Does nitric oxide modulate mitochondrial energy generation and apoptosis?

The role of photobiomodulation in accelerating bone repair

Bone repair is faced with obstacles such as slow repair rates and limited bone regeneration capacity. Delayed healing even nonunion could occur in bone defects, influencing the life quality of patients severely. Photobiomodulation (PBM) utilizes different light sources to derive beneficial therapeutic effects with the advantage of being non-invasive and painless, providing a promising strategy for accelerating bone repair. In this review, we summarize the parameters, mechanisms, and effects of PBM regulating bone repair, and further conclude the current clinical application of PBM devices in bone repair. The wavelength of 635-980 nm, the output power of 40-100 mW, and the energy density of less than 100 J/cm2 are the most commonly used parameters. New technologies, including needle systems and biocompatible and implantable optical fibers, offer references to realize an efficient and safe strategy for bone repair. Further research is required to establish the reliability of outcomes from in vivo and in vitro studies and to standardize clinical trial protocols.

Ratiometric fluorescent biosensor for detection and real-time imaging of nitric oxide in mitochondria of living cells

Nitric oxide (NO), a ubiquitous gaseous messenger, plays critical roles in various pathological and physiological progresses. The abnormal levels of NO in organisms are closely related to a large number of maladies. Mitochondria are the main area that produce NO in mammalian cells. Thus, detecting and real-time imaging of NO in mitochondria is of great significance for exploring the biological functions of NO. Herein, a ratiometric fluorescent biosensor (Mito-GNP-pNO520) is developed for sensitive and selective detection and real-time imaging of NO in mitochondria of living cells. The detection is achieved through the fluorescence off-on response of Mito-GNP-pNO520 toward NO. This biosensor shows excellent characteristics, such as high sensitivity toward NO with a low detection limit of 0.25 nM, exclusive selectivity to NO without interference from other substances, good biological stability and low cytotoxicity. More importantly, the biosensor is specifically located in mitochondria, enabling the detection and real-time imaging of endogenous and exogenous NO in mitochondria of living cells. Therefore, our biosensor offers a new approach for dynamic detecting and real-time imaging of NO in subcellular organelles, providing an opportunity to explore new biological effects of NO.

Tolerant and Rapid Endochondral Bone Regeneration Using Framework-Enhanced 3D Biomineralized Matrix Hydrogels

Tissue-engineered bone has emerged as a promising alternative for bone defect repair due to the advantages of regenerative bone healing and physiological functional reconstruction. However, there is very limited breakthrough in achieving favorable bone regeneration due to the harsh osteogenic microenvironment after bone injury, especially the avascular and hypoxic conditions. Inspired by the bone developmental mode of endochondral ossification, a novel strategy is proposed for tolerant and rapid endochondral bone regeneration using framework-enhanced 3D biomineralized matrix hydrogels. First, it is meticulously designed 3D biomimetic hydrogels with both hypoxic and osteoinductive microenvironment, and then integrated 3D-printed polycaprolactone framework to improve their mechanical strength and structural fidelity. The inherent hypoxic 3D matrix microenvironment effectively activates bone marrow mesenchymal stem cells self-regulation for early-stage chondrogenesis via TGFβ/Smad signaling pathway due to the obstacle of aerobic respiration. Meanwhile, the strong biomineralized microenvironment, created by a hybrid formulation of native-constitute osteogenic inorganic salts, can synergistically regulate both bone mineralization and osteoclastic differentiation, and thus accelerate the late-stage bone maturation. Furthermore, both in vivo ectopic osteogenesis and in situ skull defect repair successfully verified the high efficiency and mechanical maintenance of endochondral bone regeneration mode, which offers a promising treatment for craniofacial bone defect repair.

A common molecular and cellular pathway in developing Alzheimer and cancer

Globally cancer and Alzheimer's disease (AD) are two major diseases and still, there is no clearly defined molecular mechanism. There is an opposite relation between cancer and AD which are the proportion of emerging cancer was importantly slower in AD patients, whereas slow emerging AD in patients with cancer. In cancer, regulation of cell mechanisms is interrupted by an increase in cell survival and proliferation, while on the contrary, AD is related to augmented neuronal death, that may be either produced by or associated with amyloid-β (Aβ) and tau deposition. Stated that the probability that disruption of mechanisms takes part in the regulation of cell survival/death and might be implicated in both diseases. The mechanism of actions such as DNA-methylation, genetic polymorphisms, or another mechanism of actions that induce alteration in the action of drugs with significant roles in resolving the finding to repair and live or die might take part in the pathogenesis of these two ailments. The functions of miRNA, p53, Pin1, the Wnt signaling pathway, PI3 KINASE/Akt/mTOR signaling pathway GRK2 signaling pathway, and the pathophysiological role of oxidative stress are presented in this review as potential candidates which hypothetically describe inverse relations between cancer and AD. Innovative materials almost mutual mechanisms in the aetiology of cancer and AD advocates novel treatment approaches. Among these treatment strategies, the most promising use treatment such as tyrosine kinase inhibitor, nilotinib, protein kinase C, and bexarotene.

Current trends in gas-synergized phototherapy for improved antitumor theranostics

Phototherapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), has been considered an elegant solution to eradicate tumors due to its minimal invasiveness and low systemic toxicity. Nevertheless, it is still challenging for phototherapy to achieve ideal outcomes and clinical translation due to its inherent drawbacks. Owing to the unique biological functions, diverse gases have attracted growing attention in combining with phototherapy to achieve super-additive therapeutic effects. Specifically, gases such as nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S) have been proven to kill tumor cells by inducing mitochondrial damage in synergy with phototherapy. Additionally, several gases not only enhance the thermal damage in PTT and the reactive oxygen species (ROS) production in PDT but also improve the tumor accumulation of photoactive agents. The inflammatory responses triggered by hyperthermia in PTT are also suppressed by the combination of gases. Herein, we comprehensively review the latest studies on gas-synergized phototherapy for cancer therapy, including (1) synergistic mechanisms of combining gases with phototherapy; (2) design of nanoplatforms for gas-synergized phototherapy; (3) multimodal therapy based on gas-synergized phototherapy; (4) imaging-guided gas-synergized phototherapy. Finally, the current challenges and future opportunities of gas-synergized phototherapy for tumor treatment are discussed. STATEMENT OF SIGNIFICANCE: 1. The novelty and significance of the work with respect to the existing literature. (1) Strategies to design nanoplatforms for gas-synergized anti-tumor phototherapy have been summarized for the first time. Meanwhile, the integration of various imaging technologies and therapy modalities which endow these nanoplatforms with advanced theranostic capabilities has been summarized. (2) The mechanisms by which gases synergize with phototherapy to eradicate tumors are innovatively and comprehensively summarized. 2. The scientific impact and interest. This review elaborates current trends in gas-synergized anti-tumor phototherapy, with special emphases on synergistic anti-tumor mechanisms and rational design of therapeutic nanoplatforms to achieve this synergistic therapy. It aims to provide valuable guidance for researchers in this field.

A Phase 1 randomized, open-label clinical trial to evaluate the effect of a far-infrared emitting patch on local skin perfusion, microcirculation and oxygenation

Far-infrared radiation (FIR) has been investigated for reduction of pain and improvement of dermal blood flow. The FIRTECH patch is a medical device designed to re-emit FIR radiated by the body. This phase 1 study was conducted to evaluate the local effects of the FIRTECH patch on local skin perfusion, microcirculation and oxygenation. This prospective, randomized, open-label, parallel designed study admitted 20 healthy participants to a medical research facility for treatment for 31 h on three anatomical locations. During treatment, imaging assessments consisting of laser speckle contrast imaging, near-infrared spectroscopy, side-stream dark-field microscopy, multispectral imaging and thermography were conducted regularly on patch-treated skin and contralateral non-treated skin. The primary endpoint was baseline perfusion increase during treatment on the upper back. Secondary endpoints included change in baseline perfusion, oxygen consumption and temperature of treated versus untreated areas. The primary endpoint was not statistically significantly different between treated and non-treated areas. The secondary endpoints baseline perfusion on the forearm (least square means [LSMs] difference 2.63 PU, 95% CI: 0.97, 4.28), oxygen consumption (LSMs difference: 0.42 arbitrary units [AUs], 95% CI: 0.04, 0.81) and skin temperature (LSMs difference 0.35°C, 95% CI: 0.16, 0.6) were statistically significantly higher in treated areas. Adverse events observed during the study were mild and transient. The vascular response to the FIRTECH patch was short-lived suggesting a non-thermal vasodilatory effect of the patch. The FIRTECH patch was well tolerated, with mild and transient adverse events observed during the study. These results support the therapeutic potential of FIR in future investigations.

Cancer Resistance Is Mediated by the Upregulation of Several Anti-Apoptotic Gene Products via the Inducible Nitric Oxide Synthase/Nitric Oxide Pathway: Therapeutic Implications

Significance: Several therapeutic strategies for cancer treatments have been developed with time, and significant milestones have been achieved recently. However, with these novel therapies, not all cancer types respond and in the responding cancer types only a subset is affected. The failure to respond is principally the result that these cancers develop several mechanisms of resistance. Thus, a focus of current research investigations is to unravel the various mechanisms that regulate resistance and identify suitable targets for new therapeutics. Recent Advances: Hence, many human cancer types have been reported to overexpress the inducible nitric oxide synthase (iNOS) and it has been suggested that iNOS/nitric oxide (NO) plays a pivotal role in the regulation of resistance. We have postulated that iNOS overexpression or NO regulates the overexpression of pivotal anti-apoptotic gene products such as B-cell lymphoma 2 (Bcl-2), B-cell lymphoma extra large (Bcl-xL), myeloid cell leukemia-1 (Mcl-1), and survivin. In this report, we describe the various mechanisms, transcriptional, post-transcriptional, and post-translational, by which iNOS/NO regulates the expression of the above anti-apoptotic gene products. Critical Issues: The iNOS/NO-mediated regulation of the four gene products is not the same with both specific and overlapping pathways. Our findings are, in large part, validated by bioinformatic analyses demonstrating, in several cancers, several direct correlations between the expression of iNOS and each of the four examined anti-apoptotic gene products. Future Directions: We have proposed that targeting iNOS may be highly efficient since it will result in the underexpression of multiple anti-apoptotic proteins and shifting the balance toward the proapoptotic gene products and reversal of resistance. Antioxid. Redox Signal. 39, 853-889.

Shuttle between arginine and lysine: influence on cancer immunonutrition

Amino acids which are essential nutrients for all cell types' survival are also recognised to serve as opportunistic/alternative fuels in cancers auxotrophic for specific amino acids. Accordingly, restriction of amino acids has been utilised as a therapeutic strategy in these cancers. Contrastingly, amino acid deficiencies in cancer are found to greatly impair immune functions, increasing mortality and morbidity rates. Dietary and supplemental amino acids in such conditions have revealed their importance as 'immunonutrients' by modulating cellular homeostasis processes and halting malignant progression. L-arginine specifically has attracted interest as an immunonutrient by acting as a nodal regulator of immune responses linked to carcinogenesis processes through its versatile signalling molecule, nitric oxide (NO). The quantum of NO generated directly influences the cytotoxic and cytostatic processes of cell cycle arrest, apoptosis, and senescence. However, L-lysine, a CAT transporter competitor for arginine effectively limits arginine input at high L-lysine concentrations by limiting arginine-mediated effects. The phenomenon of arginine-lysine antagonism can, therefore, be hypothesised to influence the immunonutritional effects exerted by arginine. The review highlights aspects of lysine's interference with arginine-mediated NO generation and its consequences on immunonutritional and anti-cancer effects, and discusses possible alternatives to manage the condition. However, further research that considers monitoring lysine levels in arginine immunonutritional therapy is essential to conclude the hypothesis.

The angiotensin-converting enzyme I/D polymorphism does not impact training-induced adaptations in exercise capacity in patients with stable coronary artery disease

Systematic exercise training effectively improves exercise capacity in patients with coronary artery disease (CAD), but the magnitude of improvements is highly heterogeneous. We investigated whether this heterogeneity in exercise capacity gains is influenced by the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene. Patients with CAD (n = 169) were randomly assigned to 12 weeks of exercise training or standard care, and 142 patients completed the study. The ACE polymorphism was determined for 128 patients (82% males, 67 ± 9 years). Peak oxygen uptake was measured before and after the 12-week intervention. The ACE I/D polymorphism frequency was n = 48 for D/D homozygotes, n = 61 for I/D heterozygotes and n = 19 for I/I homozygotes. Baseline peak oxygen uptake was 23.3 ± 5.0 ml/kg/min in D/D homozygotes, 22.1 ± 5.3 ml/kg/min in I/D heterozygotes and 23.1 ± 6.0 ml/kg/min in I/I homozygotes, with no statistical differences between genotype groups (P = 0.50). The ACE I/D polymorphism frequency in the exercise group was n = 26 for D/D, n = 21 for I/D and n = 12 for I/I. After exercise training, peak oxygen uptake was increased (P < 0.001) in D/D homozygotes by 2.6 ± 1.7 ml/kg/min, in I/D heterozygotes by 2.7 ± 1.9 ml/kg/min, and in I/I homozygotes by 2.1 ± 1.3 ml/kg/min. However, the improvements were similar between genotype groups (time × genotype, P = 0.55). In conclusion, the ACE I/D polymorphism does not affect baseline exercise capacity or exercise capacity gains in response to 12 weeks of high-intensity exercise training in patients with stable CAD.Clinical trial registration: www.clinicaltrials.gov (NCT04268992).

Mixed β-γ-Cyclodextrin Branched Polymer with Multiple Photo-Chemotherapeutic Cargos

The achievement of biocompatible platforms for multimodal therapies is one of the major challenges in the burgeoning field of nanomedicine. Here, we report on a mixed β- and γ-cyclodextrin-based branched polymeric material (βγCD-NOPD) covalently integrating a nitric oxide (NO) photodonor (NOPD) within its macromolecular scaffold, and its supramolecular ensemble with a singlet oxygen (1O2) photosensitizer (PS) Zn(II) phthalocyanine (ZnPc) and the chemodrug Lenvatinib (LVB). This polymer is highly water-soluble and generates NO under visible blue light stimuli with an efficiency of more than 1 order of magnitude higher than that of the single NOPD. The PS, which in an aqueous solution is aggregated and non-photoresponsive, can be entangled in the polymeric network as a photoresponsive monomeric species. In addition, the poorly water-soluble LVB can be co-encapsulated within the polymeric host, which increases the drug solubility by more than 30-fold compared to the free drug and more than 2-fold compared with a similar branched polymer containing only βCD units. The supramolecular nanoensemble, ca. 15 nm in diameter, retains well the photochemical properties of both the NOPD and PS, which can operate in parallel under light stimuli of different energies. Irradiation with blue and red light results in the photogeneration of NO and 1O2 associated with red fluorescence emission, without inducing any photodegradation of LVB. This result is not trivial and is due to the absence of significant, mutual interactions between the NOPD, the PS and LVB both in the ground and excited states, despite these components are confined in the same host. The proposed polymeric nanoplatform may represent a potential trimodal nanomedicine for biomedical research studies, since it combines the double photodynamic action of NO and 1O2, two species that do not suffer multidrug resistance, with the therapeutic activity of a conventional chemodrug.

Red-Light-Photosensitized NO Release and Its Monitoring in Cancer Cells with Biodegradable Polymeric Nanoparticles

The role of nitric oxide (NO) as an "unconventional" therapeutic and the strict dependence of biological effects on its concentration require the generation of NO with precise spatiotemporal control. The development of precursors and strategies to activate NO release by excitation in the so-called "therapeutic window" with highly biocompatible and tissue-penetrating red light is desirable and challenging. Herein, we demonstrate that one-photon red-light excitation of Verteporfin, a clinically approved photosensitizer (PS) for photodynamic therapy, activates NO release, in a catalytic fashion, from an otherwise blue-light activatable NO photodonor (NOPD) with an improvement of about 300 nm toward longer and more biocompatible wavelengths. Steady-state and time-resolved spectroscopic and photochemical studies combined with theoretical calculations account for an NO photorelease photosensitized by the lowest triplet state of the PS. In view of biological applications, the water-insoluble PS and NOPD have been co-entrapped within water-dispersible, biodegradable polymeric nanoparticles (NPs) of mPEG-b-PCL (about 84 nm in diameter), where the red-light activation of NO release takes place even more effectively than in an organic solvent solution and almost independently by the presence of oxygen. Moreover, the ideal spectroscopic prerequisites and the restricted environment of the NPs permit the green-fluorescent co-product formed concomitantly to NO photorelease to communicate with the PS via Förster resonance energy transfer. This leads to an enhancement of the typical red emission of the PS offering the possibility of a double color optical reporter useful for the real-time monitoring of the NO release through fluorescence techniques. The suitability of this strategy applied to the polymeric NPs as potential nanotherapeutics was evaluated through biological tests performed by using HepG2 hepatocarcinoma and A375 melanoma cancer cell lines. Fluorescence investigation in cells and cell viability experiments demonstrates the occurrence of the NO release under one-photon red-light illumination also in the biological environment. This confirms that the adopted strategy provides a valuable tool for generating NO from an already available NOPD, otherwise activatable with the poorly biocompatible blue light, without requiring any chemical modification and the use of sophisticated irradiation sources.

NO-IL-6/10-IL-1β axis: a new pathway in steatotic and non-steatotic liver grafts from brain-dead donor rats

Introduction

Brain death (BD) and steatosis are both risk factors for organ dysfunction or failure in liver transplantation (LT).

Material and methods

Here, we examine the role of interleukin 6 (IL- 6) and IL-10 in LT of both non-steatotic and steatotic liver recovered from donors after brain death (DBDs), as well as the molecular signaling pathways underlying the effects of such cytokines.

Results

BD reduced IL-6 levels only in nonsteatotic grafts, and diminished IL-10 levels only in steatotic ones. In both graft types, BD increased IL-1β, which was associated with hepatic inflammation and damage. IL-6 administration reduced IL-1β only in non-steatotic grafts and protected them against damage and inflammation. Concordantly, IL-1β inhibition via treatment with an IL-1 receptor antagonist caused the same benefits in non-steatotic grafts. Treatment with IL-10 decreased IL-1β only in steatotic grafts and reduced injury and inflammation specifically in this graft type. Blockading the IL-1β effects also reduced damage and inflammation in steatotic grafts. Also, blockade of IL-1β action diminished hepatic cAMP in both types of livers, and this was associated with a reduction in liver injury and inflammation, then pointing to IL-1β regulating cAMP generation under LT and BD conditions. Additionally, the involvement of nitric oxide (NO) in the effects of interleukins was evaluated. Pharmacological inhibition of NO in LT from DBDs prompted even more evident reductions of IL-6 or IL-10 in non-steatotic and steatotic grafts, respectively. This exacerbated the already high levels of IL-1β seen in LT from DBDs, causing worse damage and inflammation in both graft types. The administration of NO donors to non-steatotic grafts potentiated the beneficial effects of endogenous NO, since it increased IL-6 levels, and reduced IL-1β, inflammation, and damage. However, treatment with NO donors in steatotic grafts did not modify IL-10 or IL-1β levels, but induced more injurious effects tan the induction of BD alone, characterized by increased nitrotyrosine, lipid peroxidation, inflammation, and hepatic damage.

Conclusion

Our study thus highlights the specificity of new signaling pathways in LT from DBDs: NO-IL-6-IL-1β in non-steatotic livers and NO-IL-10-IL-1β in steatotic ones. This opens up new therapeutic targets that could be useful in clinical LT.

Vericiguat preserved cardiac function and mitochondrial quality in a rat model of mitral regurgitation

AIMS

New drugs for heart failure (HF) that target restoring the impaired NO-sGC-cGMP pathway are being developed. We aimed to investigate the effects of vericiguat, an sGC stimulator, on cardiac function, blood pressure (BP), cardiac mitochondrial quality, and cardiac fibrosis in rat models of chronic mitral regurgitation (MR).

MATERIALS AND METHODS

We surgically induced MR in 20 Sprague-Dawley rats and performed sham procedures on 10 rats (negative control). Four weeks post-surgery, we randomly divided the MR rats into two groups: MR group and MR + vericiguat group. Vericiguat (0.5 mg/kg, PO) was administered once a day via oral gavage for 8 weeks, while the sham and MR groups received equivalent volumes of drinking water instead. We took echocardiography and BP measurements at baseline (4 weeks post-surgery) and at the end of study (8 weeks after treatment). At the study end, all rats were euthanized and their hearts were immediately collected, weighed, and used for histopathology and mitochondrial quality assessments.

KEY FINDINGS

Vericiguat preserved cardiac functions and structural remodeling in the MR rats, with significantly lower systolic BPs than baseline values (P < 0.05). Additionally, vericiguat significantly improved the mitochondrial quality by attenuating ROS production, depolarization and swelling when comparing the values in both groups (P < 0.05). The fibrosis area also significantly decreased in the MR + vericiguat group (P < 0.05).

SIGNIFICANCE

Vericiguat demonstrated cardioprotective effects on cardiac function, BP, and fibrosis by preserving mitochondrial quality in rats with HF due to MR.

Current understanding of Plasma-activated solutions for potential cancer therapy

Cancer therapy consists of multidisciplinary treatment combining surgery, chemotherapy, radiotherapy, and immunotherapy. Despite the elucidation of cancer mechanisms by comprehensive genomic and epigenomic analyses and the development of molecular therapy, drug resistance and severe side effects have presented challenges to the long-awaited development of new therapies. With the rapid technological advances in the last decade, there are now reports concerning potential applications of non-equilibrium atmospheric pressure plasma (NEAPP) in cancer therapy. Two approaches have been tried: direct irradiation with NEAPP (direct plasma) and the administration of a liquid (e.g., culture medium, saline, Ringer's lactate) activated by NEAPP (plasma-activated solutions: PAS). Direct plasma is a unique treatment method in which various active species, charged ions, and photons are delivered to the affected area, but the direct plasma approach has physical limitations related to the device used, such as a limited depth of reach and limited irradiation area. PAS is a liquid that contains reactive oxygen species generated by PAS, and it has been confirmed to have antitumor activity that functions in the same manner as direct plasma. This review introduces recent studies of PAS and informs researchers about the potential of PAS for cancer therapy.Key Policy HighlightsPotential applications of plasma-activated solutions (PAS) in cancer therapy are described.Plasma-activated species generated in PAS, its effect on tumor cells, contribution to non-malignant immune cells, selectivity and safety are presented.The proposed anti-tumor mechanisms of PAS to date are described.Efficacy and safety evaluations of PAS have been studied in experimental animal models, but no human studies have been conducted.

In-Tumor Biosynthetic Construction of Upconversion Nanomachines for Precise Near-Infrared Phototherapy

Targeted construction of therapeutic nanoplatforms in tumor cells with specific activation remains appealing but challenging. Here, we design a cancer-motivated upconversion nanomachine (UCNM) based on porous upconversion nanoparticles (p-UCNPs) for precise phototherapy. The nanosystem is equipped with a telomerase substrate (TS) primer and simultaneously encapsulates 5-aminolevulinic acid (5-ALA) and d-arginine (d-Arg). After coating with hyaluronic acid (HA), it can readily get into tumor cells, where 5-ALA induces efficient accumulation of protoporphyrin IX (PpIX) via the inherent biosynthetic pathway, and the overexpressed telomerase prolonged the TS to form G-quadruplexes (G4) for binding the resulting PpIX as a nanomachine. This nanomachine can respond to near-infrared (NIR) light and promote the active singlet oxygen (¹O₂) production due to the efficiency of Förster resonance energy transfer (FRET) between p-UCNPs and PpIX. Intriguingly, such oxidative stress can oxidize d-Arg into nitric oxide (NO), which relieves the tumor hypoxia and in turn improves the phototherapy effect. This in situ assembly approach significantly enhances targeting in cancer therapy and might be of considerable clinical value.

A composition-tunable cold atmospheric plasma chip for multiplex-treatment of cells

Cold atmospheric plasma treatment promises a targeted cancer therapy due to its selectivity and specificity in killing tumor cells. However, the current plasma exposure devices produce diverse and coupled reactive species, impeding the investigation of the underlying plasma-anticancer mechanisms. Also, the limited mono-sample and mono-dosage treatment modality result in tedious and manual experimental tasks. Here, we propose a cold atmospheric plasma chip producing targeted species, delivering multiple dosages, and treating multiple cell lines in a single treatment. Three modules are integrated into the chip. The environment control module and multi-inlet gas-feed module coordinately ignite component-tunable and uniformly distributed plasma. The multi-sample holding module enables multiplex treatment: multi-sample and -dosage treatment with single radiation. By exposing the HepG2 cell line to nitrogen-feed plasmas, we prove the crucial role of nitrogen-based species in inhibiting cell growth and stimulating apoptosis. By loading four-type cell lines on our chip, we can identify the most vulnerable cell line for plasma oncotherapy. Simultaneously, three-level treatment dosages are imposed on the cells with single radiation to optimize the applicable treatment dosage for plasma oncotherapy. Our chip will broaden the design principles of plasma exposure devices, potentially help clarify plasma-induced anticancer mechanisms, and guide the clinical application of plasma-based oncotherapy.

A Supramolecular Nanoassembly of Lenvatinib and a Green Light-Activatable NO Releaser for Combined Chemo-Phototherapy

The chemotherapeutic Lenvatinib (LVB) and a nitric oxide (NO) photodonor based on a rhodamine antenna (RD-NO) activatable by the highly compatible green light are supramolecularly assembled by a β-cyclodextrin branched polymer (PolyCD). The poorly water-soluble LVB and RD-NO solubilize very well within the polymeric host leading to a ternary supramolecular nanoassembly with a diameter of ~55 nm. The efficiency of the NO photorelease and the typical red fluorescence of RD-NO significantly enhance within the polymer due to its active role in the photochemical and photophysical deactivation pathways. The co-presence of LVB within the same host does not affect either the nature or the efficiency of the photoinduced processes of RD-NO. Besides, irradiation of RD-NO does not lead to the decomposition of LVB, ruling out any intermolecular photoinduced process between the two guests despite sharing the same host. Ad-hoc devised Förster Resonance Energy Transfer experiments demonstrate this to be the result of the not close proximity of the two guests, which are confined in different compartments of the same polymeric host. The supramolecular complex is stable in a culture medium, and its biological activity has been evaluated against HEP-G2 hepatocarcinoma cell lines in the dark and under irradiation with visible green light, using LVB at a concentration well below the IC₅₀. Comparative experiments performed using the polymeric host encapsulating the individual LVB and RD-NO components under the same experimental conditions show that the moderate cell mortality induced by the ternary complex in the dark increases significantly upon irradiation with visible green light, more likely as the result of synergism between the NO photogenerated and the chemotherapeutic.

The Therapeutic Strategies Targeting Mitochondrial Metabolism in Cardiovascular Disease

Cardiovascular disease (CVD) is a group of systemic disorders threatening human health with complex pathogenesis, among which mitochondrial energy metabolism reprogramming has a critical role. Mitochondria are cell organelles that fuel the energy essential for biochemical reactions and maintain normal physiological functions of the body. Mitochondrial metabolic disorders are extensively involved in the progression of CVD, especially for energy-demanding organs such as the heart. Therefore, elucidating the role of mitochondrial metabolism in the progression of CVD is of great significance to further understand the pathogenesis of CVD and explore preventive and therapeutic methods. In this review, we discuss the major factors of mitochondrial metabolism and their potential roles in the prevention and treatment of CVD. The current application of mitochondria-targeted therapeutic agents in the treatment of CVD and advances in mitochondria-targeted gene therapy technologies are also overviewed.

Considerations for the Use of Photobiomodulation in the Treatment of Retinal Diseases

Photobiomodulation (PBM) refers to the beneficial effect produced from low-energy light irradiation on target cells or tissues. Increasing evidence in the literature suggests that PBM plays a positive role in the treatment of retinal diseases. However, there is great variation in the light sources and illumination parameters used in different studies, resulting in significantly different conclusions regarding PBM's therapeutic effects. In addition, the mechanism by which PBM improves retinal function has not been fully elucidated. In this study, we conducted a narrative review of the published literature on PBM for treating retinal diseases and summarized the key illumination parameters used in PBM. Furthermore, we explored the potential molecular mechanisms of PBM at the retinal cellular level with the goal of providing evidence for the improved utilization of PBM in the treatment of retinal diseases.

Cell-To-Cell Communication in the Resistance Vasculature

The arterial vasculature can be divided into large conduit arteries, intermediate contractile arteries, resistance arteries, arterioles, and capillaries. Resistance arteries and arterioles primarily function to control systemic blood pressure. The resistance arteries are composed of a layer of endothelial cells oriented parallel to the direction of blood flow, which are separated by a matrix layer termed the internal elastic lamina from several layers of smooth muscle cells oriented perpendicular to the direction of blood flow. Cells within the vessel walls communicate in a homocellular and heterocellular fashion to govern luminal diameter, arterial resistance, and blood pressure. At rest, potassium currents govern the basal state of endothelial and smooth muscle cells. Multiple stimuli can elicit rises in intracellular calcium levels in either endothelial cells or smooth muscle cells, sourced from intracellular stores such as the endoplasmic reticulum or the extracellular space. In general, activation of endothelial cells results in the production of a vasodilatory signal, usually in the form of nitric oxide or endothelial-derived hyperpolarization. Conversely, activation of smooth muscle cells results in a vasoconstriction response through smooth muscle cell contraction. © 2022 American Physiological Society. Compr Physiol 12: 1-35, 2022.

Nitroglycerin as a model of migraine: Clinical and preclinical review

Migraine stands as one of the most disabling neurological conditions worldwide. It is a disorder of great challenge to study given its heterogeneous representation, cyclic nature, and complexity of neural networks involved. Despite this, clinical and preclinical research has greatly benefitted from the use of the nitric oxide donor, nitroglycerin (NTG), to model this disorder, dissect underlying mechanisms, and to facilitate the development and screening of effective therapeutics. NTG is capable of triggering a migraine attack, only in migraineurs or patients with a history of migraine and inducing migraine-like phenotypes in rodent models. It is however unclear to what extent NTG and NO, as its breakdown product, is a determinant factor in the underlying pathophysiology of migraine, and importantly, whether it really does facilitate the translation from the bench to the bedside, and vice-versa. This review provides an insight into the evidence supporting the strengths of this model, as well as its limitations, and shines a light into the possible role of NO-related mechanisms in altered molecular signalling pathways.

A molecular dyad delivered by biodegradable polymeric nanoparticles for combined PDT and NO-PDT in cancer cells

The design, synthesis, photochemical properties, and biological evaluation of a novel molecular dyad with double photodynamic action and its formulation within biodegradable polymeric nanoparticles (NPs) are reported. A BODIPY-based singlet oxygen (¹O₂) photosensitizer (PS) and a nitric oxide (NO) photodonor (NOPD) based on an amino-nitro-benzofurazan moiety have been covalently joined in a new molecular dyad, through a flexible alkyl spacer. Excitation of the dyad with visible light in the range 400-570 nm leads to the concomitant generation of the cytotoxic ¹O₂ and NO with effective quantum yields, being Φ_Δ = 0.49 ± 0.05 and Φ_NO = 0.18 ± 0.01, respectively. Besides, the non-fluorescent NOPD unit becomes highly fluorescent after the NO release, acting as an optical reporter for the NO photogenerated. The dyad is not soluble in water medium but can be effectively entrapped in water-dispersible, biodegradable polymeric NPs made of mPEG-PCL, ca. 66 nm in diameter. The polymeric nano-environment affects in an opposite way the photochemical performances of the dyad, reducing Φ_Δ to 0.16 ± 0.02 and increasing Φ_NO to 0.92 ± 0.03, respectively. The NPs effectively deliver the photoactive cargo into the cytoplasm of HepG2 hepatocellular carcinoma cells. A remarkable level of cell mortality is observed for the loaded NPs at very low concentrations of the dyad (1-5 µM) and very low light doses (≤0.8 J cm^-2) more likely as the result of the combined photodynamic action of ¹O₂ and NO.

Inhaled nitric oxide: role in the pathophysiology of cardio-cerebrovascular and respiratory diseases

Nitric oxide (NO) is a key molecule in the biology of human life. NO is involved in the physiology of organ viability and in the pathophysiology of organ dysfunction, respectively. In this narrative review, we aimed at elucidating the mechanisms behind the role of NO in the respiratory and cardio-cerebrovascular systems, in the presence of a healthy or dysfunctional endothelium. NO is a key player in maintaining multiorgan viability with adequate organ blood perfusion. We report on its physiological endogenous production and effects in the circulation and within the lungs, as well as the pathophysiological implication of its disturbances related to NO depletion and excess. The review covers from preclinical information about endogenous NO produced by nitric oxide synthase (NOS) to the potential therapeutic role of exogenous NO (inhaled nitric oxide, iNO). Moreover, the importance of NO in several clinical conditions in critically ill patients such as hypoxemia, pulmonary hypertension, hemolysis, cerebrovascular events and ischemia-reperfusion syndrome is evaluated in preclinical and clinical settings. Accordingly, the mechanism behind the beneficial iNO treatment in hypoxemia and pulmonary hypertension is investigated. Furthermore, investigating the pathophysiology of brain injury, cardiopulmonary bypass, and red blood cell and artificial hemoglobin transfusion provides a focus on the potential role of NO as a protective molecule in multiorgan dysfunction. Finally, the preclinical toxicology of iNO and the antimicrobial role of NO-including its recent investigation on its role against the Sars-CoV2 infection during the COVID-19 pandemic-are described.

Therapeutic Effects of Cold Atmospheric Plasma on Solid Tumor

Cancer is a devastating disease, and there is no particularly effective treatment at present. Recently, a new treatment, cold atmospheric plasma (CAP), has been proposed. At present, CAP is confirmed to have selective killing effect on tumor by many studies in vitro and in vivo. A targeted literature search was carried out on the study of cold atmospheric plasma. Through analysis and screening, a narrative review approach was selected to describe therapeutic effects of cold atmospheric plasma on solid tumor. According to the recent studies on plasma, some hypothetical therapeutic schemes of CAP are proposed in this paper. The killing mechanism of CAP on solid tumor is expounded in terms of the selectivity of CAP to tumor, the effects of CAP on cells, tumor microenvironment (TME) and immune system. CAP has many effects on solid tumors, and these effects are dose-dependent. The effects of optimal doses of CAP on solid tumors include killing tumor cells, inhibiting non-malignant cells and ECM in TME, affecting the communication between tumor cells, and inducing immunogenic death of tumor cells. In addition, several promising research directions of CAP are proposed in this review, which provide guidance for future research.

Restoration of Sarco/Endoplasmic Reticulum Ca2+-ATPase Activity Functions as a Pivotal Therapeutic Target of Anti-Glutamate-Induced Excitotoxicity to Attenuate Endoplasmic Reticulum Ca2+ Depletion

Glutamate-induced excitotoxicity is a pathological basis of many acute/chronic neurodegenerative diseases. Sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA2b) is a membrane-embedded P-type ATPase pump that manages the translocation of calcium ions (Ca²⁺) from cytosol into the lumen of the endoplasmic reticulum (ER) calcium stores. It participates in a wide range of biological functions in the central nervous system (CNS). However, the role of SERCA2b in glutamate-induced excitotoxicity and its mechanism must be elucidated. Herein, we demonstrate that SERCA2b mutants exacerbate the excitotoxicity of hypo-glutamate stimulation on HT22 cells. In this study, SERCA2b mutants accelerated Ca²⁺ depletion through loss-of-function (reduced pumping capacity) or gain-of-function (acquired leakage), resulting in ER stress. In addition, the occurrence of ER Ca²⁺ depletion increased mitochondria-associated membrane formation, which led to mitochondrial Ca²⁺ overload and dysfunction. Moreover, the enhancement of SERCA2b pumping capacity or inhibition of Ca²⁺ leakage attenuated Ca²⁺ depletion and impeded excitotoxicity in response to hypo-glutamate stimulation. In conclusion, SERCA2b mutants exacerbate ER Ca²⁺-depletion-mediated excitotoxicity in glutamate-sensitive HT22 cells. The mechanism of disruption is mainly related to the heterogeneity of SERCA2b mutation sites. Stabilization of SRECA2b function is a critical therapeutic approach against glutamate-induced excitotoxicity. These data will expand understanding of organelle regulatory networks and facilitate the discovery and creation of drugs against excitatory/inhibitory imbalance in the CNS.

Rationale for 1068 nm Photobiomodulation Therapy (PBMT) as a Novel, Non-Invasive Treatment for COVID-19 and Other Coronaviruses: Roles of NO and Hsp70

Researchers from across the world are seeking to develop effective treatments for the ongoing coronavirus disease 2019 (COVID-19) outbreak, which arose as a major public health issue in 2019, and was declared a pandemic in early 2020. The pro-inflammatory cytokine storm, acute respiratory distress syndrome (ARDS), multiple-organ failure, neurological problems, and thrombosis have all been linked to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) fatalities. The purpose of this review is to explore the rationale for using photobiomodulation therapy (PBMT) of the particular wavelength 1068 nm as a therapy for COVID-19, investigating the cellular and molecular mechanisms involved. Our findings illustrate the efficacy of PBMT 1068 nm for cytoprotection, nitric oxide (NO) release, inflammation changes, improved blood flow, and the regulation of heat shock proteins (Hsp70). We propose, therefore, that PBMT 1068 is a potentially effective and innovative approach for avoiding severe and critical illness in COVID-19 patients, although further clinical evidence is required.

Imaging Assessment of Endothelial Function: An Index of Cardiovascular Health

Endothelial dysfunction is a key early mechanism in a variety of cardiovascular diseases and can be observed in larger conduit arteries as well as smaller resistance vessels (microvascular dysfunction). The presence of endothelial dysfunction is a strong prognosticator for cardiovascular events and mortality, and assessment of endothelial function can aid in selecting therapies and testing their response. While the gold standard method of measuring coronary endothelial function remains invasive angiography, several non-invasive imaging techniques have emerged for investigating both coronary and peripheral endothelial function. In this review, we will explore and summarize the current invasive and non-invasive modalities available for endothelial function assessment for clinical and research use, and discuss the strengths, limitations and future applications of each technique.

Gas regulation of complex II reversal via electron shunting to fumarate in the mammalian ETC

The electron transport chain (ETC) is a major currency converter that exchanges the chemical energy of fuel oxidation to proton motive force and, subsequently, ATP generation, using O₂ as a terminal electron acceptor. Discussed herein, two new studies reveal that the mammalian ETC is forked. Hypoxia or H₂S exposure promotes the use of fumarate as an alternate terminal electron acceptor. The fumarate/succinate and CoQH₂/CoQ redox couples are nearly iso-potential, revealing that complex II is poised for facile reverse electron transfer, which is sensitive to CoQH₂ and fumarate concentrations. The gas regulators, H₂S and ^•NO, modulate O₂ affinity and/or inhibit the electron transfer rate at complex IV. Their induction under hypoxia suggests a mechanism for how traffic at the ETC fork can be regulated.

Permeability-Controlled Probe for Directly Visualizing the Opening of Mitochondrial Permeability Transition Pore in Native Status

The opening of mitochondrial permeability transition pore (mPTP) plays a fundamental role in cell apoptosis regulation, ischemia-reperfusion injury, and neurodegenerative disorders. However, the molecular tools for detecting mPTP open in cellular native status have not been reported yet. Herein, we de novo designed a robust fluorescent probe mPTP-F to monitor mPTP opening in cellular native status for the first time. The membrane-permeable probe could accumulate into mitochondria and convert to a product poorly permeable to biomembranes, which was trapped in mitochondria to form near-infrared (NIR)-emissive aggregates. After mPTP opening, the product was released from mitochondria through the pore to form green-emissive monomers. Significantly, with mPTP-F, we discovered that formaldehyde, a signaling molecule, could induce mPTP opening. Therefore, the new probe could serve as a desirable molecular tool for the study of ischemia-reperfusion injury, cell apoptosis, and relative areas.

Enhancing the Anticancer Activity of Sorafenib through Its Combination with a Nitric Oxide Photodelivering β-Cyclodextrin Polymer

In this contribution, we report a strategy to enhance the therapeutic action of the chemotherapeutic Sorafenib (SRB) through its combination with a multifunctional β-cyclodextrin-based polymer able to deliver nitric oxide (NO) and emit green fluorescence upon visible light excitation (PolyCDNO). The basically water-insoluble SRB is effectively encapsulated in the polymeric host (1 mg mL⁻¹) up to a concentration of 18 μg mL⁻¹. The resulting host-guest supramolecular complex is able to release SRB in sink conditions and to preserve very well the photophysical and photochemical properties of the free PolyCDNO, as demonstrated by the similar values of the NO release and fluorescence emission quantum efficiencies found. The complex PolyCDNO/SRB internalizes in HEP-G2 hepatocarcinoma, MCF-7 breast cancer and ACHN kidney adenocarcinoma cells, localizing in all cases mainly at the cytoplasmic level. Biological experiments have been performed at SRB concentrations below the IC₅₀ and with light doses producing NO at nontoxic concentrations. The results demonstrate exceptional mortality levels for PolyCDNO/SRB upon visible light irradiation in all the different cell lines tested, indicating a clear synergistic action between the chemotherapeutic drug and the NO. These findings can open up exciting avenues to potentiate the anticancer action of SRB and, in principle, to reduce its side effects through its use at low dosages when in combination with the photo-regulated release of NO.

Doxorubicin-NO Releaser Molecular Hybrid Activatable by Green Light to Overcome Resistance in Breast Cancer Cells

The biological activity of a molecular hybrid (DXNO-GR) joining doxorubicin (DOX) and an N-nitroso moiety releasing nitric oxide (NO) under irradiation with the biocompatible green light has been investigated against DOX-sensitive (MCF7) and -resistant (MDA-MB-231) breast cancer cells in vitro. DXNO-GR shows significantly higher cellular internalization than DOX in both cell lines and, in contrast to DOX, does not experience cell efflux in MDR overexpressing MDA-MB-231 cells. The higher cellular internalization of the DXNO-GR hybrid seems to be mediated by bovine serum albumin (BSA) as a suitable carrier among serum proteins, according to the high binding constant measured for DXNO-GR, which is more than one order of magnitude larger than that reported for DOX. Despite the higher cellular accumulation, DXNO-GR is not toxic in the dark but induces remarkable cell death following photoactivation with green light. This lack of dark toxicity is strictly related to the different cellular compartmentalization of the molecular hybrid that, different from DOX, does not localize in the nucleus but is mainly confined in the Golgi apparatus and endoplasmic reticulum and therefore does not act as a DNA intercalator. The photochemical properties of the hybrid are not affected by binding to BSA as demonstrated by the direct detection of NO photorelease, suggesting that the reduction of cell viability observed under light irradiation is a combined effect of DOX phototoxicity and NO release which, ultimately, inhibits MDR1 efflux pump in DOX-resistant cells.

The mechanistic target of rapamycin as a regulator of metabolic function in oligodendroglia during remyelination

Despite evidence for prominent metabolic dysfunction within multiple sclerosis (MS) lesions, the mechanisms controlling metabolic shifts in oligodendroglia are poorly understood. The cuprizone model of demyelination and remyelination is a valuable tool for assessing metabolic insult during oligodendrocyte death and myelin degradation, closely resembling the distal oligodendrogliopathy seen in Pattern III MS lesions. In this review we discuss how metabolic processes in oligodendrocytes are disrupted in both MS and the cuprizone model, as well as the evidence for mechanistic target of rapamycin (mTOR) signaling as a key regulator of oligodendroglial metabolic function and efficient remyelination.

X-ray-Triggered CO Release Based on GdW10/MnBr(CO)5 Nanomicelles for Synergistic Radiotherapy and Gas Therapy

Carbon monoxide (CO) therapy has become a hot topic in the field of gas therapy because of its application prospect in the treatment of various diseases. Due to the high affinity for human hemoglobin, the main challenge of CO-loaded nanomedicine is the lack of selectivity and toxicity in the delivery process. Although many commercial CO-releasing molecules (CORMs) have been widely developed because of their ability to deliver CO, CORMs still have some disadvantages, including difficult on-demand controlled CO release, poor solubility, and potential toxicity, which are limiting their further application. Herein, an X-ray-triggered CO-releasing nanomicelle system (GW/MnCO@PLGA) based on GdW₁₀ nanoparticles (NPs) (GW) and MnBr(CO)₅ (MnCO) encapsulating in the poly(lactic-co-glycolic acid) (PLGA) polymer was constructed for synergistic CO radiotherapy (RT). The production of strongly oxidative superoxide anion (O₂^-•) active species can lead to cell apoptosis under the X-ray sensitization of GW. Moreover, strongly oxidative O₂^-• radicals further oxidize and compete with the Mn center, resulting in the on-demand release of CO. The radio/gas therapy synergy to enhance the efficient tumor inhibition of the nanomicelles was investigated in vivo and in vitro. Therefore, the establishment of an X-ray-triggered controlled CO release system has great application potential for further synergistic RT CO therapy in deep tumor sites.

Complex Interplay of Heme-Copper Oxidases with Nitrite and Nitric Oxide

Nitrite and nitric oxide (NO), two active and critical nitrogen oxides linking nitrate to dinitrogen gas in the broad nitrogen biogeochemical cycle, are capable of interacting with redox-sensitive proteins. The interactions of both with heme-copper oxidases (HCOs) serve as the foundation not only for the enzymatic interconversion of nitrogen oxides but also for the inhibitory activity. From extensive studies, we now know that NO interacts with HCOs in a rapid and reversible manner, either competing with oxygen or not. During interconversion, a partially reduced heme/copper center reduces the nitrite ion, producing NO with the heme serving as the reductant and the cupric ion providing a Lewis acid interaction with nitrite. The interaction may lead to the formation of either a relatively stable nitrosyl-derivative of the enzyme reduced or a more labile nitrite-derivative of the enzyme oxidized through two different pathways, resulting in enzyme inhibition. Although nitrite and NO show similar biochemical properties, a growing body of evidence suggests that they are largely treated as distinct molecules by bacterial cells. NO seemingly interacts with all hemoproteins indiscriminately, whereas nitrite shows high specificity to HCOs. Moreover, as biologically active molecules and signal molecules, nitrite and NO directly affect the activity of different enzymes and are perceived by completely different sensing systems, respectively, through which they are linked to different biological processes. Further attempts to reconcile this apparent contradiction could open up possible avenues for the application of these nitrogen oxides in a variety of fields, the pharmaceutical industry in particular.

Ways and Means of Cellular Reconditioning for Kidney Regeneration

BACKGROUND

Mitochondrial, lysosomal, and peroxisomal dysfunction; defective autophagy; mitophagy; and pexophagy, as well as the loss of glycocalyx integrity are known contributors to initiation and progression of diverse kidney diseases. Those cellular organelles are tightly interactive in health, and during development of a disease, damage in one may propagate to others. By extension, it follows that restoring an individual defect may culminate in a broader restorative spectrum and improvement of cell and organ functions.

SUMMARY

A novel strategy of reconditioning cellular organellar dysfunction, which we define as refurbishment of pathogenically pivotal intra- or extracellular elements, damaged in the course of disease and impeding restoration, is briefly outlined in this overview. Individual therapeutic reconditioning approaches targeting selected organelles are cataloged. We anticipate that the proposed reconditioning strategy in the future may enrich the arsenal of regenerative medicine and nephrology.

KEY MESSAGE

The arsenal of regenerative medicine and nephrology consisting of organ transplantation, use of stem cells, cell-free approaches, cell reprogramming strategies, and organ engineering has been enriched by the reconditioning strategy. The latter is based on the recognition of two facts that (a) impairment of diverse cellular organelles contributes to pathogenesis of kidney disease and (b) individual organelles are functionally interactively coupled, which explains the "domino effect" leading to their dysfunction. Reconditioning takes advantage of these facts and, while initially directed to restore the function of individual cellular organelles, culminates in the propagation of a therapeutic intervention to account for improved cell and organ function. Examples of such interventions are briefly summarized along the presentation of defective cellular organelles contributing to pathogenesis of kidney disease.

Role of Nitric Oxide and Protein S-Nitrosylation in Ischemia-Reperfusion Injury

Ischemia-reperfusion injury (IRI) is a process in which damage is induced in hypoxic tissue when oxygen supply is resumed after ischemia. During IRI, restoration of reduced nitric oxide (NO) levels may alleviate reperfusion injury in ischemic organs. The protective mechanism of NO is due to anti-inflammatory effects, antioxidant effects, and the regulation of cell signaling pathways. On the other hand, it is generally known that S-nitrosylation (SNO) mediates the detrimental or protective effect of NO depending on the action of the nitrosylated target protein, and this is also applied in the IRI process. In this review, the effect of each change of NO and SNO during the IRI process was investigated.

Nanoscale covalent organic frameworks: from controlled synthesis to cancer therapy

Covalent organic frameworks (COFs), as a new type of crystalline porous materials, mainly consist of light-weight elements (H, B, C, N and O) linked by dynamic covalent bonds to form periodical structures of two or three dimensions. As an attribute of their low density, large surface area, and excellent adjustable pore size, COFs show great potential in many fields including energy storage and separation, catalysis, sensing, and biomedicine. However, compared with metal organic frameworks (MOFs), the relatively large size and irregular morphology of COFs affect their biocompatibility and bioavailability in vivo, thus impeding their further biomedical applications. This Review focuses on the controlled design strategies of nanoscale COFs (NCOFs), unique properties of NCOFs for biomedical applications, and recent progress in NCOFs for cancer therapy. In addition, current challenges for the biomedical use of NCOFs and perspectives for further improvements are presented.

Light-triggered nitric oxide release and structure transformation of peptide for enhanced intratumoral retention and sensitized photodynamic therapy

Tumor-targeted delivery of nanomedicine is of great importance to improve therapeutic efficacy of cancer and minimize systemic side effects. Unfortunately, nowadays the targeting efficiency of nanomedicine toward tumor is still quite limited and far from clinical requirements. In this work, we develop an innovative peptide-based nanoparticle to realize light-triggered nitric oxide (NO) release and structural transformation for enhanced intratumoral retention and simultaneously sensitizing photodynamic therapy (PDT). The designed nanoparticle is self-assembled from a chimeric peptide monomer, TPP-RRRKLVFFK-Ce6, which contains a photosensitive moiety (chlorin e6, Ce6), a β-sheet-forming peptide domain (Lys-Leu-Val-Phe-Phe, KLVFF), an oligoarginine domain (RRR) as NO donor and a triphenylphosphonium (TPP) moiety for targeting mitochondria. When irradiated by light, the constructed nanoparticles undergo rapid structural transformation from nanosphere to nanorod, enabling to achieve a significantly higher intratumoral accumulation by 3.26 times compared to that without light irradiation. More importantly, the conversion of generated NO and reactive oxygen species (ROS) in a light-responsive way to peroxynitrite anions (ONOO^-) with higher cytotoxicity enables NO to sensitize PDT in cancer treatment. Both in vitro and in vivo studies demonstrate that NO sensitized PDT based on the well-designed transformable nanoparticles enables to eradicate tumors efficiently. The light-triggered transformable nanoplatform developed in this work provides a new strategy for enhanced intratumoral retention and improved therapeutic outcome.

The wHole Story About Fenestrations in LSEC

The porosity of liver sinusoidal endothelial cells (LSEC) ensures bidirectional passive transport of lipoproteins, drugs and solutes between the liver capillaries and the liver parenchyma. This porosity is realized via fenestrations - transcellular pores with diameters in the range of 50-300 nm - typically grouped together in sieve plates. Aging and several liver disorders severely reduce LSEC porosity, decreasing their filtration properties. Over the years, a variety of drugs, stimulants, and toxins have been investigated in the context of altered diameter or frequency of fenestrations. In fact, any change in the porosity, connected with the change in number and/or size of fenestrations is reflected in the overall liver-vascular system crosstalk. Recently, several commonly used medicines have been proposed to have a beneficial effect on LSEC re-fenestration in aging. These findings may be important for the aging populations of the world. In this review we collate the literature on medicines, recreational drugs, hormones and laboratory tools (including toxins) where the effect LSEC morphology was quantitatively analyzed. Moreover, different experimental models of liver pathology are discussed in the context of fenestrations. The second part of this review covers the cellular mechanisms of action to enable physicians and researchers to predict the effect of newly developed drugs on LSEC porosity. To achieve this, we discuss four existing hypotheses of regulation of fenestrations. Finally, we provide a summary of the cellular mechanisms which are demonstrated to tune the porosity of LSEC.

Mechanism of Endoplasmic Reticulum Stress in Cerebral Ischemia

Endoplasmic reticulum (ER) is the main organelle for protein synthesis, trafficking and maintaining intracellular Ca²⁺ homeostasis. The stress response of ER results from the disruption of ER homeostasis in neurological disorders. Among these disorders, cerebral ischemia is a prevalent reason of death and disability in the world. ER stress stemed from ischemic injury initiates unfolded protein response (UPR) regarded as a protection mechanism. Important, disruption of Ca²⁺ homeostasis resulted from cytosolic Ca²⁺ overload and depletion of Ca²⁺ in the lumen of the ER could be a trigger of ER stress and the misfolded protein synthesis. Brain cells including neurons, glial cells and endothelial cells are involved in the complex pathophysiology of ischemic stroke. This is generally important for protein underfolding, but even more for cytosolic Ca²⁺ overload. Mild ER stress promotes cells to break away from danger signals and enter the adaptive procedure with the activation of pro-survival mechanism to rescue ischemic injury, while chronic ER stress generally serves as a detrimental role on nerve cells via triggering diverse pro-apoptotic mechanism. What’s more, the determination of some proteins in UPR during cerebral ischemia to cell fate may have two diametrically opposed results which involves in a specialized set of inflammatory and apoptotic signaling pathways. A reasonable understanding and exploration of the underlying molecular mechanism related to ER stress and cerebral ischemia is a prerequisite for a major breakthrough in stroke treatment in the future. This review focuses on recent findings of the ER stress as well as the progress research of mechanism in ischemic stroke prognosis provide a new treatment idea for recovery of cerebral ischemia.

Novel Mitochondria-targeted Drugs for Cancer Therapy

The search for mitochondria-targeted drugs has dramatically risen over the last decade. Mitochondria are essential organelles serving not only as a powerhouse of the cell but also as a key player in cell proliferation and cell death. Their central role in the energetic metabolism, calcium homeostasis and apoptosis makes them an intriguing field of interest for cancer pharmacology. In cancer cells, many mitochondrial signaling and metabolic pathways are altered. These changes contribute to cancer development and progression. Due to changes in mitochondrial metabolism and changes in membrane potential, cancer cells are more susceptible to mitochondria-targeted therapy. The loss of functional mitochondria leads to the arrest of cancer progression and/or a cancer cell death. Identification of mitochondrial changes specific for tumor growth and progression, rational development of new mitochondria-targeted drugs and research on delivery agents led to the advance of this promising area. This review will highlight the current findings in mitochondrial biology, which are important for cancer initiation, progression and resistance, and discuss approaches of cancer pharmacology with a special focus on the anti-cancer drugs referred to as 'mitocans'.

Astaxanthin-s-allyl cysteine diester against high glucose-induced neuronal toxicity in vitro and diabetes-associated cognitive decline in vivo: Effect on p53, oxidative stress and mitochondrial function

Neuroprotective effect of astaxanthin-s-allyl cysteine diester (AST-SAC) against high glucose (HG)-induced oxidative stress in in vitro and cognitive decline under diabetes conditions in in vivo has been explored. Pretreatment of AST-SAC (5, 10 and 15 μM) dose-dependently preserved the neuronal cells (SH-SY5Y) viability against HG toxicity through i) decreasing oxidative stress (decreasing reactive oxygen species generation and increasing endogenous antioxidants level); ii) protecting mitochondrial function [oxidative phosphorylation (OXPHOS) complexes activity and mitochondrial membrane potential (MMP)]; and iii) decreasing p53 level thereby subsequently decreasing the level of apoptotic marker proteins. Male Spraque-Dawley rats were orally administered AST-SAC (1 mg/kg/day) for 45 days in streptozotocin-induced diabetes mellitus (DM) rats. AST-SAC administration prevented the loss of spatial memory in DM rats as determined using the novel object location test. AST-SAC administration alleviated the DM-induced injury in brain such as increased cholinesterases activity, elevated oxidative stress and mitochondrial dysfunction. Altogether, the results from the present study demonstrated that AST-SAC averted the neuronal apoptosis and preserved the cognitive function against HG toxicity under DM conditions.

Nitric Oxide Photoreleasers with Fluorescent Reporting

Nitric oxide (NO) plays a multifaceted role in human physiology and pathophysiology, and its controlled delivery has great prospects in therapeutic applications. The light-activated uncaging of NO from NO caging compounds allows this free radical to be released with accurate control of site and dosage, which strictly determine its biological effects. Molecular constructs able to activate fluorescence concomitantly to NO release offer the important advantage of easy and real-time tracking of the amount of NO uncaged in a non-invasive fashion even in the cell environment. This contribution provides an overview of the advances in photoactivatable NO releasers bearing fluorescent reporting functionalities achieved in our and other laboratories, highlighting the rationale design and their potential therapeutic applications.

Methylene blue and photobiomodulation recover cognitive impairment in hepatic encephalopathy through different effects on cytochrome c-oxidase

Mitochondrial dysfunction plays a central role in hepatic encephalopathy (HE), due to changes in enzyme cytochrome c-oxidase (CCO), causing a decline in brain metabolism. We used an HE animal model and applied intracranial administration of methylene blue (MB) and transcranial photobiomodulation (PBM), both targeting CCO, to determine their differential effects on recovering cognition. Five groups of rats were used: sham-operated group + saline (SHAM + SAL, n = 6), hepatic encephalopathy + SAL (HE + SAL, n = 7), SHAM + methylene blue (SHAM + MB, n = 7), HE + MB (n = 7), HE + PBM (n = 7). PBM animals were exposed transcranially to 670 +/- 10 nm LED light at a dose of 9 J/cm2 once a day for 7 days, and the MB and SAL groups were injected with 2.2 μg/0.5 μL in the accumbens. Cognitive dysfunction was evaluated on a striatal stimulus-response task using the Morris water maze. Our results showed cognitive improvement in the HE group when treated with MB. This improvement was accompanied by a decrease in CCO activity in the prefrontal cortex, dorsal striatum, and dorsal hippocampus. When comparing MB and PBM, we found that, although both treatments effectively improved the HE-memory deficit, there was a differential effect on CCO. A general decrease in CCO activity was found in the prefrontal and entorhinal cortices, dorsal striatum, and hippocampus when PBM, compared to MB, was applied. Our results suggest that mitochondrial dysfunction and brain metabolic decline in HE might involve CCO alteration and can be improved by administering MB and PBM.

A Bacteria-Inspired Morphology Genetic Biomedical Material: Self-Propelled Artificial Microbots for Metastatic Triple Negative Breast Cancer Treatment

Morphology genetic biomedical materials (MGBMs), referring to fabricating materials by learning from the genetic morphologies and strategies of natural species, hold great potential for biomedical applications. Inspired by the cargo-carrying-bacterial therapy (microbots) for cancer treatment, a MGBM (artificial microbots, AMBs) was constructed. Rather than the inherent bacterial properties (cancerous chemotaxis, tumor invasion, cytotoxicity), AMBs also possessed ingenious nitric oxide (NO) generation strategy. Mimicking the bacterial construction, the hyaluronic acid (HA) polysaccharide was induced as a coating capsule of AMBs to achieve long circulation in blood and specific tissue preference (tumor tropism). Covered under the capsule-like polysaccharide was the combinatorial agent, the self-assembly constructed by the amphiphilic dendrons with abundant l-arginine residues peripherally (as endogenous NO donor) and hydrophobic chemotherapeutic drugs at the core stacking on the surface of SWNTs (the photothermal agent) for a robust chemo-photothermal therapy (chemo-PTT) and the elicited immune therapy. Subsequently, the classic inducible nitric oxide synthase (iNOS) pathway aroused by immune response was revolutionarily utilized to oxidize the l-arginine substrates for NO production, the process for which could also be promoted by the high reactive oxygen species level generated by chemo-PTT. The NO generated by AMBs was intended to regulate vasodilation and cause a dramatic invasion (as the microbots) to disperse the therapeutic agents throughout the solid tumor for a much more enhanced curative effect, which we defined as "self-propulsion". The self-propelled AMBs exhibiting impressive primary tumor ablation, as well as the distant metastasis regression to conquer the metastatic triple negative breast cancer, provided pioneering potential therapeutic opportunities, and enlightened broad prospects in biomedical application.

Endothelial function and dysfunction: Impact of sodium-glucose cotransporter 2 inhibitors

Diabetes mellitus is associated with endothelial dysfunction that leads to cardiovascular complications. Sodium-glucose cotransporter 2 (SGLT2) inhibitors demonstrated efficacy in glycemic control in type 2 diabetes patients with positive cardiovascular outcome. Recent research revealed a link between SGLT2 inhibition and improved macro- and microvascular endothelial functions. Mechanisms underlying this phenomenon could be due to the role of SLGT2 in the regulation of endothelial physiology. In this review, current knowledge and hypothesis on the link between SGLT2 and endothelial function were critically appraised and the impact of SGLT2 inhibitors on endothelial dysfunction in pre-clinical and clinical studies was discussed.

Inhibition of Inducible Nitric Oxide Synthase Prevents IL-1β-Induced Mitochondrial Dysfunction in Human Chondrocytes

Interleukin (IL)-1β is an important pro-inflammatory cytokine in the progression of osteoarthritis (OA), which impairs mitochondrial function and induces the production of nitric oxide (NO) in chondrocytes. The aim was to investigate if blockade of NO production prevents IL-1β-induced mitochondrial dysfunction in chondrocytes and whether cAMP and AMP-activated protein kinase (AMPK) affects NO production and mitochondrial function. Isolated human OA chondrocytes were stimulated with IL-1β in combination with/without forskolin, L-NIL, AMPK activator or inhibitor. The release of NO, IL-6, PGE₂, MMP3, and the expression of iNOS were measured by ELISA or Western blot. Parameters of mitochondrial respiration were measured using a seahorse analyzer. IL-1β significantly induced NO release and mitochondrial dysfunction. Inhibition of iNOS by L-NIL prevented IL-1β-induced NO release and mitochondrial dysfunction but not IL-1β-induced release of IL-6, PGE₂, and MMP3. Enhancement of cAMP by forskolin reduced IL-1β-induced NO release and prevented IL-1β-induced mitochondrial impairment. Activation of AMPK increased IL-1β-induced NO production and the negative impact of IL-1β on mitochondrial respiration, whereas inhibition of AMPK had the opposite effects. NO is critically involved in the IL-1β-induced impairment of mitochondrial respiration in human OA chondrocytes. Increased intracellular cAMP or inhibition of AMPK prevented both IL-1β-induced NO release and mitochondrial dysfunction.