Application of Platelet-Rich Plasma as a Stem Cell Treatment - an Attempt to Clarify a Common Public Misconception.

In recent years, there has been a significant increase in the practice of regenerative medicine by health practitioners and direct-to-consumer businesses globally. Among different tools of regenerative medicine, platelet-rich plasma (PRP) and stem cell-based therapies have received considerable attention. The use of PRP, in particular, has gained popularity due to its easy access, simple processing techniques, and regenerative potential. However, it is important to address a common misconception amongst the general public equating to PRP and stem cells due to the demonstrated efficacy of PRP in treating musculoskeletal and dermatological disorders. Notably, PRP promotes regeneration by providing growth factors or other paracrine factors only. Therefore, it cannot replenish or replace the lost cells in conditions where a large number of cells are required to regenerate tissues and/or organs. In such cases, cell-based therapies are the preferred option. Additionally, other tools of regenerative medicine, such as bioprinting, organoids, and mechanobiology also rely on stem cells for their success. Hence, healthcare and commercial entities offering direct-to-customer regenerative therapies should not mislead the public by claiming that the application of PRP is a stem cell-based therapy. Furthermore, it is important for regulatory bodies to strictly monitor these profit-driven entities to prevent them from providing unregulated regenerative treatments and services that claim a broad variety of benefits with little proof of efficacy, safety concerns, and obscure scientific justification.

Uncovering the gray zone: mapping the global landscape of direct-to-consumer businesses offering interventions based on secretomes, extracellular vesicles, and exosomes.

BACKGROUND: The last decade has seen a significant increase in media attention, industrial growth, and patient interest in stem cell-based interventions. This led to a rise in direct-to-consumer businesses offering stem cell "therapies" for multiple indications with little evidence of safety and efficacy. In parallel, the use of stem cell secretomes as a substitute for stem cell transplantation has become an increasing trend in regenerative medicine with multiple clinical trials currently assessing their efficacy and safety profile. As a result, multiple businesses and private clinics have now started to exploit this situation and are offering secretome-based interventions despite the lack of supporting data. This poses significant risks for the patients and could lead to a credibility crisis in the field. METHODS: Internet searches were used to locate clinics marketing and selling interventions based on stem cell secretomes, exosomes, or extracellular vesicles. Data were extracted from websites with a particular focus on the global distribution of the businesses, the cellular source of the secretome, the indication spectrum, and the pricing of the provided services. Lastly, the types of evidence used on the websites of the businesses to market their services were extracted. RESULTS: Overall, 114 companies market secretome-based therapies in 28 countries. The vast majority of the interventions are based on allogenic stem cells from undisclosed cellular sources and skin care is the most marketed indication. The price range is USD99-20,000 depending on the indication. CONCLUSIONS: The direct-to-consumer industry for secretome-based therapies appears to be primed for growth in the absence of appropriate regulatory frameworks and guidelines. We conclude that such business activity requires tight regulations and monitoring by the respective national regulatory bodies to prevent patients from being conned and more importantly from being put at risk.

Cell Therapy with Human Reprogrammed CD8+ T-Cells Has Antimetastatic Effects on Lewis Lung Carcinoma in C57BL/6 Mice.

Using a model of Lewis lung carcinoma (LLC) in vitro and in vivo, we previously demonstrated increased antitumor activity in CD8+ T-cells reprogrammed with an MEK inhibitor and PD-1 blocker. In this follow-up study, we carried out the reprogramming of human CD8+ T-cells (hrT-cell) using the MEK inhibitor and PD-1 blocker and targeted LLC cells. The effects of hrT-cell therapy were studied in a mouse model of spontaneous metastasis of a solid LLC tumor. We found antimetastatic activity of hrT-cells, a decrease in the number of cancer cells and cancer stem cells in the lungs, and an increase in the number of T-cells in the blood (including effector T-cells). Thus, reprogramming of human CD8+ T-cells with an MEK inhibitor and PD-1 blocker with targeted training by tumor target cells is a potential platform for developing a new approach to targeted lung cancer therapy.

Computational pharmacology: New avenues for COVID-19 therapeutics search and better preparedness for future pandemic crises.

The COVID-19 pandemic created an unprecedented global healthcare emergency prompting the exploration of new therapeutic avenues, including drug repurposing. A large number of ongoing studies revealed pervasive issues in clinical research, such as the lack of accessible and organised data. Moreover, current shortcomings in clinical studies highlighted the need for a multi-faceted approach to tackle this health crisis. Thus, we set out to explore and develop new strategies for drug repositioning by employing computational pharmacology, data mining, systems biology, and computational chemistry to advance shared efforts in identifying key targets, affected networks, and potential pharmaceutical intervention options. Our study revealed that formulating pharmacological strategies should rely on both therapeutic targets and their networks. We showed how data mining can reveal regulatory patterns, capture novel targets, alert about side-effects, and help identify new therapeutic avenues. We also highlighted the importance of the miRNA regulatory layer and how this information could be used to monitor disease progression or devise treatment strategies. Importantly, our work bridged the interactome with the chemical compound space to better understand the complex landscape of COVID-19 drugs. Machine and deep learning allowed us to showcase limitations in current chemical libraries for COVID-19 suggesting that both in silico and experimental analyses should be combined to retrieve therapeutically valuable compounds. Based on the gathered data, we strongly advocate for taking this opportunity to establish robust practices for treating today's and future infectious diseases by preparing solid analytical frameworks.

Analysis of Circulating Tumor and Cancer Stem Cells Provides New Opportunities in Diagnosis and Treatment of Small Cell Lung Cancer.

Current methods for diagnosis and treatment of small cell lung cancer (SCLC) have only a modest efficacy. In this pilot study, we analyzed circulating tumor cells (CTCs) and cancer stem cells (CSCs) in patients with SCLC to search for new diagnostic and prognostic markers and novel approaches to improve the treatment of the disease. In other forms of lung cancer, we showed a heterogeneity of blood CTCs and CSCs populations, as well as changes in other cell populations (ALDH+, CD87+CD276+, and EGF+Axl+) in smokers. A number of CTCs and CSCs in patients with SCLC have been shown to be resistant to chemotherapy (CT). High cytotoxic activity and resistance to apoptosis of reprogrammed CD3+CD8+ T-lymphocytes (rTcells) in relation to naive CD3+CD8+ T-lymphocytes was demonstrated in a smoking patient with SCLC (Patient G) in vitro. The target for rTcells was patient G's blood CSCs. Reprogramming of CD3+CD8+ T-lymphocytes was carried out with the MEK1/2 inhibitor and PD-1/PD-L1 pathway blocker nivolumab. The training procedure was performed with a suspension of dead CTCs and CSCs obtained from patient's G blood. The presented data show a new avenue for personalized SCLC diagnosis and targeted improvement of chemotherapy based on the use of both CTCs and CSCs.

Reprogrammed CD8+ T-Lymphocytes Isolated from Bone Marrow Have Anticancer Potential in Lung Cancer.

CD8+ T-lymphocytes play a key role in antitumor immune response. Patients with lung cancer often suffer from T-lymphocyte dysfunction and low T-cell counts. The exhaustion of effector T-lymphocytes largely limits the effectiveness of therapy. In this study, reprogrammed T-lymphocytes used MEK inhibitors and PD-1 blockers to increase their antitumor activity. Antitumor effects of reprogrammed T-lymphocytes were shown in vitro and in vivo in the Lewis lung carcinoma model. The population of T- lymphocytes with persistent expression of CCR7 was formed as a result of reprogramming. Reprogrammed T-lymphocytes were resistant to apoptosis and characterized by high cytotoxicity against Lewis lung carcinoma (LLC) cells in vitro. Administration of reprogrammed T-lymphocytes to C57BL/6 mice with LLC reduced the number of lung metastases. The antitumor effect resulted from the elimination of tumor cells and cancer stem cells, and the effect of therapy on cytotoxic T-lymphocyte counts. Thus, reprogramming of T-lymphocytes using MEK inhibitors is a promising approach for targeted therapy of lung cancer.

Isolation and Characterization of Extracellular Vesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells.

The safety and efficacy of mesenchymal stem cells/marrow stromal cells (MSC) have been widely studied. Since they are hypoimmunogenic, MSC can escape immune recognition, thus making them an attractive tool in clinical settings beyond autologous cell-based therapy. Paracrine factors including extracellular vesicles (EVs) released by MSC play a significant role in exerting therapeutic effects of MSC. Since their first discovery, MSC-EVs have been widely studied in an attempt to tackle the mechanisms of their therapeutic effects in various disease models. However, currently there are no standard methods to isolate EVs. Here, we describe a differential centrifugation-based protocol for isolation of EVs derived from human umbilical cord MSC (huc-MSC). In addition, the protocol describes methods for characterization of the EVs using transmission electron microscope, Western blot, and nanoparticle tracking analysis.

Genome-nanosurface interaction of titania nanotube arrays: evaluation of telomere, telomerase and NF-κB activities on an epithelial cell model.

Titanium dioxide nanotube arrays (TNAs) provide a promising platform for medical implants and nanomedicine applications. The present cell-TNA study has provided profound understanding on protection of genome integrity via telomere, telomerase and NF-κB activities using an epithelial cell model. It has been revealed in this study that cell-TNA interaction triggers the telomere shortening activity and inhibition of telomerase activity at the mRNA and protein level. The present work supported that the cell-TNA stimulus might involve controlled transcription and proliferative activities via NBN and TERF21P mechanisms. Moreover, inhibition of NF-κB may promote molecular sensitivity via senescence-associated secretory phenotype activities and might result in reduced inflammatory response which would be good for cell and nanosurface adaptation activities. Thus, this nanomaterial-molecular knowledge is beneficial for further nanomaterial characterization and advanced medical application.

Extracellular Vesicles from Stem and Progenitor Cells for Cell-Free Regenerative Therapy.

Cell-based regenerative therapies involving stem or progenitor cells are considered as possible therapeutic modalities to treat non-communicable and degenerative diseases. Recently, regenerative outcomes of cell-based therapies have been linked to paracrine factors and extracellular vesicles [EVs] released by the transplanted cells rather than the transplanted cells themselves. EVs contain a cargo that includes microRNAs [miRNAs], mRNAs, as well as proteins. Their role in mediating intercellular communication has been acknowledged in several studies. However, the regenerative potential of the miRNAs, mRNAs, and proteins that are present in EVs is a matter of ongoing scientific debate. In this review, we discuss EVs as an alternative to stem cell-based therapy to treat some of the non-communicable and degenerative diseases. Moreover, we also propose that pre-treatment of the cells could help to produce EVs enriched with particular miRNAs, mRNAs, and/or proteins that could support the successful regeneration of a targeted organ.

Potential of Stem Cells and CART as a Potential Polytherapy for Small Cell Lung Cancer.

Despite the increasing urgency of the problem of treating small cell lung cancer (SCLC), information on the causes of its development is fragmentary. There is no complete understanding of the features of antitumor immunity and the role of the microenvironment in the development of SCLC resistance. This impedes the development of new methods for the diagnosis and treatment of SCLC. Lung cancer and chronic obstructive pulmonary disease (COPD) have common pathogenetic factors. COPD is a risk factor for lung cancer including SCLC. Therefore, the search for effective approaches to prevention, diagnosis, and treatment of SCLC in patients with COPD is an urgent task. This review provides information on the etiology and pathogenesis of SCLC, analyses the effectiveness of current treatment options, and critically evaluates the potential of chimeric antigen receptor T cells therapy (CART therapy) in SCLC. Moreover, we discuss potential links between lung cancer and COPD and the role of endothelium in the development of COPD. Finally, we propose a new approach for increasing the efficacy of CART therapy in SCLC.

Recent Advances in Translational Adipose-Derived Stem Cell Biology.

Multipotent mesenchymal stem cells/marrow stromal cells (MSCs), originally discovered in the bone marrow by Alexander Friedenstein as early as 1968 [...].

Time-Dependent Reduction of Calcium Oscillations in Adipose-Derived Stem Cells Differentiating towards Adipogenic and Osteogenic Lineage.

Adipose-derived mesenchymal stromal cells (ASCs) are multipotent stem cells which can differentiate into various cell types, including osteocytes and adipocytes. Due to their ease of harvesting, multipotency, and low tumorigenicity, they are a prime candidate for the development of novel interventional approaches in regenerative medicine. ASCs exhibit slow, spontaneous Ca2+ oscillations and the manipulation of Ca2+ signalling via electrical stimulation was proposed as a potential route for promoting their differentiation in vivo. However, the effects of differentiation-inducing treatments on spontaneous Ca2+ oscillations in ASCs are not yet fully characterised. In this study, we used 2-photon live Ca2+ imaging to assess the fraction of cells showing spontaneous oscillations and the frequency of the oscillation (measured as interpeak interval-IPI) in ASCs undergoing osteogenic or adipogenic differentiation, using undifferentiated ASCs as controls. The measurements were carried out at 7, 14, and 21 days in vitro (DIV) to assess the effect of time in culture on Ca2+ dynamics. We observed that both time and differentiation treatment are important factors associated with a reduced fraction of cells showing Ca2+ oscillations, paralleled by increased IPI times, in comparison with untreated ASCs. Both adipogenic and osteogenic differentiation resulted in a reduction in Ca2+ dynamics, such as the fraction of cells showing intracellular Ca2+ oscillations and their frequency. Adipogenic differentiation was associated with a more pronounced reduction of Ca2+ dynamics compared to cells differentiating towards the osteogenic fate. Changes in Ca2+ associated oscillations with a specific treatment had already occurred at 7 DIV. Finally, we observed a reduction in Ca2+ dynamics over time in untreated ASCs. These data suggest that adipogenic and osteogenic differentiation cell fates are associated with specific changes in spontaneous Ca2+ dynamics over time. While this observation is interesting and provides useful information to understand the functional correlates of stem cell differentiation, further studies are required to clarify the molecular and mechanistic correlates of these changes. This will allow us to better understand the causal relationship between Ca2+ dynamics and differentiation, potentially leading to the development of novel, more effective interventions for both bone regeneration and control of adipose growth.

1,8-Cineole Affects Agonists-Induced Platelet Activation, Thrombus Formation and Haemostasis.

1,8-cineole, a monoterpenoid is a major component of eucalyptus oil and has been proven to possess numerous beneficial effects in humans. Notably, 1,8-cineole is the primary active ingredient of a clinically approved drug, Soledum® which is being mainly used for the maintenance of sinus and respiratory health. Due to its clinically valuable properties, 1,8-cineole has gained significant scientific interest over the recent years specifically to investigate its anti-inflammatory and antioxidant effects. However, the impact of 1,8-cineole on the modulation of platelet activation, thrombosis and haemostasis was not fully established. Therefore, in this study, we demonstrate the effects of 1,8-cineole on agonists-induced platelet activation, thrombus formation under arterial flow conditions and haemostasis in mice. 1,8-cineole largely inhibits platelet activation stimulated by glycoprotein VI (GPVI) agonists such as collagen and cross-linked collagen-related peptide (CRP-XL), while it displays minimal inhibitory effects on thrombin or ADP-induced platelet aggregation. It inhibited inside-out signalling to integrin αIIbß3 and outside-in signalling triggered by the same integrin as well as granule secretion and intracellular calcium mobilisation in platelets. 1,8-cineole affected thrombus formation on collagen-coated surface under arterial flow conditions and displayed a minimal effect on haemostasis of mice at a lower concentration of 6.25 µM. Notably, 1,8-cineole was found to be non-toxic to platelets up to 50 µM concentration. The investigation on the molecular mechanisms through which 1,8-cineole inhibits platelet function suggests that this compound affects signalling mediated by various molecules such as AKT, Syk, LAT, and cAMP in platelets. Based on these results, we conclude that 1,8-cineole may act as a potential therapeutic agent to control unwarranted platelet reactivity under various pathophysiological settings.

Cancer Stem Cells and Somatic Stem Cells as Potential New Drug Targets, Prognosis Markers, and Therapy Efficacy Predictors in Breast Cancer Treatment.

New drug targets, markers of disease prognosis, and more efficient treatment options are an unmet clinical need in breast cancer (BC). We have conducted a pilot study including patients with luminal B stage breast cancer IIA-IIIB. The presence and frequency of various populations of cancer stem cells (CSC) and somatic stem cells were assessed in the blood, breast tumor tissue, and normal breast tissue. Our results suggest that patients with BC can be divided into two distinct groups based on the frequency of aldehyde dehydrogenase positive cells (ALDH1+ cells) in the blood (ALDH1hi and ALDH1low). In the ALDH1hi cells group, the tumor is dominated by epithelial tumor cells CD44+CD24low, CD326+CD44+CD24-, and CD326-CD49f+, while in the ALDH1low cells group, CSCs of mesenchymal origin and epithelial tumor cells (CD227+CD44+CD24- and CD44+CD24-CD49f+) are predominant. In vitro CSCs of the ALDH1low cells group expressing CD326 showed high resistance to cytostatics, CD227+ CSCs of the ALDH1hi cells group are sensitive to cytostatics. Epithelial precursors of a healthy mammary gland were revealed in normal breast tissue of patients with BC from both groups. The cells were associated with a positive effect of chemotherapy and remission in BC patients. Thus, dynamic control of their presence in blood and assessment of the sensitivity of CSCs to cytostatics in vitro can improve the effectiveness of chemotherapy in BC.

Micellar Hyaluronidase and Spiperone as a Potential Treatment for Pulmonary Fibrosis.

Concentration of hyaluronic acid (HA) in the lungs increases in idiopathic pulmonary fibrosis (IPF). HA is involved in the organization of fibrin, fibronectin, and collagen. HA has been proposed to be a biomarker of fibrosis and a potential target for antifibrotic therapy. Hyaluronidase (HD) breaks down HA into fragments, but is a subject of rapid hydrolysis. A conjugate of poloxamer hyaluronidase (pHD) was prepared using protein immobilization with ionizing radiation. In a model of bleomycin-induced pulmonary fibrosis, pHD decreased the level of tissue IL-1ß and TGF-ß, prevented the infiltration of the lung parenchyma by CD16+ cells, and reduced perivascular and peribronchial inflammation. Simultaneously, a decrease in the concentrations of HA, hydroxyproline, collagen 1, total soluble collagen, and the area of connective tissue in the lungs was observed. The effects of pHD were significantly stronger compared to native HD which can be attributed to the higher stability of pHD. Additional spiperone administration increased the anti-inflammatory and antifibrotic effects of pHD and accelerated the regeneration of the damaged lung. The potentiating effects of spiperone can be explained by the disruption of the dopamine-induced mobilization and migration of fibroblast progenitor cells into the lungs and differentiation of lung mesenchymal stem cells (MSC) into cells of stromal lines. Thus, a combination of pHD and spiperone may represent a promising approach for the treatment of IPF and lung regeneration.

Impact of 3D cell culture on bone regeneration potential of mesenchymal stromal cells.

As populations age across the world, osteoporosis and osteoporosis-related fractures are becoming the most prevalent degenerative bone diseases. More than 75 million patients suffer from osteoporosis in the USA, the EU and Japan. Furthermore, it is anticipated that the number of patients affected by osteoporosis will increase by a third by 2050. Although conventional therapies including bisphosphonates, calcitonin and oestrogen-like drugs can be used to treat degenerative diseases of the bone, they are often associated with serious side effects including the development of oesophageal cancer, ocular inflammation, severe musculoskeletal pain and osteonecrosis of the jaw.The use of autologous mesenchymal stromal cells/mesenchymal stem cells (MSCs) is a possible alternative therapeutic approach to tackle osteoporosis while overcoming the limitations of traditional treatment options. However, osteoporosis can cause a decrease in the numbers of MSCs, induce their senescence and lower their osteogenic differentiation potential.Three-dimensional (3D) cell culture is an emerging technology that allows a more physiological expansion and differentiation of stem cells compared to cultivation on conventional flat systems.This review will discuss current understanding of the effects of different 3D cell culture systems on proliferation, viability and osteogenic differentiation, as well as on the immunomodulatory and anti-inflammatory potential of MSCs.

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles ameliorate airway inflammation in a rat model of chronic obstructive pulmonary disease (COPD).

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an incurable and debilitating chronic disease characterized by progressive airflow limitation associated with abnormal levels of tissue inflammation. Therefore, stem cell-based approaches to tackle the condition are currently a focus of regenerative therapies for COPD. Extracellular vesicles (EVs) released by all cell types are crucially involved in paracrine, extracellular communication. Recent advances in the field suggest that stem cell-derived EVs possess a therapeutic potential which is comparable to the cells of their origin. METHODS: In this study, we assessed the potential anti-inflammatory effects of human umbilical cord mesenchymal stem cell (hUC-MSC)-derived EVs in a rat model of COPD. EVs were isolated from hUC-MSCs and characterized by the transmission electron microscope, western blotting, and nanoparticle tracking analysis. As a model of COPD, male Sprague-Dawley rats were exposed to cigarette smoke for up to 12 weeks, followed by transplantation of hUC-MSCs or application of hUC-MSC-derived EVs. Lung tissue was subjected to histological analysis using haematoxylin and eosin staining, Alcian blue-periodic acid-Schiff (AB-PAS) staining, and immunofluorescence staining. Gene expression in the lung tissue was assessed using microarray analysis. Statistical analyses were performed using GraphPad Prism 7 version 7.0 (GraphPad Software, USA). Student's t test was used to compare between 2 groups. Comparison among more than 2 groups was done using one-way analysis of variance (ANOVA). Data presented as median ± standard deviation (SD). RESULTS: Both transplantation of hUC-MSCs and application of EVs resulted in a reduction of peribronchial and perivascular inflammation, alveolar septal thickening associated with mononuclear inflammation, and a decreased number of goblet cells. Moreover, hUC-MSCs and EVs ameliorated the loss of alveolar septa in the emphysematous lung of COPD rats and reduced the levels of NF-κB subunit p65 in the tissue. Subsequent microarray analysis revealed that both hUC-MSCs and EVs significantly regulate multiple pathways known to be associated with COPD. CONCLUSIONS: In conclusion, we show that hUC-MSC-derived EVs effectively ameliorate by COPD-induced inflammation. Thus, EVs could serve as a new cell-free-based therapy for the treatment of COPD.

A muscle growth-promoting treatment based on the attenuation of activin/myostatin signalling results in long-term testicular abnormalities.

Activin/myostatin signalling acts to induce skeletal muscle atrophy in adult mammals by inhibiting protein synthesis as well as promoting protein and organelle turnover. Numerous strategies have been successfully developed to attenuate the signalling properties of these molecules, which result in augmenting muscle growth. However, these molecules, in particular activin, play major roles in tissue homeostasis in numerous organs of the mammalian body. We have recently shown that although the attenuation of activin/myostatin results in robust muscle growth, it also has a detrimental impact on the testis. Here, we aimed to discover the long-term consequences of a brief period of exposure to muscle growth-promoting molecules in the testis. We demonstrate that muscle hypertrophy promoted by a soluble activin type IIB ligand trap (sActRIIB) is a short-lived phenomenon. In stark contrast, short-term treatment with sActRIIB results in immediate impact on the testis, which persists after the sessions of the intervention. Gene array analysis identified an expansion in aberrant gene expression over time in the testis, initiated by a brief exposure to muscle growth-promoting molecules. The impact on the testis results in decreased organ size as well as quantitative and qualitative impact on sperm. Finally, we have used a drug-repurposing strategy to exploit the gene expression data to identify a compound - N6-methyladenosine - that may protect the testis from the impact of the muscle growth-promoting regime. This work indicates the potential long-term harmful effects of strategies aimed at promoting muscle growth by attenuating activin/myostatin signalling. Furthermore, we have identified a molecule that could, in the future, be used to overcome the detrimental impact of sActRIIB treatment on the testis.