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Losartan improves memory, neurogenesis and cell motility in transgenic Alzheimer's mice

Angiotensin receptor blockers (ARBs) have demonstrated multiple neuroprotective benefits in Alzheimer’s disease (AD) models. However, their beneficial effects on memory deficits, cholinergic activity, neurogenesis and Amyloid beta (Aβ) clearance reveal significant interstudy variability. The delivery route can impact not only delivery but also targeting and therapeutic efficacy of ARBs. Our previous findings on the beneficial effects of intranasally delivered losartan in the APP/PS1 model of AD prompted us to explore the influence of the delivery route by employing here the systemic administration of losartan. Consistent with our previous results with intranasal losartan, repeated intraperitoneal administration (10 mg/kg) resulted in a remarkable decrease in Aβ plaques and soluble Aβ42, as well as inflammatory cytokines (IL-2, IL-6 and TNFα). The Aβ reduction can be ascribed to its facilitated degradation by neprilysin and diminished generation by BACE1. Losartan increased neurogenesis in vivo and in vitro and improved migratory properties of astrocytes isolated from adult transgenic AD mice. In summary, this data together with our previous results suggest therapeutic features of losartan which are independent of delivery route. The improvement of cell motility of Aβ-affected astrocytes by losartan deserves further in vivo investigation, which may lead to new strategies for AD treatment.

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Neutrophil dysfunction in cystic fibrosis

Background: Excessive neutrophil inflammation is the hallmark of cystic fibrosis (CF) airway disease. Novel technologies for characterizing neutrophil dysfunction may provide insight into the nature of these abnormalities, revealing a greater mechanistic understanding and new avenues for CF therapies that tar- get these mechanisms. Methods: Blood was collected from individuals with CF in the outpatient clinic, CF individuals hospital- ized for a pulmonary exacerbation, and non-CF controls. Using microfluidic assays and advanced imaging technologies, we characterized 1) spontaneous neutrophil migration using microfluidic motility mazes, 2) neutrophil migration to and phagocytosis of Staphylococcal aureus particles in a microfluidic arena, 3) neutrophil swarming on Candida albicans clusters, and 4) Pseudomonas aeruginosa -induced neutrophil transepithelial migration using micro-optical coherence technology (μOCT). Results: Participants included 44 individuals: 16 Outpatient CF, 13 Hospitalized CF, and 15 Non-CF indi- viduals. While no differences were seen with spontaneous migration, CF neutrophils migrated towards S. aureus particles more quickly than non-CF neutrophils (p < 0.05). CF neutrophils, especially Hospitalized CF neutrophils, generated significantly larger aggregates around S. aureus particles over time. Hospitalized CF neutrophils were more likely to have dysfunctional swarming (p < 0.01) and less efficient clearing of C. albicans (p < 0.0 0 01). When comparing trans-epithelial migration towards Pseudomonas aeruginosa ep- ithelial infection, Outpatient CF neutrophils displayed an increase in the magnitude of transmigration and adherence to the epithelium (p < 0.05). Conclusions: Advanced technologies for characterizing CF neutrophil function reveal significantly altered migratory responses, cell-to-cell clustering, and microbe containment. Future investigations will probe mechanistic basis for abnormal responses in CF to identify potential avenues for novel anti-inflammatory therapeutics.

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Differential effects of gold nanoparticles and ionizing radiation on cell motility between primary human colonic and melanocytic cells and their cancerous counterparts

This study examined the effects of gold nanoparticles (AuNPs) and/or ionizing radiation (IR) on the viability and motility of human primary colon epithelial (CCD841) and colorectal adenocarcinoma (SW48) cells as well as human primary epidermal melanocytes (HEM) and melanoma (MM418-C1) cells. AuNPs up to 4 mM had no effect on the viability of these cell lines. The viability of the cancer cells was ~60% following exposure to 5 Gy. Exposure to 5 Gy X-rays or 1 mM AuNPs showed the migration of the cancer cells ~85% that of untreated controls, while co-treatment with AuNPs and IR decreased migration to ~60%. In the non-cancerous cell lines gap closure was enhanced by ~15% following 1 mM AuNPs or 5 Gy treatment, while for co-treatment it was ~22% greater than that for the untreated controls. AuNPs had no effect on cell re-adhesion, while IR enhanced only the re-adhesion of the cancer cell lines but not their non-cancerous counterparts. The addition of AuNPs did not enhance cell adherence. This different reaction to AuNPs and IR in the cancer and normal cells can be attributed to radiation-induced adhesiveness and metabolic differences between tumour cells and their non-cancerous counterparts.

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Perilla (Perilla frutescens) leaf extract inhibits SARS-CoV-2 via direct virus inactivation

While severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection presents with mild or no symptoms in most cases, a significant number of patients become critically ill. Remdesivir has been approved for the treatment of coronavirus disease 2019 (COVID-19) in several countries, but its use as monotherapy has not substantially lowered mortality rates. Because agents from traditional Chinese medicine (TCM) have been successfully utilized to treat pandemic and endemic diseases, we designed the current study to identify novel anti-SARS-CoV-2 agents from TCM. We initially used an antivirus-induced cell death assay to screen a panel of herbal extracts. The inhibition of the viral infection step was investigated through a time-of-drug-addition assay, whereas a plaque reduction assay was carried out to validate the antiviral activity. Direct interaction of the candidate TCM compound with viral particles was assessed using a viral inactivation assay. Finally, the potential synergistic efficacy of remdesivir and the TCM compound was examined with a combination assay. The herbal medicine Perilla leaf extract (PLE, approval number 022427 issued by the Department of Health and Welfare of Taiwan) had EC50 of 0.12 ± 0.06 mg/mL against SARS-CoV-2 in Vero E6 cells – with a selectivity index of 40.65. Non-cytotoxic PLE concentrations were capable of blocking viral RNA and protein synthesis. In addition, they significantly decreased virus-induced cytokine release and viral protein/RNA levels in the human lung epithelial cell line Calu-3. PLE inhibited viral replication by inactivating the virion and showed additive-to-synergistic efficacy against SARS-CoV-2 when used in combination with remdesivir.Our results demonstrate for the first time that PLE is capable of inhibiting SARS-CoV-2 replication by inactivating the virion. Our data may prompt additional investigation on the clinical usefulness of PLE for preventing or treating COVID-19.

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Growing bio-nanomachine networks: Application to malignant tumor evolution and progression

Networks of bio-nanomachines that communicate through molecular communication are expected to perform complex functionalities within biological systems. The natural history of malignant tumors can be defined by the evolution of growing bio-nanomachine networks within an interplay between proliferation or self-renewal (Grow) and invasion (Go) potential of mutually exclusive phenotypes. Herein we present a model of two populations of bio-nanomachines representing distinct phenotypes propagating throughout the progression of malignant gliomas within spatiotemporally evolving bionanomachine networks, driven by either attractive and linkforming or repulsive and cluster-forming forces. This model is further applied in computer simulations to examine the growth of bio-nanomachine networks in terms of size and network connectivity. Understanding the mechanisms by which malignant cells form bio-nanomachine networks and controlling network connectivity can contribute to deciphering mechanisms of tumor evolution and progression and provide new nanonetwork-based therapeutic approaches.

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Anti-austerity activity of Thai medicinal plants: Chemical constituents and anti-pancreatic cancer activities of Kaempferia parviflora

Human pancreatic tumor cells have an intrinsic ability to tolerate nutrition starvation and survive in the hypovascular tumor microenvironment, the phenomenon termed as “austerity”. Searching for an agent that inhibits such tolerance to nutrient starvation and kills the pancreatic cancer cells preferentially in nutrient-starvation is a unique anti-austerity strategy in anti-cancer drug discovery. In this strategy, plant extracts and compounds are tested against PANC-1 human pancreatic cancer cell line under the conditions of nutrient-deprived medium (NDM) and nutrient-rich medium (DMEM), to discover the compounds that show selective cytotoxicity in NDM. Screening of twenty-five Thai indigenous medicinal plant extracts for their anti-austerity activity against the PANC-1 human pancreatic cancer cell line in nutrient deprived medium (NDM) resulted in the identification of four active plants, Derris scandens, Boesenbergia pandurata, Citrus hystrix, and Kaempferia parviflora, with PC50 values 0.5–8.9 µg/mL. K. parviflora extract also inhibited PANC-1 cancer cell colony formation. Phytochemical investigation of K. parviflora extract led to the isolation of fourteen compounds, including two polyoxygenated cyclohexanes (1 and 2), eleven flavonoids (3–13), and β-sitosterol (14). Stereochemical assignment of compound 1 was confirmed through X-ray analysis. All isolated compounds were tested for their preferential cytotoxicity against PANC-1 cells. Among them, 5-hydroxy-7-methoxyflavone (3) displayed the most potent activity with a PC50 value of 0.8 µM. Mechanistically, it was found to induce apoptosis in PANC-1 cell death in NDM as evident by caspase cleavage. It was also found to inhibit PANC-1 cancer cell colony formation in DMEM. Therefore, compound 3 can be considered as a potential lead compound for the anticancer drug development based on the anti-austerity strategy.

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A flexible micro-piston device for mechanical cell stimulation and compression in microfluidic settings

Evidence continues to emerge that cancer is not only a disease of genetic mutations, but also of altered mechanobiological profiles of the cells and microenvironment. This mutation-independent element might be a key factor in promoting development and spread of cancer. Biomechanical forces regulate tumor microenvironment by solid stress, matrix mechanics, interstitial pressure and flow. Compressive stress by tumor growth and stromal tissue alters the cell deformation, and recapitulates the biophysical properties of cells to grow, di↵erentiate, spread or invade. Such a solid stress can be introduced externally to change the cell response and to mechanically induce cell lysis by dynamic compression. In this work we report a microfluidic cell-culture platform with an integrated, actively-modulated actuator for the application of compressive forces on cancer cells. Our platform is composed of a control microchannel in a top layer for introducing external force and a polydimethylsiloxane (PDMS) membrane with monolithically integrated actuators. The integrated actuator, herein called micro-piston, was used to apply compression on SKOV-3 ovarian cancer cells in a dynamic and controlled manner by modulating applied gas pressure, localization, shape and size of the micro-piston. We report fabrication of the platform, characterization of the mechanical actuator experimentally and computationally, as well as cell loading and culture in the device. We further show use of the actuator to perform both, repeated dynamic cell compression at physiological pressure levels, and end-point mechanical cell lysis, demonstrating suitability for mechanical stimulation to study the role of compressive forces in cancer microenvironments.

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Toxicity of organic and inorganic Nickel in pancreatic cell cultures: comparison to Cadmium.

Nickel compounds are Group 1 carcinogens and possibly cancer-causing in the pancreas. We examined the toxicity of nickel in both 2-D and 3-D pancreatic cell cultures, to determine the LD50 for organic and inorganic nickel in normal and cancerous cells. Assays with cadmium chloride were performed to be a comparison to potential nickel-induced toxicity. Cells were exposed to twelve concentrations of NiCl2 or Ni-(Ac)2 for 48h (2-D), or six concentrations for 48 hours (3-D). There was a significant (P=0.0016) difference between HPNE and AsPC-1 LD50 values after cadmium exposure, at 69.9 μM and 29.2 μM, respectively. Neither form of nickel exhibited toxicity in 2-D or 3-D cultures, but after 48h, changes in spheroid morphology were observed. The inability of Ni to reduce viable cell numbers suggests a toxic mechanism that differs from cadmium, also a Group 1 carcinogen. The cell microenvironment was not a factor in nickel toxicity with no changes in viable cells in either 2-D or 3-D cultures. These studies only examined cytotoxicity, and not genotoxicity, a potential mechanism of nickel carcinogenicity. Alterations in DNA function or the expression of apoptotic proteins/processes would take longer to manifest. Current work focuses on cellular changes following extended nickel exposure.

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Simple and rapid non-enzymatic procedure allows the isolation of structurally preserved connective tissue micro-fragments enriched with SVF

The stromal vascular fraction (SVF) consists of a heterogeneous population of stem and stromal cells, generally obtained from adipose tissue by enzymatic digestion. For human cellbased therapies, mechanical process methods to obtain SVF represent an advantageous approach because they have fewer regulatory restrictions for their clinical use. The aim of this study was to characterize a novel commercial system for obtaining SVF from adipose tissue by a mechanical approach without substantial manipulations. Lipoaspirate samples collected from 27 informed patients were processed by a simple and fast mechanical system (by means of Hy-Tissue SVF). The Hy-Tissue SVF product contained a free cell fraction and micro-fragments of stromal connective tissue. The enzymatic digestion of the micro-fragments increased the yield of free cells (3.2 times) and CFU-F (2.4 times). Additionally, 10% of free cells from SVF were positive for CD34+, suggesting the presence of endothelial cells, pericytes, and potential adipose-derived stem cells (ADSC). Moreover, the SVF cells were able to proliferate and differentiate in vitro toward adipocytes, osteocytes, and chondrocytes. The immunophenotypic analysis of expanded cells showed positivity for typical mesenchymal stem cell markers. The Hy-Tissue SVF system allows the isolation of stromal vascular fraction, making this product of potential interest in regenerative medicine.

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