Mechanotransductive Receptor Piezo1 as a Promising Target in the Treatment of Neurological Diseases.

In recent years, increasing attention has been paid to the role of physical factors in biological processes. This direction was ultimately confirmed by the recent 2021 Nobel Prize in medicine and physiology awarded in ½ to Ardem Patapoutian for his discovery of Piezo1 and Piezo2 mechanosensitive receptors. Among them, Piezo2 is responsible for sensing touch, while Piezo1 is engaged in a variety of mechanotransduction events. Piezo1 is expressed in various central nervous system cells, while its expression may be affected in the course of various pathological conditions. Recently, thanks to the development of Piezo1 modulators (i.e. Yoda1, Jedi1/2 and Dooku2), it is possible to study the role of Piezo1 in the pathogenesis of various neurological diseases including ischemia, glioma, and age-related dementias. The results obtained in this field suggest that proper modulation of Piezo1 receptor might be beneficial in the course of various neurological diseases.

Stiffening of DU145 prostate cancer cells driven by actin filaments - microtubule crosstalk conferring resistance to microtubule-targeting drugs.

The crucial role of microtubules in the mitotic-related segregation of chromosomes makes them an excellent target for anticancer microtubule targeting drugs (MTDs) such as vinflunine (VFL), colchicine (COL), and docetaxel (DTX). MTDs affect mitosis by directly perturbing the structural organisation of microtubules. By a direct assessment of the biomechanical properties of prostate cancer DU145 cells exposed to different MTDs using atomic force microscopy, we show that cell stiffening is a response to the application of all the studied MTDs (VFL, COL, DTX). Changes in cellular rigidity are typically attributed to remodelling of the actin filaments in the cytoskeleton. Here, we demonstrate that cell stiffening can be driven by crosstalk between actin filaments and microtubules in MTD-treated cells. Our findings improve the interpretation of biomechanical data obtained for living cells in studies of various physiological and pathological processes.

Nanomechanics in Monitoring the Effectiveness of Drugs Targeting the Cancer Cell Cytoskeleton.

Increasing attention is devoted to the use of nanomechanics as a marker of various pathologies. Atomic force microscopy (AFM) is one of the techniques that could be applied to quantify the nanomechanical properties of living cells with a high spatial resolution. Thus, AFM offers the possibility to trace changes in the reorganization of the cytoskeleton in living cells. Impairments in the structure, organization, and functioning of two main cytoskeletal components, namely, actin filaments and microtubules, cause severe effects, leading to cell death. That is why these cytoskeletal components are targets for antitumor therapy. This review intends to describe the gathered knowledge on the capability of AFM to trace the alterations in the nanomechanical properties of living cells induced by the action of antitumor drugs that could translate into their effectiveness.

Multilineage Differentiation Potential of Human Dental Pulp Stem Cells-Impact of 3D and Hypoxic Environment on Osteogenesis In Vitro.

Human dental pulp harbours unique stem cell population exhibiting mesenchymal stem/stromal cell (MSC) characteristics. This study aimed to analyse the differentiation potential and other essential functional and morphological features of dental pulp stem cells (DPSCs) in comparison with Wharton's jelly-derived MSCs from the umbilical cord (UC-MSCs), and to evaluate the osteogenic differentiation of DPSCs in 3D culture with a hypoxic microenvironment resembling the stem cell niche. Human DPSCs as well as UC-MSCs were isolated from primary human tissues and were subjected to a series of experiments. We established a multiantigenic profile of DPSCs with CD45-/CD14-/CD34-/CD29+/CD44+/CD73+/CD90+/CD105+/Stro-1+/HLA-DR- (using flow cytometry) and confirmed their tri-lineage osteogenic, chondrogenic, and adipogenic differentiation potential (using qRT-PCR and histochemical staining) in comparison with the UC-MSCs. The results also demonstrated the potency of DPSCs to differentiate into osteoblasts in vitro. Moreover, we showed that the DPSCs exhibit limited cardiomyogenic and endothelial differentiation potential. Decreased proliferation and metabolic activity as well as increased osteogenic differentiation of DPSCs in vitro, attributed to 3D cell encapsulation and low oxygen concentration, were also observed. DPSCs exhibiting elevated osteogenic potential may serve as potential candidates for a cell-based product for advanced therapy, particularly for bone repair. Novel tissue engineering approaches combining DPSCs, 3D biomaterial scaffolds, and other stimulating chemical factors may represent innovative strategies for pro-regenerative therapies.

Indenting soft samples (hydrogels and cells) with cantilevers possessing various shapes of probing tip.

The identification of cancer-related changes in cells and tissues based on the measurements of elastic properties using atomic force microscopy (AFM) seems to be approaching clinical application. Several limiting aspects have already been discussed; however, still, no data have shown how specific AFM probe geometries are related to the biomechanical evaluation of cancer cells. Here, we analyze and compare the nanomechanical results of mechanically homogenous polyacrylamide gels and heterogeneous bladder cancer cells measured using AFM probes of various tip geometry, including symmetric and non-symmetric pyramids and a sphere. Our observations show large modulus variability aligned with both types of AFM probes used and with the internal structure of the cells. Altogether, these results demonstrate that it is possible to differentiate between compliant and rigid samples of kPa elasticity; however, simultaneously, they highlight the strong need for standardized protocols for AFM-based elasticity measurements if applied in clinical practice including the use of a single type of AFM cantilever.

Impact of developmental origin, niche mechanics and oxygen availability on osteogenic differentiation capacity of mesenchymal stem/stromal cells.

Mesenchymal Stem/Stromal Cells (MSCs) have been widely considered as a promising source of cells for tissue regeneration. Among other stem cells, they are characterized by a high osteogenic potential. Intensive studies in this field had shown that even if basic osteogenic differentiation is relatively simple, its clinical application requires more sophisticated approaches to prepare effective and safe cell therapy products. The aim of this review is to underline biological, physical and chemical factors which play a crucial role in osteogenic differentiation of MSCs. Existence of two distinct mechanisms of ossification (intramembranous and endochondral) indicate that choosing a proper source of MSCs may be critical for successful regeneration of a particular bone type. In this context, Dental Pulp Stem Cells representing a group of MSCs and originating from neural crest ( a structure responsible for development of cranial bones) are considered as the most promising for skull bone defect repair. Factors which facilitate osteogenic differentiation of MSCs include changes in forces exerted on cells during development. Thus, culturing of cells in hydrogels or on biocompatible three-dimensional scaffolds improves osteogenic differentiation of MSCs by both, the mechanotransductive and chemical impact on cells. Moreover, atmospheric oxygen concentration routinely used for cell cultures in vitro does not correspond to lower oxygen concentration present in stem cell niches. A decrease in oxygen concentration allows to create more physiological cell culture conditions, mimicking the ones in stem cell niches, which promote the MSCs stemness. Altogether, factors discussed in this review provide exciting opportunities to boost MSCs propagation and osteogenic differentiation which is crucial for successful clinical applications.