Is the Mitochondrial Membrane Potential (∆Ψ) Correctly Assessed? Intracellular and Intramitochondrial Modifications of the ∆Ψ Probe, Rhodamine 123

Diosmin protects the testicles from doxorubicin-induced damage by increasing steroidogenesis and suppressing oxido-inflammation and apoptotic mediators

BACKGROUND

Cancer chemotherapy with doxorubicin (DOX) has been linked to serious testicular damage and spermatotoxicity due to the induction of oxidative stress, inflammation, and apoptosis. Thus, the current study was carried out to assess the potential ameliorative impact of diosmin, an antioxidant drug, against DOX-mediated spermatoxicity and testicular injury in rats.

MATERIAL AND METHODS

In the experimental protocol, rats were grouped into 4: Group 1 received vehicle and saline for 8 weeks while group 2 received diosmin and saline concomitantly for 8 weeks. Group 3 was given 3 mg/kg intraperitoneal DOX once every 7 days for 8 weeks. Group 4 was given 40 mg/kg of diosmin orally for 56 days followed by DOX diosmin administration after one hour. After 56 days of treatment, sperm quality, hormonal testing, biochemical parameters, and histological alterations in the testes were evaluated.

RESULTS

DOX-induced reduce spermatogenic function, testicular 3- and 17β-Hydroxysteroid dehydrogenases, and serum follicle stimulating hormone, luteinizing hormone, and testosterone. It also enhanced inflammation, testicular oxidative damage, and apoptosis. The histopathologic examinations corroborated the biochemical results obtained. Significantly, diosmin treatment reduced DOX-induced injury, as evidenced by restored testicular architecture, increased steroidogenesis, preservation of spermatogenesis, suppression of oxide-inflammatory response, and apoptosis.

CONCLUSION

It was found that through diosmin antioxidant, anti-apoptotic, and anti-oxido-inflammatory it presents a possible therapeutic alternative for protecting testicular tissue against DOX's harmful effects.

Unlocking the Mitochondria for Nanomedicine-based Treatments: Overcoming Biological Barriers, Improving Designs, and Selecting Verification Techniques

Enhanced targeting approaches will support the treatment of diseases associated with dysfunctional mitochondria, which play critical roles in energy generation and cell survival. Obstacles to mitochondria-specific targeting include the presence of distinct biological barriers and the need to pass through (or avoid) various cell internalization mechanisms. A range of studies have reported the design of mitochondrially-targeted nanomedicines that navigate the complex routes required to influence mitochondrial function; nonetheless, a significant journey lies ahead before mitochondrially-targeted nanomedicines become suitable for clinical use. Moving swiftly forward will require safety studies, in vivo assays confirming effectiveness, and methodologies to validate mitochondria-targeted nanomedicines' subcellular location/activity. From a nanomedicine standpoint, we describe the biological routes involved (from administration to arrival within the mitochondria), the features influencing rational design, and the techniques used to identify/validate successful targeting. Overall, rationally-designed mitochondria-targeted-based nanomedicines hold great promise for precise subcellular therapeutic delivery.

Targeting Mitochondria for Cancer Treatment

There is an increasing accumulation of data on the exceptional importance of mitochondria in the occurrence and treatment of cancer, and in all lines of evidence for such participation, there are both energetic and non-bioenergetic functional features of mitochondria. This analytical review examines three specific features of adaptive mitochondrial changes in several malignant tumors. The first feature is characteristic of solid tumors, whose cells are forced to rebuild their energetics due to the absence of oxygen, namely, to activate the fumarate reductase pathway instead of the traditional succinate oxidase pathway that exists in aerobic conditions. For such a restructuring, the presence of a low-potential quinone is necessary, which cannot ensure the conventional conversion of succinate into fumarate but rather enables the reverse reaction, that is, the conversion of fumarate into succinate. In this scenario, complex I becomes the only generator of energy in mitochondria. The second feature is the increased proliferation in aggressive tumors of the so-called mitochondrial (peripheral) benzodiazepine receptor, also called translocator protein (TSPO) residing in the outer mitochondrial membrane, the function of which in oncogenic transformation stays mysterious. The third feature of tumor cells is the enhanced retention of certain molecules, in particular mitochondrially directed cations similar to rhodamine 123, which allows for the selective accumulation of anticancer drugs in mitochondria. These three features of mitochondria can be targets for the development of an anti-cancer strategy.

Multilayer nanodrug delivery system with spatiotemporal drug release improves tumor microenvironment for synergistic anticancer therapy

The inflammatory response is one of the general symptoms that accompany tumorigenesis, the pro-inflammatory factors cyclooxygenase-2 (COX-2) and COX-2-derived prostaglandin-2 (PGE-2) in the inflammatory environment surrounding tumors possess promoting tumor development, metastasis and angiogenesis effects. In addition, the hypoxic environment of tumors severely limits the effectiveness of photodynamic therapy (PDT). In this study, a universal extracellular-intracellular 'on-demand' release nanomedicine DOX@PDA-ICG@MnO2@GN-CEL was developed for the combined fight against malignant tumors using a spatiotemporal controlled gelatin coated polydopamine (PDA@GN) as the carrier and loaded with the chemotherapeutic drug doxorubicin (DOX), the photosensitizer indocyanine green (ICG), the PDT enhancer MnO2and the anti-inflammatory drug celecoxib (CEL) individually. Our results showed that DOX@PDA-ICG@MnO2@GN-CEL could release CEL extracellularly by matrix metalloproteinase-2 response and inhibit the COX-2/PGE-2 pathway, reduce chemotherapy resistance and attenuate the concurrent inflammation. After entering the tumor cells, the remaining DOX@PDA-ICG@MnO2released DOX, ICG and MnO2intracellularly through PDA acid response. MnO2promoted the degradation of endogenous H2O2to generate oxygen under acidic conditions to alleviate the tumor hypoxic environment, enhance PDT triggered by ICG. PDA and ICG exhibited photothermal therapy synergistically, and DOX exerted chemotherapy with reduced chemotherapy resistance. The dual responsive drug release switch enabled the chemotherapeutic, photothermal, photodynamic and anti-inflammatory drugs precisely acted on different sites of tumor tissues and realized a promising multimodal combination therapy.

Exposure to low dose of Bisphenol A (BPA) intensifies kidney oxidative stress, inflammatory factors expression and modulates Angiotensin II signaling under hypertensive milieu

Humans are constantly exposed to low concentrations of ubiquitous environmental pollutant, Bisphenol A (BPA). Due to the prevalence of hypertension (one of the major risk factors of cardiovascular disease [CVD]) in the population, it is necessary to explore the adverse effect of BPA under hypertension associated pathogenic milieu. The current study exposed the Nω-nitro-l-arginine methyl ester (L-NAME) induced hypertensive Wistar rats to low dose BPA (50 μg/kg) for 30 days period. In tissue samples immunohistochemistry, real-time quantitative polymerase chain reaction and enzymatic assays were conducted. Moreover, studies on primary kidney cell culture were employed to explore the impact of low dose of BPA exposure at nanomolar level (20-80 nM range) on renal cells through various fluorescence assays. The observed results illustrate that BPA exposure potentiates/aggravates hypertension induced tissue abnormalities (renal fibrosis), oxidative stress (ROS generation), elevated angiotensin-converting enzyme activity, malfunction of the antioxidant and tricarboxylic acid cycle enzymes, tissue lipid abnormalities and inflammatory factor expression (both messenger RNA and protein level of TNF-α and IL-6). Further, in vitro exposure of nM levels of BPA to primary kidney cells modulates oxidative stress (both superoxide and total ROS), mitochondrial physiology (reduced mitochondrial transmembrane potential-∆ψm) and lipid peroxidation in a dose dependent manner. In addition, angiotensin II induced ROS generation was aggravated further by BPA during coexposure in kidney cells. Therefore, during risk assessment, a precise investigation on BPA exposure in hypertensive (CVD vulnerable) populations is highly suggested.

Bisphenol A (BPA) exposure aggravates hepatic oxidative stress and inflammatory response under hypertensive milieu - Impact of low dose on hepatocytes and influence of MAPK and ER stress pathways

Human exposure to the hazardous chemical, Bisphenol A (BPA), is almost ubiquitous. Due to the prevalence of hypertension (CVD risk factor) in the aged human population, it is necessary to explore its adverse effect in hypertensive subjects. The current study exposed the Nω-nitro-l-arginine methyl ester (L-NAME) induced hypertensive Wistar rats to human exposure relevant low dose of BPA (50 μg/kg) for 30 days period. The liver biochemical parameters, histopathology, immunohistochemistry, gene expression (RT-qPCR), trace elements (ICP-MS), primary rat hepatocytes cell culture and metabolomic (1H NMR) assessments were performed. Results illustrate that BPA exposure potentiates/aggravates hypertension induced tissue abnormalities (hepatic fibrosis), oxidative stress, ACE activity, malfunction of the antioxidant system, lipid abnormalities and inflammatory factor (TNF-α and IL-6) expression. Also, in cells, BPA increased ROS generation, mitochondrial dysfunction and lipid peroxidation without any impact on cytotoxicity and caspase 3 and 9 activation. Notably, BPA exposure modulate lipid metabolism (cholesterol and fatty acid) in primary hepatocytes. Finally, the influence of ERK1/2, p38MAPK, ER stress and oxidative stress during relatively high dose of BPA elicited cytotoxicity was observed. Therefore, a precise hazardous risk investigation of BPA exposure in hypertensive populations is highly recommended.

Intracellular Trafficking of Size-Tuned Nanoparticles for Drug Delivery

Polymeric nanoparticles (NPs) are widely used as drug delivery systems in nanomedicine. Despite their widespread application, a comprehensive understanding of their intracellular trafficking remains elusive. In the present study, we focused on exploring the impact of a 20 nm difference in size on NP performance, including drug delivery capabilities and intracellular trafficking. For that, poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PLGA-PEG) NPs with sizes of 50 and 70 nm were precisely tailored. To assess their prowess in encapsulating and releasing therapeutic agents, we have employed doxorubicin (Dox), a well-established anticancer drug widely utilized in clinical settings, as a model drug. Then, the beneficial effect of the developed nanoformulations was evaluated in breast cancer cells. Finally, we performed a semiquantitative analysis of both NPs' uptake and intracellular localization by immunostaining lysosomes, early endosomes, and recycling endosomes. The results show that the smaller NPs (50 nm) were able to reduce the metabolic activity of cancer cells more efficiently than NPs of 70 nm, in a time and concentration-dependent manner. These findings are corroborated by intracellular trafficking studies that reveal an earlier and higher uptake of NPs, with 50 nm compared to the 70 nm ones, by the breast cancer cells. Consequently, this study demonstrates that NP size, even in small increments, has an important impact on their therapeutic effect.

The significance of bioelectricity on all levels of organization of an organism. Part 1: From the subcellular level to cells

Bioelectricity plays an essential role in the structural and functional organization of biological organisms. In this first article of our three-part series, we summarize the importance of bioelectricity for the basic structural level of biological organization, i.e. from the subcellular level (charges, ion channels, molecules and cell organelles) to cells.

Isn't It Time for Establishing Mitochondrial Nomenclature Breaking Mitochondrial Paradigm?

In this work, we decided to initiate a discussion concerning heterogeneity of mitochondria, suggesting that it is time to build classification of mitochondria, like the one that exists for their progenitors, α-proteobacteria, proposing possible separation of mitochondrial strains and maybe species. We continue to adhere to the general line that mitochondria are friends and foes: on the one hand, they provide the cell and organism with the necessary energy and signaling molecules, and, on the other hand, participate in destruction of the cell and the organism. Current understanding that the activity of mitochondria is not only limited to energy production, but also that these alternative non-energetic functions are unique and irreplaceable in the cell, allowed us to speak about the strong subordination of the entire cellular metabolism to characteristic functional manifestations of mitochondria. Mitochondria are capable of producing not only ATP, but also iron-sulfur clusters, steroid hormones, heme, reactive oxygen and nitrogen species, participate in thermogenesis, regulate cell death, proliferation and differentiation, participate in detoxification, etc. They are a mandatory attribute of eukaryotic cells, and, so far, no eukaryotic cells performing a non-parasitic or non-symbiotic life style have been found that lack mitochondria. We believe that the structural-functional intracellular, intercellular, inter-organ, and interspecific diversity of mitochondria is large enough to provide grounds for creating a mitochondrial nomenclature. The arguments for this are given in this analytical work.

Amelioration of Radiation-Induced Cell Death in Neuro2a Cells by Neutralizing Oxidative Stress and Reducing Mitochondrial Dysfunction Using N-Acetyl-L-Tryptophan

The deleterious effects of ionizing radiation on the central nervous system (CNS) are poorly understood. Radiation exposure during an accidental nuclear explosion, nuclear war, or radiotherapy causes severe brain damage. As a result, the current work is carried out to assess the radioprotective potential of N-acetyl-L-tryptophan (L-NAT) in neuronal cells. Radiation-induced cell death and its amelioration by L-NAT pretreatment were investigated using MTT, SRB, CFU, and comet assays. Flow cytometric and microscopic fluorescence assays were used to investigate radiation-induced oxidative stress, alteration in mitochondrial redox, Ca2+ homeostasis, depolarization of mitochondrial membrane potential, and its prevention with L-NAT pretreatment. Western blot analysis of Caspase-3, γ-H2aX, p53, ERK-1/2, and p-ERK-1/2 expression was carried out to identify the effects of L-NAT pretreatment on radiation-induced apoptosis and its regulatory proteins expression. The study demonstrated (MTT, SRB, and CFU assay) significant (~80%; p <0.001%) radioprotection in irradiated (LD50 IR dose) Neuro2a cells that were pretreated with L-NAT. In comparison to irradiated cells, L-NAT pretreatment resulted in significant (p <0.001%) DNA protection. A subsequent study revealed that L-NAT pretreatment of irradiated Neuro2a cells establishes oxidative stress by increasing antioxidant enzymes and mitochondrial redox homeostasis by inhibiting Ca2+ migration from the cytoplasm to the mitochondrial matrix and thus protects the mitochondrial membrane hyperpolarization. Caspase-3 and γ-H2aX protein expression decreased, while p-ERK1/2 and p53 expression increased in L-NAT pretreated irradiated cells compared to irradiated cells. Hence, L-NAT could be a potential radioprotective that may inhibit oxidative stress and DNA damage and maintain mitochondrial health and Ca2+ levels by activating p-ERK1/2 and p53 expression in Neuronal cells.

A Smart Nanoreactor Based on an O2-Economized Dual Energy Inhibition Strategy Armed with Dual Multi-stimuli-Responsive "Doorkeepers" for Enhanced CDT/PTT of Rheumatoid Arthritis

Activated fibroblast-like synovial (FLS) cells are regarded as an important target for rheumatoid arthritis (RA) treatment via starvation therapy mediated by glucose oxidase (GOx). However, the hypoxic RA-FLS environment greatly reduces the oxidation process of glucose and leads to a poor therapeutic effect of the GOx-based starvation therapy. In this work, we designed a hollow mesoporous copper sulfide nanoparticles (CuS NPs)-based smart GOx/atovaquone (ATO) codelivery system (named as V-HAGC) targeting RA-FLS cells to realize a O₂-economized dual energy inhibition strategy to solve the limitation of GOx-based starvation therapy. V-HAGC armed with dual multi-stimuli-responsive "doorkeepers" can guard drugs intelligently. Once under the stimulation of photothermal and acidic conditions at the targeted area, the dual intelligent responsive "doors" would orderly open to realize the controllable release of drugs. Besides, the efficacy of V-HAGC would be much improved by the additional chemodynamic therapy (CDT) and photothermal therapy (PTT) stimulated by CuS NPs. Meanwhile, the upregulated H₂O₂ and acid levels by starvation therapy would promote the Fenton-like reaction of CuS NPs under O₂-economized dual energy inhibition, which could enhance the PTT and CDT efficacy as well. In vitro and in vivo evaluations revealed V-HAGC with much improved efficacy of this combination therapy for RA. In general, the smart V-HAGC based on the O₂-economized dual energy inhibition strategy combined with enhanced CDT and PTT has the potential to be an alternative methodology in the treatment of RA.

Do Extracellular Vesicles Derived from Mesenchymal Stem Cells Contain Functional Mitochondria?

Extracellular vesicles (EV) derived from stem cells have become an effective complement to the use in cell therapy of stem cells themselves, which has led to an explosion of research into the mechanisms of vesicle formation and their action. There is evidence demonstrating the presence of mitochondrial components in EV, but a definitive conclusion about whether EV contains fully functional mitochondria has not yet been made. In this study, two EV fractions derived from mesenchymal stromal stem cells (MSC) and separated by their size were examined. Flow cytometry revealed the presence of mitochondrial lipid components capable of interacting with mitochondrial dyes MitoTracker Green and 10-nonylacridine orange; however, the EV response to the probe for mitochondrial membrane potential was negative. Detailed analysis revealed components from all mitochondria compartments, including house-keeping mitochondria proteins and DNA as well as energy-related proteins such as membrane-localized proteins of complexes I, IV, and V, and soluble proteins from the Krebs cycle. When assessing the functional activity of mitochondria, high variability in oxygen consumption was noted, which was only partially attributed to mitochondrial respiratory activity. Our findings demonstrate that the EV contain all parts of mitochondria; however, their independent functionality inside EV has not been confirmed, which may be due either to the absence of necessary cofactors and/or the EV formation process and, probably the methodology of obtaining EV.

Neuroprotective effect of Ginsenoside Re against neurotoxin‑induced Parkinson's disease models via induction of Nrf2

The aim of the present study was to examine the neuroprotective effects of a panel of active components of ginseng and to explore their molecular mechanisms of action in two rotenone (Rot)-induced models of Parkinson's disease: An in vitro model using the human neuroblastoma cell line SH-SY5Y and an in vivo model using Drosophila. Ginsenoside Re (Re) was identified as the most potent inhibitor of Rot-induced cytotoxicity in SH-SY5Y cells by Cell Counting kit-8 assay and lactate dehydrogenase release assay. Flow cytometry, Hoechst staining, Rhodamine 123 staining, ATP and cytochrome c release revealed that Re rescue of Rot-induced mitochondrial dysfunction and inhibition of the mitochondrial apoptotic pathway. Western blot analysis demonstrated that Re alleviated Rot-induced oxidative stress by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) anti-oxidant pathway, and these effects were abolished by RNA interference-mediated knockdown of Nrf2. Re enhanced phosphorylation of components of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and extracellular regulated protein kinase (ERK) pathways, and pharmacological inhibition of these pathways reduced Re-mediated Nrf2 activation and neuroprotection. In the Drosophila model, Immunofluorescence microscopy, reactive oxygen species (ROS), hydrogen peroxide and knockdown analysis revealed that Re reversed Rot-induced motor deficits and dopaminergic neuron loss while concomitantly alleviating Rot-induced oxidative damage. The findings of the present study suggest that Re protects neurons against Rot-induced mitochondrial dysfunction and oxidative damage, at least in part, by inducing Nrf2/heme oxygenase-1 expression and activation of the dual PI3K/AKT and ERK pathways.