Adipose and Muscle Cell Co-Culture System: A Novel In Vitro Tool to Mimic the In Vivo Cellular Environment

Transcriptome Analysis of Mesenchymal Progenitor Cells Revealed Molecular Insights into Metabolic Dysfunction and Inflammation in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a female endocrine disorder with metabolic issues. Hyperandrogenism combined with hyperinsulinemia exacerbates the reproductive, metabolic, and inflammatory problems in PCOS patients. The etiology of PCOS is unclear. Patient-specific induced pluripotent stem cells (iPSCs) offer a promising model for studying disease mechanisms and conducting drug screening. Here, we aim to use mesenchymal progenitor cells (MPCs) derived from PCOS iPSCs to explore the mechanism of PCOS. We compared the transcriptome profiles of PCOS and healthy control (HC) iPSC-derived MPCs (iPSCMs). Moreover, we assess the impact of androgens on iPSCMs. In the comparison between PCOS and HC, the expression levels of 1026 genes were significantly different. A gene set enrichment analysis (GSEA) revealed that adipogenesis- and metabolism-related genes were downregulated, whereas inflammation-related genes were upregulated in the PCOS iPSCMs. Dysregulation of the TGF-β1 and Wnt signaling pathways was observed in the PCOS iPSCMs. Furthermore, there was impaired adipogenesis and decreased lipolysis in the PCOS iPSCMs-derived adipocytes. With testosterone treatment, genes related to metabolism were upregulated in the HC iPSCMs but downregulated in the PCOS iPSCMs. The impact of testosterone varied among HCs and PCOS iPSCMs, possibly because of a genetic predisposition toward PCOS. This study found specific signaling pathways that could serve as therapeutic targets for PCOS.

Proteomics Analysis of Interactions between Drug-Resistant and Drug-Sensitive Cancer Cells: Comparative Studies of Monoculture and Coculture Cell Systems

Cell-cell interactions, which allow cells to communicate with each other through molecules in their microenvironment, are critical for the growth, health, and functions of cells. Previous studies show that drug-resistant cells can interact with drug-sensitive cells to elevate their drug resistance level, which is partially responsible for cancer recurrence. Studying protein targets and pathways involved in cell-cell communication provides essential information for fundamental cell biology studies and therapeutics of human diseases. In the current studies, we performed direct coculture and indirect coculture of drug-resistant and drug-sensitive cell lines, aiming to investigate intracellular proteins responsible for cell communication. Comparative studies were carried out using monoculture cells. Shotgun bottom-up proteomics results indicate that the P53 signaling pathway has a strong association with drug resistance mechanisms, and multiple TP53-related proteins were upregulated in both direct and indirect coculture systems. In addition, cell-cell communication pathways, including the phagosome and the HIF-signaling pathway, contribute to both direct and indirect coculture systems. Consequently, AK3 and H3-3A proteins were identified as potential targets for cell-cell interactions that are relevant to drug resistance mechanisms. We propose that the P53 signaling pathway, in which mitochondrial proteins play an important role, is responsible for inducing drug resistance through communication between drug-resistant and drug-sensitive cancer cells.

Dairy, Plant, and Novel Proteins: Scientific and Technological Aspects

Alternative proteins have gained popularity as consumers look for foods that are healthy, nutritious, and sustainable. Plant proteins, precision fermentation-derived proteins, cell-cultured proteins, algal proteins, and mycoproteins are the major types of alternative proteins that have emerged in recent years. This review addresses the major alternative-protein categories and reviews their definitions, current market statuses, production methods, and regulations in different countries, safety assessments, nutrition statuses, functionalities and applications, and, finally, sensory properties and consumer perception. Knowledge relative to traditional dairy proteins is also addressed. Opportunities and challenges associated with these proteins are also discussed. Future research directions are proposed to better understand these technologies and to develop consumer-acceptable final products.

Principles of Indirect Co-culture Method Using Transwell

The co-culture method is a simple type of cell culture method used to evaluate the effects of communication between various types of cells in an in vitro setting. In the co-culture method, two or more eukaryotic cell types, or eukaryotic and prokaryotic cells, are cultured together. The co-culture method reflects in vivo cell behaviors and thereby emerges as a pivotal technique with diverse applications in cancer research and cell biology. Two categories of co-culture methods (indirect methods and direct methods) are well known. Direct co-culture methods allow physical contact between the various cell types (juxtacrine signaling). In indirect methods, cells are physically separated into two different populations (for example, using a Transwell) that allow communication only via secretory factors (paracrine signaling). Herein, we focus on the principles of the indirect co-culture method. Nowadays, this method is used to explore the effects of mesenchymal stem cell (MSC) secretome on cancer cells. These studies have unveiled intricate cell behavior dynamics, demonstrating how the MSC secretome influences cancer cell proliferation, invasion, apoptosis, and polarity.

Cultured meat in the European Union: Legislative context and food safety issues

The current food system, which is responsible for about one third of all global gas emissions, is considered one of the main causes of resource depletion. For this reason, scientific research is investigating new alternatives capable of feeding an ever-growing population that is set to reach 9-11 billion by 2050. Among these, cell-based meat, also called cultured meat, is one possible solution. It is part of a larger branch of science called cellular agriculture, whose goal is to produce food from individual cells rather than whole organisms, tracing their molecular profile. To date, however, cultured meat aroused conflicting opinions. For this reason, the aim of this review was to take an in-depth look at the current European legislative framework, which reflects a 'precautionary approach' based on the assumption that these innovative foods require careful risk assessment to safeguard consumer health. In this context, the assessment of possible risks made it possible not only to identify the main critical points during each stage of the production chain (proliferation, differentiation, scaffolding, maturation and marketing), but also to identify solutions in accordance with the recommendations of the European Food Safety Authority (EFSA). Further, the main challenges related to organoleptic and nutritional properties have been reviewed.. Finally, possible future markets were studied, which would complement that of traditional meat, implementing the offer for the consumer, who is still sceptical about the acceptance of this new product. Although further investigation is needed, the growing demand for market diversification and the food security opportunities associated with food shortages, as well as justifying the commercialisation of cultured meat, would present an opportunity to position cultured meat as beneficial.

Influence of polystyrene nanoparticles on the toxicity of tetrabromobisphenol A in human intestinal cell lines

Research and regulatory efforts in toxicology are increasingly focused on the development of suitable non-animal methodologies for human health risk assessment. In this work we used human intestinal Caco-2 and HT29/MTX cell lines to address the potential risks of mixtures of the emerging contaminants tetrabromobisphenol A (TBBPA) and commercial polystyrene nanoparticles (PSNPs). We employed different in vitro settings to evaluate basal cytotoxicity through three complementary endpoints (metabolic activity, plasmatic, and lysosomal membrane integrity) and the induction of the oxidative stress and DNA damage responses with specific endpoints. Although no clear pattern was observed, our findings highlight the predominant impact of TBBPA in the combined exposures under subcytotoxic conditions and a differential behavior of the Caco-2 and HT29/MTX co-culture system. Distinctive outcomes detected with the mixture treatments include reactive oxygen species (ROS) increases, disturbances of mitochondrial inner membrane potential, generation of alkali-sensitive sites in DNA, as well as significant changes in the expression levels of relevant DNA and oxidative stress related genes.

An immortal porcine preadipocyte cell strain for efficient production of cell-cultured fat

Adding adipose cells to cell-cultured meat can provide a distinctive aroma and juicy texture similar to real meat. However, a significant challenge still exists in obtaining seed cells that can be propagated for long periods, maintain their adipogenic potential, and reduce production costs. In this study, we present a cell strain derived from immortalized porcine preadipocytes that can be subculture for over 40 passages without losing differentiation capacity. This cell strain can be differentiated within 3D bioscaffolds to generate cell-cultured fat using fewer chemicals and less serum. Additionally, it can be expanded and differentiated on microcarriers with upscaled culture to reduce costs and labor. Moreover, it can co-differentiate with muscle precursor cells, producing a pattern similar to real meat. Therefore, our cell strain provides an exceptional model for studying and producing cell-cultured fat.

3D bioprinted multilayered cerebrovascular conduits to study cancer extravasation mechanism related with vascular geometry

Cerebral vessels are composed of highly complex structures that facilitate blood perfusion necessary for meeting the high energy demands of the brain. Their geometrical complexities alter the biophysical behavior of circulating tumor cells in the brain, thereby influencing brain metastasis. However, recapitulation of the native cerebrovascular microenvironment that shows continuities between vascular geometry and metastatic cancer development has not been accomplished. Here, we apply an in-bath 3D triaxial bioprinting technique and a brain-specific hybrid bioink containing an ionically crosslinkable hydrogel to generate a mature three-layered cerebrovascular conduit with varying curvatures to investigate the physical and molecular mechanisms of cancer extravasation in vitro. We show that more tumor cells adhere at larger vascular curvature regions, suggesting that prolongation of tumor residence time under low velocity and wall shear stress accelerates the molecular signatures of metastatic potential, including endothelial barrier disruption, epithelial-mesenchymal transition, inflammatory response, and tumorigenesis. These findings provide insights into the underlying mechanisms driving brain metastases and facilitate future advances in pharmaceutical and medical research.

Assessing the Genotoxicity of Cellulose Nanomaterials in a Co-Culture of Human Lung Epithelial Cells and Monocyte-Derived Macrophages

Cellulose micro/nanomaterials (CMNMs) are innovative materials with a wide spectrum of industrial and biomedical applications. Although cellulose has been recognized as a safe material, the unique properties of its nanosized forms have raised concerns about their safety for human health. Genotoxicity is an endpoint that must be assessed to ensure that no carcinogenic risks are associated with exposure to nanomaterials. In this study, we evaluated the genotoxicity of two types of cellulose micro/nanofibrils (CMF and CNF) and one sample of cellulose nanocrystals (CNC), obtained from industrial bleached Eucalyptus globulus kraft pulp. For that, we exposed co-cultures of human alveolar epithelial A549 cells and THP-1 monocyte-derived macrophages to a concentration range of each CMNM and used the micronucleus (MN) and comet assays. Our results showed that only the lowest concentrations of the CMF sample were able to induce DNA strand breaks (FPG-comet assay). However, none of the three CMNMs produced significant chromosomal alterations (MN assay). These findings, together with results from previous in vitro studies using monocultures of A549 cells, indicate that the tested CNF and CNC are not genotoxic under the conditions tested, while the CMF display a low genotoxic potential.

Towards a More Realistic In Vitro Meat: The Cross Talk between Adipose and Muscle Cells

According to statistics and future predictions, meat consumption will increase in the coming years. Considering both the environmental impact of intensive livestock farming and the importance of protecting animal welfare, the necessity of finding alternative strategies to satisfy the growing meat demand is compelling. Biotechnologies are responding to this demand by developing new strategies for producing meat in vitro. The manufacturing of cultured meat has faced criticism concerning, above all, the practical issues of culturing together different cell types typical of meat that are partly responsible for meat’s organoleptic characteristics. Indeed, the existence of a cross talk between adipose and muscle cells has critical effects on the outcome of the co-culture, leading to a general inhibition of myogenesis in favor of adipogenic differentiation. This review aims to clarify the main mechanisms and the key molecules involved in this cross talk and provide an overview of the most recent and successful meat culture 3D strategies for overcoming this challenge, focusing on the approaches based on farm-animal-derived cells.

Types of cell culture inserts affect cell crosstalk between co-cultured macrophages and adipocytes

Cell culture inserts offer an in vivo-like microenvironment to investigate cell-cell interactions between co-cultivated cells. However, it is unclear if types of inserts affect cell crosstalk. Here, we developed an environment-friendly cell culture insert, XL-insert, which can reduce plastic waste with lower cost. We compared XL insert with two types of commercial disposable culture inserts, Koken® insert with atelocollagen membrane (Col-inserts) and Falcon® inserts with plastic membrane (PET-inserts) on cell-cell interactions in co-cultivated THP-1 macrophages and OP9 adipocytes. Scanning electron microscope, immunoassay and imaging analysis showed that among three types of inserts, XL-inserts allowed cytokines from co-cultivated macrophages and adipocytes to diffuse freely and offered preferable in vivo-like microenvironment for cell-cell interactions. PET-inserts showed limitations for intercellular communication due to some pores being blocked by somas on the membrane that caused much lower permeability for cytokines passing through. Col-inserts blocked large sized cytokines but allowed small sized molecules to permeate resulting in improved lipid accumulation and adiponectin secretion in OP9 adipocytes. Taken together, our data demonstrated that membrane type and pore size on the membrane affect the cross-talk between co-cultivated cells very differently. Some previous co-culture studies might have different results if the inserts were changed.

Reassessment of adipocyte technology for cellular agriculture of alternative fat

Alternative proteins, such as cultivated meat, have recently attracted significant attention as novel and sustainable food. Fat tissue/cell is an important component of meat that makes organoleptic and nutritional contributions. Although adipocyte biology is relatively well investigated, there is limited focus on the specific techniques and strategies to produce cultivated fat from agricultural animals. In the assumed standard workflow, stem/progenitor cell lines are derived from tissues of animals, cultured for expansion, and differentiated into mature adipocytes. Here, we compile information from literature related to cell isolation, growth, differentiation, and analysis from bovine, porcine, chicken, other livestock, and seafood species. A diverse range of tissue sources, cell isolation methods, cell types, growth media, differentiation cocktails, and analytical methods for measuring adipogenic levels were used across species. Based on our analysis, we identify opportunities and challenges in advancing new technology era toward producing "alternative fat" that is suitable for human consumption.

L-Arginine increases AMPK phosphorylation and the oxidation of energy substrates in hepatocytes, skeletal muscle cells, and adipocytes

Previous work has shown that dietary L-arginine (Arg) supplementation reduced white fat mass in obese rats. The present study was conducted with cell models to define direct effects of Arg on energy-substrate oxidation in hepatocytes, skeletal muscle cells, and adipocytes. BNL CL.2 mouse hepatocytes, C2C12 mouse myotubes, and 3T3-L1 mouse adipocytes were treated with different extracellular concentrations of Arg (0, 15, 50, 100 and 400 µM) or 400 µM Arg + 0.5 mM N^G-nitro-L-arginine methyl ester (L-NAME; an NOS inhibitor) for 48 h. Increasing Arg concentrations in culture medium dose-dependently enhanced (P < 0.05) the oxidation of glucose and oleic acid to CO₂ in all three cell types, lactate release from C2C12 cells, and the incorporation of oleic acid into esterified lipids in BNL CL.2 and 3T3-L1 cells. Arg at 400 µM also stimulated (P < 0.05) the phosphorylation of AMP-activated protein kinase (AMPK) in all three cell types and increased (P < 0.05) NO production in C2C12 and BNL CL.2 cells. The inhibition of NOS by L-NAME moderately reduced (P < 0.05) glucose and oleic acid oxidation, lactate release, and the phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) in BNL CL.2 cells, but had no effect (P > 0.05) on these variables in C2C12 or 3T3-L1 cells. Collectively, these results indicate that Arg increased AMPK activity and energy-substrate oxidation in BNL CL.2, C2C12, and 3T3-L1 cells through both NO-dependent and NO-independent mechanisms.

Metabolomics studies of cell-cell interactions using single cell mass spectrometry combined with fluorescence microscopy

Cell-cell interactions are critical for transmitting signals among cells and maintaining their normal functions from the single-cell level to tissues. In cancer studies, interactions between drug-resistant and drug-sensitive cells play an important role in the development of chemotherapy resistance of tumors. As metabolites directly reflect the cell status, metabolomics studies provide insight into cell-cell communication. Mass spectrometry (MS) is a powerful tool for metabolomics studies, and single cell MS (SCMS) analysis can provide unique information for understanding interactions among heterogeneous cells. In the current study, we utilized a direct co-culture system (with cell-cell contact) to study metabolomics of single cells affected by cell-cell interactions in their living status. A fluorescence microscope was utilized to distinguish these two types of cells for SCMS metabolomics studies using the Single-probe SCMS technique under ambient conditions. Our results show that through interactions with drug-resistant cells, drug-sensitive cancer cells acquired significantly increased drug resistance and exhibited drastically altered metabolites. Further investigation found that the increased drug resistance was associated with multiple metabolism regulations in drug-sensitive cells through co-culture such as the upregulation of sphingomyelins lipids and lactic acid and the downregulation of TCA cycle intermediates. The method allows for direct MS metabolomics studies of individual cells labeled with fluorescent proteins or dyes among heterogeneous populations.

Scaffolding Biomaterials for 3D Cultivated Meat: Prospects and Challenges

Cultivating meat from stem cells rather than by raising animals is a promising solution to concerns about the negative externalities of meat production. For cultivated meat to fully mimic conventional meat's organoleptic and nutritional properties, innovations in scaffolding technology are required. Many scaffolding technologies are already developed for use in biomedical tissue engineering. However, cultivated meat production comes with a unique set of constraints related to the scale and cost of production as well as the necessary attributes of the final product, such as texture and food safety. This review discusses the properties of vertebrate skeletal muscle that will need to be replicated in a successful product and the current state of scaffolding innovation within the cultivated meat industry, highlighting promising scaffold materials and techniques that can be applied to cultivated meat development. Recommendations are provided for future research into scaffolds capable of supporting the growth of high-quality meat while minimizing production costs. Although the development of appropriate scaffolds for cultivated meat is challenging, it is also tractable and provides novel opportunities to customize meat properties.

Extracellular Matrix and the Production of Cultured Meat

Cultured meat production is an evolving method of producing animal meat using tissue engineering techniques. Cells, chemical factors, and suitable biomaterials that serve as scaffolds are all essential for the cultivation of muscle tissue. Scaffolding is essential for the development of organized meat products resembling steaks because it provides the mechanical stability needed by cells to attach, differentiate, and mature. In in vivo settings, extracellular matrix (ECM) ensures substrates and scaffolds are provided for cells. The ECM of skeletal muscle (SM) maintains tissue elasticity, creates adhesion points for cells, provides a three-dimensional (3D) environment, and regulates biological processes. Consequently, creating mimics of native ECM is a difficult task. Animal-derived polymers like collagen are often regarded as the gold standard for producing scaffolds with ECM-like properties. Animal-free scaffolds are being investigated as a potential source of stable, chemically defined, low-cost materials for cultured meat production. In this review, we explore the influence of ECM on myogenesis and its role as a scaffold and vital component to improve the efficacy of the culture media used to produce cultured meat.

Bioprocessing technology of muscle stem cells: implications for cultured meat

Muscle stem cells (MuSCs) are essential for the growth, maintenance, and repair of skeletal muscle. In the emerging area of cultured meat, meat products are manufactured with MuSCs using theory and technology from the fields of cell culture, tissue engineering, and food processing. Recently, considerable progress has been made in bioprocessing technologies for MuSCs, including isolation, expansion, differentiation, and tissue building. Here we summarize cutting-edge operational strategies and recently characterized regulatory mechanisms for MuSCs. Furthermore, we discuss their applicability to refining the production process for cultured meat and accelerating its industrialization.

Comparison of lipid deposition of intramuscular preadipocytes in Tan sheep co-cultured with satellite cells or alone

The purpose of this study was to investigate the effect of the skeletal muscle satellite cells (SMSCs) on the lipid deposition of the intramuscular preadipocytes (IMPs) in a co-culture system of the Tan sheep cells. The SMSCs and IMPs from Tan sheep were separated and cultured. After the two kinds of cells were separated and cultured, they were inoculated onto a transwell cell chamber co-culture plate for co-cultivation. When the cell density reached more than 90%, the cells were induced to differentiate. After the induction of the SMSCs differentiation for 8 days, the level of the IMPs differentiation and the expression levels of the differentiation marker genes and the key enzymes of the lipid metabolism were assessed. The results showed that the number and area of the lipid droplets in the IMPs in the co-culture system were significantly reduced compared to those in the IMPs culture alone (p < 0.05). Meanwhile, the expression levels of the PPARγ, c/EBPα, ACC, FAS mRNA in the IMPs were significantly decreased (p < 0.05); the expression level of aP2 mRNA was decreased, but the difference was not significant (p > 0.05).These findings indicate that the SMSCs of the Tan sheep in the co-culture system inhibited the lipid deposition by the IMPs.