Irreversible Cell Injury Research Articles

Development of A 3D Lung Tumor Model For Cell Death Assessment in Microwave Ablation

AbstractPrimary lung cancer is the leading cause of cancer‐related death worldwide. Recent statistics estimate 1.8 million new cases and 1.6 million deaths per year. Despite significant advances in surgery, chemotherapy, and radiotherapy, the 5‐year survival rate remains at just 18%. Thermal ablation is an established treatment that is safe and effective. It refers to the local application of controlled heat to induce irreversible cell injury and ultimately tumor apoptosis and necrosis. This approach is particularly suitable for the treatment of small tumors in patients who are not suitable for surgery. However, the lack of suitable benchtop models to assess ablation devices complicates prognostic prediction and the development of effective treatment strategies. In this context, the development of a 3D lung tumor model is presented using a cancer cell‐laden hydrogel composed of 2% hyaluronic acid–tyramine (HA‐TA) and 0.5% agarose, resulting in a tumor mimetic of clinically relevant size. This innovative model provides a valuable platform for testing ablation devices and provides insights that can significantly improve prognostic ability and refine treatment approaches for lung cancer patients.

Study on influencing factors of anthracycline-induced subclinical cardiotoxicity in DLBCL patients administered (R)-CHOP

BackgroundAnthracycline-induced cardiotoxicity is an irreversible cardiac cell injury. Therefore, it’s very important to identify influencing factors of anthracycline-induced subclinical cardiotoxicity (AISC). This study was designed to analyze the influencing factors of AISC in patients with diffuse large B-cell lymphoma (DLBCL) treated with the (R)-CHOP chemotherapy regimen.MethodsThis is an ongoing observational prospective clinical trial. All patients underwent conventional echocardiography and speckle tracking echocardiography at the time of enrollment and during treatment. Changes of global longitudinal peak systolic strain were assessed after 3 cycles of (R)-CHOP chemotherapy, and patients were divided into the AISC and No-AISC groups. Demographic data, clinical variables, and biochemical variables were measured. Regression models, receiver operating characteristic curve analysis, and difference values were used to explore the relationships between variables and AISC.ResultsAmong 70 patients who completed 3 cycles of (R)-CHOP chemotherapy, 26 developed AISC. In multiple logistic regression, HDL-C (P = 0.047), ApoA1 (P = 0.022), TG (P = 0.029) and e’ (P = 0.008) were associated with AISC. The combination of HDL-C and NT-proBNP had the highest area under curves (AUC) for the diagnosis of AISC than HDL-C and NT-proBNP alone (AUC = 0.752, 95%CI: 0.63–0.87, P = 0.001). Between the No-AISC and AISC groups, there was no significant difference in HDL-C, ApoA1, and e’ at baseline and after 3 cycles of chemotherapy, respectively. The dynamic changes of HDL-C, ApoA1, and e’ from baseline to the end of the 3rd cycle of chemotherapy showed statistically significant differences.ConclusionsHDL-C, ApoA1, TG, and e’ are independent predictive factors in DLBCL cases treated with the (R)-CHOP chemotherapy regimen. The combination of HDL-C and NT-proBNP may improve the predictive ability for AISC in patients with DLBCL administered 3 cycles of (R)-CHOP chemotherapy. Dynamic changes of HDL-C, ApoA1, and e’ may be meaningful for predicting AISC.Trial registrationOur study was registered in the Chinese Clinical Trial Registry (Approval ID. ChiCTR2100054721 http://www.chictr.org.cn/showproj.aspx?proj=145082).

Cichoric Acid May Play a Role in Protecting Hair Cells from Ototoxic Drugs.

Ototoxic hearing loss due to antibiotic medication including aminoglycosides and excess free radical production causes irreversible hair cell injury. Cichoric acid, a naturally occurring phenolic acid, has recently been found to exert anti-oxidative and anti-inflammatory properties through its free radical scavenging capacity. The present study aimed to investigate the protective effects of cichoric acid against neomycin-induced ototoxicity using transgenic zebrafish (pvalb3b: TagGFP). Our results indicated that cichoric acid in concentrations up to 5 μM did not affect zebrafish viability during the 2 h treatment period. Therefore, the otoprotective concentration of cichoric acid was identified as 5 μM under 2 h treatment by counting viable hair cells within the neuromasts of the anterior- and posterior-lateral lines in the study. Pretreatment of transgenic zebrafish with 5 μM of cichoric acid for 2 h significantly protected against neomycin-induced hair cell death. Protection mediated by cichoric acid was, however, lost over time. A terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and FM4-64 staining, respectively, provided in situ evidence that cichoric acid ameliorated apoptotic signals and mechanotransduction machinery impairment caused by neomycin. A fish locomotor test (distance move, velocity, and rotation frequency) assessing behavioral alteration after ototoxic damage revealed rescue due to cichoric acid pretreatment before neomycin exposure. These findings suggest that cichoric acid in 5 μM under 2 h treatment has antioxidant effects and can attenuate neomycin-induced hair cell death in neuromasts. Although cichoric acid offered otoprotection, there is only a small difference between pharmacological and toxic concentrations, and hence cichoric acid can be considered a rather prototypical compound for the development of safer otoprotective compounds.

Ibuprofen and diclofenac differentially affect cell viability, apoptosis and morphology changes of human cholangiocarcinoma cell lines

ObjectivesCholangiocarcinoma is a malignant biliary epithelial duct neoplasm caused by chronic inflammation after liver fluke infection. It is a major public health concern in the Greater Mekong sub-region in northeast Thailand. Herein, the effects of the non-steroidal anti-inflammatory drugs (NSAIDs) ibuprofen and diclofenac on the cell proliferation activity of the human cholangiocarcinoma cell lines KKU-M139 and KKU-213B were studied. MethodsCell viability was assessed with MTT assays. Inverted phase-contrast light microscopy, scanning electron microscopy and transmission electron microscopy were used to investigate the cells’ morphological alterations. Caspase 3/7 and Annexin V/PI were detected with a multimode microplate reader. ResultsIbuprofen and diclofenac decreased viability in both cell lines, and ibuprofen-treated cells exhibited reversible cell injury. In both KKU-M139 and KKU-213B cell lines, the diclofenac-treated cells had the greatest injury. The cells exhibited features of irreversible cell injury. In addition, caspase 3/7 and Annexin V/PI detection revealed early cell apoptotic characteristics. ConclusionThese findings suggest that NSAIDs may potentially suppress cell viability. Ibuprofen and diclofenac both induced morphological changes and apoptosis.

Peripheral shift in the viable chondrocyte population of the medial femoral condyle after anterior cruciate ligament injury in the porcine knee.

Anterior cruciate ligament injuries result in posttraumatic osteoarthritis in the medial compartment of the knee, even after surgical treatment. How the chondrocyte distribution within the articular cartilage changes early in this process is currently unknown. The study objective was to investigate the chondrocyte distribution within the medial femoral condyle after an anterior cruciate ligament transection in a preclinical model. Forty-two adolescent Yucatan minipigs were allocated to receive unilateral anterior cruciate ligament surgery (n = 36) or no surgery (n = 6). Central coronal sections of the medial femoral condyle were obtained at 1- and 4 weeks after surgery, and the chondrocyte distribution was measured via whole slide imaging and a cell counting batch processing tool utilized in ImageJ. Ki-67 immunohistochemistry was performed to identify proliferating cells. Empty lacunae, karyolysis, karyorrhexis, and pyknosis were used to identify areas of irreversible cell injury. The mean area of irreversible cell injury was 0% in the intact controls, 13.4% (95% confidence interval: 6.4, 20.3) at 1-week post-injury and 19.3% (9.7, 28.9) at 4 weeks post-injury (p < .015). These areas occurred closest to the femoral intra-articular notch. The remaining areas containing viable chondrocytes had Ki-67-positive cells (p < .02) and increased cell density in the middle (p < .03) and deep zones (p = .001). For the entire section, the total chondrocyte number did not change significantly post-operatively; however, the density of cells in the peripheral regions of the medial femoral condyle increased significantly at 1- and 4 weeks post-injury relative to the intact control groups (p = .032 and .004, respectively). These data demonstrate a peripheral shift in the viable chondrocyte population of the medial femoral condyle after anterior cruciate ligament injury and further suggest that chondrocytes with the capacity to proliferate are not confined to one particular cartilage layer.

TO STUDY THE EFFICACY OF POLY HERBO-MINERAL COMPOUND IN THE MANAGEMENT OF GRADE I &amp; GRADE II FATTY LIVER (HEPATIC STEATOSIS)

Hepatic Steatosis is a common predicament in society due to changes in lifestyle and food practices. Depending upon the cause and amount of accumulation, fatty change may be mild and reversible, or severe producing irreversible cell injury and cell death. Disturbances of lipid metabolism in the liver due to various etiological factors lead to Fatty Liver. Ayurveda has immense potential in the management of Non-Communicable Diseases, and Fatty liver is one among them. In Ayurveda, a direct correlation of Fatty liver is not found but it can be considered under Yakrit roga and Medo roga, as a Santarpanjanya Vyadhi. Hepatic steatosis patients are treated with Triphaladi yoga and Yashtimadhu churna for 3 months, in the Department of Kayachikitsa, Govt. Ayurvedic College and Hospital, Guwahati. This trial aims to formulate a practical Ayurvedic protocol for the management of Grade I and Grade II Fatty liver. However, further research studies are needed to fulfil the aims and objectives. Keywords: Yakrit Roga, Hepatic steatosis, Santarpanjanya Vyadhi, poly-herbo mineral compound, clinical trial.

TO STUDY THE EFFICACY OF POLY HERBO-MINERAL COMPOUND IN THE MANAGEMENT OF GRADE I &amp; GRADE II FATTY LIVER (HEPATIC STEATOSIS)

Hepatic Steatosis is a common predicament in society due to changes in lifestyle and food practices. Depending upon the cause and amount of accumulation, fatty change may be mild and reversible, or severe producing irreversible cell injury and cell death. Disturbances of lipid metabolism in the liver due to various etiological factors lead to Fatty Liver. Ayurveda has immense potential in the management of Non-Communicable Diseases, and Fatty liver is one among them. In Ayurveda, a direct correlation of Fatty liver is not found but it can be considered under Yakrit roga and Medo roga, as a Santarpanjanya Vyadhi. Hepatic steatosis patients are treated with Triphaladi yoga and Yashtimadhu churna for 3 months, in the Department of Kayachikitsa, Govt. Ayurvedic College and Hospital, Guwahati. This trial aims to formulate a practical Ayurvedic protocol for the management of Grade I and Grade II Fatty liver. However, further research studies are needed to fulfil the aims and objectives. Keywords: Yakrit roga, Hepatic steatosis, Santarpanjanya Vyadhi, poly-herbo mineral compound, clinical trial.

Clinical Study Demonstrates that Electromagnetic Muscle Stimulation Does Not Cause Injury to Fat Cells

Background and ObjectivesA previous pre‐clinical study on electromagnetic muscle stimulation (EMMS) suggested that fat cell apoptosis occurs following treatment in a porcine model. While EMMS can induce changes in muscle, the effect on fat tissue is not established. This clinical study sought to assess adipose tissue response to EMMS in comparison to cryolipolysis treatment.Study Design/Materials and MethodsStudy subjects were recruited prior to abdominoplasty to receive body contouring treatments and subsequently to obtain tissue for histological analysis. Non‐invasive abdominal treatments were delivered using a commercially available (n = 6) or prototype (n = 3) EMMS system or a cryolipolysis system (n = 2). Subjects received a single EMMS treatment (100% intensity for 30 minutes) or a single cryolipolysis treatment (−11°C for 35 minutes) to the abdomen. Superficial and deep (i.e., adjacent to muscle layer) subcutaneous adipose tissue was harvested at set timepoints post‐treatment. The presence or absence of an inflammatory response was evaluated using standard hematoxylin and eosin (H&E) staining. As adipocytes that are destined to become apoptotic cannot be distinguished by traditional H&E staining during the early phases of injury, irreversible fat cell injury was assessed using perilipin immunofluorescence.ResultsFollowing H&E histological analysis at 3, 10, 11, and 17 days post‐treatment, no EMMS‐treated samples showed an inflammatory response in either the superficial or deep subcutaneous adipose tissue. For the cryolipolysis‐treated adipose tissue, however, the H&E staining revealed a marked inflammatory response with an influx of neutrophils, lymphocytes, and macrophages at timepoints consistent with previous histological studies. Further, loss of perilipin staining provided clear visual evidence of irreversible fat cell injury in the cryolipolysis‐treated adipose tissue. In contrast, the electromagnetic muscle stimulation‐treated samples showed persistence of perilipin staining of adipose tissue indicating that all fat cells were viable.ConclusionThis study failed to demonstrate either fat cell injury or inflammatory response following EMMS treatment. While electromagnetic muscle stimulation may non‐invasively induce muscle changes, this clinical study found no evidence of an impact injurious or otherwise on subcutaneous fat. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC

A new experimental model of intrinsic denervation in ileum from wistar rats through intramural microinjections of benzalkonium chloride

ABSTRACT: Extensive literature is available about the intrinsic denervation of segments of the digestive tube through the application of CB in the serosa of the viscera. However, this technique has some disadvantages like causing peritonitis, flanges and high mortality, limiting its use in humans. The aim of the present study was to evaluate the feasibility of benzalkonium chloride (CB) to induce intrinsic chemical denervation, through applications of CB in the intramural ileum of wistar rats, as well as deepen the knowledge about the evolution of neuronal injury caused in the process. We used 40 rats, divided into two groups (control-GC and benzalkonium-GB) of 20 animals each, divided into four sub-groups according to the time of postoperative assessment of 24, 48 hours, 30 and 90 days. The animals were submitted to intramural microinjections of sterile saline solution 0.9% (GC) or benzalkonium chloride (GB) in ileal portion, and subsequent histopathological analysis and immunohistochemistry for evaluation of neuronal injury. A significant decrease (p&lt;0.05) was found of the neuronal myenteric count over time in groups, GB3, GB4 and GB2. The specific positive immunolabeling for H2AX and Caspase-3 confirmed the results obtained in the histopathological evaluation, denoting the ignition of irreversible cell injury in 24 hours, evolving into neuronal apoptosis in 48 hours after application of the CB 0.3%. Under the conditions in which this work was conducted, it can be concluded that the application of CB 0.3% by means of microinjections intramural in the ileal wall is able to induce intrinsic chemical denervation of the diverticulum of wistar rats and that the main mechanism of neuronal death is induction of apoptosis.

Multiscale x-ray phase-contrast tomography in a mouse model of transient focal cerebral ischemia

Cerebral ischemia is associated with a lack of oxygen and high-energy phosphates within the brain tissue, leading to irreversible cell injury. Visualizing these cellular injuries has long been a focus of experimental stroke research with application of immunohistochemistry as one of the standard approaches. It is, however, a destructive imaging technique with non-isotropic resolution, as only the two-dimensional tissue structure of a thin brain section is visualized using optical microscopy and specific stainings. Herein, we extend the structural analysis of mouse brain tissue after cerebral ischemia to the third dimension via microfocus computed tomography (µ-CT). Contrast of the weakly absorbing unstained brain tissue is enhanced by phase contrast. We show that recordings at two different magnifications and fields of view can be combined as a single approach for visualization of the associated structural alterations at isotropic resolution, from the level of the whole organ down to single cells.

Cyclosporine-insensitive mode of cell death after prolonged myocardial ischemia: Evidence for sarcolemmal permeabilization as the pivotal step.

A prominent theory of cell death in myocardial ischemia/reperfusion (I/R) posits that the primary and pivotal step of irreversible cell injury is the opening of the mitochondrial permeability transition (MPT) pore. However, the predominantly positive evidence of protection against infarct afforded by the MPT inhibitor, Cyclosporine A (CsA), in experimental studies is in stark contrast with the overall lack of benefit found in clinical trials of CsA. One reason for the discrepancy might be the fact that relatively short experimental ischemic episodes (<1 hour) do not represent clinically-realistic durations, usually exceeding one hour. Here we tested the hypothesis that MPT is not the primary event of cell death after prolonged (60–80 min) episodes of global ischemia. We used confocal microcopy in Langendorff-perfused rabbit hearts treated with the electromechanical uncoupler, 2,3-Butanedione monoxime (BDM, 20 mM) to allow tracking of MPT and sarcolemmal permeabilization (SP) in individual ventricular myocytes. The time of the steepest drop in fluorescence of mitochondrial membrane potential (ΔΨm)-sensitive dye, TMRM, was used as the time of MPT (TMPT). The time of 20% uptake of the normally cell-impermeable dye, YO-PRO1, was used as the time of SP (TSP). We found that during reperfusion MPT and SP were tightly coupled, with MPT trending slightly ahead of SP (TSP-TMPT = 0.76±1.31 min; p = 0.07). These coupled MPT/SP events occurred in discrete myocytes without crossing cell boundaries. CsA (0.2 μM) did not reduce the infarct size, but separated SP and MPT events, such that detectable SP was significantly ahead of MPT (TSP -TMPT = -1.75±1.28 min, p = 0.006). Mild permeabilization of cells with digitonin (2.5–20 μM) caused coupled MPT/SP events which occurred in discrete myocytes similar to those observed in Control and CsA groups. In contrast, deliberate induction of MPT by titration with H2O2 (200–800 μM), caused propagating waves of MPT which crossed cell boundaries and were uncoupled from SP. Taken together, these findings suggest that after prolonged episodes of ischemia, SP is the primary step in myocyte death, of which MPT is an immediate and unavoidable consequence.

The Neuro-Immune-Regulators (NIREGs) Promote Tissue Resilience; a Vital Component of the Host's Defense Strategy against Neuroinflammation.

An effective protective inflammatory response in the brain is crucial for the clearance of pathogens (e.g. microbes, amyloid fibrils, prionSC) and should be closely regulated. However, the CNS seems to have limited tissue resilience to withstand the detrimental effects of uncontrolled inflammation compromising functional recovery and tissue repair. Newly described neuro-immune-regulators (NIREGs) are functionally related proteins regulating the severity and duration of the host inflammatory response. NIREGs such as CD200, CD47 and CX3CL1 are vital for increasing tissue resilience and are constitutively expressed by neurons. The interaction with co-receptors (CD200R, CD172a, CX3CR1) will maintain microglia in the resting phenotype, directing aggressive microglia phenotype and limiting bystander injuries. Neurons can also express many of the complement NIREGs (CD55, CD46, CD59 and factor H). Neurons and glia also express suppressor of cytokine signaling proteins (SOCS) down regulating janus kinase-signal transducer and activator of transcription (JAK/STAT) pathway and to lead to the polarization of microglia towards anti-inflammatory phenotype. Other NIREGs such as serine protease inhibitors (serpins) and thrombomodulin (CD141) inhibit neurotoxic systemic coagulation proteins such as thrombin. The unfolded protein response (UPR) detects misfolded proteins and other stressors to prevent irreversible cell injury. Microglial pattern recognition receptors (PRR) (TREM-2, CR3, FcγR) are important to clear apoptotic cells and cellular debris but in non-phlogystic manner through inhibitory signaling pathways. The TYRO3, Axl, Mer (TAM) tyrosine receptor kinases activated by Gas 6 and PROS1 regulate inflammation by inhibiting Toll like receptors (TLR) /JAK-STAT activation and contribute to NIREG's functions.

Antineoplastic Drug-Induced Cardiotoxicity: A Redox Perspective.

Antineoplastic drugs can be associated with several side effects, including cardiovascular toxicity (CTX). Biochemical studies have identified multiple mechanisms of CTX. Chemoterapeutic agents can alter redox homeostasis by increasing the production of reactive oxygen species (ROS) and reactive nitrogen species RNS. Cellular sources of ROS/RNS are cardiomyocytes, endothelial cells, stromal and inflammatory cells in the heart. Mitochondria, peroxisomes and other subcellular components are central hubs that control redox homeostasis. Mitochondria are central targets for antineoplastic drug-induced CTX. Understanding the mechanisms of CTX is fundamental for effective cardioprotection, without compromising the efficacy of anticancer treatments. Type 1 CTX is associated with irreversible cardiac cell injury and is typically caused by anthracyclines and conventional chemotherapeutic agents. Type 2 CTX, associated with reversible myocardial dysfunction, is generally caused by biologicals and targeted drugs. Although oxidative/nitrosative reactions play a central role in CTX caused by different antineoplastic drugs, additional mechanisms involving directly and indirectly cardiomyocytes and inflammatory cells play a role in cardiovascular toxicities. Identification of cardiologic risk factors and an integrated approach using molecular, imaging, and clinical data may allow the selection of patients at risk of developing chemotherapy-related CTX. Although the last decade has witnessed intense research related to the molecular and biochemical mechanisms of CTX of antineoplastic drugs, experimental and clinical studies are urgently needed to balance safety and efficacy of novel cancer therapies.

The effect of ellagic acid on photodynamic therapy in leukemia cells.

Ellagic acid (EA) is a naturally phenolic acid presented in different foods. It has a variety of biological activities including antioxidant, anti-inflammatory, anti-microbiological and anti-cancer properties. On account of its antioxidant activity, EA might protect cancer cells from free radical damage in photodynamic therapy (PDT) during which reactive oxygen species (ROS) production was stimulated leading to irreversible tumor cell injury. In this study, the influence of EA on K562 cells in 5-aminolevulinic acid (ALA)-based PDT is demonstrated. Cell apoptosis was assayed by flow cytometry. Oxidative damage induced by PDT was investigated by measurement of malondialdehyde (MDA). Comet assay was used to evaluate the potential genotoxic effect induced by PDT on the cells. The results showed that EA supplementation alone did not affect the lipid peroxidation, DNA damage and apoptosis in K562 cells. It increases the lipid peroxidation, DNA damage, apoptosis and decreases the survival rate in K562 cells induced by ALA-PDT. The singlet oxygen quencher sodium azide suppresses apoptosis, lipid peroxidation and DNA damage induced by EA in PDT. In conclusion, EA consumption during PDT did not decrease the effectiveness of cancer therapy on malignant cells. The effect of antioxidants on PDT maybe was determined by its sensitization ability to singlet oxygen.

From Molecular Mechanisms to Clinical Management of Antineoplastic Drug-Induced Cardiovascular Toxicity: A Translational Overview.

Significance: Antineoplastic therapies have significantly improved the prognosis of oncology patients. However, these treatments can bring to a higher incidence of side-effects, including the worrying cardiovascular toxicity (CTX). Recent Advances: Substantial evidence indicates multiple mechanisms of CTX, with redox mechanisms playing a key role. Recent data singled out mitochondria as key targets for antineoplastic drug-induced CTX; understanding the underlying mechanisms is, therefore, crucial for effective cardioprotection, without compromising the efficacy of anti-cancer treatments. Critical Issues: CTX can occur within a few days or many years after treatment. Type I CTX is associated with irreversible cardiac cell injury, and it is typically caused by anthracyclines and traditional chemotherapeutics. Type II CTX is generally caused by novel biologics and more targeted drugs, and it is associated with reversible myocardial dysfunction. Therefore, patients undergoing anti-cancer treatments should be closely monitored, and patients at risk of CTX should be identified before beginning treatment to reduce CTX-related morbidity. Future Directions: Genetic profiling of clinical risk factors and an integrated approach using molecular, imaging, and clinical data may allow the recognition of patients who are at a high risk of developing chemotherapy-related CTX, and it may suggest methodologies to limit damage in a wider range of patients. The involvement of redox mechanisms in cancer biology and anticancer treatments is a very active field of research. Further investigations will be necessary to uncover the hallmarks of cancer from a redox perspective and to develop more efficacious antineoplastic therapies that also spare the cardiovascular system.

Perillyl alcohol, a pleiotropic natural compound suitable for brain tumor therapy, targets free radicals.

Monoterpenes such as limonene and perillyl alcohol (POH) are promising natural compounds with pro-oxidant properties partly due to endoplasmic reticulum (ER) stress-induced cytotoxicity, and antioxidant activity owing to their activity as free radical scavengers, inhibition of coenzyme Q synthesis, activation of antioxidant-responsive elements (inducing detoxification enzymes) and induction of apoptosis. Activation of ER-stress responses generates reactive oxygen species (ROS), which are highly reactive free radicals mainly produced during mitochondrial electron transfer for adenosine triphosphate (ATP) synthesis. When cells are subjected to oxidative stress conditions, there is an accumulation of ROS that can lead to irreversible cell injury caused primarily by lipid peroxidation, protein aggregation and/or DNA damage. Malignant tumors, such as glioblastoma multiforme, display elevated rates of oxygen consumption, necrosis and abnormal structural microvasculature. Alterations in the tumor microenvironment are tightly linked to tumor progression and occur as a result of activation of complex signaling networks involving inter-clonal cooperation, cell-matrix interactions and an ongoing inflammatory response leading to genetic and epigenetic alterations. This review will focus on the pro- and anti-oxidant activities of POH, which are greatly dependent on the respective ROS levels within the tumor microenvironment and involve the ER stress response system. As well, some critical aspects of tumor-associated metabolic changes and the consequences of endogenous ROS production for tumor progression will be discussed.

Research on the effect of formononetin on photodynamic therapy in K562 cells.

At the present time, many cancer patients combine some forms of complementary and alternative medicine therapies with their conventional therapies. The most common choice of these therapies is the use of antioxidants. Formononetin is presented in different foods. It has a variety of biological activities including antioxidant and anti-cancer properties. On account of its antioxidant activity, formononetin might protect cancer cells from free radical damage in photodynamic therapy (PDT) during which reactive oxygen species (ROS) production was stimulated leading to irreversible tumor cell injury. In this study, the influence of formononetin on K562 cells in PDT was demonstrated. The results showed that formononetin supplementation alone did not affect the lipid peroxidation, DNA damage and apoptosis in K562 cells. It increases the lipid peroxidation, DNA damage and apoptosis in K562 cells induced by PDT. The singlet oxygen quencher sodium azide suppresses the apoptosis induced by PDT with formononetin. In conclusion, formononetin consumption during PDT increases the effectiveness of cancer therapy on malignant cells. The effect of antioxidants on PDT maybe was determined by its sensitization ability to singlet oxygen.

The anthraquinones rubiadin and its 1-methyl ether isolated from Heterophyllaea pustulata reduces Candida tropicalis biofilms formation

BackgroundCandida tropicalis is increasingly becoming among the most commonly isolated pathogens causing fungal infections with an important biofilm-forming capacity. PurposeThis study addresses the antifungal effect of rubiadin (AQ1) and rubiadin 1-methyl ether (AQ2), two photosensitizing anthraquinones (AQs) isolated from Heterophyllaea pustulata, against C. tropicalis biofilms, by studying the cellular stress and antioxidant response in two experimental conditions: darkness and irradiation. The combination with Amphotericin B (AmB) was assayed to evaluate the synergic effect. Study design/MethodsBiofilms of clinical isolates and reference strain of Candida tropicalis were treated with AQs (AQ1 or AQ2) and/or AmB, and the biofilms depletion was studied by crystal violet and confocal scanning laser microscopy (CSLM). The oxidant metabolites production and the response of antioxidant defense system were also evaluated under dark and irradiation conditions, being the light a trigger for photo-activation of the AQs. The Reactive Oxygen Species (ROS) were detected by the reduction of Nitro Blue Tetrazolium test, and Reactive Nitrogen Intermediates (RNI) by the Griess assay. ROS accumulation was also detected inside biofilms by using 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) probe, which was visualized by CSLM. Superoxide dismutase (SOD) activity and the total antioxidant capacity of biofilms were measured by spectrophotometric methods.The minimun inhibitory concentration for sessile cells (SMIC) was determined for each AQs and AmB. The fractional inhibitory concentration index (FICI) was calculated for the combinations of each AQ with AmB by the checkerboard microdilution method. ResultsBiofilm reduction of both strains was more effective with AQ1 than with AQ2. The antifungal effect was mediated by an oxidative and nitrosative stress under irradiation, with a significant accumulation of endogenous ROS detected by CSLM and an increase in the SOD activity. Thus, the prooxidant-antioxidant balance was altered especially by AQ1. The best synergic combination with AmB was also obtained with AQ1 (80.5%) (FICI=0.74). ConclusionUnder irradiation, the oxidative stress was the predominant effect, altering the prooxidant-antioxidant balance, which may be the cause of the irreversible cell injury in the biofilm. Our results showed synergism of these natural AQs with AmB. Therefore, the photosensitizing AQ1 could be an alternative for the Candida infections treatment, which deserves further investigation.

The Application of Clinical Lithotripter Shock Waves to RNA Nucleotide Delivery to Cells

The delivery of genes into cells through the transfer of ribonucleic acids (RNAs) has been found to cause a change in the level of target protein expression. RNA-based transfection is conceptually more efficient than commonly delivered plasmid DNA because it does not require division or damage of the nuclear envelope, thereby increasing the chances of the cell remaining viable. Shock waves (SWs) have been found to induce cellular uptake by transiently altering the permeability of the plasma membrane, thereby overcoming a critical step in gene therapy. However, accompanying SW bio-effects include dose-dependent irreversible cell injury and cytotoxicity. Here, the effect of SWs generated by a clinical lithotripter on the viability and permeabilisation of three different cell lines in vitro was investigated. Comparison of RNA stability before and after SW exposure revealed no statistically significant difference. Optimal SW exposure parameters were identified to minimise cell death and maximise permeabilisation, and applied to enhanced green fluorescent protein (eGFP) messenger RNA (mRNA) or anti-eGFP small interfering RNA delivery. As a result, eGFP mRNA expression levels increased up to 52-fold in CT26 cells, whereas a 2-fold decrease in GFP expression was achieved after anti-eGFP small interfering RNA delivery to MCF-7/GFP cells. These results indicate that SW parameters can be employed to achieve effective nucleotide delivery, laying the foundation for non-invasive and high-tolerability RNA-based gene therapy.

The Role of Mitochondrial Functional Proteins in ROS Production in Ischemic Heart Diseases.

Ischemic heart diseases (IHD) have become the leading cause of death around the world, killing more than 7 million people annually. In IHD, the blockage of coronary vessels will cause irreversible cell injury and even death. As the “powerhouse” and “apoptosis center” in cardiomyocytes, mitochondria play critical roles in IHD. Ischemia insult can reduce myocardial ATP content, resulting in energy stress and overproduction of reactive oxygen species (ROS). Thus, mitochondrial abnormality has been identified as a hallmark of multiple cardiovascular disorders. To date, many studies have suggested that these mitochondrial proteins, such as electron transport chain (ETC) complexes, uncoupling proteins (UCPs), mitochondrial dynamic proteins, translocases of outer membrane (Tom) complex, and mitochondrial permeability transition pore (MPTP), can directly or indirectly influence mitochondria-originated ROS production, consequently determining the degree of mitochondrial dysfunction and myocardial impairment. Here, the focus of this review is to summarize the present understanding of the relationship between some mitochondrial functional proteins and ROS production in IHD.