Higher Reactive Oxygen Species Research Articles

A General Strategy for Enhanced Photodynamic Antimicrobial Therapy with Perylenequinonoid Photosensitizers Using a Macrocyclic Supramolecular Carrier.

Perylenequinonoid natural products are a class of photosensitizers (PSs) that exhibit high reactive oxygen species (ROS) generation and excellent activity for Type I/Type II dual photodynamic therapy. However, their limited activity against gram-negative bacteria and poor water solubility significantly restrict their potential in broad-spectrum photodynamic antimicrobial therapy (PDAT). Herein, a general approach to overcome the limitations of perylenequinonoid photosensitizers (PQPSs) in PDAT by utilizing a macrocyclic supramolecular carrier is presented. Specifically, AnBox·4Cl, a water-soluble cationic cyclophane, is identified as a universal macrocyclic host for PQPSs such as elsinochrome C, hypocrellin A, hypocrellin B, and hypericin, forming 1:1 host-guest complexes with high binding constants (≈107 m -1) in aqueous solutions. Each AnBox·4Cl molecule carries four positive charges that promote strong binding with the membrane of gram-negative bacteria. As a result, the AnBox·4Cl-PQPS complexes can effectively anchor on the surfaces of gram-negative bacteria, while the PQPSs alone cannot. In vitro and in vivo experiments demonstrate that these supramolecular PSs have excellent water solubility and high ROS generation, with broad-spectrum PDAT effect against both gram-negative and gram-positive bacteria. This work paves a new path to enhance PDAT by showcasing an efficient approach to improve PQPSs' water solubility and killing efficacy for gram-negative bacteria.

Zinc Oxide/Carbon Material-Embedded Supramolecular Drug Delivery System with Photoswitching Properties for Highly Selective and Effective Chemotherapy.

Phototherapy has become a hopeful procedure for the treatment of cancer. Nevertheless, the straightforward creation of a theranostic system that can achieve both tumor localization and production of oxygen species is greatly desired yet remains a challenging endeavor. In this study, we synthesized spherical nanostructures by decorating zinc oxide (ZnO) with peanut shell-based carbon (PNS-C) in an aqueous solution. The PNS-C-decorated ZnO (ZnO/PNS-C)-embedded supramolecular system exhibited spontaneous self-assembly. The nanogels that are produced have several desirable characteristics, including exceptional resistance to degradation by light, highly stable nanostructures that form spontaneously in biological environments, outstanding ability to prevent the destruction of red blood cells, and a high level of sensitivity to changes in pH and light. Under light irradiation, the addition of ZnO/PNS-C-incorporated supramolecular provided high reactive oxygen species production. Moreover, in vitro cellular assays demonstrated ZnO/PNS-C-incorporated supramolecular exhibited highly selective and induced phototoxicity into cancer cells and no effect on the viability of normal cells both before and after irradiation. Overall, the ZnO/PNS-C-incorporated supramolecular system has the potential to stimulate advancements in phototherapy by utilizing highly tumor-selective therapeutic molecules. This can lead to a more effective targeted therapy for cancers.

A Mitochondria-Targeted Photosensitizer for Combined Pyroptosis and Apoptosis with NIR-II Fluorescence/Photoacoustic Imaging-Guided Phototherapy.

Overcoming tumor apoptosis resistance is a major challenge in enhancing cancer therapy. Pyroptosis, a lytic form of programmed cell death (PCD) involving inflammasomes, Gasdermin family proteins, and cysteine proteases, offers potential in cancer treatment. While photodynamic therapy (PDT) can induce pyroptosis by generating reactive oxygen species (ROS) through the activation of photosensitizers (PSs), many PSs lack specific subcellular targets and are limited to the first near-infrared window, potentially reducing treatment effectiveness. Therefore, developing effective, deep-penetrating, organelle-targeted pyroptosis-mediated phototherapy is essential for cancer treatment strategies. Here, we synthesized four molecules with varying benzene ring numbers in thiopyrylium structures to preliminarily explore their photodynamic properties. The near-infrared-II (NIR-II) PS Z1, with a higher benzene ring count, exhibited superior ROS generation and mitochondria-targeting abilities, and a large Stokes shift. Through nano-precipitation method, Z1 nanoparticles (NPs) also demonstrated high ROS generation (especially type-I ROS) upon 808 nm laser irradiation, leading to efficient mitochondria dysfunction and combined pyroptosis and apoptosis. Moreover, they exhibited exceptional tumor-targeting ability via NIR-II fluorescence imaging (NIR-II FI) and photoacoustic imaging (PAI). Furthermore, Z1 NPs-mediated phototherapy effectively inhibited tumor growth with minimal adverse effects. Our findings offer a promising strategy for cancer therapy, warranting further preclinical investigations in PDT.

A Mitochondria‐Targeted Photosensitizer for Combined Pyroptosis and Apoptosis with NIR‐II Fluorescence/Photoacoustic Imaging‐Guided Phototherapy

Overcoming tumor apoptosis resistance is a major challenge in enhancing cancer therapy. Pyroptosis, a lytic form of programmed cell death (PCD) involving inflammasomes, Gasdermin family proteins, and cysteine proteases, offers potential in cancer treatment. While photodynamic therapy (PDT) can induce pyroptosis by generating reactive oxygen species (ROS) through the activation of photosensitizers (PSs), many PSs lack specific subcellular targets and are limited to the first near‐infrared window, potentially reducing treatment effectiveness. Therefore, developing effective, deep‐penetrating, organelle‐targeted pyroptosis‐mediated phototherapy is essential for cancer treatment strategies. Here, we synthesized four molecules with varying benzene ring numbers in thiopyrylium structures to preliminarily explore their photodynamic properties. The near‐infrared‐II (NIR‐II) PS Z1, with a higher benzene ring count, exhibited superior ROS generation and mitochondria‐targeting abilities, and a large Stokes shift. Through nano‐precipitation method, Z1 nanoparticles (NPs) also demonstrated high ROS generation (especially type‐I ROS) upon 808 nm laser irradiation, leading to efficient mitochondria dysfunction and combined pyroptosis and apoptosis. Moreover, they exhibited exceptional tumor‐targeting ability via NIR‐II fluorescence imaging (NIR‐II FI) and photoacoustic imaging (PAI). Furthermore, Z1 NPs‐mediated phototherapy effectively inhibited tumor growth with minimal adverse effects. Our findings offer a promising strategy for cancer therapy, warranting further preclinical investigations in PDT.

P-025 Mitochondrial activity in sperm is associated to blastocyst development: a double-donation study

Abstract Study question Do oxidative parameters in sperm affect oocyte fertilization or blastocyst development in double-donation ICSI cycles? Summary answer While intracellular oxidative stress in sperm does not suppose an impact on fertilization or embryo development, mitochondrial activity is related to increased blastocyst development rates What is known already Reactive oxygen species(ROS) are molecules causing a detrimental effect on sperm quality and function, especially when they are imbalanced with respect to the sperm and seminal plasma antioxidant capacity. Previous research have extensively demonstrated that sperm affected by oxidative stress(OS) show reduced fertilizing capacity, and lead to embryos with impaired development after conventional IVF. The role of OS in sperm in the case of ICSI is, however, controversial because many factors may cause a bias. Not only could this explain the inconsistent results reported thus far, but would also support the need of testing healthy donor gametes to reduce variability. Study design, size, duration This research was devised in the context of a collaboration between a sperm bank and a public university, and was set as a blinded, retrospective study that included samples from 45 sperm donors used in a total of 55 oocyte donation cycles. Intracellular levels of total ROS and of superoxides (O2•-), oxidative stress and mitochondrial activity (MA) were evaluated in frozen-thawed sperm donor samples, and related to the embryo outcomes obtained from the same samples. Participants/materials, setting, methods Samples from selected sperm donors were used to fertilize oocytes through ICSI in oocyte donation programs, and fertilization and blastocyst rates were recorded. Sperm viability and intracellular levels of total ROS and superoxides were determined through a combined assay (2’,7’-Dichlorofluorescin diacetate/Hydroethidine/Sytox Red); oxidative stress and sperm viability were assessed through co-staining with CellRox Far Red and propidium iodide (PI); and MA (mitochondrial membrane potential) and sperm viability were evaluated after staining with DiOC6(3) and PI. Main results and the role of chance The average and standard deviation for fertilization and blastocyst rates were 76.8%±17.3% and 67.5%±22.8%, respectively. Taking the viable sperm population into account, percentages of sperm with high ROS and low O2•- were 17.6%±15.9%, those with high ROS and high O2•- were 0.5%±0.4%, percentages of sperm with low ROS and low O2•- were 25.9%±9.2%, and those with low ROS and high O2•- were 54.5%±21.1%. The evaluation of oxidative stress with CellRox revealed that the percentage of viable sperm with high OS was 63.1%±16.5%. Neither intracellular levels of ROS and superoxides, nor oxidative stress in viable sperm were found to be correlated to fertilization or blastocyst rates (P>0.05). In spite of this, the percentage of viable sperm with high MA, which was 20.7%±10.5%, was observed to be positively correlated to blastocyst rates (Rs=0.276; P=0.04). While sperm mitochondria do not participate in further embryo development, a greater mitochondrial activity in post-thawed donor sperm could indicate a healthier sperm function. Mitochondrial activity could, therefore, be used as a predictive biomarker for embryo development. Limitations, reasons for caution The sample size is the main limitation of this study, despite the efforts made to include a high number of sperm donors. Wider implications of the findings Results obtained in the present study show that ICSI evades the detrimental effects of sperm oxidative stress on fertilization and embryo development. Yet, sperm mitochondrial activity could be used as a biomarker to test the ability of a sperm donor to generate healthy embryos that develop up to blastocyst stage. Trial registration number Not applicable

ZIPK collaborates with STAT5A in p53-mediated ROS accumulation in hyperglycemia-induced vascular injury.

In this study we investigate the role of Zipper-interacting protein kinase (ZIPK) in high glucose-induced vascular injury, focusing on its interaction with STAT5A and its effects on p53 and inducible nitric oxide synthase (NOS2) expression. Human umbilical vein endothelial cells (HUVECs) are cultured under normal (5 mM) and high (25 mM) glucose conditions. Protein and gene expression levels are assessed by western blot analysis and qPCR respectively, while ROS levels are measured via flow cytometry. ZIPK expression is manipulated using overexpression plasmids, siRNAs, and shRNAs. The effects of the ZIPK inhibitor TC-DAPK6 are evaluated in a diabetic rat model. Our results show that high glucose significantly upregulates ZIPK, STAT5A, p53, and NOS2 expressions in HUVECs, thus increasing oxidative stress. Silencing of STAT5A reduces p53 and NOS2 expressions and reactive oxygen species (ROS) accumulation. ZIPK is essential for high glucose-induced p53 expression and ROS accumulation, while silencing of ZIPK reverses these effects. Overexpression of ZIPK combined with STAT5A silencing attenuates glucose-induced alterations in p53 and NOS2 expression, thereby preventing cell damage. Coimmunoprecipitation reveals a direct interaction between ZIPK and STAT5A in the nucleus under high-glucose condition. In diabetic rats, TC-DAPK6 treatment significantly decreases ZIPK, p53, and NOS2 expressions. Our findings suggest that ZIPK plays a critical role in high glucose-induced vascular injury via STAT5A-mediated pathways, proposing that ZIPK is a potential therapeutic target for diabetic vascular complications.

Perfluorooctanoic acid triggers premature ovarian insufficiency by impairing NAD+ synthesis and mitochondrial function in adult zebrafish.

High-dose perfluorooctanoic acid (PFOA) impairs oocyte maturation and offspring quality. However, the physiological concentrations of PFOA in follicular fluids of patients with premature ovarian insufficiency (POI) were detected at lower levels, thus the relationship between physiological PFOA and reproductive disorders remains elusive. Here, we investigated whether physiological PFOA exposure affects gonad function in adult zebrafish. Physiological PFOA exposure resulted in POI-like phenotypes in adult females, which exhibited decreased spawning frequency, reduced number of ovulated eggs, abnormal gonadal index, and aberrant embryonic mortality. Meanwhile, oocytes from PFOA-exposed zebrafish showed mitochondrial disintegration and diminished mitochondrial membrane potential (MMP). Unlike the high-dose treated oocytes exhibiting high reactive oxygen species (ROS) levels and excessive apoptosis, physiological PFOA reduced the ROS levels and did not trigger apoptosis. Interestingly, physiological PFOA exposure would not affect testis function, indicating specific toxicity in females. Mechanistically, PFOA suppressed the NAD+ biosynthesis and impaired mitochondrial function in oocytes, thus disrupting oocyte maturation and ovarian fertility. Nicotinamide mononucleotide (NMN), a precursor for NAD+ biosynthesis, alleviated the PFOA-induced toxic effects in oocytes and improved the oocyte maturation and fertility upon PFOA exposure. Our findings discover new insights into PFOA-induced reproductive toxicity and provide NMN as a potential drug for POI therapy.

A ROS-responsive and scavenging hydrogel for postoperative abdominal adhesion prevention

Postoperative abdominal adhesion (PAA) widely occurs after abdominal surgery, which often produces severe complications. However, there were still no satisfactory anti-adhesive products including barriers and anti-adhesive agents. Herein, we developed a ROS-responsive and scavenging hydrogel barrier, termed AHBC/PSC, wherein the monomer AHBC was synthesized by phenylboronic acid (PBA)-modified hyaluronic acid (HA-PBA) further grafted with adipic dihydrazide (ADH) and PBA-based chlorogenic acid (CGA) via ROS-sensitive borate ester bond, and the other monomer PSC was constructed by polyvinyl alcohol (PVA) grafted with sulfated betaine (SB) and p-hydroxybenzaldehyde (-CHO). Further, the double crosslinked AHBC/PSC hydrogel was successfully fabricated between AHBC and PSC via forming dynamic covalent acylhydrazone bonds and borate ester bonds. Results showed that AHBC/PSC hydrogel had in situ gelation behavior, satisfactory mechanical properties (storage modulus of about 1 kPa and loss factor Tan δ of about 0.5), suitable wet tissue adhesion strength of about 2.3 kPa on rat abdominal wall, and good biocompatibility, achieving an ideal physical barrier. Particularly, CGA could be responsively released from the hydrogel by breakage of borate ester bonds between CGA and PBA based on high reactive oxygen species (ROS) levels of damaged tissue and exhibited great ROS scavenging capability to regulate inflammation and promote the polarization of macrophages from pro-inflammatory M1 phenotype to anti-inflammatory M2 phenotype. Moreover, the grafted SB as a zwitterionic group could reduce protein adsorption and fibroblast adhesion. Finally, the in vivo experiments revealed that AHBC/PSC hydrogel with good safety and in vivo retention behavior of about 2 weeks, effectively prevented PAA by regulating the inflammatory microenvironment and alleviating the fibrosis process. In brief, the versatile AHBC/PSC hydrogel would provide a more convenient and efficient approach for PAA prevention. Statement of significancePostoperative abdominal adhesion (PAA) widely occurs after surgery and is often accompanied by severe complications. Excessive inflammation and oxidative stress are very crucial for PAA formation. This study provides a ROS-responsive and scavenging hydrogel with suitable mechanical properties, good biocompatibility and biodegradability, and resistance to protein and fibroblast. The antioxidant and anti-inflammatory active ingredient could be responsively released from the hydrogel via triggering by the high ROS levels in the postoperative microenvironment thereby regulating the inflammatory balance. Finally, the hydrogel would effectively regulate the development process of PAA thereby achieving non-adhesion wound healing.

Unique cartilage matrix-associated protein inhibits osteoclast differentiation by alleviating RANKL-induced reactive oxygen species

Unique cartilage matrix-associated protein (UCMA) is a γ-carboxyglutamic acid-rich secretory protein primarily expressed in adult cartilage. UCMA promotes osteoblast differentiation and reduces high glucose-induced reactive oxygen species (ROS) production in osteoblasts; however, its role in osteoclasts remains unclear. Since Ucma is not expressed in osteoclasts, treatment with recombinant UCMA protein (rUCMA) was employed to investigate the effect of UCMA on osteoclasts. The rUCMA-treated osteoclasts exhibited significantly reduced osteoclast differentiation, resorption activity, and osteoclast-specific gene expression. Moreover, rUCMA treatment reduced RANKL-induced ROS production and increased the expression of antioxidant genes in osteoclasts. This study demonstrates that UCMA effectively inhibits RANKL-stimulated osteoclast differentiation and oxidative stress.

Dual-Polymer Functionalized Melanin-AgNPs Nanocomposite with Hydroxyapatite Binding Ability to Penetrate and Retain in Biofilm Sequentially Treating Periodontitis.

Periodontitis is the leading cause of adult tooth missing. Thorny bacterial biofilm and high reactive oxygen species (ROS) levels in tissue are key elements for the periodontitis process. It is meaningful to develop an advanced therapeutic system with sequential antibacterial/ antioxidant ability to meet the overall goals of periodontitis therapy. Herein, a dual-polymer functionalized melanin-AgNPs (P/D-MNP-Ag) with biofilm penetration, hydroxyapatite binding, and sequentially treatment ability are fabricated. Polymer enriched with 2-(Dimethylamino)ethyl methacrylate (D), can be protonated in an acid environment with enhanced positive charge, promoting penetration in biofilm. The other polymer is rich in phosphate group (P) and can chelate Ca2+, promoting the polymer to adhere to the hydroxyapatite surface. Melanin has good ROS scavenging and photothermal abilities, after in situ reduction Ag, melanin-AgNPs composite has sequentially transitioned between antibacterial and antioxidative ability due to heat and acid accelerated Ag+ release. The released Ag+ and heat have synergistic antibacterial effects for bacterial killing. With Ag+ consumption, the antioxidant ability of MNP recovers to scavenge ROS in the inflammatory area. When applied in the periodontitis model, P/D-MNP-Ag has good therapeutical effects to ablate biofilm, relieve inflammation state, and reduce alveolar bone loss. P/D-MNP-Ag with sequential treatment ability provides a reference for developing advanced oral biofilm eradication systems.

Janus liposozyme for the modulation of redox and immune homeostasis in infected diabetic wounds.

Diabetic foot ulcers often become infected, leading to treatment complications and increased risk of loss of limb. Therapeutics to manage infection and simultaneously promote healing are needed. Here we report on the development of a Janus liposozyme that treats infections and promotes wound closure and re-epithelialization. The Janus liposozyme consists of liposome-like selenoenzymes for reactive oxygen species (ROS) scavenging to restore tissue redox and immune homeostasis. The liposozymes are used to encapsulate photosensitizers for photodynamic therapy of infections. We demonstrate application in methicillin-resistant Staphylococcus aureus-infected diabetic wounds showing high ROS levels for antibacterial function from the photosensitizer and nanozyme ROS scavenging from the liposozyme to restore redox and immune homeostasis. We demonstrate that the liposozyme can directly regulate macrophage polarization and induce a pro-regenerative response. By employing single-cell RNA sequencing, T cell-deficient Rag1-/- mice and skin-infiltrated immune cell analysis, we further reveal that IL-17-producing γδ T cells are critical for mediating M1/M2 macrophage transition. Manipulating the local immune homeostasis using the liposozyme is shown to be effective for skin wound repair and tissue regeneration in mice and mini pigs.

Small‐Bandgap Transducers Induced Carrier Separation for In Situ Dual‐Amplified Tumor Oxidative Stress

AbstractThe inherent and unique charge‐carrier release characteristics of piezoelectric sonosensitizers with desired bandgap can be leveraged to initiate reactive oxygen species (ROS) reactions that have considerable potential for sonodynamic therapy (SDT). In this study, a bimetallic Bi4NbO8Br‐polyvinylpyrrolidone (BNOBP) with a small bandgap (2.45 eV) is synthesized as a potential piezoelectric sonosensitizer. The robust interactions within and between the Bi─O and Nb─O layers narrow the bandgap, facilitating carrier transfer. Concurrently, compared with that of TiO2 and BiOBr, BNOBP exhibits a rapid acoustoelectric response and desirable electron–hole separation efficiency, enabling the generation of ·O2− under ultrasound (US) irradiation. Notably, BNOBP alleviates the overexpression of glutathione (GSH) in tumors and prevents the consumption of the generated ROS by GSH. Combining the previous small bandgap endow the high ROS generation efficiency, this study provides a paradigm for in situ regulation of oxidative stress levels in tumor tissue microenvironment based on bimetallic piezoelectric sonosensitizers.

Scopoletin alleviates high glucose-induced toxicity in human renal proximal tubular cells via inhibition of oxidative damage, epithelial-mesenchymal transition, and fibrogenesis.

Recent years of evidence suggest the crucial role of renal tubular cells in developing diabetic kidney disease. Scopoletin (SCOP) is a plant-based coumarin with numerous biological activities. This study aimed to determine the effect of SCOP on renal tubular cells in developing diabetic kidney disease and to elucidate mechanisms. In this study, SCOP was evaluated in vitro using renal proximal tubular (HK-2) cells under hyperglycemic conditions to understand its mechanism of action. In HK-2 cells, SCOP alleviated the high glucose-generated reactive oxygen species (ROS), restored the levels of reduced glutathione, and decreased lipid peroxidation. High glucose-induced alteration in the mitochondrial membrane potential was markedly restored in the SCOP-treated cells. Moreover, SCOP significantly reduced the high glucose-induced apoptotic cell population in the Annexin V-FITC flow cytometry study. Furthermore, high glucose markedly elevated the mRNA expression of fibrotic and extracellular matrix (ECM) components, namely, transforming growth factor (TGF)-β, alfa-smooth muscle actin (α-SMA), collagen I, and collagen III, in HK-2 cells compared to the untreated cells. SCOP treatment reduced these mRNA expressions compared to the high glucose-treated cells. Collagen I and TGF-β protein levels were also significantly reduced in the SCOP-treated cells. Further findings in HK-2 cells revealed that SCOP interfered with the epithelial-mesenchymal transition (EMT) in the high glucose-treated HK-2 cells by normalizing E-cadherin and downregulating the vimentin and α-SMA proteins. In conclusion, SCOP modulates the high glucose-generated renal tubular cell oxidative damage and accumulation of ECM components and may be a promising molecule against diabetic nephropathy.

Activation of the Nrf-2 pathway improves the mitochondrial phenotype in skeletal muscle cells

Aging muscle displays a reduction in mitochondrial content, along with elevated reactive oxygen species (ROS) emission and reduced levels of antioxidant enzymes. These characteristics enhance tissue susceptibility to oxidative damage, facilitating sub-optimal cellular metabolism and subsequent muscle atrophy. While these perturbations to metabolic homeostasis are a natural course of the aging process, there has been ongoing research investigating how to implement interventions to reduce this decline in muscle health. Regular exercise is one possible treatment modality, however this may be unsuitable for some populations who are unable to participate due to their health status. The objective of this study was to examine the activation of the Nrf-2 pathway using the nutraceutical Sulforaphane (SFN) and evaluate its role as a potential exercise mimetic. We hypothesized that SFN would act through similar pathways activated with chronic exercise to improve mitochondrial content, respiration, and ROS emission. To address our objective, C2C12 myotubes were treated with SFN for various timepoints basally, and in the presence of the Complex-I inhibitor rotenone to induce oxidative stress. Western blotting revealed an 8-fold increase in Nrf-2 nuclear localization following 24hrs of SFN treatment, which subsequently led to the upregulation of antioxidant enzymes NQO1, Heme Oxygenase-1, catalase, glutathione reductase and Glucose-6-Phosphate Dehydrogenase by 2-to 3-fold. These protein changes, were accompanied by dramatic reductions in both total cellular and mitochondrial ROS emission with SFN, detected with CellROX Green and MitoSOX Red respectively. Interestingly, this led to an increase in mitochondrial membrane potential, detected via MitoTracker Red (MTR), despite rotenone-induced oxidative stress. Western blotting revealed TFAM upregulation at 24hrs, suggesting an increase in mitochondrial DNA (mtDNA) replication and transcription. This was corroborated by an increase in COX subunit I protein, a mitochondrially-encoded subunit of cytochrome c oxidase, as well as MitoTracker Green and MTR staining by 48hrs. Mitochondrial respiration was evaluated using Seahorse analysis, demonstrating a marked increase in ATP production as well as basal and maximal respiration. Together these data suggest that activation of the Nrf-2 pathway via SFN may lead to adaptations similar to chronic exercise. Additionally, SFN may have applications in disorders characterized by mitochondrial loss and high ROS emission. To fully elucidate the precise mechanisms underlying this agent, SFN will be combined with chronic contractile activity to determine if these two interventions operate through independent pathways. This work was supported by funds from the Natural Science and Engineering Research Council (NSERC). Sabrina Champsi is the recipient of the NSERC Alexander Graham Bell Canada Graduate Scholarship-Master’s (CGS-M). David A. Hood is the holder of a Canadian Research Chair in Cell Physiology. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Melanin-Ce6-loaded polydopamine nanoparticles-based enhanced phototherapy for B16 melanoma cancer cells

Melanoma is one of the most aggressive and lethal types of cancer owing to its metastatic propensity and chemoresistance property. An alternative therapeutic option is photodynamic and photothermal therapies (PDT/PTT), which employ near-infrared (NIR) light to generate heat and reactive oxygen species (ROS). As per previous reports, Melanin (Mel), and its synthetic analogs (i.e. polydopamine nanoparticles) can induce NIR light-mediated heat energy, thereby selectively targeting and ameliorating cancer cells. Similarly, chlorin e6 (Ce6) also has high ROS generation ability and antitumor activity against various types of cancer. Based on this tenet, In the current study, we have encapsulated Mel-Ce6 in a polydopamine (PDA) nanocarrier (MCP NPs) synthesized by the oxidation polymerization method. The hydrodynamic diameter of the synthesized spherical MCP NPs was 139 ± 10 nm. The MCP NPs, upon irradiation with NIR 690 nm laser for 6 min, showed photothermal efficacy of more than 50 °C. Moreover, the red fluorescence in the MCP NPs due to Ce6 can be leveraged for diagnostic purposes. Further, the MCP NPs exhibited considerable biocompatibility with the L929 cell line and exerted nearly 70% ROS-mediated cytotoxicity on the B16 melanoma cell line after the laser irradiation. Thus, the prepared MCP NPs could be a promising theranostic agent for treating the B16 melanoma cancer.

Less is More: Asymmetric D-A Type Agent to Achieve Dynamic Self-Assembled Nanoaggregates for Long-Acting Photodynamic Therapy.

To enhance the phototheranostic performance, agents with high reactive oxygen species (ROS) generation, good tumor-targeting ability, and prolonged retention are urgently needed. However, symmetric donor-acceptor (D-A) type agents usually produce spherical nanoaggregates, leading to good tumor targeting but inferior retention. Rod-like nanoaggregates are desired to extend their retention in tumors; however, this remains a challenge. In particular, agents with dynamically changeable shapes that integrate merits of different morphologies are seldomly reported. Therefore, self-assembled organic nanoaggregates with smart shape tunability are designed here using an asymmetric D-A type TIBT. The photoluminescence quantum yield in solids is up to 52.24% for TIBT. TIBT also exhibits high ROS generation in corresponding nanoaggregates (TIBT-NCs). Moreover, dynamic self-assembly in shape changing from nanospheres to nanorods occurrs in TIBT-NCs, contributing to the enhancement of ROS quantum yield from 0.55 to 0.72. In addition, dynamic self-assembly can be observed for both in vitro and in vivo, conferring TIBT-NCs with strong tumor targeting and prolonged retention. Finally, efficient photodynamic therapy to inhibit tumor growth is achieved in TIBT-NCs, with an inhibition rate of 90%. This work demonstrates that asymmetric D-A type agents can play significant roles in forming self-assembled organic nanoaggregates, thus showing great potential in long-acting cancer therapy.

"Cicada Out of the Shell" Deep Penetration and Blockage of the HSP90 Pathway by ROS-Responsive Supramolecular Gels to Augment Trimodal Synergistic Therapy.

Deep penetration and downregulation of heat shock protein (HSP) expression in multimodal synergistic therapy are promising approaches for curing cancer in clinical trials. However, free small-molecule drugs and most drug vehicles have a low delivery efficiency deep into the tumor owing to poor drug penetration and hypoxic conditions at the tumor site. In this study, the objective is to use reactive oxygen species (ROS)-responsive supramolecular gels co-loaded with the photosensitizer Zn(II) phthalocyanine tetrasulfonic acid (ZnPCS4) and functionalized tetrahedral DNA (TGSAs) (G@P/TGSAs) to enhance deep tissue and cell penetration and block the HSP90 pathway for chemo- photodynamic therapy (PDT) - photothermal therapy (PTT) trimodal synergistic therapy. The (G@P/TGSAs) are injected in situ into the tumor to release ZnPCS4 and TGSAsunder high ROS concentrations originating from both the tumor and PDT. TGSAs penetrate deeply into tumor tissues and augment photothermal therapy by inhibiting the HSP90 pathway. Proteomics show that HSP-related proteins and molecular chaperones are inhibited/activated, inhibiting the HSP90 pathway. Simultaneously, the TGSA-regulated apoptotic pathway is activated. In vivo study demonstrates efficient tumor penetration and excellent trimodal synergistic therapy (45% tumor growth inhibition).

Hippo pathway activated by circulating reactive oxygen species mediates cardiac diastolic dysfunction after acute kidney injury

Acute kidney injury (AKI) can cause distal cardiac dysfunction; however, the underlying mechanism is unknown. Oxidative stress is proved prominent in AKI-induced cardiac dysfunction, and a possible bridge role of oxidative-stress products in cardio-renal interaction has been reported. Therefore, this study aimed to investigate the critical role of circulating reactive oxygen species (ROS) in mediating cardiac dysfunction after bilateral renal ischemia-reperfusion injury (IRI). We observed the diastolic dysfunction in the mice following renal IRI, accompanied by reduced ATP levels, oxidative stress, and branched-chain amino acids (BCAA) accumulation in the heart. Notably, ROS levels showed a sequential increase in the kidneys, circulation, and heart. Treatment with tempol, an ROS scavenger, significantly restored cardiac diastolic function in the renal IRI mice, corroborating the bridge role of circulating ROS. Accumulating evidence has identified oxidative stress as upstream of Mst1/Hippo in cardiac injury, which could regulate the expression of downstream genes related to mitochondrial quality control, leading to lower ATP, higher ROS and metabolic disorder. To verify this, we examined the activation of the Mst1/Hippo pathway in the heart of renal IRI mice, which was alleviated by tempol treatment as well. In vitro, analysis revealed that Mst1-knockdown cardiomyocytes could be activated by hydrogen peroxide (H2O2). Analysis of Mst1-overexpression cardiomyocytes confirmed the critical role of the Mst1/Hippo pathway in oxidative stress and BCAA dysmetabolism. Therefore, our results indicated that circulating ROS following renal IRI activates the Mst1/Hippo pathway of myocardium, leading to cardiac oxidative stress and diastolic dysfunction. This finding provides new insights for the clinical exploration of improved treatment options for cardiorenal syndrome.

Increased ROS levels in mitochondrial outer membrane protein Mul1-deficient oocytes result in abnormal preimplantation embryogenesis.

Reactive oxygen species (ROS) are associated with oocyte maturation inhibition, and N-acetyl-l-cysteine (NAC) partially reduces their harmful effects. Mitochondrial E3 ubiquitin ligase 1 (Mul1) localizes to the mitochondrial outer membrane. We found that female Mul1-deficient mice are infertile, andtheir oocytes contain high ROS concentrations. After fertilization, Mul1-deficient embryos showed a DNA damage response (DDR) and abnormal preimplantation embryogenesis, which was rescued by NAC addition and ROS depletion. These observations clearly demonstrate that loss of Mul1 in oocytes increases ROS concentrations and triggers DDR, resulting in abnormal preimplantation embryogenesis. We conclude that manipulating the mitochondrial ROS levels in oocytes may be a potential therapeutic approach to target infertility.

Alternaria brassicicola‐induced ROS accumulation during black spot disease differentially affects antioxidant efficiency, phenolic content and susceptibility of Brassica species

AbstractEarly‐stage responses of Brassica juncea, B. napus and B. oleracea during black spot disease and the development of Alternaria brassicicola were evaluated. Infection of plant cells by the fungus occurred mainly through direct penetration or by appressoria and, rarely, stomata in B. juncea and B. oleracea; in B. napus, penetration was mostly direct. The process of conidial germination, germ tubes and appressoria formation on a leaf surface was correlated with the post‐inoculation time and host species (p < 0.05). Changes in the leaf surface were observed at successful infection sites as bright, wax‐deprived areas. Significant differences in progression of infection between Brassica species were observed, with B. oleracea being the most susceptible and B. napus the least. Accumulation of superoxide anion radicals and hydrogen peroxide was not only observed in plant cells, but also in A. brassicicola germ tubes and appressoria at 8 and 12 h post‐inoculation (hpi). Enhanced production of reactive oxygen species (ROS) and lipid peroxidation during infection triggered diverse patterns of enzymatic and non‐enzymatic antioxidant activities and phenolic compound contents in response to A. brassicicola. In each Brassica species, a different antioxidant was the most active. With their antioxidant properties, phenolic compounds also played an essential role in these interactions. This phenomenon could be related to the disparate levels of susceptibility of the Brassica species to A. brassicicola; for example, the most susceptible, B. oleracea, showed high ROS accumulation with decreasing tendency during disease progression, unchanged phenolics content, and the highest catalase activity, differentiating it from B. juncea and B. napus.