inhibition of autophagy induced by OGB in osteoclasts.

CONCLUSION

OGB inhibited osteoclastogenesis by promoting apoptosis and diminishing autophagy via JNK1 signaling.

An Adaptive Low-Rank Modeling-Based Active Learning Method for Medical Image Annotation

Active learning is an effective solution to interactively select a limited number of informative examples and use them to train a learning algorithm that can achieve its optimal performance for specific tasks. It is suitable for medical image applications in which unlabeled data are abundant but manual annotation could be very time-consuming and expensive. However, designing an effective active learning strategy for informative example selection is a challenging task, due to the intrinsic presence of noise in medical images, the large number of images, and the variety of imaging modalities. In this study, a novel low-rank modeling-based multi-label active learning (LRMMAL) method is developed to address these challenges and select informative examples for training a classifier to achieve the optimal performance. The proposed method independently quantifies image noise and integrates it with other measures to guide a pool-based sampling process to determine the most informative examples for training a classifier. In addition, an automatic adaptive cross entropy-based parameter determination scheme is proposed for further optimizing the example sampling strategy. Experimental results on varied medical image datasets and comparisons with other state-of-the-art multi-label active learning methods illustrate the superior performance of the proposed method.

[microRNA-106a-5p regulated the funcation human umbilical vein endothelial cells by targeting STAT3]

Objective: To investigate the effects of miR-106a-5p on the proliferation and migration of vascular endothelial cells, and the possible target gene of miR-106a-5p in endothelial cells. Methods: Human umbilical vein endothelial cells (HUVEC) were cultured in vitro, and the expression of mir-106a-5p in HUVECs was detected by real-time fluorescent quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 (CCK-8) and wound healing assays were used to detected the proliferation and migration of HUVECs respectively.Dual luciferase repoter assay was used to identify the possible target gene of miR-106a-5p--STAT3. Results: mir-106a-5p inhibited the proliferation function of HUVECs (F=13.62, P<0.01). And mir-106a-5p expressed the migration of HUVEC,the closure rate in the mimic group was reduced after 12 h and 24 h of scratching (49.93/31.31) (χ(2)=8.240, P<0.05), (78.87/44.80) (χ(2)=10.50, P<0.01). The direct target gene of mir-106a-5p was STAT3, and miR-106a-5p regulated the expression of STAT3 through post-transcriptionally controlling. Conclusion: mir-106a-5p could inhibit proliferation and migration of HUVEC, and the possible target gene was STAT3.

Human Umbilical Cord Mesenchymal Stem Cells: Subpopulations and Their Difference in Cell Biology and Effects on Retinal Degeneration in RCS Rats

BACKGROUND

Human umbilical cord mesenchymal stem cells (hUC-MSCs) are potential candidates for treating retinal degeneration (RD).

OBJECTIVE

To further study the biology and therapeutic effects of the hUC-MSCs on retinal degeneration.

METHODS

Two hUC-MSC subpopulations, termed hUC-MSC1 and hUC-MSC2, were isolated by single-cell cloning method and their therapeutic functions were compared in RCS rat, a RD model.

RESULTS

Although both subsets satisfied the basic requirements for hUC-MSCs, they were significantly different in morphology, proliferation rate, differentiation capacity, phenotype and gene expression. Furthermore, only the smaller, fibroblast-like, faster growing subset hUC-MSC1 displayed stronger colony forming potential as well as adipogenic and osteogenic differentiation capacities. When the two subsets were respectively transplanted into the subretinal spaces of RCS rats, both subsets survived, but only hUC-MSC1 expressed RPE cell markers Bestrophin and RPE65. More importantly, hUC-MSC1 showed stronger rescue effect on the retinal function as indicated by the higher b-wave amplitude on ERG examination, thicker retinal nuclear layer, and decreased apoptotic photoreceptors. When both subsets were treated with interleukin-6, mimicking the inflammatory environment when the cells were transplanted into the eyes with degenerated retina, hUC-MSC1 expressed much higher levels of trophic factors in comparison with hUC-MSC2.

CONCLUSION

The data here, in addition to prove the heterogeneity of hUC-MSCs, confirmed that the stronger therapeutic effects of hUC-MSC1 were attributed to its stronger anti-apoptotic effect, paracrine of trophic factors and potential RPE cell differentiation capacity. Thus, the subset hUC-MSC1, not the other subset or the ungrouped hUC-MSCs should be used for effective treatment of RD.

Erythropoietin Protects Retina Against Ceramide 2-Induced Damage in Rat

BACKGROUND

Ceramide plays critical roles in cell proliferation, senescence and apoptosis, and is implicated in neurodegenerative diseases, etc. To clarify if ceramide plays some roles in retinal diseases, we established in vivo and in vitro retinal injury models with ceramide 2 (C2) treatment. In addition, Erythropoietin (EPO), which showed protective effects on retinal cells and blood-retinal barrier (BRB), was also tested for its protection and possible mechanism(s) in these models.

METHODS

Male Sprague-Dawley rats were divided into four groups, i.e., normal control, vehicle control, C2 treatment, and C2+EPO treatment. After intravitreal injection, the rats were examined for eye fundus, electroretinogram, histological study, and immunostaining, etc. In vitro, retinal neuronal cell line (R28) and the primary human retinal microvascular endothelial cells (HRMECs) were treated with C2, cell viability assay, transendothelial electrical resistance (TEER) and BRB-related molecules were studied to test the protective effect of EPO.

RESULTS

Intravitreal C2-treatment caused significant vision loss in rats, as reflected by reduced b-wave amplitude, increased TUNEL positive cells and GFAP immunostaining in retina. Another major retinal injury observed was BRB breakdown following C2- treatment. Such C2-induced injuries were further confirmed by in vitro study. When HRMECs were treated with C2, the TEER was significantly reduced. The mechanisms for C2 to induce such injuries might be through evidently increased expressions of the related molecules like plasmalemma vesicle-associated protein (PLVAP or PV-1), ecto- 5'-nucleotidase (CD73) and intercellular adhesion molecule-1 (ICAM-1), as observed in C2-treated R28 cells. All these injuries induced by C2 were significantly prevented by EPO both in vivo and in vitro, and its protective mechanisms here might be, in addition to neuroprotective, closely related to its maintenance of BRB integrity, through reducing the expressions of PV-1, CD73 and ICAM-1.

CONCLUSION

C2 could induce severe retinal injury, and such injuries could be effectively prevented by EPO treatment.

miR-25 Mediates Retinal Degeneration Via Inhibiting ITGAV and PEDF in Rat

BACKGROUND

Age-related macular degeneration (AMD) is the main cause of irreversible blindness in the elderly. Oxidative stress in retinal pigment epithelium (RPE) is deemed to play a pivotal role in the pathogenesis of AMD. miR-25 functions as an essential modulator in response to oxidative-stress in several cell types, but its function in RPE cells is poorly understood.

OBJECTIVE

To explore the roles of miR-25 in RPE cells and in the development of AMD.

METHODS

A rat model of retinal degeneration was induced by sodium iodate (SI). Subretinal injection of antagomiR-25 was performed for the intervention while the scramble as control. Visual responses were recorded with Electroretinogram (ERG). TUNEL assay was performed to detect apoptosis. Phagosome quantification in vivo was performed to evaluate RPE cell function. Oxygen-glucose deprivation treatment was performed to mimic in vitro oxidative stress. Gene expression at mRNA level and protein level were performed by quantitative polymerase chain reaction (qPCR) and Western Blot, respectively. The pigment epithelium derived factor (PEDF) level in the cultured medium was measured by Enzyme-linked immunosorbent assay (ELISA). The interaction between miR-25 and integrin αV (IGTAV) / PEDF 3'UTR was examined by dual luciferase assay. Chromatin immunoprecipitation (ChIP) assay was performed to examine its transcriptional regulation of miR-25.

RESULTS

Oxidative stress up-regulated miR-25 in RPE cells in very early stage, accompanied by decreased phagocytosis and reduced growth factor secretion in those cells. Such changes preceded RPE cell apoptosis and visual impairment in the SItreated rats. Furthermore, antagomiR-25 intervention effectively rescued RPE cells from degeneration in such model. The increased miR-25 was confirmed to mediate RPE degeneration through direct targeting IGTAV and PEDF. On the other hand, upstream, miR-25 was found to be up-regulated by STAT3 signaling under oxidative stress in both in vivo and in vitro models.

CONCLUSION

Our findings demonstrate that, in SI-treated rats, oxidative stress activates STAT3 signaling which up-regulates miR-25 expression, in a very early stage. The increased miR-25 then inhibits ITGAV and PEDF expressions, resulting in RPE phagocytosis dysfunction and then RPE apoptosis and visual impairment as observed in patients with AMD. These findings lead us to a better understanding of AMD pathogenesis, and suggest that miR-25 could be a potential therapeutic target for oxidative stress related RPE diseases, like AMD.

Pityriasis rubra pilaris-like erythroderma secondary to phosphoinositide 3-kinase inhibition

BACKGROUND

Phosphoinositide 3-kinase (PI3K) inhibitors are a class of small-molecule inhibitors approved for the treatment of certain leukaemias and lymphomas. Their dermatological adverse event profile is poorly described.

AIM

To characterize a rare cutaneous adverse event from PI3K inhibitors in order to help dermatologists and oncologists identify and effectively manage such eruptions.

METHODS

This was a retrospective analysis of patients receiving PI3K inhibitors referred to the Skin Toxicities Program in The Center for Cutaneous Oncology.

RESULTS

Three patients on PI3K inhibitors for treatment of malignancy developed diffuse erythroderma and keratoderma. Clinical and histopathological findings were consistent with pityriasis rubra pilaris (PRP)-like reactions. All patients improved with topical and oral corticosteroids, oral acitretin, and drug discontinuation.

CONCLUSIONS

PRP-like cutaneous eruptions may develop secondary to PI3K inhibition. Early dermatological evaluation of cutaneous toxicities to PI3K inhibitors as well as rapid initiation of disease-specific treatments may help keep patients on life-prolonging anti-cancer therapies.

Human Adipose-Derived Stem Cells Delay Retinal Degeneration in Royal College of Surgeons Rats Through Anti-Apoptotic and VEGF-Mediated Neuroprotective Effects

Stem cell therapy is a promising therapeutic approach for retinal degeneration (RD). Our study investigated the effects of human adipose derived stem cell (hADSCs) on Royal College of Surgeons (RCS) rats.

METHODS

Green fluorescent protein (GFP)-labeled hADSCs were transplanted subretinally into RCS rats at postnatal (PN) 21 days to explore potential therapeutic effects, while adeno-associated viral vector (AAV2)-vascular endothelial growth factor (VEGF) and siVEGF-hADSCs were used to aid the mechanistic dissections. Visual function was evaluated by Electroretinogram (ERG) recording. Potential transdifferentiations were examined by Immunofluorescence (IF) and gene expressions were analyzed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Apoptotic retinal cells were detected by Terminal Deoxynucleotidyl Transferase dUTP Nick End Labeling (TUNEL) assay and the cytokines secreted by hADSCs were measured by Enzyme-linked Immunosorbent Assay (ELISA).

RESULTS

The visual function of RCS rats began to decrease one week after their eyes opened at PN week 3 and almost lost in PN 5 weeks, accompanied by the loss of retinal outer nuclear layer (ONL). Subretinal transplantation of hADSCs significantly improved the visual function 2 weeks after the transplantation and such therapeutic effect persisted up to 8 weeks after the treatment (PN 11 weeks), with 3-4 rows of photoreceptors remained in the ONL and reduced apoptosis. Consistent with these phenotypic changes, the gene expression of rod photoreceptor markers Rhodopsin (Rho), Crx and Opsin (Opn1) in RCS rats showed obvious decreasing trends over time after PN 3 weeks, but were elevated with hADSC treatment. hADSC transplantation also repressed the expressions of Bax, Bak and Caspase 3, but not the expression of anti-apoptotic genes, including Bcl-2 and Bcl-XL. Finally, substantial VEGF, hepatocyte growth factor (HGF) and pigment epithelium-derived factor (PEDF) secretions from hADSCs were detected, while endogenous Vegf expression level decreased over time in RCS rats. The treatment of AAV2-VEGF showed comparable therapeutic effects as hADSCs but siRNA knockdown of VEGF in hADSCs essentially abolished the therapeutic effects.

CONCLUSIONS

Subretinal transplantation of hADSCs in RCS rats effectively delayed the retinal degeneration, enhanced the retinal cell survival and improved the visual function. Mechanistically this was mainly due to hADSC dependent anti-apoptotic and neuroprotective effects through its secretion of growth and neurotrophic factors including VEGF. Clinical application of hADSCs merits further investigation.

Functional single nucleotide polymorphism in C20orf54 modifies susceptibility to esophageal squamous cell carcinoma

The aim of this study was to explore the association of C20orf54 functional single nucleotide polymorphism (SNP) with the susceptibility to esophageal squamous cell carcinoma (ESCC) in a northern China population. The C20orf54 SNP was genotyped by direct sequencing in 240 cancer patients and 198 controls in northern China. The results showed that drinking status, family history of ESCC, and body mass index have great influence on the risk of developing ESCC. The overall genotype frequencies of C20orf54 in ESCC patients have a significant difference with healthy controls (χ(2)  = 8.06, P = 0.018). By using C/C genotype as the reference, the C/T genotype showed a significantly decreased risk to the development of ESCC. Thus, compared with the C/C genotype, smokers, drinkers with C/T genotype significantly decreased the risk of developing ESCC. A positive family history of ESCC with C/T and T/T genotype both increased the risk of developing ESCC. Body mass index between 18.5 and 24 with C/T genotype significantly decreased the risk of developing ESCC. The present study suggests that the C20orf54 functional SNP might be associated with a risk of development in ESCC.

Effects of humoral factors on ventilation kinetics during recovery after impulse-like exercise

To clarify the ventilatory kinetics during recovery after impulse-like exercise, subjects performed one impulse-like exercise test (one-impulse) and a five-times repeated impulse-like exercises test (five-impulse). Duration and intensity of the impulse-like exercise were 20 sec and 400 watts (80 rpm), respectively. Although blood pH during recovery (until 10 min) was significantly lower in the five-impulse test than in the one-impulse test, ventilation (.VE) in the two tests was similar except during the first 30 sec of recovery, in which it was higher in the five-impulse test. In one-impulse, blood CO2 pressure (PCO2) was significantly increased at 1 min during recovery and then returned to the pre-exercise level at 5 min during recovery. In the five-impulse test, PCO2 at 1 min during recovery was similar to the pre-exercise level, and then it decreased to a level lower than the pre-exercise level at 5 min during recovery. Accordingly, PCO2 during recovery (until 30 min) was significantly lower in the five-impulse than in one-impulse test..VE and pH during recovery showed a curvilinear relationship, and at the same pH, ventilation was higher in the one-impulse test. These results suggest that ventilatory kinetics during recovery after impulse-like exercise is attributed partly to pH, but the stimulatory effect of lower pH is diminished by the inhibitory effect of lower PCO2.

Genotype of Candida species associated with different conditions of vulvovaginal candidosis

It is unknown whether strains isolated from recurrent vulvovaginal candidosis (RVVC), vulvovaginal candidosis (VVC) and asymptomatic carriers are varying or not in genotyping. Candida isolates were genotyped to determine whether specific types were associated with RVVC and VVC. A total of 97 Candida isolates from RVVC patients (n = 43), from VVC patients (n = 47) and asymptomatic carriers (n = 7) were identified by germ tube test, chlamydospore test, CHROMagar Candida and API20 system and were genotyped by polymerase chain reaction (PCR) fingerprinting employing random amplification of polymorphic DNA (RAPD) assay with nine random primers screened. The RAPD identified distinct genotypes that were shared among isolates from most different individuals. Most of the 85 C. albicans strains failed to corroborate any obvious differences in the genotypic variability in the VVC, RVVC patient groups and carriers by clustering analysis. Only a few individuals were found to harbor a distinct genotype of C. albicans isolates associated with a specific disease condition.

Outcrossing and paternity analysis of Pinus densiflora (Japanese red pine) by microsatellite polymorphism

This study employed microsatellite loci to analyse outcrossing rate and pollen dispersal in Japanese red pine (Pinus densiflora) in an isolated stand. The average offspring outcrossing rate for 29 cones was 0.955. Significant differences in outcrossing rates between offspring groups on individual branches that extended in different directions at different heights were not detected. Male parents of 874 offspring collected from the maternal tree were assessed by exclusion using polymorphisms at three microsatellite loci. Paternity analysis indicated that at least 31% of the offspring were fertilized by pollen from trees outside the stand. The average distance of pollen migration within the study stand was 68 m, with a maximum value of 325 m. There was excess mating with nearby P. densiflora trees, of which only a few were predominant pollen donors. In addition, a weakly directional bias in P. densiflora pollination was also detected in the study stand, suggesting that female strobili on a branch of the maternal tree were more easily fertilized by pollen from trees in that direction.

Distamycin A modulates the sequence specificity of DNA alkylation by duocarmycin A

Duocarmycin A (Duo) normally alkylates adenine N3 at the 3' end of A + T-rich sequences in DNA. The efficient adenine alkylation by Duo is achieved by its monomeric binding to the DNA minor groove. The addition of another minor groove binder, distamycin A (Dist), dramatically modulates the site of DNA alkylation by Duo, and the alkylation switches preferentially to G residues in G + C-rich sequences. HPLC product analysis using oligonucleotides revealed a highly efficient G-N3 alkylation via the cooperative binding of a heterodimer between Duo and Dist to the minor groove. The three-dimensional structure of the ternary alkylated complex of Duo/Dist/d(CAGGTGGT).d(ACCACCTG) has been determined by nuclear Overhauser effect (NOE)-restrained refinement using 750 MHz two-dimensional NOE spectroscopy data. The refined NMR structure fully explains the sequence requirement of such modulated alkylations. This is the first demonstration of Duo DNA alkylation through cooperative binding with another structurally different natural product, and it suggests a promising new way to alter or modify the DNA alkylation selectivity in a predictable manner.

Fluorine-19 nuclear magnetic resonance spectroscopic study of fluorophenylalanine- and fluorotryptophan-labeled avian egg white lysozymes

We report the 470-MHz (11.7 T) 19F solution nuclear magnetic resonance (NMR) spectra of 2-, 3-, and 4-fluorophenylalanine incorporated into the egg white lysozymes (EC 3.2.1.17) of chicken, pheasant, and duck, as well as spectra of 4-fluorotryptophan incorporated into chicken, California valley quail, and Bob White quail and 5- and 6-fluorotryptophan-labeled chicken lysozyme. The 19F solution NMR spectrum of [4-F]Phe hen egg white lysozyme (HEWL) consists of three sharp resonances, which span a total chemical shift range of 4.8 ppm (at p2H = 6.1). For [3-F]Phe HEWL, the chemical shift range is much smaller, 1.0 ppm (at p2H = 5.9), due presumably to the occurrence of fast phenyl ring flips about the C beta-C gamma bond axis. For [2-F]Phe HEWL, six resonances are observed, spanning a chemical shift range of 7.4 ppm (at p2H = 5.8), due to slow C beta-C gamma ring flips, i.e., both ring-flip isomers appear to be "frozen in" because of steric hindrance. Rotation of the [2-F]Phe residues remains slow up to 55 degrees C (p2H = 4.7). With the [F]Trp-labeled proteins, we find a maximal 14.6-ppm shielding range for [4-F]Trp HEWL but only a 2.8- and 2.4-ppm range for [5- and 6-F]Trp HEWL, respectively, due presumably to increased solvent exposure in the latter cases. Guanidinium chloride denaturation causes loss of essentially all chemical shift nonequivalence, as does thermal denaturation. Spectra recorded as a function of pH show relatively small chemical shift changes (< 1.4 ppm) over the pH range of approximately 1.2-7.8.(ABSTRACT TRUNCATED AT 250 WORDS)