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Photodynamic therapy prevented the recurrence of lymphomatoid papulosis
摘要： Lymphomatoid papulosis (LyP) is a benign lymphoproliferative disorder which often takes indolent course. Topical steroid application and/or photochemotherapy are usually employed. Herein we report a case of LyP whose recurrence was successfully prevented by topical photodynamic therapy (PDT). A 55-year-old woman visited our hospital, with a five-year history of erythematous macules, papules, and erosions scattered on her trunk and extremities, and concentrated especially on her left thigh. She had been treated with topical potent corticosteroid. Although most of the skin lesions resolved within a few weeks, new papules had continuously appeared. The biopsy from the left thigh revealed perivascular dense infiltration of small lymphocytes admixed with large lymphocytes. The large lymphocytes were positive for CD3, CD4, and CD30. Whole body CT scan did not disclose visceral or lymph node involvement. The blood examination data were unremarkable. The diagnosis of LyP was established. Photochemotherapy with psoralen and UVA on her whole body, once a week for three months could not prevent the recurrence of the papules. Based on the successful treatment of mycosis fungoides with PDT [1], we applied PDT with topical 20% aminolevulinic acid (ALA) on her left thigh. The PDT-treated area developed hematoma within a day, as we observed in mycosis fungoides on PDT [1]; it gradually resolved in several weeks. One year after PDT, LyP lesion did not recur in the PDT-treated area, although a few papules appeared on her extremities every month. In our previous report of mycosis fungoides treated with PDT [1], the PDT-treated area formed hematoma. The biopsy taken five days after PDT revealed totally degenerated blood vessels with massive hemorrhage in the dermis. In order to investigate the mechanism of PDT on LyP, we took a biopsy immediately after PDT, before developing hematoma. The biopsy taken from pigmented lesion revealed scattered perivascular infiltration of small lymphocytes. The reticular dermis and capillary endothelium were edematous. Apoptotic cells were not found with hematoxylin and eosin stain or with TUNEL technique (data not shown). Immunostain for high mobility group box 1 (HMGB1) was positive in the cytoplasm of lymphocytes and vascular endothelium. Calreticulin immunostain was positive on the surface of vascular endothelium and sweat gland apparatus. Although the direct effect of PDT on actinic keratosis usually appears immediately after the procedure, we could not find an apparent change histologically, immediately after PDT, however, the treated area formed hematoma within a day. Thus, we sought an indirect mechanism to induce cell death and vascular change, which took several hours or days. Along with the result of immunostain for HMGB1 and calreticulin, we assumed that immunogenic cell death (ICD) might occur in the PDT-treated lesion. HMGB1 secretion from nuclei and calreticulin binding to cell membrane are among the danger-associated molecular patterns (DAMPs), which are the features most commonly associated with ICD [2]. ICD is a self-defense mechanism against malignant neoplasms. Once neoplastic cells are damaged by chemotherapeutic agents or PDT [2], DAMPs are relocated to the surface of the cells, and released from the damaged cells. Then the DAMPs stimulate surrounding dendritic cells and Natural Killer cells, and induce apoptosis in the neoplastic cells. Thus, this process is not tumor-specific, but can induce broad degeneration in the surrounding tissue. Among the chemicals utilized in PDT, only hypericin [3] and glycoconjugated chlorin [4] were proved to induce ICD, so far. Herein we demonstrated that ALA could induce DAMPs, and speculate that ALA-PDT may work via ICD mechanism. LyP lesions can appear anywhere on the body, occasionally in a concentrated manner. In the early report of LyP treated with ALA-PDT [5], the authors observed not only its efficacy on the treatment-resistant lesion, but a preventive effect, as we experienced. PDT can be a good candidate for a field therapy of LyP, as suggested in the treatment of actinic keratosis [6].
关键词： HMGB1,immunogenic cell death,calreticulin
更新于2025-09-23 15:23:52
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Cell death mechanisms in a mouse model of retinal degeneration in Spinocerebellar ataxia 7
摘要： Spino-cerebellar ataxia type 7 (SCA7) is a polyglutamine (polyQ) disorder characterized by neurodegeneration of the brain, cerebellum, and retina caused by a polyglutamine expansion in ataxin 7. The presence of an expanded polyQ tract in a mutant protein is known to induce protein aggregation, cellular stress, toxicity, and finally cell death. However, the consequences of the presence of mutant ataxin7 in the retina and the mechanisms underlying photoreceptor degeneration remain poorly understood. In this study, we show that in a retinal SCA7 mouse model, polyQ ataxin7 induces stress within the retina and activates Muller cells. Moreover, Unfolded Protein Response and autophagy are activated in SCA7 photoreceptors. We have also shown that the photoreceptor death does not involve a caspase-dependent apoptosis but instead involves apoptosis inducing factor (AIF) and Leukocyte Elastase Inhibitor (LEI/L-DNase II). When these two cell death effectors are downregulated by their siRNA, a significant reduction of photoreceptor death is observed. These results highlight the consequences of polyQ protein expression in the retina and the role of caspase-independent pathways involved in photoreceptor cell death.
关键词： retina,toxicity,Spinocerebellar ataxia type 7,caspase-independent cell death,photoreceptors,polyglutamine disorder,autophagy,unfolded protein response
更新于2025-09-23 15:22:29
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Photobiomodulation of human osteoblasta??like cells <i>in vitro</i> by lowa??intensity pulsed LED light
摘要： Visible light irradiation is an emerging area in regenerative medicine research. We hypothesized that low intensity pulsed LED light irradiance may exert photobiomodulatory effects on cultured osteoblast-like cells. To test this hypothesis, we investigated cell proliferation and markers of cell maturation and metabolic activity following pulsed LED irradiance. Monolayer explant cultures of human osteoblast-like cells were exposed four times in 24-hour intervals to 2 minutes of pulsed white LED irradiance of 2.4-2.5 mW/cm2 and its different spectra of 0.2-0.5 mW/cm2 (frequency range of 10-40 Hz). Cell proliferation was estimated from microscopic cell counting and cell death by lactate dehydrogenase activity in culture media (measured by a colorimetric method). The early markers of osteoblast maturation and metabolic activity, i.e. cellular alkaline phosphatase activity and osteocalcin content, were measured using a colorimetric method and ELISA, respectively. Irradiance of 40 Hz caused the highest increase in cell number (p<0.01). Osteocalcin content in cells decreased following 40 Hz and 10 Hz irradiance (p<0.05). The 40 Hz blue range irradiance (diffuse transmittance 420-580 nm, maximal cell irradiance 0.5 mW/cm2) caused a decrease in alkaline phosphatase cellular activity (p<0.001) and an increase in media osteocalcin content (p<0.05). The 40 Hz green range (diffuse transmittance 560-650 nm, maximal cell irradiance 0.4 mW/cm2) irradiance caused an increase in the number of cells and in cell death. In summary, pulsed (40 Hz) white light irradiance has photomodulatory effects, with its green range spectrum affecting cell proliferation and cell death, and its blue range spectrum affecting cellular maturation and metabolism. The results indicate a low intensity threshold of photobiomodulation of osteoblast-like cells in vitro.
关键词： cell maturation,pulse light photobiomodulation,cell death,osteoblast-like cells,LED
更新于2025-09-23 15:21:01
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Monitoring Neuronal Survival via Longitudinal Fluorescence Microscopy
摘要： Standard cytotoxicity assays, which require the collection of lysates or fixed cells at multiple time points, have limited sensitivity and capacity to assess factors that influence neuronal fate. These assays require the observation of separate populations of cells at discrete time points. As a result, individual cells cannot be followed prospectively over time, severely limiting the ability to discriminate whether subcellular events, such as puncta formation or protein mislocalization, are pathogenic drivers of disease, homeostatic responses, or merely coincidental phenomena. Single-cell longitudinal microscopy overcomes these limitations, allowing the researcher to determine differences in survival between populations and draw causal relationships with enhanced sensitivity. This video guide will outline a representative workflow for experiments measuring single-cell survival of rat primary cortical neurons expressing a fluorescent protein marker. The viewer will learn how to achieve high-efficiency transfections, collect and process images enabling the prospective tracking of individual cells, and compare the relative survival of neuronal populations using Cox proportional hazards analysis.
关键词： fluorescence microscopy,automation,Cell death,transfection,neurodegeneration,survival analysis
更新于2025-09-19 17:15:36
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The apoptosis pathway of photodynamic therapy using 9-HpbD-a in?AMC-HN3 human head and?neck cancer cell line and?in vivo
摘要： 9-Hydroxypheophorbide-a (9-HpbD-a), a new photosensitizer was extracted from the green alga Spirulina platensis. The anticancer effects of photodynamic therapy (PDT) treatment using 9-HpbD-a against human head and neck cancer cell HN3 and in vivo mice model were investigated. Cells were incubated with 9-HpbD-a for at least 6 hours or more followed by the laser irradiation. Cytotoxicity of 9-HpbD-a against HN3 cell was determined using the MTT assay, propidium iodide and Hoechst 33342 staining and transmission electron microscopy (TEM). To determine the mechanism of cell death, Western blot analysis was performed. The antitumor effect was confirmed in a cancer cell xenograft nude mouse model by photodynamic therapy (PDT) using 9-HpbD-a. For normal control and the 9-HpbD-a only treated group, tumor tissues showed continuous tumor growth (100%). For laser only treated experimental group, 3 treatments showed no remission (75.0%), and was one recurrence (25.0%). Out of 16 tumors in the fourth group of photodynamic treatment, 10 cured (62.5%), 4 recurrence (25.0%), and 2 did not heal (12.5%) were confirmed. PDT using a 9-HpbD-a and 665 nm diode laser showed significant antitumor effects. Thus PDT using 9-HpbD-a can be a useful new treatment method in the treatment of cancer in the future.
关键词： Photosensitizer,Photodynamic therapy,9-Hydroxypheophorbide-a,Apoptosis,Cell death mechanism
更新于2025-09-19 17:15:36
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Single-Cell ATP Content Monitoring during Hyperthermia Cell Death by using Plasmonic Fluorescent Nanoflare
摘要： Gold nanorods-based plasmonic photothermal therapy (AuNRs-PPTT) has been a prospective anti-cancer approach in which AuNRs absorbs near-infrared (NIR) light and converts it into heat, leading to cell death. Investigating molecular energy metabolism of single cells, especially cancer cells, during hyperthermia cell death process is therefore of great significance, as it can help us to better understand the photothermal lethal mechanism of cancer cells and design new photothermal probes more rationally. However, during the AuNRs-PPTT process, how the cells respond to heat stimulation, and how their energy metabolism changes, these basic issues have rarely been studied. Herein, we selected adenosine triphosphate (ATP) as a target molecule, and by preparing a plasmonic and turn-on type fluorescent nanoprobe we examined the ATP metabolism difference between cancerous cells and normal cells during the AuNRs-PPTT process. We found that the fluorescence intensity increased ~ 60% after 5 min laser irradiation as compared to the initial intensity in single HeLa cells, but only ~ 20% increasement was observed for single H8 cells; obviously the increase of ATP content in cancerous cells was notably higher than that in normal cells during the hyperthermia cell death.
关键词： Plasmonic photothermal therapy,Fluorescent nanoprobe,ATP,Gold nanorods,Hyperthermia cell death
更新于2025-09-19 17:13:59
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<p>The Destruction Of Laser-Induced Phase-Transition Nanoparticles Triggered By Low-Intensity Ultrasound: An Innovative Modality To Enhance The Immunological Treatment Of Ovarian Cancer Cells</p>
摘要： Photodynamic therapy (PDT), sonodynamic therapy (SDT), and oxaliplatin (OXP) can induce immunogenic cell death (ICD) following damage-associated molecular patterns (DAMPs) exposure or release and can be united via the use of nanoplatforms to deliver drugs that can impart anti-tumor effects. The aim of this study was to develop phase-transition nanoparticles (OI_NPs) loaded with perfluoropentane (PFP), indocyanine green (ICG), and oxaliplatin (OXP), to augment anti-tumor efficacy and the immunological effects of chemotherapy, photodynamic therapy and sonodynamic therapy (PSDT).
关键词： photo-sonodynamic therapy,multifunctional nanoparticles,immunogenic cell death,reactive oxygen species,ovarian cancer
更新于2025-09-12 10:27:22
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Glutathione Capped Core/shell CdSeS/ZnS Quantum Dots as a Medical Imaging tool for Cancer Cells
摘要： Nanomaterials have secured an enduring position as a promising contender for various biological applications. Quantum dot (QD) is one such example of nano sized semiconductor material having unique optical characteristics that makes it an ideal candidate to be used as imaging tool for today’s medical industry. In the present study, the L-Glutathione (L-GSH) capped L-GSH-CdSeS/ZnS core/shell QDs were applied to visualize MCF-7 human breast cancer cells. Time and dose dependent studies were done, to study the cell penetration and visualization of QDs within the cancer cells. MTT assay was done to derive the percent cell viability of cancer cells at different QDs dose concentrations. Cell cytotoxicity of the capped CdSeS/ZnS QDs were also studied on non-cancerous healthy cells. Human cancerous cells were treated with the selected doses of QDs for different time durations followed by counter staining of the cells with fluorescent DAPI nuclear stain to observe the reflected QD mediated effects. The small sized QDs were localized predominantly in the cytoplasm of MCF-7 cells and displayed no significant cytotoxicity on healthy cells. Our findings suggest that our new synthesized L-GSH-CdSeS/ZnS core/shell QDs could be highly biocompatible and can have a high probability of applications in bio-labeling and imaging for cancer diagnostics.
关键词： Diagnostics,CdSeS/ZnS Quantum dot,Toxicity,Biocompatible,Cancer,Cell death,MCF-7
更新于2025-09-12 10:27:22
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Controlling Surface Chemical Heterogeneities of Ultrasmall Fluorescent Core–Shell Silica Nanoparticles as Revealed by High-Performance Liquid Chromatography
摘要： Ultrasmall (diameter below 10 nm) fluorescent core?shell silica nanoparticles have garnered increasing attention in recent years as a result of their high brightness and favorable biodistribution properties important for applications including bioimaging and nanomedicine. Here, we present an in-depth study that provides new insights into the physical parameters that govern full covalent fluorescent dye encapsulation within the silica core of poly(ethylene glycol)-coated core?shell silica nanoparticles referred to as Cornell prime dots (C′ dots). We use a combination of high-performance liquid chromatography (HPLC), gel-permeation chromatography, and fluorescence correlation spectroscopy to monitor the result of ammonia concentration in the synthesis of C′ dots from negatively and positively charged versions of near-infrared dyes Cy5 and Cy5.5. HPLC, in particular, allows the distinction between cases of full versus partial dye encapsulation in the silica particle core leading to surface chemical heterogeneities in the form of hydrophobic surface patches, which, in turn, modulate biological response in ferroptotic cell death experiments. Our results demonstrate that there is a complex interplay between dye?dye and dye?silica cluster interactions originally formed in the sol?gel synthesis governing optimal dye encapsulation. We expect that the reduced surface chemical heterogeneities will make the resulting nanoparticles attractive for a number of applications in biology and medicine.
关键词： gel-permeation chromatography,ferroptotic cell death,high-performance liquid chromatography,fluorescent core?shell silica nanoparticles,fluorescence correlation spectroscopy
更新于2025-09-11 14:15:04
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Proton versus photon radiation-induced cell death in head and neck cancer cells
摘要： Background: Photon (X-ray) radiotherapy (XRT) kills cells via DNA damage, however, how proton radiotherapy (PRT) causes cell death in head and neck squamous cell carcinoma (HNSCC) is unclear. We investigated mechanisms of HNSCC cell death after XRT versus PRT. Methods: We assessed type of death in 2 human papillomavirus (HPV)-positive and two HPV-negative cell lines: necrosis and apoptosis (Annexin-V fluorescein isothiocyanate [FITC]); senescence (β-galactosidase); and mitotic catastrophe (γ-tubulin and diamidino-phenylindole [DAPI]). Results: The XRT-induced or PRT-induced cellular senescence and mitotic catastrophe in all cell lines studied suggested that PRT caused cell death to a greater extent than XRT. After PRT, mitotic catastrophe peaked in HPV-negative and HPV-positive cells at 48 and 72 hours, respectively. No obvious differences were noted in the extent of cell necrosis or apoptosis after XRT versus PRT. Conclusion: Under the conditions and in the cell lines reported here, mitotic catastrophe and senescence were the major types of cell death induced by XRT and PRT, and PRT may be more effective.
关键词： photon radiotherapy,radiation-induced cell death,head and neck cancer,cell death mechanisms,proton radiotherapy
更新于2025-09-04 15:30:14