The effect of Fernblock® in preventing blue-light-induced oxidative stress and cellular damage in retinal pigment epithelial cells is associated with NRF2 induction

Blue light exposure of the ocular apparatus is currently rising. This has motivated a growing concern about potential deleterious effects on different eye structures. To address this, ARPE-19 cells were used as a model of the retinal pigment epithelium and subjected to cumulative expositions of blue light. The most relevant cellular events previously associated with blue-light-induced damage were assessed, including alterations in cell morphology, viability, cell proliferation, oxidative stress, inflammation, and the induction of DNA repair cellular mechanisms. Consistent with previous reports, our results provide evidence of cellular alterations resulting from repeated exposure to blue light irradiation. In this context, we explored the potential protective properties of the vegetal extract from Polypodium leucotomos, Fernblock® (FB), using the widely known treatment with lutein as a reference for comparison. The only changes observed as a result of the sole treatment with either FB or lutein were a slight but significant increase in γH2AX+ cells and the raise in the nuclear levels of NRF2. Overall, our findings indicate that the treatment with FB (similarly to lutein) prior to blue light irradiation can alleviate blue-light-induced deleterious effects in RPE cells, specifically preventing the drop in both cell viability and percentage of EdU+ cells, as well as the increase in ROS generation, percentage of γH2AX+ nuclei (more efficiently with FB), and TNF-α secretion (the latter restored only by FB to similar levels to those of the control). On the contrary, the induction in the P21 expression upon blue light irradiation was not prevented neither by FB nor by lutein. Notably, the nuclear translocation of NRF2 induced by blue light was similar to that observed in cells pre-treated with FB, while lutein pre-treatment resulted in nuclear NRF2 levels similar to control cells, suggesting key differences in the mechanism of cellular protection exerted by these compounds. These results may represent the foundation ground for the use of FB as a new ingredient in the development of alternative prophylactic strategies for blue-light-associated diseases, a currently rising medical interest.

New trends on personalized sunscreens

BACKGROUND/PURPOSE

Nowadays, there are emerging trends in customized and personalized photoprotection, focusing on the innovative approaches to enhance sun protection efficacy tailored to individual needs.

METHODS

We conducted an electronic search of the following databases: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Skin Group Specialised Skin Register, and TESEO. Specific search terms related to personalized photoprotection and the variables of age, genetic predisposition, skin phototype, photodermatosis, and physiological conditions such as pregnancy, as well as lifestyle habits were used.

RESULTS/CONCLUSION

The article highlights the challenges and opportunities in adopting personalized photoprotection strategies, aiming to promote skin health and prevent the harmful effects of UV radiation in the era of precision medicine.

[Translated article] Reflectance Confocal Microscopy Terminology in Spanish: A Delphi Consensus Study

The terminology used to describe reflectance confocal microscopy (RCM) findings in both melanocytic and nonmelanocytic lesions has been standardized in English. We convened a panel of Spanish-speaking RCM experts and used the Delphi method to seek consensus on which Spanish terms best describe RCM findings in this setting. The experts agreed on 52 terms: 28 for melanocytic lesions and 24 for nonmelanocytic lesions. The resulting terminology will facilitate homogenization, leading to a better understanding of structures, more standardized descriptions in clinical registries, and easier interpretation of clinical reports exchanged between dermatologists.

Impact of a pulmonary embolism response team (PERT) in the prognosis of patients with acute symptomatic pulmonary embolism

BACKGROUND

The effect of a pulmonary embolism response team (PERT) in the short-term prognosis of patients with acute symptomatic pulmonary embolism (PE) lacks clarity. We therefore aimed at evaluating the effect of a PERT team on short-term mortality among patients with acute PE.

METHODS

We retrospectively reviewed consecutive patients with acute symptomatic PE enrolled in a single-center registry between 2007 and 2022. We used propensity score matching to compare treatment effects for patients with similar predicted probabilities of receiving management by the PERT team. The primary outcome was all-cause mortality within 30 days following the diagnosis of PE. The secondary outcome was 30-day PE-related mortality.

RESULTS

Of the 2,902 eligible patients who had acute symptomatic PE, 223 (7.7%; 95% confidence interval [CI], 6.7%-8.7%) were managed by the PERT team. Two hundred and seven patients who were treated by the PERT were matched with 207 patients who were not. Matched pairs did not show a statistically significant lower all-cause (odds ratio [OR], 1.09; 95% CI, 0.63-1.89) or PE-related death (OR, 1.30; 95% CI, 0.47-3.62) for PERT management compared with no PERT management through 30 days after diagnosis of PE.

CONCLUSIONS

Our results suggest that multidisciplinary care of patients with acute symptomatic PE by a PERT team is not associated with a significant reduction in short-term all-cause or PE-related mortality.

Reflectance Confocal Microscopy Terminology in Spanish: A Delphi Consensus Study

The terminology used to describe reflectance confocal microscopy (RCM) findings in both melanocytic and nonmelanocytic lesions has been standardized in English. We convened a panel of Spanish-speaking RCM experts and used the Delphi method to seek consensus on which Spanish terms best describe RCM findings in this setting. The experts agreed on 52 terms: 28 for melanocytic lesions and 24 for nonmelanocytic lesions. The resulting terminology will facilitate homogenization, leading to a better understanding of structures, more standardized descriptions in clinical registries, and easier interpretation of clinical reports exchanged between dermatologists.

Evaluation of the effectiveness and safety of combined oral and topical photoprotection with a standardized extract of Polypodium leucotomos (Fernblock®) in a Moroccan population with xeroderma pigmentosum

BACKGROUND

Xeroderma pigmentosum (XP) is a rare autosomal-recessive genodermatosis resulting from a DNA-repair defect syndrome. The purpose was to evaluate the prevention on new malignant lesions in patients taking a supplement with Fernblock® (Polypodium leucotomos extract [PLE]) and secondarily correlation with the photoprotective behavior.

METHODS

A prospective, single-center and open cohort study was conducted over a 12-month period. The study was performed in Morocco. Optimal photoprotection behavior was recommended. Patients were instructed to take one capsule containing 480 mg of Fernblock® and 5 mcg vitamin D and to apply sunscreen with a SPF50+ and Fernblock® every 2 h during sun exposure. The demographic, clinical, and dermatoscopic patient data were collected at baseline (T0) and following visits at 3 months (T3), 6 months (T6), and 12 months (T12) when it was assessed: Investigator Global Assessment (IGA), Patient/Guardian Global Assessment (PGA), Patient/Guardian Satisfaction Questionnaire, and Photographic and Adverse Events Registration. Pertinent statistical study was performed.

RESULTS

Eighteen patients completed the study. Eleven patients (61%) finished the study without new lesions. Seven patients developed new lesions by the end of the study. Among them, only 30% showed an ideal photoprotective behavior. The lack of an optimal photoprotective behavior increased the probability of developing lesions by 2.5 times with 95% confidence interval.

CONCLUSIONS

In our study, more than 60% of patients taking a supplement with Fernblock® did not develop new lesions, and furthermore, we detected that patients following almost ideal photoprotection were 2.5 times less likely to develop NMSC lesions.

Clinical Applications of Polypodium leucotomos (Fernblock®): An Update

Exposure to sun radiation leads to higher risk of sunburn, pigmentation, immunosuppression, photoaging and skin cancer. In addition to ultraviolet radiation (UVR), recent research indicates that infrared radiation (IR) and visible light (VIS) can play an important role in the pathogenesis of some of these processes. Detrimental effects associated with sun exposure are well known, but new studies have shown that DNA damage continues to occur long after exposure to solar radiation has ended. Regarding photoprotection strategies, natural substances are emerging for topical and oral photoprotection. In this sense, Fernblock^®, a standardized aqueous extract of the fern Polypodium Leucotomos (PLE), has been widely administered both topically and orally with a strong safety profile. Thus, this extract has been used extensively in clinical practice, including as a complement to photodynamic therapy (PDT) for treating actinic keratoses (AKs) and field cancerization. It has also been used to treat skin diseases such as photodermatoses, photoaggravated inflammatory conditions and pigmentary disorders. This review examines the most recent developments in the clinical application of Fernblock^® and assesses how newly investigated action mechanisms may influence its clinical use.

Introduction to the Special Issue on "Keratinocyte Carcinomas: Biology and Evolving Non-Invasive Management Paradigms"

Keratinocyte carcinomas (KCs) are the most prevalent form of cancer worldwide, and their incidence is rising dramatically, with an increasing trend in recent years [...].

Protective Effect of the Hydrophilic Extract of Polypodium leucotomos, Fernblock®, against the Synergistic Action of UVA Radiation and Benzo[a]pyrene Pollutant

Oxidative stress is a harmful effect induced on the skin by polycyclic aromatic hydrocarbons (PAH), including benzo[a]pyrene (BaP) air pollutants. This effect is amplified by the additive damaging effect of the sun, especially through the UVA light component. Besides being one of the main compounds that make up air pollution, BaP can also be found in tar, tobacco smoke, and various foods. In addition to its direct carcinogenic potential, BaP can act as a photosensitizer absorbing sunlight in the UVA range and thus generating ROS and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Fernblock^® (FB) is an aqueous extract from the leaves of Polypodium leucotomos that has been proven to exert photoprotective and antioxidant effects on skin cells. In this study, we evaluate the potential of FB to prevent the damage induced by a combination of BaP and UVA light on human keratinocyte and mouse melanocyte cell lines (HaCaT and B16-F10, respectively). In particular, we have analyzed the capacity of FB to counteract the alterations caused on cellular morphology, viability, oxidative stress and melanogenic signaling pathway activation. Our data indicate that FB prevented cell damage and reduced oxidative stress and melanogenic signaling pathway activation caused by a combination of BaP and UVA light irradiation. Altogether, our findings support the fact that FB is able to prevent skin damage caused by the exposure to a combination of UVA and the air pollutant BaP.

Potent Virucidal Activity In Vitro of Photodynamic Therapy with Hypericum Extract as Photosensitizer and White Light against Human Coronavirus HCoV-229E

The emergent human coronavirus SARS-CoV-2 and its high infectivity rate has highlighted the strong need for new virucidal treatments. In this sense, the use of photodynamic therapy (PDT) with white light, to take advantage of the sunlight, is a potent strategy for decreasing the virulence and pathogenicity of the virus. Here, we report the virucidal effect of PDT based on Hypericum extract (HE) in combination with white light, which exhibits an inhibitory activity of the human coronavirus HCoV-229E on hepatocarcinoma Huh-7 cells. Moreover, despite continuous exposure to white light, HE has long durability, being able to maintain the prevention of viral infection. Given its potent in vitro virucidal capacity, we propose HE in combination with white light as a promising candidate to fight against SARS-CoV-2 as a virucidal compound.

Tumor microenvironment in non-melanoma skin cancer resistance to photodynamic therapy

Non-melanoma skin cancer has recently seen an increase in prevalence, and it is estimated that this grow will continue in the coming years. In this sense, the importance of therapy effectiveness has increased, especially photodynamic therapy. Photodynamic therapy has attracted much attention as a minimally invasive, selective and repeatable approach for skin cancer treatment and prevention. Although its high efficiency, this strategy has also faced problems related to tumor resistance, where the tumor microenvironment has gained a well-deserved role in recent years. Tumor microenvironment denotes a wide variety of elements, such as cancer-associated fibroblasts, immune cells, endothelial cells or the extracellular matrix, where their interaction and the secretion of a wide diversity of cytokines. Therefore, the need of designing new strategies targeting elements of the tumor microenvironment to overcome the observed resistance has become evident. To this end, in this review we focus on the role of cancer-associated fibroblasts and tumor-associated macrophages in the resistance to photodynamic therapy. We are also exploring new approaches consisting in the combination of new and old drugs targeting these cells with photodynamic therapy to enhance treatment outcomes of non-melanoma skin cancer.

In vitro 5-Fluorouracil resistance produces enhanced photodynamic therapy damage in SCC and tumor resistance in BCC

Non-melanoma skin cancer (NMSC) is the most common malignancy worldwide, with rising incidence in the recent years. It includes basal cell carcinoma (BCC), and squamous cell carcinoma (SCC). Several non-invasive therapies have been developed for its treatment such as topical 5-Fluorouracil (5FU) and photodynamic therapy (PDT), among others. Despite both are appropriated for NMSC treatment, recurrence cases have been reported. To prevent this, in this work we explore the potential of the combination of PDT and 5FU to treat SCC and BCC. First we evaluate the efficacy of PDT in cells resistant to 5FU. For this purpose, we use SCC-13 and CSZ-1 cells, obtained from a human SCC and a murine BCC, respectively. We first induced 5FU resistance in these cell lines by repeated treatments with the drug and then, the efficacy to PDT was evaluated. The results obtained indicated that SCC-5FU resistant cells were sensible to PDT administration, whereas BCC-5FU resistant cells were also resistant to PDT. The observed responses in both cell lines are in concordance to Protoporphyrin IX (PpIX) and reactive oxygen species (ROS) levels produced after the incubation with MAL and subsequent light exposure. The obtained data support the fact that PDT seems to be an appropriate therapeutic option to be administered after 5FU resistance in SCC. However, PDT would not be a choice therapy for resistant BCC cells to 5FU.

Home range of pampas deer in a human–dominated agro–ecosystem

The subspecies of pampas deer Ozotocerus bezoarticus uruguayensis is an endemic and endangered cervid from southeast Uruguay. However, knowledge regarding its home range requirements in agroecosystems is scarce. Our aim was to survey ten radio–collared pampas deer for two years to monitor their movements. The mean home–range size was 5.54 ± 3.18 km2. The core area size for all individuals monitored was 0.87 km2, which concurs with grazing crops for beef cattle. The population showed philopatric behavior and no significant differences were detected in the total area of occupation in respect to sex and season.

Food industrial biowaste-based magnetic activated carbons as sustainable adsorbents for anthropogenic mercury emissions

Bio-derived magnetic activated carbons from industrial chestnut shell waste have been obtained through a novel, optimized and sustainable methodology where impregnation, pyrolysis, acid washing or other intermediate steps commonly used in the activation process were eliminated saving time, energy and costs. The resulting materials (MACs) were obtained at 220-800 °C showed interesting properties: textural (SBET up to 568 m² g-1) and magnetic (different iron species developed), depending on the activation temperature employed. Data showed outstanding results when MACs were tested for Hg removal in pollution emissions at 150 °C in lab-scale device. In MACs obtained at 500-600 °C, where the highest concentration of magnetite was found, the best Hg adsorption capacity was achieved, while it decreased when metallic iron or iron carbides were present (MACs obtained at 800 °C). Moreover, the difference of Hg0 removal/adsorption in N2+O2 and Simulated Flue Gas atmosphere between MACs obtained at 500 and 600 °C pointed out the influence on Hg removal of additional parameters, as surface chemistry and the existence of sulfur or chloride. The determination of Hg species in post-retention solids confirmed the mercury oxidation by high-valence iron ions (Fe3+) and the involvement of physisorption and chemisorption processes for the gas-solid interaction mechanism.

POS0100 ACTIVATION OF THE CELLULAR INTEGRATED STRESS RESPONSE IN LABIAL SALIVARY GLANDS FROM SJÖGREN’S SYNDROME PATIENTS

Background

Sjögren’s syndrome (SS) is a chronic autoimmune disease characterized by inflammation of the exocrine glands and severe symptoms of eye and mouth dryness. Disorders in the saliva secretion process have been associated with oxidative and endoplasmic reticulum (ER) stress in combination with inflammatory responses. The integrated stress response (ISR) is a mechanism that allows cells to modify their gene expression program to restore homeostasis and promote their survival against various extrinsic and intrinsic stress signals, such as hypoxia, nutrient deprivation, viral infections, inflammatory factors (cytokines, chemokines, inflammasomes), and accumulation of unfolded proteins in the ER, among others (1). The ISR is regulated by four kinases: PERK, PKR, HRI and GCN2, that dimerize and autophosphorylate to become active and each one responds to different stress stimuli. The signaling pathways that are activated in response to stress factors stimulate the phosphorylation of eIF2α, which causes a transient inhibition of global protein synthesis and induction of synthesis of some specific genes like ATF4 and NRF2. ATF4 induces the transcription of genes involved in metabolism and nutrient uptake, redox status, and regulation of apoptosis. Dephosphorylation of eIF2α is the ISR termination signal to restore protein synthesis and is mediated by the PP1 complex, which recruits the catalytic subunit PP1c and one of its two regulatory subunits: GADD34 or CREP.

Objectives

To evaluate the presence and functional state (phosphorylation) of the ISR sensing kinases: PERK, PKR, HRI and GCN2; the levels of eIF2α /p-eIF2α and the key ISR transcription factors ATF4 and NRF2, as well as subunits of the complex involved in the ISR termination: PP1c, GADD34 and CREP in labial salivary glands (LSG) of SS-patients.

Methods

Biopsies of LSG from 12 SS-patients and 11 control subjects were studied. The levels of mRNA, protein and phospho (p)-protein of the ISR components were determined by RT-qPCR and Western blotting.

Results

Our results show increased levels of p-PERK/PERK ratio (11/11), PKR (7/11), p-PKR (7/11), p-PKR/PKR ratio (7/11), eIF2α (5/11), p-eIF2α (5/11) and ATF4 (11/11) in LSG from SS-patients compared to control subjects. No significant changes were found in mRNA levels of HRI, GCN2, and GADD34 between LSG from SS-patients and control subjects. Decreased protein levels of HRI (8/12), p-GCN2 (6/11), eIF2α (6/11), p-eIF2α (6/11), NRF2 (11/12), and p-NRF2 (12/12) were found in LSG showing scarce parenchyma and high fibrosis and fat infiltration. On the other hand, PP1c and CREP showed decreased mRNA and protein levels in all SS-patients LSG. Interestingly, Ro autoantibodies and focus score were negatively correlated with PP1c and NRF2 mRNA and protein levels whereas positively correlated with PKR mRNA levels.

Conclusion

The overexpression and activation of some ISR kinases together with the decrease in the PP1c/CREP phosphatase complex suggests a continuous activation of ISR, resulting in p-eIF2α to remain activated in LSG from SS-patients. This would explain the high protein levels of ATF4 and of target genes involved in the antioxidant response in LSG from SS patients suggesting that ISR activation plays a key role in pro-survival response to cellular stress.

References

[1]Pakos-Zebrucka K, Koryga I, Mnich K, Ljujic M, Samali A, Gorman AM. The integrated stress response. EMBO Rep. 2016;17(10):1374-95.

Acknowledgements

This work was supported by Fondecyt-Chile 1210055; Enlace-VID Universidad de Chile [ENL04/20 to MJG]; Fondecyt Iniciacion 11201058 and PhD fellowship Conicyt Chile.

Disclosure of Interests

None declared

POS0455 TOFACITINIB DECREASES INFLAMMATORY MARKERS AND MITOCHONDRIAL MORPHOLOGICAL DAMAGE IN SALIVARY GLANDS OF A MURINE MODEL OF SJÖGREN’S SYNDROME

Background

Altered homeostasis of salivary gland (SG) epithelial cells in Sjögren’s syndrome (SS) patients could be the initiating factor that leads to inflammation, as well as secretory dysfunction. Mitochondria are important organelles involved in cellular metabolism and their dysfunction can induce a loss of homeostasis and inflammation. Altered mitochondrion can release mitochondrial components that can act as damage-associated molecular patterns (DAMPs) and induce an inflammatory response via pattern recognition receptors (PRRs) such as the NLRP3 inflammasome, TLR9, cGAS/STING, and ZBP1 (1). Previously we determined that SG from SS patients showed and altered autophagy, which is associated to an increased pro-inflammatory cytokines expression. Interestingly, increased expression of pro-inflammatory markers such as IL-6, was reversed by JAK inhibitor tofacitinib in three-dimensional (3D)-acini deficient in autophagy (2). It is not clear whether the alterations in autophagy found in SG patients include alterations in mitochondrial clearance (mitophagy) that may lead to the accumulation of damaged mitochondria and enhanced inflammation. In this context, recent results of our laboratory showed, for the first time, severe ultrastructural alterations of mitochondria in SG cells from SS patients (1). However, it remains to be determined if these alterations are related to inflammation and if an anti-inflammatory agent could regulate these processes.

Objectives

To analyze the effect of tofacitinib on the mitochondrial ultrastructure in submandibular glands of a murine model of SS. In addition, to evaluate the effect of tofacitinib on the expression and activation of some PRRs involved in the recognition of mitochondrial DAMPs in the same murine model.

Methods

Six-month-old female NOD.B10Sn-H2b/J mice (Jackson Laboratories, USA) were used with 4-5 mice per group. Procedures were approved by the Universidad de Chile Animal Care and Use Committee. 30 mg/kg/day tofacitinib citrate was administered by oral gavage. After 28 days of tofacitinib or vehicle administration, their submandibular glands were obtained, which were processed to evaluate the mitochondrial ultrastructure by electron microscopy or lysed in RIPA buffer to obtain proteins. The protein levels of PRRs: NLRP3, TLR9, ZBP-1, and cGAs, as well as molecules activated downstream of cGAS and ZBP-1 such as TBK1, pTBK1, pSTING, and STING were determined by Western blotting.

Results

The results show that the mitochondria of the glandular epithelial cells of NOD.B10Sn-H2b/J mice treated with vehicle (control) present alterations such as swelling, disruption of membranes and crest disorganization that previously were reported in patients with SS (1). Interestingly, tofacitinib treatment improves the architecture of mitochondria. On the other hand, the protein levels of PRRs such as NLRP3 and cGAS decreased in mice treated with tofacitinib, as well as pTBK1.

Conclusion

The altered morphology of mitochondria together with the increased protein levels of PRRs and downstream markers of these PRRs suggests release of mitochondrial DAMPs in submandibular glands of NOD.B10Sn-H2b/J mice. The improvement in mitochondrial morphology as well as the decrease in PRRs activation under tofacitinib treatment suggest a potential use of this anti-inflammatory agent in mitochondrial alterations associated with inflammation. Many questions remain to be addressed, such as determining which mitochondrial DAMP might be being released and whether this is associated with impaired mitochondrial function in SS.

References

[1]Barrera, M. J., et al (2021). Dysfunctional mitochondria as critical players in the inflammation of autoimmune diseases: Potential role in Sjögren’s syndrome. Autoimmunity reviews, 20(8), 102867.

[2]Barrera, M. J., et al (2021). Tofacitinib counteracts IL-6 overexpression induced by deficient autophagy: implications in Sjögren’s syndrome. Rheumatology (Oxford, England), 60(4), 1951–1962.

Acknowledgements

This work was supported by Fondecyt Iniciación 11201058 and Fondecyt-Chile 1210055.

Disclosure of Interests

None declared.

Extracellular miR-6723-5p could serve as a biomarker of limbal epithelial stem/progenitor cell population

BACKGROUND

Dysfunction or loss of limbal stem cells can result in limbal stem cell deficiency (LSCD), a disease that cause corneal opacity, pain, and loss of vision. Cultivated limbal epithelial transplantation (CLET) can be used to restore stem cell niche homeostasis and replenish the progenitor pool. Transplantation has been reported with high success rate, but there is an unmet need of prognostic markers that correlate with clinical outcomes. To date, the progenitor content in the graft is the only parameter that has been retrospectively linked to success.

METHODS

In this study, we investigate extracellular micro RNAs (miRNAs) associated with stem/progenitor cells in cultivated limbal epithelial cells (cLECs). Using micro RNA sequencing and linear regression modelling, we identify a miRNA signature in cultures containing high proportion of stem/progenitor cells. We then develop a robust RNA extraction workflow from culture media to confirm a positive miRNA correlation with stem/progenitor cell proportion.

RESULTS

miR-6723-5p is associated with cultures containing high proportion of stem/progenitor cells, and is detected in the basal layer of corneal epithelium.

CONCLUSIONS

These results indicate that miR-6723-5p could potentially serve as a stem/progenitor cell marker in cLECs.

Clinical guide to perioperative management for videothoracoscopy lung resection (Section of Cardiac, Vascular and Thoracic Anesthesia, SEDAR; Spanish Society of Thoracic Surgery, SECT; Spanish Society of Physiotherapy)

The introduction of video-assisted thoracoscopic (VATS) techniques has led to a new approach in thoracic surgery. VATS is performed by inserting a thoracoscope through a small incisions in the chest wall, thus maximizing the preservation of muscle and tissue. Because of its low rate of morbidity and mortality, VATS is currently the technique of choice in most thoracic procedures. Lung resection by VATS reduces prolonged air leaks, arrhythmia, pneumonia, postoperative pain and inflammatory markers. This reduction in postoperative complications shortens hospital length of stay, and is particularly beneficial in high-risk patients with low tolerance to thoracotomy. Compared with conventional thoracotomy, the oncological results of VATS surgery are similar or even superior to those of open surgery. This aim of this multidisciplinary position statement produced by the thoracic surgery working group of the Spanish Society of Anesthesiology and Reanimation (SEDAR), the Spanish Society of Thoracic Surgery (SECT), and the Spanish Association of Physiotherapy (AEF) is to standardize and disseminate a series of perioperative anaesthesia management guidelines for patients undergoing VATS lung resection surgery. Each recommendation is based on an in-depth review of the available literature by the authors. In this document, the care of patients undergoing VATS surgery is organized in sections, starting with the surgical approach, and followed by the three pillars of anaesthesia management: preoperative, intraoperative, and postoperative anaesthesia.

Metformin overcomes metabolic reprogramming-induced resistance of skin squamous cell carcinoma to photodynamic therapy

Objective

Cancer metabolic reprogramming promotes resistance to therapies. In this study, we addressed the role of the Warburg effect in the resistance to photodynamic therapy (PDT) in skin squamous cell carcinoma (sSCC). Furthermore, we assessed the effect of metformin treatment, an antidiabetic type II drug that modulates metabolism, as adjuvant to PDT.

Methods

For that, we have used two human SCC cell lines: SCC13 and A431, called parental (P) and from these cell lines we have generated the corresponding PDT resistant cells (10GT).

Results

Here, we show that 10GT cells induced metabolic reprogramming to an enhanced aerobic glycolysis and reduced activity of oxidative phosphorylation, which could influence the response to PDT. This result was also confirmed in P and 10GT SCC13 tumors developed in mice. The treatment with metformin caused a reduction in aerobic glycolysis and an increase in oxidative phosphorylation in 10GT sSCC cells. Finally, the combination of metformin with PDT improved the cytotoxic effects on P and 10GT cells. The combined treatment induced an increase in the protoporphyrin IX production, in the reactive oxygen species generation and in the AMPK expression and produced the inhibition of AKT/mTOR pathway. The greater efficacy of combined treatments was also seen in vivo, in xenografts of P and 10GT SCC13 cells.

Conclusions

Altogether, our results reveal that PDT resistance implies, at least partially, a metabolic reprogramming towards aerobic glycolysis that is prevented by metformin treatment. Therefore, metformin may constitute an excellent adjuvant for PDT in sSCC.

•

Cell resistant to Photodynamic therapy (PDT) is due to the metabolic reprogramming.

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Metformin modulates energetic metabolism in PDT-resistant cells, sensitizing to PDT.

•

Metformin increases protoporphyrin IX and reactive oxygen species generation.

•

Metformin+PDT is proposed as potential therapy against skin squamous cell carcinoma.

Expert Recommendations on the Evaluation of Sunscreen Efficacy and the Beneficial Role of Non-filtering Ingredients

A variety of non-filtering agents have been introduced to enhance sunscreen photoprotection. Most of those agents have only weak erythema protective properties but may be valuable and beneficial in supporting protection against other effects of UV radiation, such as photoimmunosuppression, skin aging, and carcinogenesis, as well as photodermatoses. The question arises how to measure and evaluate this efficacy since standard SPF testing is not appropriate. In this perspective, we aim to provide a position statement regarding the actual value of SPF and UVA-PF to measure photoprotection. We argue whether new or additional parameters and scales can be used to better indicate the protection conferred by these products against the detrimental effects of natural/artificial, UV/visible light beyond sunburn, including DNA damage, photoimmunosuppression and pigmentation, and the potential benefits of the addition of other ingredients beyond traditional inorganic and organic filters to existing sunscreens. Also, we debate the overall usefulness of adding novel parameters that measure photoprotection to reach two tiers of users, that is, the general public and the medical community; and how this can be communicated to convey the presence of additional beneficial effects deriving from non-filtering agents, e.g., biological extracts. Finally, we provide a perspective on new challenges stemming from environmental factors, focusing on the role of the skin microbiome and the role of air pollutants and resulting needs for photoprotection.

Formation of Cyclobutane Pyrimidine Dimers after UVA Exposure (Dark-CPDs) Is Inhibited by an Hydrophilic Extract of Polypodium leucotomos

Exposure to sun and especially to ultraviolet radiation (UVR) exerts well known detrimental effects on skin which are implicated in malignancy. UVR induces production of cyclobutane pyrimidine dimers (CPDs), immediately during exposure and even hours after the exposure, these latter being called dark-CPDs, as consequence of the effects of different reactive species that are formed. Fernblock^® (FB), an aqueous extract of Polypodium leucotomos, has proven to have photoprotective and antioxidant effects on skin. The aim of our work was to investigate the potential photoprotective effect of FB against dark-CPD formation. Murine melanocytes (B16-F10) were exposed to UVA radiation and the production of dark-CPDs and different reactive oxygen and nitrogen species (ROS and RNS) was measured. Significant dark-CPD formation could be seen at 3 h after UVA irradiation, which was inhibited by the pre-treatment of cells with FB. Formation of nitric oxide, superoxide and peroxynitrite was increased after irradiation, consistent with the increased CPD formation. FB successfully reduced the production of these reactive species. Hence, these results show how dark-CPDs are formed in UVA irradiated melanocytes, and that FB acts as a potential antioxidant and ROS scavenger, preventing the DNA damage induced by sun exposure.