Untargeted metabolomics yields insight into extramammary Paget's disease mechanisms

Background

Extramammary Paget's disease (EMPD) is a rare cutaneous malignancy, commonly affecting the external genitalia and perianal area of the elderly with unclear pathogenesis. Metabolomics provides a novel perspective for uncovering the metabolic mechanisms of a verity of cancers.

Materials and methods

Here, we explored the metabolome of EMPD using an untargeted strategy. In order to further investigate the potential relationship between metabolites and gene expression, we re-analyzed the gene expression microarray data (GSE117285) using differential expression analysis and functional enrichment analyses.

Results

Results showed that a total of 896 metabolites were identified and 87 metabolites including 37 upregulated and 50 downregulated significantly in EMPD were sought out. In the following feature selection analyses, four metabolites, namely, cyclopentyl fentanyl-d5, LPI 17:0, guanosine-3',5'-cyclic monophosphate, kynurenine (KYN, high in EMPD) were identified by both random forest and support vector machine analyses. We then identified 1,079 dysfunctional genes: 646 upregulated and 433 downregulated in EMPD. Specifically, the tryptophan-degrading enzyme including indoleamine-2,3-dioxygenase-1 (IDO1) and tryptophan 2,3-dioxygenase (TDO2) were also increased. Generally, cancers exhibit a high expression of IDO1 and TDO2 to catabolize tryptophan, generating abundant KYN. Moreover, we also noticed the abnormal activation of sustaining proliferative signaling in EMPD.

Conclusion

In conclusion, this study was the first to reveal the metabolome profile of EMPD. Our results demonstrate that IDO1/TDO2-initialized KYN metabolic pathway may play a vital role in the development and progression of EMPD, which may serve as a potential therapeutic target for treating EMPD.

Deoxynivalenol exposure induces oxidative stress and apoptosis in human keratinocytes via PI3K/Akt and MAPK signaling pathway

Deoxynivalenol (DON) is a mycotoxin frequently occurring in human and animal food worldwide, which raises increasing public health concerns. In the present study, we used human keratinocytes (HaCaT cells) as an in vitro model to explore the cytotoxic effect of DON. The results showed that the cells exhibited varying degrees of damage, including decreased cell number and viability, cell shrinkage and floating, when treated with 0.125, 0.25, and 0.5 μg/mL DON for 6, 12, and 24 h, respectively. Furthermore, exposure to DON for 24 h significantly increased the lactate dehydrogenase (LDH) release and intracellular reactive oxygen species (ROS), and prominently decreased the superoxide dismutase (SOD) and catalase (CAT) activity. Additionally, DON exposure induced mitochondrial damage and cell apoptosis through reducing mitochondrial membrane potential. Then, we performed RNA-sequencing to investigate the molecular changes in HaCaT cells after DON exposure. The RNA-sequencing results revealed that DON exposure altered the gene expression involved in apoptosis, MAPK signaling pathway, and PI3K/Akt signaling pathway. Moreover, DON exposure significantly decreased the mRNA and protein expression of Bcl-2, and increased the mRNA and protein expression of Bax, Caspase 3 and COX-2, the protein expression of PI3K, and the phosphorylation levels of Akt, ERK, p38, and JNK. Taken together, these findings suggest that DON exposure could induce cell damage, oxidative stress, and apoptosis in HaCaT cells through the activation of PI3K/Akt and MAPK pathways.

Chlorogenic acid attenuates deoxynivalenol-induced apoptosis and pyroptosis in human keratinocytes via activating Nrf2/HO-1 and inhibiting MAPK/NF-κB/NLRP3 pathways

Deoxynivalenol (DON) is a common mycotoxic contaminant, frequently found in food and feed, causing a severe threat to human and animal health. Because of the widespread contamination of DON, humans involved in agricultural practices may be directly exposed to DON through the skin route. Chlorogenic acid (CGA) is a phenolic acid, which has anti-inflammatory and antioxidant properties. However, it is still unclear whether CGA can protect against DON-induced skin damage. Here, the effect of CGA on mitigating damage to human keratinocytes (HaCaT) triggered by DON, as well as its underlying mechanisms were investigated. Results demonstrated that DON exposure significantly decreased cell viability, and induced excessive mitochondrial reactive oxygen species (mtROS) generation, mitochondrial damage, oxidative stress, cell apoptosis and pyroptosis. However, CGA pretreatment for 2 h significantly increased cell viability and reversed DON-induced oxidative stress by improving antioxidant enzyme activities such as superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), reducing mtROS generation and enhancing mitochondrial function through activating Nrf2/HO-1 pathway. Moreover, CGA significantly increased the Bcl-2 protein expression, decreased the protein expressions of Bax and cleaved Caspase-3, and suppressed the phosphorylated of ERK, JNK, NF-κB. Further experiments revealed that CGA could also inhibit the pyroptosis-related protein expressions including NLRP3, cleaved Caspase-1, GSDMD-N, cleaved IL-1β and IL-18. In conclusion, our results suggest that CGA could attenuate DON-induced oxidative stress, inflammation, and apoptosis by activating the Nrf2/HO-1 pathway and inhibiting MAPK/NF-κB/NLRP3 pathway. CGA might be a novel promising therapeutic agent for alleviating the dermal damage triggered by DON.

Triptolide Induces Apoptosis and Autophagy in Cutaneous Squamous Cell Carcinoma via Akt/mTOR Pathway

BACKGROUND

Tripterygium wilfordii Hook F provided the source of the first diterpenoid triepoxide lactone, Triptolide, identified as the primary constituent causing the anticancer activity. So far, it has not been reported whether triptolide has a therapeutic effect on cutaneous squamous cell carcinoma (cSCC).

OBJECTIVE

This study investigates the triptolide's therapeutic impact on cSCC both in vitro and in vivo and investigates the triptolide's potential involvement in signaling pathways.

METHODS

The CCK-8 assays, wound healing assays, and colony formation assays were used to assess the effects of triptolide on the proliferation and migration of cSCC cells. The alteration in gene expression following triptolide treatment was shown by RNA sequencing. Flow cytometry was then applied to evaluate cell apoptosis. Western blot was used to find the associated proteins' expressions. The effectiveness of triptolide was then evaluated in vivo using a xenograft model, and histological staining was employed to determine the visceral toxicity.

RESULTS

Triptolide greatly reduces the migratory and proliferative capacity of cSCC cells. Triptolide dramatically decreased cell viability and migration in the A431 and SCL-1 cells compared to the control group, according to the CCK8 assay, wound healing assay, and colony formation assay. Flow cytometry demonstrated that treatment with 10- 40 nM triptolide increased apoptosis in a concentration-dependent manner, with a statistically significant difference. Furthermore, mice given triptolide had smaller tumor sizes than those in the control group. Triptolide treatment drastically altered the expression of autophagic and apoptotic proteins. The considerable reduction in the proteins Akt and mTOR levels further illustrated the critical function of triptolide in cSCC.

CONCLUSION

Triptolide caused cSCC cells to engage in autophagy and apoptosis by inhibiting the Akt/mTOR signaling pathways. Triptolide may be a possible antitumor agent for the treatment of cSCC.

Quantum Criticality of the Ising-like Screw Chain Antiferromagnet SrCo_{2}V_{2}O_{8} in a Transverse Magnetic Field

The quantum criticality of an Ising-like screw chain antiferromagnet SrCo_{2}V_{2}O_{8}, with a transverse magnetic field applied along the crystalline a axis, is investigated by ultralow temperature NMR measurements. The Néel temperature is rapidly and continuously suppressed by the field, giving rise to a quantum critical point (QCP) at H_{C_{1}}≈7.03  T. Surprisingly, a second QCP at H_{C_{2}}≈7.7  T featured with gapless excitations is resolved from both the double-peak structure of the field-dependent spin-lattice relaxation rate 1/^{51}T_{1} at low temperatures and the weakly temperature-dependent 1/^{51}T_{1} at this field. Our data, combined with numerical calculations, suggest that the induced effective staggered transverse field significantly lowers the critical fields, and leads to an exposed QCP at H_{C_{2}}, which belongs to the one-dimensional transverse-field Ising universality.

Bio-syncretic tweezers actuated by microorganisms: modeling and analysis

Advancements in micro-/nano-technology have led to the development of micro-manipulators. However, some challenges remain; for instance, the efficiency, precision and flexibility of micro-manipulators restrain their applications. This paper proposes a bio-tweezer system to flexibly manipulate micro-objects with bio-actuation via local light-induced high-concentration microorganisms in two different manipulation modes: light-spot induced mode and geometric shape-induced mode. Depending on the shape of micro-objects, either 2-dimensional translation or 1-dimensional rotation can be achieved. Based on the Langevin equation, a mathematical model considering both hydrodynamics and mimicked Brownian motion is proposed to analyze the bio-manipulation performance of the microorganisms; the model was validated by experiments to translate micro-particles in a two-dimensional plane and to rotate a micro-gear structure around its axis. This paper will aid in the development of micro-manipulators and the quantitative understanding of micro-/nano-manipulation actuated by microorganisms.

Nanoscale distribution of CD20 on B-cell lymphoma tumour cells and its potential role in the clinical efficacy of rituximab

Rituximab is an exciting monoclonal antibody drug approved for treating B-cell lymphomas and its target is the CD20 antigen which is expressed on the surface of B cells. In recent years, the variable efficacies of rituximab among different lymphoma patients have become an important clinical issue and urgently need to be solved for further development of antibodies with enhanced efficacies. In this work, atomic force microscopy (AFM) was used to investigate the nanoscale distribution of CD20 on the surface of tumour B cells from lymphoma patients to examine its potential role in the clinical therapeutic effects of rituximab. By performing ROR1 fluorescence labelling (ROR1 is a specific tumour cell surface marker) on the bone marrow cells prepared from B-cell lymphoma patients, the tumour B cells were recognized, and then AFM tips carrying rituximabs via polyethylene glycol crosslinkers were moved to the tumour cells to probe the specific CD20-rituximab interactions. By applying AFM single-molecule force spectroscopy (SMFS) at the local areas (500×500 nm²) on the surface of tumour B cells, the nanoscale distributions of CD20 on the surface of tumour B cells were mapped, visually showing that CD20 distributed heterogeneously on the cell surface. Bone marrow cell samples from three clinical B-cell lymphoma cases were collected to analyze the binding affinity and nanoscale distribution of CD20 on tumour cells. The experimental results showed that CD20 distribution on tumour cells were to some extent related to the clinical therapeutic outcomes while the CD20-rituximab binding forces did not have distinct effects to the clinical outcomes. These results can provide novel insights in understanding the rituximab's clinical efficacies from the nanoscale distribution of CD20 on the tumour cells at single-cell and single-molecule levels.

Gate dependent photo-responses of carbon nanotube field effect phototransistors

Gate dependent photoconductivity of carbon nanotube (CNT) field effect phototransistors (FEPs) was systematically investigated in this study. The photo-response comparisons of CNT FEPs with symmetric and asymmetric metal structures connecting to the same CNT revealed that the gate effect contributed to a sensitivity improvement with a lower dark current, a higher photocurrent, and an enhanced photovoltage. A functionalized asymmetric FEP, fabricated by partially doping the CNT utilizing a polyethylene imine (PEI) polymer, verified that FEPs delivered a better performance by using asymmetric structures. A multi-gate FEP, with three pairs of side-gates that can electrostatically dope different sections of a CNT independently, was fabricated to examine the gate structure dependent photo-responses. Experimental measurements showed an unconventional photocurrent improvement that was weakly dependent on the gate location, which was attributed to the unique charge distribution of one-dimensional semiconductors.

Childhood psoriasis treatment: evidence published over the last 5 years

Psoriasis is a common skin condition seen in pediatrics. Treatment modalities used to treat psoriasis in children are different from those prevailing in the adult population and require adequate testing in pediatric subjects. This article reviews the published evidence on the different treatment modalities for pediatric psoriasis over the past 5 years.

Force measurement and mechanical characterization of living Drosophila embryos for human medical study

The objective of this paper is to investigate and characterize the force behaviour and mechanical properties of living Drosophila embryos using an in situ polyvinylidene fluoride (PVDF) piezoelectric microforce-sensing tool with a resolution in the range of submicro newtons. The Drosophila embryo is one of the most studied organisms in biological research, medical research, genetics, and developmental biology and has implications in the cure of human diseases. It is also used to study the wiring of the human brain and the nervous system. For a highly efficient and accurate microinjection of genetic material into a Drosophila embryo, it is absolutely necessary to allow close monitoring of the magnitude and direction of microinjection and other biomanipulation forces acting on the embryo during the injection process. In this paper, a networked microrobotic biomanipulation platform integrating a twoaxis (two-dimensional) PVDF microforce-sensing tool is used to implement force sensing and injection of living Drosophila embryos. Based on the event synchronization for the feedback of injection video and microforce, the developed networked microrobotic platform can greatly advance operations in microinjection and biomanipulation. Through experiments, quantitative relationships between the applied force and membrane structural deformation of embryos in different stages of embryogenesis and their microinjection force behaviours were investigated. Ultimately, the technology will provide a critical and major step towards the development of automated biomanipulation for batch injection of living embryos in genetic and developmental studies, which will facilitate the development of medicine for the cure of human diseases.

Interaction of Cu(II) 3,5-diisopropylsalicylate with human serum albumin--an evaluation of spectroscopic data

The copper(II) complex of 3,5-diisopropylsalicylate is a lipophilic water-insoluble binuclear complex, Cu(II)2(3,5-DIPS)4, that has attracted interest because of a wide range of pharmacological activities. This study was undertaken to examine bonding interactions between the complex and human serum albumin (HSA) to help elucidate the mode of transport of the complex in vivo. Electron paramagnetic resonance, numerical magnetic resonance and UV-visible absorption spectroscopic studies were performed using 200 microM aqueous solutions (pH 7.5) of HSA to which had been added up to three molar equivalents of CuCl2, CuSO4, or Cu(II)2(3,5-DIPS)4. Both EPR and UV-visible spectra demonstrated the presence of more than one copper bonding site on HSA, and proton NMR spectra showed that the 3,5-DIPS ligand is also bonded to HSA. These results indicate that there is no observable direct coordination of the ligand to copper in the presence of HSA, and that the majority of the copper and 3,5-DIPS bond to HSA at separate sites. Addition of solid Cu(II)2(3,5-DIPS)4 to HSA at pH 7.5 similarly resulted in spectra suggest that there are no ternary Cu(II)(3,5-DIPS), Cu(II)(3,5-DIPS)2, or Cu(II)2(3,5-DIPS)4 complexes formed with HSA. It is concluded that any ternary complexes formed in the presence of HSA are below the spectroscopic detection limits and represent less than 5% of the total copper.