Small Extracellular Vesicles from Human Amniotic Fluid Samples as Promising Theranostics

Since the first evidence that stem cells can provide pro-resolving effects via paracrine secretion of soluble factors, growing interest has been addressed to define the most ideal cell source for clinical translation. Leftover or clinical waste samples of human amniotic fluid obtained following prenatal screening, clinical intervention, or during scheduled caesarean section (C-section) delivery at term have been recently considered an appealing source of mesenchymal progenitors with peculiar regenerative capacity. Human amniotic fluid stem cells (hAFSC) have been demonstrated to support tissue recovery in several preclinical models of disease by exerting paracrine proliferative, anti-inflammatory and regenerative influence. Small extracellular vesicles (EVs) concentrated from the hAFSC secretome (the total soluble trophic factors secreted in the cell-conditioned medium, hAFSC-CM) recapitulate most of the beneficial cell effects. Independent studies in preclinical models of either adult disorders or severe diseases in newborns have suggested a regenerative role of hAFSC-EVs. EVs can be eventually concentrated from amniotic fluid (hAF) to offer useful prenatal information, as recently suggested. In this review, we focus on the most significant aspects of EVs obtained from either hAFSC and hAF and consider the current challenges for their clinical translation, including isolation, characterization and quantification methods.

Experimental Models of Glaucoma

Optic nerve pits are a mono- or bilateral congenital anomaly represented by optic disc depressions of various sizes. In half of the cases, the pits are complicated by edema, central retinal detachment and retinoschisis, and cause visual function decrease. Visual acuity losses can be either insignificant or pronounced. Optic discs pits have been investigated massively over the last century and a half, but their etiology is still underresearched. In recent years, however, due to the development of digital scanning and data processing technologies and the emergence of non-invasive highly informative diagnostic methods, it has become possible to reveal structural and functional changes of the optic disc in vivo, in addition to the traditional detection of histological changes in cadaveric eyes.Glaucomatous process modeling is one of the challenges in ophthalmology. And this is due primarily to the fact that, so far, the main reasons for the onset and progression of glaucoma. Numerous works on experimental research in its core model ocular. However, there are forms of glaucoma, which are independent of the level of intraocular pressure. Ideal model of glaucoma is considered a model with the development of the characteristic symptom in which a key symptom is a slowly progressive excavation of the optic nerve. But given the new knowledge in the pathogenesis of neurodegenerative changes in glaucoma in this model should be added and the opportunity to study the brain, vascular factors of progression, the level of neurotransmitters, trophic factors, etc. Therefore, we tried to make the analysis of models of glaucoma in various experimental animals and determine the most appropriate model for studying the pathogenesis of glaucoma.

Growth of tench (Tinca tinca L., 1758) (Cyprinidae) in reservoirs of K. Satpayev canal

The reservoirs of the K. Satpayev canal are the important fishery water bodies in the Central Kazakhstan. Some of these reservoirs are inhabited by tench, a fish species relatively widely represented in other water systems of the region. In the reservoirs of the canal this species is not the main commercial one but it has a fairly high commercial value due to its popularity with consumers. As part of the research, the growth indicators of Tinca tinca from 4 reservoirs were evaluated, and the data on its growth from 3 more reservoirs were also provided. These samples differ in efficiency and growth rates. It has been found that there is no sexual or generation variability. Growth rates in successive fish generations strongly correlate with each other, which may indirectly indicate the stability of living conditions. The R. Lee’s phenomenon was not marked. In this regard, the calculation of variables of the von Bertalanffy growth equation was carried out without additional data processing. The highest rates of linear growth were characteristic of Tinca tinca from the reservoir of HS No. 9. However, the effectiveness of its growth scheme was the lowest. Population with a longer age range from the reservoir HS No. 3 did not have high linear growth rates, but its growth efficiency was higher. In this case, it is obvious that any assessment of growth will be relative and depend on the goals set for it. In the reservoirs of the canal there are more or less similar conditions for tench populations living due to the specifics of its functioning. The main limiting factor for the growth rate, in our opinion, will be abundance of the species in the reservoir and related trophic factors with a certain influence of withdrawal (fishing, predators).

Modulation of Mesenchymal Stem Cells for Enhanced Therapeutic Utility in Ischemic Vascular Diseases

Mesenchymal stem cells are multipotent stem cells isolated from various tissue sources, including but not limited to bone marrow, adipose, umbilical cord, and Wharton Jelly. Although cell-mediated mechanisms have been reported, the therapeutic effect of MSCs is now recognized to be primarily mediated via paracrine effects through the secretion of bioactive molecules, known as the “secretome”. The regenerative benefit of the secretome has been attributed to trophic factors and cytokines that play neuroprotective, anti-angiogenic/pro-angiogenic, anti-inflammatory, and immune-modulatory roles. The advancement of autologous MSCs therapy can be hindered when introduced back into a hostile/disease environment. Barriers include impaired endogenous MSCs function, limited post-transplantation cell viability, and altered immune-modulatory efficiency. Although secretome-based therapeutics have gained popularity, many translational hurdles, including the heterogeneity of MSCs, limited proliferation potential, and the complex nature of the secretome, have impeded the progress. This review will discuss the experimental and clinical impact of restoring the functional capabilities of MSCs prior to transplantation and the progress in secretome therapies involving extracellular vesicles. Modulation and utilization of MSCs–secretome are most likely to serve as an effective strategy for promoting their ultimate success as therapeutic modulators.

Depression and Autoimmune Thyroiditis - Their Relationship and the Effects of Treating Psychiatric and Thyroid Disorders on Changes in Clinical and Biochemical Parameters Including BDNF and Other Cytokines

Various autoimmune diseases, including autoimmune hypothyroidism (AHT), are associated with a higher risk of developing mood disorders throughout life. Depression is accompanied by the changes in the levels of inflammatory and trophic factors, including interleukines (IL-1beta, IL-2, IL-6), interferon alpha (IFN-alpha), tumor necrosis factor alpha (TNF-alpha), C-reactive protein (CRP) and brain derived neurotrophic factor (BDNF). Similar disturbances in the cytokine profile are seen in AHT patients and their relatives. Disclosure of the relationship between the co-existence of depression and autoimmune subclinical thyroiditis indicates that the pathomecha-nism of depression may be related to the changes in the immune system, it is possible that both conditions may be caused by the same immune processes. The above hypothesis is indirectly sup-ported by the observations that the treatment with both antidepressants and levothyroxine leads to a decrease in the levels of proinflammatory cytokines with an increase in BDNF concentrations, simultaneously correlating with an improvement in the clinical parameters. However, so far there are no long-term studies determining the causal relationship between depression, thyroid auto-antibodies, and cytokine profile, which could bring us closer to understanding the interrelation-ships between them and facilitate the use of an adequate pharmacotherapy, not necessarily psy-chiatric. We consider the above issues insufficiently investigated but of great importance. This ar-ticle is an overview of the available literature as well as an introduction to our research project.

Scalable Enrichment of Immunomodulatory Human Acute Myeloid Leukemia Cell Line-Derived Extracellular Vesicles

Acute myeloid leukemia (AML) cells can secrete trophic factors, including extracellular vesicles (EVs), instructing the stromal leukemic niche. Here, we introduce a scalable workflow for purification of immunomodulatory AML-EVs to compare their phenotype and function to the parental AML cells and their secreted soluble factors. AML cell lines HL-60, KG-1, OCI-AML3, and MOLM-14 released EVs with a peak diameter of approximately 80 nm in serum-free particle-reduced medium. We enriched EVs >100x using tangential flow filtration (TFF) and separated AML-derived soluble factors and cells in parallel. EVs were characterized by electron microscopy, immunoblotting, and flow cytometry, confirming the double-membrane morphology, purity and identity. AML-EVs showed significant enrichment of immune response and leukemia-related pathways in tandem mass-tag proteomics and a significant dose-dependent inhibition of T cell proliferation, which was not observed with AML cells or their soluble factors. Furthermore, AML-EVs dose-dependently reduced NK cell lysis of third-party K-562 leukemia targets. This emphasizes the peculiar role of AML-EVs in leukemia immune escape and indicates novel EV-based targets for therapeutic interventions.

3D spheroids of human placenta-derived mesenchymal stem cells attenuate spinal cord injury in mice

Mesenchymal stem cell (MSC) is an absorbing candidate for cell therapy in treating spinal cord injury (SCI) due to its great potential for multiple cell differentiation, mighty paracrine secretion as well as vigorous immunomodulatory effect, of which are beneficial to the improvement of functional recovery post SCI. However, the therapeutic effects of MSC on SCI have been limited because of the gradual loss of MSC stemness in the process of expanding culture. Therefore, in this study, we aimed to maintain those beneficial properties of MSC via three-dimensional spheroid cell culture and then compared them with conventionally-cultured MSCs in the treatment of SCI both in vitro and in vivo with the aid of two-photon microscope. We found that 3D human placenta-derived MSCs (3D-HPMSCs) demonstrated a significant increase in secretion of anti-inflammatory factors and trophic factors like VEGF, PDGF, FGF via QPCR and Bio-Plex assays, and showed great potentials on angiogenesis and neurite morphogenesis when co-cultured with HUVECs or DRGs in vitro. After transplantation into the injured spinal cord, 3D-HPMSCs managed to survive for the entire experiment and retained their advantageous properties in secretion, and exhibited remarkable effects on neuroprotection by minimizing the lesion cavity, inhibiting the inflammation and astrogliosis, and promoting angiogenesis. Further investigation of axonal dieback via two-photon microscope indicated that 3D-HPMSCs could effectively alleviate axonal dieback post injury. Further, mice only treated with 3D-HPMSCs obtained substantial improvement of functional recovery on electrophysiology, BMS score, and Catwalk analysis. RNA sequencing suggested that the 3D-HPMSCs structure organization-related gene was significantly changed, which was likely to potentiate the angiogenesis and inflammation regulation after SCI. These results suggest that 3D-HPMSCs may hold great potential for the treatment of SCI.

Preconditioning of Hypoxic Culture Increases The Therapeutic Potential of Adipose Derived Mesenchymal Stem Cells

Various in vitro preconditioning strategies have been implemented to increase the regenerative capacity of MSCs. Among them are modulation of culture atmosphere (hypoxia or anoxia), three-dimensional culture (3D), addition of trophic factors (in the form of growth factors, cytokines or hormones), lipopolysaccharides, and pharmacological agents. Preconditioning mesenchymal stem cells by culturing them in a hypoxic environment, which resembles the natural oxygen environment of the tissues (1% –7%) and not with standard culture conditions (21%), increases the survival of these cells via Hypoxia Inducible Factor-1α (HIF-1a) and via Akt-dependent mechanisms. In addition, the hypoxic precondition stimulates the secretion of pro-angiogenic growth factors, increases the expression of chemokines SDF-1 (stromal cell-derived factor-1) and its receptor CXCR4 (chemokine receptor type 4) - CXCR7 (chemokine receptor type 7) and increases engraftment of stem cell. This review aims to provide an overview of the preconditioned hypoxic treatment to increase the therapeutic potential of adipose-derived mesenchymal stem cells.