Measurement of cell death in mammalian cells

Mechanistic Insights into Sphingomyelin Nanoemulsions as Drug Delivery Systems for Non-Small Cell Lung Cancer Therapy

Sphingomyelin nanoemulsions (SNs) are promising drug delivery systems with potential for treating challenging tumors, including non-small cell lung cancer (NSCLC), which has a poor prognosis and a 5-year survival rate below 5%. Understanding the toxicity mechanisms and intracellular behavior of SNs is crucial for optimizing their therapeutic application. This study aims to investigate the interaction between SNs and A549 lung adenocarcinoma cells, focusing on their cytotoxic effects and mechanisms of cellular toxicity. SNs were synthesized and characterized for size, surface charge, and stability. A549 cells were treated with varying concentrations of SNs, and cellular uptake pathways were assessed using inhibitors of energy-dependent processes. Cytotoxicity was evaluated through an alamarBlue assay to determine the IC50 value after 24 h. Mechanisms of toxicity, including lysosomal and mitochondrial involvement, were examined using co-localization studies, mitochondrial membrane potential assays, and markers of apoptosis. SNs exhibited rapid cellular uptake via energy-dependent pathways. The IC50 concentration for A549 cells was 0.89 ± 0.15 mg/mL, suggesting favorable cytocompatibility compared to other nanocarriers. At IC50, SNs induced apoptosis characterized by lysosomal damage, mitochondrial membrane permeabilization, and the release of apoptotic factors. These effects disrupted autophagic flux and contributed to cell death, demonstrating potential for overcoming drug resistance. Resveratrol-loaded SNs showed enhanced cytotoxicity, supporting their application as targeted drug delivery vehicles. This study highlights the potential of SNs as efficient drug delivery systems for NSCLC therapy, offering insights into their cellular interactions and toxicity mechanisms. These findings pave the way for the rational design of SN-based therapeutic platforms for cancer and other mitochondria-related diseases.

AI discovery of TLR agonist-driven phenotypes reveals unique features of peripheral cells from healthy donors and ART-suppressed people living with HIV

Background

Selective and potent Toll-like receptor (TLR) agonists are currently under evaluation in preclinical models and clinical studies to understand how the innate immune system can be harnessed for therapeutic potential. These molecules are designed to modulate innate and adaptive immune responses, making them promising therapeutic candidates for treating diseases such as cancer or chronic viral infections. Much is known about the expression and signaling of TLRs which varies based on cell type, cellular localization, and tissue distribution. However, the downstream effects of different TLR agonists on cellular populations and phenotypes are not well understood. This study aimed to investigate the impact of TLR pathway stimulation on peripheral blood mononuclear cell (PBMC) cultures from people living with HIV (PLWH) and healthy donors.

Methods

The effects of TLR4, TLR7, TLR7/8, TLR8 and TLR9 agonists were evaluated on cytokine production, cell population frequencies, and morphological characteristics of PBMC cultures over time. Changes in the proportions of different cell populations in blood and morphological features were assessed using high-content imaging and analyzed using an AI-driven approach.

Results

TLR4 and TLR8 agonists promoted a compositional shift and accumulation of small round (lymphocyte-like) PBMCs, whereas TLR9 agonists led to an accumulation of large round (myeloid-like) PBMCs. A related increase was observed in markers of cell death, most prominently with TLR4 and TLR8 agonists. All TLR agonists were shown to promote some features associated with cellular migration. Furthermore, a comparison of TLR agonist responses in healthy and HIV-positive PBMCs revealed pronounced differences in cytokine/chemokine responses and morphological cellular features. Most notably, higher actin contraction and nuclear fragmentation was observed in response to TLR4, TLR7, TLR7/8 and TLR9 agonists for antiretroviral therapy (ART)-suppressed PLWH versus healthy PBMCs.

Conclusions

These data suggest that machine learning, combined with cell imaging and cytokine quantification, can be used to better understand the cytological and soluble immune responses following treatments with immunomodulatory agents in vitro. In addition, comparisons of these responses between disease states are possible with the appropriate patient samples.

Methylene Blue-Mediated Photodynamic Therapy in Combination With Doxorubicin: A Novel Approach in the Treatment of HT-29 Colon Cancer Cells

Introduction: With an alarmingly growing number of patients diagnosed with colorectal cancer, adopting innovative anti-cancer approaches has recently garnered great attention. One interesting concept is the co-administration of cytotoxic agents and safer modalities such as photodynamic therapy (PDT), which can subsequently improve therapeutic efficacy and potentially reduce the risks of severe adverse effects and drug resistance. In the course of PDT, a locally injected photosensitizer (PS) is irradiated with a light source, which subsequently generates reactive oxygen species (ROS) and induces programmed cell death in tumor cells. Methods: In this study, to evaluate the potential anti-cancer effects of chemotherapy combined with PDT, in comparison to each alone, we employed PDT, comprising methylene blue (MB) and diode lasers at 630 and 810 nm wavelengths, in conjunction with the chemotherapeutic agent doxorubicin (DOX). Results: The MTT assay showed that the viability of colorectal cancer HT-29 cells decreased significantly following DOX+PDT treatment. Similarly, lactate dehydrogenase (LDH) release and lipid peroxidation rates were substantially higher in DOX+PDT treatment groups. Lastly, the catalase (CAT) assay indicated that the combination reduced the ability of CAT in the detoxification of H2 O2. Conclusion: Our study suggests that MB-mediated PDT combined with chemotherapy might provide a promising avenue to improve therapeutic efficacy and potentially reduce the risk of adverse effects and drug resistance. Without a doubt, further investigations need to delve into the pharmacological advantages and disadvantages of PTD-based combination therapy and optimize its administered doses along with other modalities.

Fucoidan based polymeric nanoparticles encapsulating epirubicin: A novel and effective chemotherapeutic formulation against colorectal cancer

Colorectal cancer (CRC) is one of the most common and challenging malignancy that needs some effective and safer chemotherapeutic agents for the treatment. In this study, anticancer agent epirubicin (Epi) was loaded in polymeric polyethylene glycol-polylactic acid-nanoparticles (mPEG-PLA-NPs) coated with a marine anti-cancer non-toxic polysaccharide fucoidan (FC), to achieve a synergistic activity against CRC. The characterization of the NPs revealed that they were spherical, monodispersed, stable, with a negative zeta potential, and exhibited good biocompatibility and controlled release. In vitro anti-cancer activity of the NPs on HCT116 cell line was found to be promising, and corroborated well with in vivo studies involving BALB/C mice injected with C26 murine cancer cells. The outcome of MTT assay demonstrated that IC50 value of free Epi was 3.72 µM, and that of non-coated and coated Epi nano-formulations was 33.67 and 10.19 µM, respectively. Higher tumor regression, better survival and reduced off-side cardiotoxicity were observed when this novel NPs formulation was used to treat tumor-bearing mice. Free FC and Epi treated mice showed 37.73 % and 61.49 % regression in tumor size, whereas there was 79.76 % and 90.34 % tumor regression in mice treated with non-coated Epi NPs and coated Epi NPs, respectively. Therefore, mPEG-PLA-FC-Epi-NPs hold a potential to be used as an effective chemotherapeutic formulation against CRC, since it exhibited better efficacy and lower toxicity.

Exploring Mucoadhesive and Toxicological Characteristics Following Modification of Linear Polyethylenimine with Various Anhydrides

Linear polyethylenimine (L-PEI) has numerous applications, such as in pharmaceutical formulations, gene delivery, and water treatment. However, due to the presence of secondary amine groups, L-PEI shows a relatively high toxicity and low biocompatibility. Here, various organic anhydrides were used to modify L-PEI to reduce its toxicity and enhance its functionality. We selected methacrylic anhydride, crotonic anhydride, maleic anhydride, and succinic anhydride to modify L-PEI. The structure of the resulting derivatives was characterized using 1H NMR and FTIR spectroscopies, and their behavior in aqueous solutions was studied using turbidimetric and electrophoretic mobility measurements over a broad range of pHs. A fluorescence flow through method determined the mucoadhesive properties of the polymers to the bovine palpebral conjunctiva. Methacrylated L-PEI and crotonylated L-PEI showed strong mucoadhesive properties at pH 7.4, likely due to covalent bonding with mucin thiol groups. In contrast, maleylated and succinylated L-PEI were poorly mucoadhesive as the pH was above their isoelectric point, resulting in electrostatic repulsion between the polymers and mucin. The toxicity of these polymers was evaluated using in vivo assays with planaria and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cell viability assay in human alveolar epithelial cells. Moreover, the irritancy of polymers was assessed using a slug mucosa irritation assay. The results demonstrated that anhydride modification mitigated the adverse toxicity effects seen for parent L-PEI.

Enhanced harvest performance predictability through advanced multivariate data analysis of mammalian cell culture particle size distribution

The industry's pursuit for higher antibody production has led to increased cell density cultures that impact the performance of subsequent product recovery steps. This increase in cell concentration has highlighted the critical role of solids concentration in centrifugation yield, while recent product degradation cases have shed light on the impact of cell lysis on product quality. Current methods for measuring solids concentration and cell lysis are not suited for early-stage high-throughput experimentation, which means that these cell culture outputs are not well characterized in early process development. This article describes a novel approach that leveraged the data from a widely-used automated cell counter (Vi-CELL™ XR) to accurately predict solids concentration and a common cell lysis indicator represented as lactate dehydrogenase (LDH) release. For this purpose, partial least squares (PLS) models were derived with k-fold cross-validation from the particle size distribution data generated by the cell counter. The PLS models showed good predictive potential for both LDH release and solids concentration. This novel approach reduced the time required for evaluating the solids concentration and LDH for a typical high-throughput cell culture system (with 48 bioreactors in parallel) from around 7 h down to a few minutes.

Defining melanoma combination therapies that provide senolytic sensitivity in human melanoma cells

Malignant Melanoma that resists immunotherapy remains the deadliest form of skin cancer owing to poor clinically lasting responses. Alternative like genotoxic or targeted chemotherapy trigger various cancer cell fates after treatment including cell death and senescence. Senescent cells can be eliminated using senolytic drugs and we hypothesize that the targeted elimination of therapy-induced senescent melanoma cells could complement both conventional and immunotherapies. We utilized a panel of cells representing diverse mutational background relevant to melanoma and found that they developed distinct senescent phenotypes in response to treatment. A genotoxic combination therapy of carboplatin-paclitaxel or irradiation triggered a mixed response of cell death and senescence, irrespective of BRAF mutation profiles. DNA damage-induced senescent melanoma cells exhibited morphological changes, residual DNA damage, and increased senescence-associated secretory phenotype (SASP). In contrast, dual targeted inhibition of Braf and Mek triggered a different mixed cell fate response including senescent-like and persister cells. While persister cells could reproliferate, senescent-like cells were stably arrested, but without detectable DNA damage and senescence-associated secretory phenotype. To assess the sensitivity to senolytics we employed a novel real-time imaging-based death assay and observed that Bcl2/Bcl-XL inhibitors and piperlongumine were effective in promoting death of carboplatin-paclitaxel and irradiation-induced senescent melanoma cells, while the mixed persister cells and senescent-like cells resulting from Braf-Mek inhibition remained unresponsive. Interestingly, a direct synergy between Bcl2/Bcl-XL inhibitors and Braf-Mek inhibitors was observed when used out of the context of senescence. Overall, we highlight diverse hallmarks of melanoma senescent states and provide evidence of context-dependent senotherapeutics that could reduce treatment resistance while also discussing the limitations of this strategy in human melanoma cells.

Experimental and computational approach to establish fit-for-purpose cell viability assays

Aim: Cell viability assays are critical for cell-based products. Here, we demonstrate a combined experimental and computational approach to identify fit-for-purpose cell assays that can predict changes in cell proliferation, a critical biological response in cell expansion. Materials & methods: Jurkat cells were systematically injured using heat (45 ± 1°C). Cell viability was measured at 0 h and 24 h after treatment using assays for membrane integrity, metabolic function and apoptosis. Proliferation kinetics for longer term cultures were modeled using the Gompertz distribution to establish predictive models between cell viability results and proliferation. Results & conclusion: We demonstrate an approach for ranking these assays as predictors of cell proliferation and for setting cell viability specifications when a particular proliferation response is required.

Current trends in luminescence-based assessment of apoptosis

Apoptosis, the most extensively studied type of cell death, is known to play a crucial role in numerous processes such as elimination of unwanted cells or cellular debris, growth, control of the immune system, and prevention of malignancies. Defective regulation of apoptosis can trigger various diseases and disorders including cancer, neurological conditions, autoimmune diseases and developmental disorders. Knowing the nuances of the cell death type induced by a compound can help decipher which therapy is more effective for specific diseases. The detection of apoptotic cells using classic methods has brought significant contribution over the years, but innovative methods are quickly emerging and allow more in-depth understanding of the mechanisms, aside from a simple quantification. Due to increased sensitivity, time efficiency, pathway specificity and negligible cytotoxicity, these innovative approaches have great potential for both in vitro and in vivo studies. This review aims to shed light on the importance of developing and using novel nanoscale methods as an alternative to the classic apoptosis detection techniques.

Empagliflozin reduces podocyte lipotoxicity in experimental Alport syndrome

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are anti-hyperglycemic agents that prevent glucose reabsorption in proximal tubular cells. SGLT2i improves renal outcomes in both diabetic and non-diabetic patients, indicating it may have beneficial effects beyond glycemic control. Here, we demonstrate that SGLT2i affects energy metabolism and podocyte lipotoxicity in experimental Alport syndrome (AS). In vitro, we found that the SGLT2 protein was expressed in human and mouse podocytes to a similar extent in tubular cells. Newly established immortalized podocytes from Col4a3 knockout mice (AS podocytes) accumulate lipid droplets along with increased apoptosis when compared to wild-type podocytes. Treatment with SGLT2i empagliflozin reduces lipid droplet accumulation and apoptosis in AS podocytes. Empagliflozin inhibits the utilization of glucose/pyruvate as a metabolic substrate in AS podocytes but not in AS tubular cells. In vivo, we demonstrate that empagliflozin reduces albuminuria and prolongs the survival of AS mice. Empagliflozin-treated AS mice show decreased serum blood urea nitrogen and creatinine levels in association with reduced triglyceride and cholesterol ester content in kidney cortices when compared to AS mice. Lipid accumulation in kidney cortices correlates with a decline in renal function. In summary, empagliflozin reduces podocyte lipotoxicity and improves kidney function in experimental AS in association with the energy substrates switch from glucose to fatty acids in podocytes.

Vaping additives cannabinoid oil and vitamin E acetate adhere to and damage the human airway epithelium

E-cigarette, or vaping product use-associated lung injury (EVALI), is a severe respiratory disorder that caused a sudden outbreak of hospitalized young people in 2019. Using cannabis oil containing vaping products, including vitamin E acetate contaminants, was found to be strongly associated with EVALI. However, the underlying tissue impacts of the condition are still largely unknown. Here, we focused on the vehicle cannabinoid oil (CBD oil) and contaminant vitamin E acetate (VEA) effects on airway epithelial cells. Primary human bronchial epithelial (HBE) cultures were exposed to e-liquid aerosols that contained CBD oil and VEA in combination or the common e-liquid components PG/VG with and without nicotine. Cell viability analysis indicated dramatically increased cell death counts after 3 days of CBD exposure, and this effect was even higher after CBD + VEA exposure. Microscopic examination of the cultures revealed cannabinoid and VEA depositions on the epithelial surfaces and cannabinoid accumulation in exposed cells, followed by cell death. These observations were supported by proteomic analysis of the cell secretions that exhibited increases in known markers of airway epithelial toxicity, such as xenobiotic enzymes, factors related to oxidative stress response, and cell death indicators. Overall, our study provides insights into the association between cannabinoid oil and vitamin E acetate vaping and lung injury. Collectively, our results suggest that the adherent accumulation of CBD oil on airway surfaces and the cellular uptake of both CBD oil- and VEA-containing condensates cause elevated metabolic stress, leading to increased cell death rates in human airway epithelial cultures.

Membrane Vesicles of Toxigenic Clostridioides difficile Affect the Metabolism of Liver HepG2 Cells

Clostridioides difficile infection (CDI) appears to be associated with different liver diseases. C. difficile secretes membrane vesicles (MVs), which may be involved in the development of nonalcoholic fatty liver disease (NALFD) and drug-induced liver injury (DILI). In this study, we investigated the presence of C. difficile-derived MVs in patients with and without CDI, and analyzed their effects on pathways related to NAFLD and DILI in HepG2 cells. Fecal extracellular vesicles from CDI patients showed an increase of Clostridioides MVs. C. difficile-derived MVs that were internalized by HepG2 cells. Toxigenic C. difficile-derived MVs decreased mitochondrial membrane potential and increased intracellular ROS compared to non-toxigenic C. difficile-derived MVs. In addition, toxigenic C. difficile-derived MVs upregulated the expression of genes related to mitochondrial fission (FIS1 and DRP1), antioxidant status (GPX1), apoptosis (CASP3), glycolysis (HK2, PDK1, LDHA and PKM2) and β-oxidation (CPT1A), as well as anti- and pro-inflammatory genes (IL-6 and IL-10). However, non-toxigenic C. difficile-derived MVs did not produce changes in the expression of these genes, except for CPT1A, which was also increased. In conclusion, the metabolic and mitochondrial changes produced by MVs obtained from toxigenic C. difficile present in CDI feces are common pathophysiological features observed in the NAFLD spectrum and DILI.

Extracellular vesicles from the CNS play pivotal roles in neuroprotection and neurodegeneration: lessons from in vitro experiments

Intercellular communication between diverse cell types is crucial for the maintenance of the central nervous system, and exosomes have been shown to play an important role in this process. Exosomes are small extracellular vesicles (EVs) that are released by all cell types and carry cargoes that can elicit downstream effects in recipient cells. Exosomal communication in the central nervous system has been implicated in many neurodegenerative diseases, ranging from Alzheimer's disease to major depressive disorder. Though there remain many unknowns in the field of EV biology, in vitro experiments can provide many insights into their potential roles in health and disease. In this review, we discuss the findings of many in vitro EV experiments, with a focus on the potential roles in regulating cell viability, inflammation, oxidative stress, and neurite integrity in the central nervous system.

Enhanced Tumor Accumulation of Multimodal Magneto-Plasmonic Nanoparticles via an Implanted Micromagnet-Assisted Delivery Strategy

One of the major shortcomings of nano carriers-assisted cancer therapeutic strategies continues to be the inadequate tumor penetration and retention of systemically administered nanoformulations and its off-target toxicity. Stromal parameters-related heterogeneity in enhanced permeability and retention effect and physicochemical properties of the nanoformulations immensely contributes to their poor tumor extravasation. Herein, a novel tumor targeting strategy, where an intratumorally implanted micromagnet can significantly enhance accumulation of magneto-plasmonic nanoparticles (NPs) at the micromagnet-implanted tumor in bilateral colorectal tumor models while limiting their off-target accumulation, is demonstrated. To this end, novel multimodal gold/iron oxide NPs comprised of an array of multifunctional moieties with high therapeutic, sensing, and imaging potential are developed. It is also discovered that cancer cell targeted NPs in combination with static magnetic field can selectively induce cancer cell death. A multimodal caspase-3 nanosensor is also developed for real-time visualization of selective induction of apoptosis in cancer cells. In addition, the photothermal killing capability of these NPs in vitro is evaluated, and their potential for enhanced photothermal ablation in tissue samples is demonstrated. Building on current uses of implantable devices for therapeutic purposes, this study envisions the proposed micromagnet-assisted NPs delivery approach may be used to accelerate the clinical translation of various nanoformulations.

PDE4 inhibitor eliminates breast cancer stem cells via noncanonical activation of mTOR

Ineffective cancer treatment is implicated in metastasis, recurrence, resistance to chemotherapy and radiotherapy, and evasion of immune surveillance. All these failures occur due to the persistence of cancer stem cells (CSCs) even after rigorous therapy, thereby rendering them as essential targets for cancer management. Contrary to the quiescent nature of CSCs, a gene profiler array disclosed that phosphatidylinositol-3-kinase (PI3K), which is known to be crucial for cell proliferation, differentiation, and survival, was significantly upregulated in CSCs. Since PI3K is modulated by cyclic adenosine 3',5' monophosphate (cAMP), analyses of cAMP regulation revealed that breast CSCs expressed increased levels of phosphodiesterase 4 (PDE4) in contrast to normal stem cells. In accordance, the effects of rolipram, a PDE4 inhibitor, were evaluated on PI3K regulators and signaling. The efficacy of rolipram was compared with paclitaxel, an anticancer drug that is ineffective in obliterating breast CSCs. Analyses of downstream signaling components revealed a switch between cell survival and death, in response to rolipram, specifically of the CSCs. Rolipram-mediated downregulation of PDE4A levels in breast CSCs led to an increase in cAMP levels and protein kinase A (PKA) expression. Subsequently, PKA-mediated upregulation of phosphatase and tensin homolog antagonized the PI3K/AKT/mTOR pathway and led to cell cycle arrest. Interestingly, direct yet noncanonical activation of mTOR by PKA, circumventing the influence of PI3K and AKT, temporally shifted the fate of CSCs toward apoptosis. Rolipram in combination with paclitaxel indicated synergistic consequences, which effectively obliterated CSCs within a tumor, thereby suggesting combinatorial therapy as a sustainable and effective strategy to abrogate breast CSCs for better patient prognosis.

3D biocomposite culture enhances differentiation of dopamine-like neurons from SH-SY5Y cells: A model for studying Parkinson's disease phenotypes

Studies of underlying neurodegenerative processes in Parkinson's Disease (PD) have traditionally utilized cell cultures grown on two-dimensional (2D) surfaces. Biomimetic three-dimensional (3D) cell culture platforms have been developed to better emulate features of the brain's natural microenvironment. We here use our bioengineered brain-like tissue model, composed of a silk-hydrogel composite, to study the 3D microenvironment's contributions on the development and performance of dopaminergic-like neurons (DLNs). Compared with 2D culture, SH-SY5Y cells differentiated in 3D microenvironments were enriched for DLNs concomitant with a reduction in proliferative capacity during the neurodevelopmental process. Additionally, the 3D DLN cultures were more sensitive to oxidative stresses elicited by the PD-related neurotoxin 1-methyl-4-phenylpyridinium (MPP). MPP induced transcriptomic profile changes specific to 3D-differentiated DLN cultures, replicating the dysfunction of neuronal signaling pathways and mitochondrial dynamics implicated in PD. Overall, this physiologically-relevant 3D platform resembles a useful tool for studying dopamine neuron biology and interrogating molecular mechanisms underlying neurodegeneration in PD.

Commercial human pulmonary artery endothelial cells have in-vitro behavior that varies by sex

It is unknown whether biological sex influences phenotypes of commercially available human pulmonary artery endothelial cells (HPAECs). Ten lots of commercial HPAECs were used (Lonza Biologics; PromoCell). Five (50%) were confirmed to be genotypically male (SRY+) and five (50%) were confirmed to be female (SRY-). Experiments were conducted between passages five and eight. HPAEC phenotype was confirmed with a panel of cell expression markers. Standard assays for proliferation, migration and tube formation were performed in triplicate with technical replicates, under three treatment conditions (EndoGRO; Sigma-Aldrich). Apoptosis was assessed by exposing cells treated with complete media or low serum media to hypoxic (1% oxygen) or normoxic (20% oxygen) conditions. Laboratory staff was blinded. The median (range) age of male and female donors from whom the HPAECs were derived was 58 (48-60) and 56 (33-67), respectively. Our results suggest decreased proliferation in genotypically female cells compared with male cells (p = 0.09). With increasing donor age, female cells were less proliferative and male cells were more proliferative (p = 0.001). Female cells were significantly more apoptotic than male cells by condition (p = 0.001). Female cells were significantly more migratory than male cells in complete media but less migratory than male cells under vascular endothelial growth factor enriched conditions (p = 0.001). There are subtle sex-based differences in the behavior of HPAECs that depend on donor sex and, less so, age. These differences may undermine rigor and reproducibility. Future studies should define whether biological sex is an important regulator of HPAEC function in health and disease.

Effect of drying method on the production of in vitro short-chain fatty acids and histone deacetylase mediation of cocoa pod husk

We evaluated the effect of cocoa pod husk (CPH) processing (microwave [MW], forced-air drying [FAD], and FAD plus extrusion [FAD-E]), and in vitro gastrointestinal digestion on the in vitro human colonic fermentation metabolism, in vitro bioactivity on human HT-29 colon cancer cell, and the in silico mechanism of selected compounds. CPH as a substrate for human colonic microbiota significantly decrease local pH (MW -0.7, FAD -0.2, and FAD-E -0.3, 24 h) and modifies their metabolic activity (short-chain fatty acids [SCFAs] production). FAD-E generated the highest butyric (7.6 mM/L, 4 h) and FAD the highest acetic and propionic acid levels (71.4 and 36.7 mM/L, 24 h). The in vitro colonic fermented FAD-E sample (FE/FAD-E) caused HT-29 colorectal cancer cells death by inducing damage on membrane integrity and inhibiting (up to 92%) histone-deacetylase (HDAC) activity. In silico results showed that chlorogenic acid, (-)-epicatechin, and (+)-catechin, followed by butyric and propionic acids, are highly involved in the HDAC6 inhibitory activity. The results highlight the potential human health postbiotic benefits of CPH consumption, mediated by colonic microbiota-derived metabolites. PRACTICAL APPLICATION: The enormous amount of CPH (10 tons/1 ton of dry beans) generated by the cocoa industry can be used as a removable source of bioactive compounds with physicochemical functionality and health bioactivity. However, their potential applications and health benefits are insufficiently explored. CPH represents a serious disposal problem; practical and innovative ideas to use this highly available and affordable material are urgent. Research exploring their potential applications can increase the sustainability of the cocoa agro-industry. This paper highlights the value addition that can be achieved with this valuable industrial co-product, generating new functional products and ingredients.

Evaluation of fluorescence-based viability stains in cells dissociated from scleractinian coral Pocillopora damicornis

The application of established cell viability assays such as the commonly used trypan blue staining method to coral cells is not straightforward due to different culture parameters and different cellular features specific to mammalian cells compared to marine invertebrates. Using Pocillopora damicornis as a model, we characterized the autofluorescence and tested different fluorescent dye pair combinations to identify alternative viability indicators. The cytotoxicity of different representative molecules, namely small organic molecules, proteins and nanoparticles (NP), was measured after 24 h of exposure using the fluorescent dye pair Hoechst 33342 and SYTOX orange. Our results show that this dye pair can be distinctly measured in the presence of fluorescent proteins plus chlorophyll. P. damicornis cells exposed for 24 h to Triton-X100, insulin or titanium dioxide (TiO₂) NPs, respectively, at concentrations ranging from 0.5 to 100 µg/mL, revealed a LC50 of 0.46 µg/mL for Triton-X100, 6.21 µg/mL for TiO₂ NPs and 33.9 µg/mL for insulin. This work presents the approach used to customize dye pairs for membrane integrity-based cell viability assays considering the species- and genotype-specific autofluorescence of scleractinian corals, namely: endogenous fluorescence characterization followed by the selection of dyes that do not overlap with endogenous signals.

Radiosensitizing effect of dendrosomal nanoformulation of curcumin on cancer cells

BACKGROUND

Curcumin was found to possess numerous pharmacological activities in clinical research, however, its biological effects together with radiation are yet to be addressed. The present study investigated whether the combined treatment of dendrosomal nanoformulation of curcumin (DNC) and gamma radiation can enhance the radiosensitivity of U87MG and MDA-MB-231 cell lines.

METHODS

U87MG and MDA-MB-231 cell lines were exposed to 2 Gray (Gy) and 10 μM DNC determined by MTT assay, then subjected to clonogenic assay, cell cycle assay, and flow cytometric apoptosis analysis. Acridine Orange/Ethidium Bromide (AO/EB) and 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) stained cells were used to study morphologic changes. The expression evaluation of putative cell cycle genes, i.e., P53, P21, CCND1, and CCNB1 was carried out by RT-qPCR.

RESULTS

Our findings indicated that the combined treatment with DNC and radiation might cooperatively augment the efficacy of ionizing radiation in the cancer cells and notably decrease the survival and viability of the cells in a time- and concentration-dependent manner. In addition to a synergistic effect deducted by sensitizer enhancement ratio (SER) assessment, co-treatment resulted in greater apoptotic cells than the individual treatments. Further experiments then indicated that DNC could effectively induce G2/M phase cell cycle arrest and apoptosis following irradiation. Conformably, there was a decrement of CCND1 and CCNB1 expression, and an increment of P53, P21 expression.

CONCLUSIONS

The data implied that DNC as a radiosensitizer can enhance the lethal effect of ionizing radiation on cancer cells which could be a promising adjuvant therapy in clinical treatments.

In vitro and In vivo Studies of Potential Anticancer Agents of Platinum(II) Complexes of Dicyclopentadiene and Dithiocarbamates

Three platinum(II) complexes of dicyclopentadiene (DCP) and dithiocarbamates (DTC), namely, [Pt(η4-DCP)(Me2DTC)]PF6 (1), [Pt(η4-DCP)(Et2DTC)]PF6 (2) and [Pt(η4-DCP)(Bz2DTC)]PF6 (3) [Me2DTC = dimethyldithiocarbamate, Et2DTC = diethyldithiocarbamate, and Bz2DTC = dibenzyldithiocarbamate] were prepared and characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy. The spectroscopic data indicated the coordination of both DCP and dithiocarbamate ligands to platinum(II). The solution chemisty of complex 1 revealed that the complexes are stable in both DMSO and 1:1 mixture of DMSO: H2O. In vitro cytotoxicity of the complexes relative to cisplatin was tested using MTT assay, against CHL-1 (human melanoma cancer cells), MDA-MB-231 (breast cancer cells), A549 (lung cancer cells), and B16 (murine melanoma cancer cells). The antiproliferative effect of all three prepared complexes was found to be significantly higher than cisplatin. Furthermore, flow cytometric analysis of complex 1 showed that the complex induced apoptosis, oxidative stress, mitochondrial potential depolarization and cell cycle arrest in a concentration-dependent pattern in the CHL-1 cells. Confirmation of apoptosis via gene expression analysis demonstrated down-regulation of anti-apoptotic genes and up-regulation of pro-apoptotic genes in the CHL-1 cells. Wound healing assays also lent support to the strong cytotoxicity of the complexes. In vivo studies showed a significant reduction of tumor volume at the end of the experiment. In addition, the drug did not change the weight of the mice. In conclusion, complex 1 inhibited cell proliferation in vitro and reduced tumor growth in vivo.

Human Heart Anoxia and Reperfusion Tissue (HEART) Model for the Rapid Study of Exosome Bound miRNA Expression As Biomarkers for Myocardial Infarction

Current biomarkers for myocardial infarction (MI) diagnosis are typically late markers released upon cell death, incapable of distinguishing between ischemic and reperfusion injury and can be symptoms of other pathologies. Circulating microRNAs (miRNAs) have recently been proposed as alternative biomarkers for MI diagnosis; however, detecting the changes in the human cardiac miRNA profile during MI is extremely difficult. Here, to study the changes in miRNA levels during acute MI, a heart-on-chip model with a cardiac channel, containing human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes in human heart decellularized matrix and collagen, and a vascular channel, containing hiPSC-derived endothelial cells, is developed. This model is exposed to anoxia followed by normoxia to mimic ischemia and reperfusion, respectively. Using a highly sensitive miRNA biosensor that the authors developed, the exact same increase in miR-1, miR-208b, and miR-499 levels in the MI-on-chip and the time-matched human blood plasma samples collected before and after ischemia and reperfusion, is shown. That the surface marker profile of exosomes in the engineered model changes in response to ischemic and reperfusion injury, which can be used as biomarkers to detect MI, is also shown. Hence, the MI-on-chip model developed here can be used in biomarker discovery.

Sars-Cov-2 Spike Protein-Induced Damage of hiPSC-Derived Cardiomyocytes

Sars-Cov-2 may trigger molecular and functional alterations of cardiomyocytes (CMs) of the heart due to the presence of receptor angiotensin-converting enzyme 2 (ACE2) of the host cells. While the endocytic itinerary of the virus via cleavage of the spike protein of Sars-Cov-2 is well understood, the role of the remaining part of the spike protein subunit and ACE2 complex is still elusive. Herein, the possible effects of this complex are investigated by using synthetic spike proteins of Sars-Cov-2, human-induced pluripotent stem cells (hiPSC), and a culture device made of an arrayed monolayer of cross-linked nanofibers. hiPSCs are first differentiated into CMs that form cardiac tissue-like constructs with regular beating and expression of both ACE2 and gap junction protein Connexin 43. When incubated with the spike proteins, the hiPSC-CMs undergo a rhythmic fluctuation with overstretched sarcomere structures and dispersed gap junction proteins. When incubated with the spike proteins and supplementary angiotensin II, the damage of the spike protein on hiPSC-CMs is enhanced due to downregulated ACE2, chromatin margination, altered Connexin 43 expression, sarcomere disruption, and beating break. This discovery may imply latent effects of the spike proteins on the heart.

Second Generation Small Molecule Inhibitors of Gankyrin for the Treatment of Pediatric Liver Cancer

Background: Gankyrin, a member of the 26S proteasome, is an overexpressed oncoprotein in hepatoblastoma (HBL) and hepatocellular carcinoma (HCC). Cjoc42 was the first small molecule inhibitor of Gankyrin developed; however, the IC50 values of >50 μM made them unattractive for clinical use. Second-generation inhibitors demonstrate a stronger affinity toward Gankyrin and increased cytotoxicity. The aim of this study was to characterize the in vitro effects of three cjoc42 derivatives. Methods: Experiments were performed on the HepG2 (HBL) and Hep3B (pediatric HCC) cell lines. We evaluated the expression of TSPs, cell cycle markers, and stem cell markers by Western blotting and/or real-time quantitative reverse transcription PCR. We also performed apoptotic, synergy, and methylation assays. Results: The treatment with cjoc42 derivatives led to an increase in TSPs and a dose-dependent decrease in the stem cell phenotype in both cell lines. An increase in apoptosis was only seen with AFM-1 and -2 in Hep3B cells. Drug synergy was seen with doxorubicin, and antagonism was seen with cisplatin. In the presence of cjoc42 derivatives, the 20S subunit of the 26S proteasome was more available to transport doxorubicin to the nucleus, leading to synergy. Conclusion: Small-molecule inhibitors for Gankyrin are a promising therapeutic strategy, especially in combination with doxorubicin.

Eriodictyol Attenuates H2O2-Induced Oxidative Damage in Human Dermal Fibroblasts through Enhanced Capacity of Antioxidant Machinery

Oxidative stress in dermal fibroblasts is strongly correlated with the aging process of the skin. The application of natural compounds that can increase the ability of dermal fibroblasts to counteract oxidative stress is a promising approach to promote skin health and beauty. Eriodictyol is a flavonoid that exerts several pharmacological actions through its antioxidant properties. However, its protective effects on dermal fibroblasts have not yet been investigated. In this study, we investigated whether eriodictyol protects human dermal fibroblasts (BJ fibroblasts) from the harmful effects of hydrogen peroxide (H₂O₂). Eriodictyol pretreatment significantly prevented necrotic cell death caused by H₂O₂ exposure. In addition, the level of 2′,7′-dichloro-dihydro-fluorescein oxidation was decreased, and that of glutathione was maintained, indicating that the beneficial effects of eriodictyol against H₂O₂ were closely associated with oxidative-stress attenuation. Eriodictyol mediates its antioxidant effects on dermal fibroblasts against H₂O₂ through (i) the direct neutralization of reactive oxygen species; (ii) the enhancement of the activities of H₂O₂-detoxifying enzymes, including catalase and glutathione peroxidase; and (iii) the induction of the expressions of catalase and glutathione peroxidase 1 via the activation of the Nrf2 signaling system. These results support the potential application of eriodictyol as an ingredient in skincare products for cosmeceutical and pharmaceutical purposes.

Acute toxicity and antitumor potential of 1,3,4-trisubstituted-1,2,3-triazole dhmtAc-loaded liposomes on a triple-negative breast cancer model

For the first time, compounds developed from the 1,2,3-triazole scaffold were evaluated as novel drugs to treat triple-negative breast cancer (TNBC). Four organic salts were idealized as nonclassical bioisosteres of miltefosine, which is used in the topical treatment for skin metastasizing breast carcinoma. Among them, derivative dhmtAc displayed better solubility and higher cytotoxicity against the human breast adenocarcinoma cell line and mouse 4T1 cell lines, which are representatives of TNBC. In vitro assays revealed that dhmtAc interferes with cell integrity, confirmed by lactate dehydogenase leakage. Due to its human peripheral blood mononuclear cell (PBMC) toxicity, dhmtAc in vivo studies were carried out with the drug incorporated in a long-circulating and pH-sensitive liposome (SpHL-dhmtAc), and the acute toxicity in BALB/c mice was determined. Free dhmtAc displayed cardiac and pulmonary toxicity after the systemic administration of 5 mg/kg doses. On the other hand, SpHL-dhmtAc displayed no toxicity at 20 mg/kg. The in vivo antitumor effect of SpHL-dhmtAc was investigated using the 4T1 heterotopic murine model. Intravenous administration of SpHL-dhmtAc reduced the tumor volume and weight, without interfering with the body weight, compared with the control group and the dhmtAc free form. The incorporation of the triazole compound in the liposome allowed the demonstration of its anticancer potential. These findings evidenced 1,3,4-trisubstituted-1,2,3-triazole as a promising scaffold for the development of novel drugs with applicability for the treatment of patients with TNBC.

Rapid and efficient testing of the toxicity of graphene-related materials in primary human lung cells

Graphene and its derivative materials are manufactured by numerous companies and research laboratories, during which processes they can come into contact with their handlers' physiological barriers—for instance, their respiratory system. Despite their potential toxicity, these materials have even been used in face masks to prevent COVID-19 transmission. The increasingly widespread use of these materials requires the design and implementation of appropriate, versatile, and accurate toxicological screening methods to guarantee their safety. Murine models are adequate, though limited when exploring different doses and lengths of exposure—as this increases the number of animals required, contrary to the Three R's principle in animal experimentation. This article proposes an in vitro model using primary, non-transformed normal human bronchial epithelial (NHBE) cells as an alternative to the most widely used model to date, the human lung tumor cell line A549. The model has been tested with three graphene derivatives—graphene oxide (GO), few-layer graphene (FLG), and small FLG (sFLG). We observed a cytotoxic effect (necrosis and apoptosis) at early (6- and 24-h) exposures, which intensified after seven days of contact between cells and the graphene-related materials (GRMs)—with cell death reaching 90% after a 5 µg/mL dose. A549 cells are more resistant to necrosis and apoptosis, yielding values less than half of NHBE cells at low concentrations of GRMs (between 0.05 and 5 µg/mL). Indeed, GRM-induced cell death in NHBE cells is comparable to that induced by toxic compounds such as diesel exhaust particles on the same cell line. We propose NHBE as a suitable model to test GRM-induced toxicity, allowing refinement of the dose concentrations and exposure timings for better-designed in vivo mouse assays.

Visceral fat inflammation and fat embolism are associated with lung's lipidic hyaline membranes in subjects with COVID-19

BACKGROUND

Preliminary data suggested that fat embolism could explain the importance of visceral obesity as a critical determinant of coronavirus disease-2019 (COVID-19).

METHODS

We performed a comprehensive histomorphologic analysis of autoptic visceral adipose tissue (VAT), lungs and livers of 19 subjects with COVID-19 (COVID-19+), and 23 people without COVID-19 (controls). Human adipocytes (hMADS) infected with SARS-CoV-2 were also studied.

RESULTS

Although there were no between-group differences in body-mass-index and adipocytes size, a higher prevalence of CD68+ macrophages among COVID-19+ VAT was detected (p = 0.005) and accompanied by crown-like structures presence, signs of adipocytes stress and death. Consistently, human adipocytes were successfully infected by SARS-CoV-2 in vitro and displayed lower cell viability. Being VAT inflammation associated with lipids spill-over from dead adipocytes, we studied lipids distribution by ORO. Lipids were observed within lungs and livers interstitial spaces, macrophages, endothelial cells, and vessels lumen, features suggestive of fat embolism syndrome, more prevalent among COVID-19+ (p < 0.001). Notably, signs of fat embolism were more prevalent among people with obesity (p = 0.03) independently of COVID-19 diagnosis, suggesting that such condition may be an obesity complication exacerbated by SARS-CoV-2 infection. Importantly, all infected subjects' lungs presented lipids-rich (ORO+) hyaline membranes, formations associated with COVID-19-related pneumonia, present only in one control patient with non-COVID-19-related pneumonia. Importantly, transition aspects between embolic fat and hyaline membranes were also observed.

CONCLUSIONS

This study confirms the lung fat embolism in COVID-19+ patients and describes for the first time novel COVID-19-related features possibly underlying the unfavorable prognosis in people with COVID-19 and obesity.

SARM1 Depletion Slows Axon Degeneration in a CNS Model of Neurotropic Viral Infection

Zika virus (ZIKV) is a neurotropic flavivirus recently linked to congenital ZIKV syndrome in children and encephalitis and Guillain-Barré syndrome in adults. Neurotropic viruses often use axons to traffic to neuronal or glial cell somas where they either remain latent or replicate and proceed to infect new cells. Consequently, it has been suggested that axon degeneration could represent an evolutionarily conserved mechanism to limit viral spread. Whilst it is not known if ZIKV transits in axons, we previously reported that ZIKV infection of glial cells in a murine spinal cord-derived cell culture model of the CNS is associated with a profound loss of neuronal cell processes. This, despite that postmitotic neurons are relatively refractory to infection and death. Here, we tested the hypothesis that ZIKV-associated degeneration of neuronal processes is dependent on activation of Sterile alpha and armadillo motif-containing protein 1 (SARM1), an NADase that acts as a central executioner in a conserved axon degeneration pathway. To test this, we infected wild type and Sarm1 homozygous or heterozygous null cell cultures with ZIKV and examined NAD⁺ levels as well as the survival of neurons and their processes. Unexpectedly, ZIKV infection led to a rapid SARM1-independent reduction in NAD⁺. Nonetheless, the subsequent profound loss of neuronal cell processes was SARM1-dependent and was preceded by early changes in the appearance of β-tubulin III staining. Together, these data identify a role for SARM1 in the pathogenesis of ZIKV infection, which may reflect SARM1's conserved prodegenerative function, independent of its NADase activity.

Spinal Cord Injury Leads to Hippocampal Glial Alterations and Neural Stem Cell Inactivation

The hippocampus encodes spatial and contextual information involved in memory and learning. The incorporation of new neurons into hippocampal networks increases neuroplasticity and enhances hippocampal-dependent learning performances. Only few studies have described hippocampal abnormalities after spinal cord injury (SCI) although cognitive deficits related to hippocampal function have been reported in rodents and even humans. The aim of this study was to characterize in further detail hippocampal changes in the acute and chronic SCI. Our data suggested that neurogenesis reduction in the acute phase after SCI could be due to enhanced death of amplifying neural progenitors (ANPs). In addition, astrocytes became reactive and microglial cells increased their number in almost all hippocampal regions studied. Glial changes resulted in a non-inflammatory response as the mRNAs of the major pro-inflammatory cytokines (IL-1β, TNFα, IL-18) remained unaltered, but CD200R mRNA levels were downregulated. Long-term after SCI, astrocytes remained reactive but on the other hand, microglial cell density decreased. Also, glial cells induced a neuroinflammatory environment with the upregulation of IL-1β, TNFα and IL-18 mRNA expression and the decrease of CD200R mRNA. Neurogenesis reduction may be ascribed at later time points to inactivation of neural stem cells (NSCs) and inhibition of ANP proliferation. The number of granular cells and CA1 pyramidal neurons decreased only in the chronic phase. The release of pro-inflammatory cytokines at the chronic phase might involve neurogenesis reduction and neurodegeneration of hippocampal neurons. Therefore, SCI led to hippocampal changes that could be implicated in cognitive deficits observed in rodents and humans.

Cushing syndrome and glucocorticoids: T-cell lymphopenia, apoptosis, and rescue by IL-21

BACKGROUND

Pediatric endogenous Cushing syndrome (eCs) is mainly caused by pituitary corticotropin-producing adenomas, and most glucocorticoid-dependent effects progressively regress upon tumor removal. eCs reproduces long-term, high-dose glucocorticoid therapy, representing a clean, natural, and unbiased model in which to study glucocorticoid bona fide effects on immunity.

OBJECTIVE

We performed extensive immunologic studies in otherwise healthy pediatric patients with eCs before and 6 to 13 months after tumor resection, as well as in in vitro glucocorticoid-treated control cells.

METHODS

Flow cytometry, immunoblotting, enzyme-linked immunosorbent assay, real-time quantitative PCR, and RNA-Seq techniques were used to characterize patients' and in vitro glucocorticoid treated cells.

RESULTS

Reduced thymic output, decreased naive T cells, diminished proliferation, and increased T-cell apoptosis were detected before surgery; all these defects eventually normalized after tumor removal in patients. In vitro studies also showed increased T-cell apoptosis, with correspondingly diminished NF-κB signaling and IL-21 levels. In this setting, IL-21 addition upregulated antiapoptotic BCL2 expression and rescued T-cell apoptosis in a PI3K pathway-dependent manner. Similar and reproducible findings were confirmed in eCs patient cells as well.

CONCLUSIONS

We identified decreased thymic output and lymphocyte proliferation, together with increased apoptosis, as the underlying causes to T-cell lymphopenia in eCs patients. IL-21 was decreased in both natural and in vitro long-term, high-dose glucocorticoid environments, and in vitro addition of IL-21 counteracted the proapoptotic effects of glucocorticoid therapy. Thus, our results suggest that administration of IL-21 in patients receiving long-term, high-dose glucocorticoid therapy may contribute to ameliorate lymphopenia and the complications associated to it.

The MTT Assay: Utility, Limitations, Pitfalls, and Interpretation in Bulk and Single-Cell Analysis

The MTT assay for cellular metabolic activity is almost ubiquitous to studies of cell toxicity; however, it is commonly applied and interpreted erroneously. We investigated the applicability and limitations of the MTT assay in representing treatment toxicity, cell viability, and metabolic activity. We evaluated the effect of potential confounding variables on the MTT assay measurements on a prostate cancer cell line (PC-3) including cell seeding number, MTT concentration, MTT incubation time, serum starvation, cell culture media composition, released intracellular contents (cell lysate and secretome), and extrusion of formazan to the extracellular space. We also assessed the confounding effect of polyethylene glycol (PEG)-coated gold nanoparticles (Au-NPs) as a tested treatment in PC-3 cells on the assay measurements. We additionally evaluated the applicability of microscopic image cytometry as a tool for measuring intracellular MTT reduction at the single-cell level. Our findings show that the assay measurements are a result of a complicated process dependant on many of the above-mentioned factors, and therefore, optimization of the assay and rational interpretation of the data is necessary to prevent misleading conclusions on variables such as cell viability, treatment toxicity, and/or cell metabolism. We conclude, with recommendations on how to apply the assay and a perspective on where the utility of the assay is a powerful tool, but likewise where it has limitations.

Highly Potent Photoinactivation of Bacteria Using a Water-Soluble, Cell-Permeable, DNA-Binding Photosensitizer

Antimicrobial photodynamic therapy (APDT) employs a photosensitizer, light, and molecular oxygen to treat infectious diseases via oxidative damage, with a low likelihood for the development of resistance. For optimal APDT efficacy, photosensitizers with cationic charges that can permeate bacteria cells and bind intracellular targets are desired to not limit oxidative damage to the outer bacterial structure. Here we report the application of brominated DAPI (Br-DAPI), a water-soluble, DNA-binding photosensitizer for the eradication of both Gram-negative and Gram-positive bacteria (as demonstrated on N99 Escherichia coli and Bacillus subtilis, respectively). We observe intracellular uptake of Br-DAPI, ROS-mediated bacterial cell death via one- and two-photon excitation, and selective photocytotoxicity of bacteria over mammalian cells. Photocytotoxicity of both N99 E. coli and B. subtilis occurred at submicromolar concentrations (IC₅₀ = 0.2-0.4 μM) and low light doses (5 min irradiation times, 4.5 J cm^-2 dose), making it superior to commonly employed APDT phenothiazinium photosensitizers such as methylene blue. Given its high potency and two-photon excitability, Br-DAPI is a promising novel photosensitizer for in vivo APDT applications.

Cellular Protein Phosphatase 2A Regulates Cell Survival Mechanisms in Influenza A Virus Infection

Influenza A viruses (IAVs) are respiratory pathogens that are able to hijack multiple cellular mechanisms to drive their replication. Consequently, several viral and cellular proteins undergo posttranslational modifications such as dynamic phosphorylation/dephosphorylation. In eukaryotic cells, dephosphorylation is mainly catalyzed by protein phosphatase 2A (PP2A). While the function of kinases in IAV infection is quite well studied, only little is known about the role of PP2A in IAV replication. Here, we show, by using knockdown and inhibition approaches of the catalytic subunit PP2Ac, that this phosphatase is important for efficient replication of several IAV subtypes. This could neither be attributed to alterations in the antiviral immune response nor to changes in transcription or translation of viral genes. Interestingly, decreased PP2Ac levels resulted in a significantly reduced cell viability after IAV infection. Comprehensive kinase activity profiling identified an enrichment of process networks related to apoptosis and indicated a synergistic action of hyper-activated PI3K/Akt, MAPK/JAK-STAT and NF-kB signaling pathways, collectively resulting in increased cell death. Taken together, while IAV seems to effectively tap leftover PP2A activity to ensure efficient viral replication, reduced PP2Ac levels fail to orchestrate cell survival mechanisms to protect infected cells from early cell death.

Azide-mediated unusual in situ transformation of Mannich base to Schiff-Mannich base and isolation of their Cu(II) complexes: crystal structure, theoretical inspection and anticancer activities

A new "end-off" compartmental Mannich ligand (HL1) namely 3-((bis(2-methoxyethyl)amino)methyl)-5-bromo-2-hydroxybenzaldehyde containing two methoxyethyl pendant arms and one-CHO functionality has been synthesized through conventional C-C and C-N coupling reactions. On treatment with Cu(ClO₄)₂, HL1 yields a dinuclear μ-phenolatocopper(II) complex having the molecular formula [Cu₂(L¹)₂](ClO₄)₂(H₂O)_1.5 (1). Surprisingly, the ligand HL1 is radically transformed into a new asymmetric Schiff-Mannich base ligand (HLF) in the presence of NaN₃ and Cu(ClO₄)₂ forming a unique dinuclear centro-symmetric Cu(II) complex [Cu(L^F)]₂ (2) as evident from single-crystal X-ray diffraction (SCXRD) analysis. A probable mechanistic rationalization has been proposed on the basis of theoretical calculations, which suggests systematic fragmentation of HL1 in the presence of azide residue and re-condensation of the fragmented units to yield the final Cu-HL^F complex (2). SCXRD analysis portrays a large inter-metallic distance in complex 2 in comparison with complex 1 (5.493 vs. 2.989 Å, respectively) along with other distinct structural features. After physicochemical characterization both the complexes have been exploited to evaluate their possible anticancer proficiency on lung adenocarcinoma cell line (A549). Complex 1 distinctly impeded the proliferation of lung adenocarcinoma cells in a dose-dependent manner more efficiently than complex 2. Due to the behavior of complex 1 as potential therapeutics, cellular transformations of A549 cells have been systematically investigated. As evidenced from various in vitro experiments, the cell death mechanism triggered by complex 1 turned out to be apoptosis, as indicated by the DNA fragmentation, chromatin condensation, membrane blebbing and imbalanced cell cycle distribution as well as retard migration in A549 cells.

Effects of the Selective Serotonin Reuptake Inhibitor Fluoxetine on Developing Neural Circuits in a Model of the Human Fetal Cortex

The developing prenatal brain is particularly susceptible to environmental disturbances. During prenatal brain development, synapses form between neurons, resulting in neural circuits that support complex cognitive functions. In utero exposure to environmental factors such as pharmaceuticals that alter the process of synapse formation increases the risk of neurodevelopmental abnormalities. However, there is a lack of research into how specific environmental factors directly impact the developing neural circuitry of the human brain. For example, selective serotonin reuptake inhibitors are commonly used throughout pregnancy to treat depression, yet their impact on the developing fetal brain remains unclear. Recently, human brain models have provided unprecedented access to the critical window of prenatal brain development. In the present study, we used human neurons and cortical spheroids to determine whether the selective serotonin reuptake inhibitor fluoxetine alters neurite and synapse formation and the development of spontaneous activity within neural circuits. We demonstrate that cortical spheroids express serotonin transporter, thus recapitulating the early developmental expression of serotonin transporter associated with cortical pyramidal neurons. Cortical spheroids also appropriately express serotonin receptors, such as synaptic 5-HT2A and glial 5-HT5A. To determine whether fluoxetine can affect developing neural circuits independent of serotonergic innervation from the dorsal and medial raphe nuclei, we treated cortical neurons and spheroids with fluoxetine. Fluoxetine alters neurite formation in a dose-dependent fashion. Intriguingly, in cortical spheroids, neither acute nor chronic fluoxetine significantly altered excitatory synapse formation. However, only acute, but not chronic fluoxetine exposure altered inhibitory synaptogenesis. Finally, fluoxetine reversibly suppresses neuronal activity in a dose-dependent manner. These results demonstrate that fluoxetine can acutely alter synaptic function in developing neural circuits, but the effects were not long-lasting. This work provides a foundation for future studies to combine serotonergic innervation with cortical spheroids and assess the contributions of fluoxetine-induced alterations in serotonin levels to brain development.

Evaluation of the Anticancer Properties of Geranyl Isovalerate, an Active Ingredient of Argyreia nervosa Extract in Colorectal Cancer Cells

Chemotherapy is a general treatment procedure for cancer. The diversity in cancer incidence and the failure of therapy due to chemoresistance lead to increased cancer-related deaths. Therefore, new drugs with fewer secondary complications targeting diverse pathways are the need of the hour. Geranyl isovalerate (GIV), one of the active ingredients of ethyl acetate fraction of Argyreia nervosa is routinely used as a food flavoring agent. In this study, we found that GIV also exhibits anticancer activity when tested against the HCT116 cell line. It influenced the viability of the cells in a dose- and time-dependent manner. We examined whether GIV could induce oxidative stress and affect the mitochondrial membrane potential, thereby leading to apoptosis induction. Moreover, GIV could suppress the expression of antiapoptotic genes, such as BCl2 and PARP, and induce the expression of proapoptotic genes, such as Caspase 3 and 9. This is the first study demonstrating the anticancer activity of GIV and providing evidence for its mechanism of action. In conclusion, this study proposes GIV as a potential lead or supplementary molecule in treating and preventing colorectal cancer (CRC). Based on our findings, we conclude that GIV may be a viable lead or supplementary molecule for treating and preventing CRC.

Isolation of HLA-G+ cells using MEM-G/9 antibody-conjugated magnetic nanoparticles for prenatal screening: a reliable, fast and efficient method

The development of an effective and noninvasive early method for obtaining fetal cells is crucial to prenatal screening. Despite proving the presence of fetal cells in the reproductive tract, their use is limited due to their inability to properly isolate them from maternal cells. Magnetic-activated cell sorting (MACS) is a simple technique to separate cells. The present study aimed to develop a MACS-based platform for the isolation of the HLA-G expressing trophoblast cells. For this purpose, first, the triazine functionalized MNPs were synthesized and characterized. Then, MNPs were directly and indirectly conjugated by the MEM-G/9 antibodies targeting HLA-G+ cells. The antibody amount on the surface of the nanoparticles was determined with the Bradford assay. The cell capture efficiency was also investigated. Various characterization methods confirmed the successful nanoparticle synthesis and antibody conjugation. The optimal initial antibody amount for the immobilization was about 20 μg and the optimal time was 3 h. The antibody-nanoparticles by the indirect method had better targeting and capture efficiency than the direct method. The MNPs indirectly conjugated with antibodies are an efficient tool for cell isolation and present considerable potential to be applied in biomedical fields.

In Vitro Miniaturized Tuberculosis Spheroid Model

Tuberculosis (TB) is a public health concern that impacts 10 million people around the world. Current in vitro models are low throughput and/or lack caseation, which impairs drug effectiveness in humans. Here, we report the generation of THP-1 human monocyte/macrophage spheroids housing mycobacteria (TB spheroids). These TB spheroids have a central core of dead cells co-localized with mycobacteria and are hypoxic. TB spheroids exhibit higher levels of pro-inflammatory factor TNFα and growth factors G-CSF and VEGF when compared to non-infected control. TB spheroids show high levels of lipid deposition, characterized by MALDI mass spectrometry imaging. TB spheroids infected with strains of differential virulence, Mycobacterium tuberculosis (Mtb) HN878 and CDC1551 vary in response to Isoniazid and Rifampicin. Finally, we adapt the spheroid model to form peripheral blood mononuclear cells (PBMCs) and lung fibroblasts (NHLF) 3D co-cultures. These results pave the way for the development of new strategies for disease modeling and therapeutic discovery.

Biological Characterization of Human Autologous Pericardium Treated with the Ozaki Procedure for Aortic Valve Reconstruction

Background: The Ozaki procedure is an innovative surgical technique aiming at reconstructing aortic valves with human autologous pericardium. Even if this procedure is widely used, a comprehensive biological characterization of the glutaraldehyde (GA)-fixed pericardial tissue is still missing. Methods: Morphological analysis was performed to assess the general organization of pericardium subjected to the Ozaki procedure (post-Ozaki) in comparison to native tissue (pre-Ozaki). The effect of GA treatment on cell viability and nuclear morphology was then investigated in whole biopsies and a cytotoxicity assay was executed to assess the biocompatibility of pericardium. Finally, human umbilical vein endothelial cells were seeded on post-Ozaki samples to evaluate the influence of GA in modulating the endothelialization ability in vitro and the production of pro-inflammatory mediators. Results: The Ozaki procedure alters the arrangement of collagen and elastic fibers in the extracellular matrix and results in a significant reduction in cell viability compared to native tissue. GA treatment, however, is not cytotoxic to murine fibroblasts as compared to a commercially available bovine pericardium membrane. In addition, in in vitro experiments of endothelial cell adhesion, no difference in the inflammatory mediators with respect to the commercial patch was found. Conclusions: The Ozaki procedure, despite alteration of ECM organization and cell devitalization, allows for the establishment of a noncytotoxic environment in which endothelial cell repopulation occurs.

Apoptosis assessment in high-content and high-throughput screening assays

Here the authors describe the development of AUTOptosis, an economical and rapid apoptosis monitoring method suitable for high-content and high-throughput screening assays. AUTOptosis is based on the quantification of nuclei intensity via staining with Hoechst 33342. First, the authors calibrated the method using standard apoptosis inducers in multiple cell lines. Next, the authors validated the applicability of this approach to high-content screening using a small library of compounds and compared it with the terminal deoxynucleotidyl transferase dUTP nick end labeling gold standard. Finally, the authors demonstrated the specificity of the method by using AUTOposis to detect apoptosis triggered by Mycobacterium tuberculosis intracellular infections.

Mito-Tempo suppresses autophagic flux via the PI3K/Akt/mTOR signaling pathway in neuroblastoma SH-SY5Y cells

The generation of excessive mitochondrial reactive oxygen species (mtROS) is associated with glutamate-stimulated neurotoxicity and pathogenesis of Alzheimer's disease (AD). Impaired mitochondrial function is accompanied with oxidative stress that is a significant contributor to initiate autophagy, but the underlying mechanisms are not fully understood. The present study aimed to investigate the neuroprotective effects of Mito-Tempo on glutamate-induced neuroblastoma SH-SY5Y cell toxicity. SH-SY5Y cells were treated with 100 μM glutamate in the presence or absence of 50 and 100 μM Mito-Tempo for 24 h. Changes in cell viability were measured by MTT assay. Cytotoxicity and intracellular ROS accumulation were also evaluated using lactate dehydrogenase (LDH) activity assay and 2,7-dichlorofluorescein diacetate (DCFDA) Reactive Oxygen Species Assay kit, respectively. Mitochondrial membrane potential was analyzed by tetraethylbenzimidazoly-lcarbocyanine iodide (JC-1) staining. Expression of PI3K/AKT/mTOR pathway and autophagy markers, including LC3 (LC3-I/-II) and p62 (SQSTM1) were performed using Western blot analysis. Our results demonstrated that glutamate-exposed cells significantly increased cellular oxidative stress by enhancing ROS production. Glutamate treatment also increased LDH release follows the loss of mitochondrial membrane potential, caused cell viability loss. Treatment with Mito-Tempo not only attenuated the generation of ROS and improved mitochondrial membrane potential but also reduced the neurotoxicity of glutamate in a concentration-dependent manner, which leads to increased cell viability and decreased LDH release. Mito-Tempo has a greater protective effect by enhancing superoxide dismutase (SOD) activity and PI3K/AKT/mTOR phosphorylation. Moreover, Mito-Tempo treatment altered the autophagy process resulting in the decline in the ratio of the autophagy markers LC3-I/-II and p62 (SQSTM1). We propose that Mito-Tempo can improve neuronal properties against glutamate cytotoxicity through its direct free radical scavenging activity and inhibit excessive autophagy signaling pathway, therefore, allow for further studies to investigate the therapeutic potentials of Mito-Tempo in animal disease models and human.

Copper(II) Pyridyl Aminophenolates: Hypoxia-Selective, Nucleus-Targeting Cytotoxins, and Magnetic Resonance Probes

Targeting the low-oxygen (hypoxic) environments found in many tumours by using redox-active metal complexes is a strategy that can enhance efficacy and reduce the side effects of chemotherapies. We have developed a series of Cu^II complexes with tridentate pyridine aminophenolate-based ligands for preferential activation in the reduction window provided by hypoxic tissues. Furthermore, ligand functionalization with a pendant CF₃ group provides a ¹⁹ F spectroscopic handle for magnetic-resonance studies of redox processes at the metal centre and behaviour in cellular environments. The phenol group in the ligand backbone was substituted at the para position with H, Cl, and NO₂ to modulate the reduction potential of the Cu^II centre, giving a range of values below the window expected for hypoxic tissues. The NO₂ -substituted complex, which has the highest reduction potential, showed enhanced cytotoxic selectivity towards HeLa cells grown under hypoxic conditions. Cell death occurs by apoptosis, as determined by analysis of the cell morphology. A combination of ¹⁹ F NMR and ICP-OES indicates localization of the NO₂ complex in HeLa cell nuclei and increased cellular accumulation under hypoxia. This correlates with DNA nuclease activity being the likely origin of cytotoxic activity, as demonstrated by cleavage of DNA plasmids in the presence of the Cu^II nitro complex and a reducing agent. Selective detection of the paramagnetic Cu^II complexes and their diamagnetic ligands by ¹⁹ F MRI suggests hypoxia-targeting theranostic applications by redox activation.

Synthesis of NNN Chiral Ruthenium Complexes and Their Cytotoxicity Studies

The synthesis and characterization of chiral pincer-ruthenium complexes of the type (^R2NNN)RuCl₂ (PPh₃) (R = 3-methylbutyl and 3,3-dimethylbutyl) is reported here. The cytotoxicity studies of these complexes were studied and compared with the corresponding activity of achiral complexes. The cytotoxic effect of pincer-ruthenium complexes on human dermal fibroblasts and human tongue carcinoma cells assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay displayed an inhibition of normal and cancer cell growth in a dose-dependent manner. Intracellular reactive oxygen species (ROS) level measurement, lactate dehydrogenase assay, DNA fragmentation, and necrosis studies revealed that treatment with pincer-ruthenium complexes induced a redox imbalance in SAS cells by upregulating ROS generation and caused necrotic cell death by disrupting the cellular membrane integrity.

Pharmacologic activation of autophagy without direct mTOR inhibition as a therapeutic strategy for treating dry macular degeneration

Dry age-related macular degeneration (AMD) is marked by the accumulation of extracellular and intracellular lipid-rich deposits within and around the retinal pigment epithelium (RPE). Inducing autophagy, a conserved, intracellular degradative pathway, is a potential treatment strategy to prevent disease by clearing these deposits. However, mTOR inhibition, the major mechanism for inducing autophagy, disrupts core RPE functions. Here, we screened autophagy inducers that do not directly inhibit mTOR for their potential as an AMD therapeutic in primary human RPE culture. Only two out of more than thirty autophagy inducers tested reliably increased autophagy flux in RPE, emphasizing that autophagy induction mechanistically differs across distinct tissues. In contrast to mTOR inhibitors, these compounds preserved RPE health, and one inducer, the FDA-approved compound flubendazole (FLBZ), reduced the secretion of apolipoprotein that contributes to extracellular deposits termed drusen. Simultaneously, FLBZ increased production of the lipid-degradation product β-hydroxybutyrate, which is used by photoreceptor cells as an energy source. FLBZ also reduced the accumulation of intracellular deposits, termed lipofuscin, and alleviated lipofuscin-induced cellular senescence and tight-junction disruption. FLBZ triggered compaction of lipofuscin-like granules into a potentially less toxic form. Thus, induction of RPE autophagy without direct mTOR inhibition is a promising therapeutic approach for dry AMD.