Expandable hESC-derived cardiovascular progenitor cells generate functional cardiac lineage cells for microtissue construction.

BACKGROUND: Cardiovascular progenitor cells (CPCs) derived from human embryonic stem cells (hESCs) are considered valuable cell sources for investigating cardiovascular physiology in vitro. Meeting the diverse needs of this application requires the large-scale production of CPCs in an in vitro environment. This study aimed to use an effective culture system utilizing signaling factors for the large-scale expansion of hESC-derived CPCs with the potential to differentiate into functional cardiac lineage cells. METHODS AND RESULTS: Initially, CPCs were generated from hESCs using a 4-day differentiation protocol with a combination of four small molecules (CHIR99021, IWP2, SB-431542, and purmorphamine). These CPCs were then expanded and maintained in a medium containing three factors (bFGF, CHIR, and A83-01), resulting in a > 6,000-fold increase after 8 passages. These CPCs were successfully cryopreserved for an extended period in late passages. The expanded CPCs maintained their gene and protein expression signatures as well as their differentiation capacity through eight passages. Additionally, these CPCs could differentiate into four types of cardiac lineage cells: cardiomyocytes, endothelial cells, smooth muscle cells, and fibroblasts, demonstrating appropriate functionality. Furthermore, the coculture of these CPC-derived cardiovascular lineage cells in rat tail collagen resulted in cardiac microtissue formation, highlighting the potential of this 3D platform for studying cardiovascular physiology in vitro. CONCLUSION: In conclusion, expandable hESC-derived CPCs demonstrated the ability to self-renewal and differentiation into functional cardiovascular lineage cells consistently across passages, which may apply as potential cell sources for in vitro cardiovascular studies.

Switchable PAMAM megamers for deep tumor penetration and enhanced cell uptake.

Nanoparticles fabricated to deliver anticancer drugs are usually designed to present optimized tumor penetration and cell internalization. However, there are some barriers and difficulties with most current technologies. Herein, size and charge switchable polyamidoamine (PAMAM) megamers (SChPMs) were prepared for the delivery of doxorubicin (DOX). SChPMs were fabricated by connecting PAMAM dendrimers with pH-sensitive bonds and surface PEGylation. At pH 7.4, the size and surface charge of these nanocarriers were approximately 100 nm and + 0.75 mV, but at the acidic extracellular pH of tumor cells (pH 6.5), their size were reduced dramatically (15 nm) and their surface charge increased to +6.7 mV. Cell studies confirmed that alteration of the size and surface charge enhanced their penetration into multicellular spheroids and cell internalization. These megamers, in addition to delivering the drug to the deeper areas of the tumor, could powerfully overcome physiological resistance to anthracycline-based drugs. The nanocarrier revealed enhanced antitumoral activity in animal studies. Toxicology studies and histopathological assessments of vital tissues of 4 T1 tumor bearing mice indicated minimal tissue damage when DOX-loaded SChPMs (DSChPMs) were used. It can be concluded that the versatile and agile nanocarriers developed in this study could be considered for further investigations into their clinical application.

Safety evaluation of bi-layered allogenic keratinocyte and fibroblast skin substitute for diabetic foot ulcers-SAFESKIN-DFU: A Phase 1 clinical trial.

AIM: To assess the safety and efficacy of a local skin substitute product in the treatment of chronic diabetic foot ulcers (DFUs). MATERIALS AND METHODS: Five patients were evaluated over 6 months. Skin substitutes were applied twice at 2-week intervals. Patients were monitored for any possible adverse effects and wound improvement. RESULTS: The results indicated the overall safety of the skin substitute, with only few adverse effects unrelated to this product. Significant reduction in wound size was observed in four patients during the initial 12-week treatment phase, with complete closure in two patients at 24 weeks. CONCLUSIONS: The application of a bi-layered allogeneic keratinocyte and fibroblast skin substitute in patients with chronic DFU was safe and associated with favourable wound healing results. Adherence to standard treatment protocols, including optimal offloading, is essential to maximize the likelihood of successful wound healing.

Exploring Advances in Reproduction and Stem Cell Biology: Highlights from The 24th and 19th International Congresses in Iran.

The 24th and 19th International Congresses on Reproduction and Stem Cell Biology in the Islamic Republic of Iran brought together experts and researchers worldwide to explore the latest advancements in these fields. Different topics were discussed, including such as reproductive health, infertility treatments, stem cell research, and regenerative medicine. This report provides a summary of the congress's key findings by emphasizing pioneer research and technologies that can influence the future of reproduction and stem cell biology programs. The presence of keynote speakers such as Professor Nicolas Rivron, Mohammad Ebrahim Parsanezhad, Ashraf Moini, Abbas Aflatoonian, Hadi Shafiee, Anna Brini, Omid Camron Farokhzad, and Jeffrey Schweitzer added value to the event, which had over 1100 participants from around the world. While foreign speakers were from various countries Iranian speakers mainly came from Tabriz, Isfahan, Shiraz, Babol, and Tehran that all discussed cutting-edge science and successful disease treatments. To ensure a more comprehensive representation, it is suggested that a wider geographic distribution of national and foreign speakers should be considered in future plan.

Correction: Firoozi et al. A Cell-Free SDKP-Conjugated Self-Assembling Peptide Hydrogel Sufficient for Improvement of Myocardial Infarction. Biomolecules 2020, 10, 205.

The authors wish to make the following corrections to this paper [...].

Extracellular vesicle-based formulation of doxorubicin: drug loading optimization, characterization, and cytotoxicity evaluation in tumor spheroids.

Doxorubicin (DOX) is a chemotherapeutic with considerable efficacy, but its application is limited due to cardiotoxicity. Nanoparticles can improve DOX efficacy and prevent its adverse effects. Herein, DOX-loaded extracellular vesicles (DOX-EVs) were prepared using different loading methods including incubation, electroporation, and sonication in different hydration buffers to permeabilize nanostructures or desalinize DOX for improved entrapment. Different protein:drug (µg:µg) ratios of 1:10, 1:5, and 1:2, and incubation parameters were also investigated. The optimal formulation was characterized by western blotting, electron microscopy, Zetasizer, infrared spectroscopy, and release study. The cellular uptake and efficacy were investigated in MCF-7 spheroids via MTS assay, spheroid formation assay (SFA), confocal microscopy, and flow cytometry. The percentage of entrapment efficiency (EE) of formulations was improved from 1.0 ± 0.1 to 22.0 ± 1.4 using a protein:drug ratio of 1:2 and sonication in Tween 80 (0.1%w/v) containing buffer. Characterization studies verified the vesicles' identity, spherical morphology, and controlled drug release properties. Cellular studies revealed the accumulation and cytotoxicity of DOX-EVs in the spheroids, and SFA and confocal microscopy confirmed the efficacy and cellular localization. Flow cytometry results revealed a comparable and amplified efficacy for DOX-EV formulations with different cell origins. Overall, the EV formulation of DOX can be applied as a promising alternative with potential advantages.

ROS scavenging activity of polydopamine nanoparticle-loaded supramolecular gelatin-based hydrogel promoted cardiomyocyte proliferation.

Reactive oxygen species (ROS) play essential roles in cellular functions, but maintaining ROS balance is crucial for effective therapeutic interventions, especially during cell therapy. In this study, we synthesized an injectable gelatin-based hydrogel, in which polydopamine nanoparticles were entrapped using supramolecular interactions. The surfaces of the nanoparticles were modified using adamantane, enabling their interactions with ß-cyclodextrin-conjugated with gelatin. We evaluated the cytotoxicity and antioxidant properties of the hydrogel on neonatal rat cardiomyocytes (NRCM), where it demonstrated the ability to increase the metabolic activity of NRCMs exposed to hydrogen peroxide (H2O2) after 5 days. Hydrogel-entrapped nanoparticle exhibited a high scavenging capability against hydroxyl radical, 1'-diphenyl-2-picrylhydrazyl radicals, and H2O2, surpassing the effectiveness of ascorbic acid solution. Notably, the presence of polydopamine nanoparticles within the hydrogel promoted the proliferation activity of NRCMs, even in the absence of excessive ROS due to H2O2 treatment. Additionally, when the hydrogel with nanoparticles was injected into an air pouch model, it reduced inflammation and infiltration of immune cells. Notably, the levels of anti-inflammatory factors, IL-10 and IL-4, were significantly increased, while the pro-inflammatory factor TNF-α was suppressed. Therefore, this novel ROS-scavenging hydrogel holds promise for both efficient cell delivery into inflamed tissue and promoting tissue repair.

A facile method to generate cerebral organoids from human pluripotent stem cells.

Human cerebral organoids (COs) are self-organizing three-dimensional (3D) neural structures that provide a human-specific platform to study the cellular and molecular processes that underlie different neurological events. The first step of CO generation from human pluripotent stem cells (hPSCs) is neural induction, which is an in vitro simulation of neural ectoderm development. Several signaling pathways cooperate during neural ectoderm development and in vitro differentiation of hPSCs toward neural cell lineages is also affected by them. In this study, we considered some of the known sources of these variable signaling cues arising from cell culture media components and sought to modulate their effects by applying a comprehensive combination of small molecules and growth factors for CO generation. Histological analysis demonstrated that these COs recapitulate the neural progenitor zone and early cortical layer organization, containing different types of neuronal and glial cells which was in accordance with single-nucleus transcriptome profiling results. Moreover, patch clamp and intracellular Ca2+ dynamic studies demonstrated that the COs behave as a functional neural network. Thus, this method serves as a facile protocol for generating hPSC-derived COs that faithfully mimic the features of their in vivo counterparts in the developing human brain. See also Figure 1(Fig. 1).

CRISPR/Cas9-Mediated Generation of COL7A1-Deficient Keratinocyte Model of Recessive Dystrophic Epidermolysis Bullosa.

OBJECTIVE: Recessive dystrophic epidermolysis bullosa (RDEB) is a genetic skin fragility and ultimately lethal blistering disease caused by mutations in the COL7A1 gene which is responsible for coding type VII collagen. Investigating the pathological mechanisms and novel candidate therapies for RDEB could be fostered by new cellular models. The aim of this study was to employ CRISPR/Cas9 technology in the development of immortalized COL7A1-deficient keratinocyte cell lines intended for application as a cellular model for RDEB in ex vivo studies. MATERIALS AND METHODS: In this experimental study, we used transient transfection to express COL7A1 -targeting guide RNA (gRNA) and Cas9 in HEK001 immortalized keratinocyte cell line followed by enrichment with fluorescent-activated cell sorting (FACS) via GFP expressing cells (GFP+ HEK001). Homogenous single-cell clones were then isolated, genotyped, and evaluated for type VII collagen expression. We performed a scratch assay to confirm the functional effect of COL7A1 knockout. RESULTS: We achieved 46.1% (P<0.001) efficiency of in/del induction in the enriched transfected cell population. Except for 4% of single nucleotide insertions, the remaining in/dels were deletions of different sizes. Out of nine single expanded clones, two homozygous and two heterozygous COL7A1-deficient cell lines were obtained with defined mutation sequences. No off-target effect was detected in the knockout cell lines. Immunostaining and western blot analysis showed lack of type VII collagen (COL7A1) protein expression in these cell lines. We also showed that COL7A1-deficient cells had higher motility compared to their wild-type counterparts. CONCLUSION: We reported the first isogenic immortalized COL7A1-deficient keratinocyte lines that provide a useful cell culture model to investigate aspects of RDEB biology and potential therapeutic options.

Rheumatoid arthritis: the old issue, the new therapeutic approach.

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease of unknown etiology. The most common form of this disease is chronic inflammatory arthritis, which begins with inflammation of the synovial membrane of the affected joints and eventually leads to disability of the affected limb. Despite significant advances in RA pharmaceutical therapies and the availability of a variety of medicines on the market, none of the available medicinal therapies has been able to completely cure the disease. In addition, a significant percentage (30-40%) of patients do not respond appropriately to any of the available medicines. Recently, mesenchymal stromal cells (MSCs) have shown promising results in controlling inflammatory and autoimmune diseases, including RA. Experimental studies and clinical trials have demonstrated the high power of MSCs in modulating the immune system. In this article, we first examine the mechanism of RA disease, the role of cytokines and existing medicinal therapies. We then discuss the immunomodulatory function of MSCs from different perspectives. Our understanding of how MSCs work in suppressing the immune system will lead to better utilization of these cells as a promising tool in the treatment of autoimmune diseases.

Immunomodulatory potential of human clonal mesenchymal stem cells and their extracellular vesicle subpopulations in an inflammatory-mediated diabetic Rhesus monkey model.

AIMS: This study aimed to investigate the therapeutic potential of a homogenous clonal population of mesenchymal stem cells (cMSC) and their extracellular vesicles (cMSC-EV) subpopulations on isolated rat islets in vitro and in inflammatory-mediated type 1 diabetes (T1D) non-human primate models. MAIN METHODS: EV subpopulations were isolated from human bone marrow-derived cMSC supernatant by low- and high-speed ultracentrifuge (EV-20K and EV-U110K) and sucrose density gradient (EV-S110K). The EVs were characterized generally and for the level of albumin, acetylcholinesterase (AChE) activity, co-isolate apoptotic markers, and expression of CD63+/annexin V+. Rat islet-derived single cells (iSCs) proliferation was measured using a Ki-67 proliferation assay. Diabetes was induced by multiple low-dose administrations of streptozotocin in rhesus monkeys. The diabetic monkeys were divided into three groups: the cMSC group, received two injections of 1.5 × 106 cMSC/kg body weight; the EV group received two injections of EVs isolated from 1.5 × 106 cMSC/kg, and the vehicle group received phosphate-buffered saline. KEY FINDINGS: EV-S110K showed higher AChE activity, lower expression of CD63+/annexin V+, and lower apoptotic co-isolates. EV-S110K induced ß-cell proliferation in vitro in a dose-dependent manner. The administration of EV-S110K and/or cMSC in diabetic monkeys demonstrated no significant changes in general diabetic indices and ß-cell mass in the pancreas of the monkeys. Both treatments demonstrated a lowering trend in blood glucose levels and reduced pro-inflammatory cytokines. In contrast, regulatory T cells and anti-inflammatory cytokines were increased. SIGNIFICANCE: cMSC and cMSC-EV provided initial evidence to attenuate clinical symptoms in inflammatory-mediated T1D non-human primates through immunomodulation.

Cryopreserved clinical-grade human embryonic stem cell-derived dopaminergic progenitors function in Parkinson's disease models.

AIM: Parkinson's Disease (PD) is a common age-related neurodegenerative disorder with a rising prevalence. Human pluripotent stem cells have emerged as the most promising source of cells for midbrain dopaminergic (mDA) neuron replacement in PD. This study aimed to generate transplantable mDA progenitors for treatment of PD. MATERIALS AND METHODS: Here, we optimized and fine-tuned a differentiation protocol using a combination of small molecules and growth factors to induce mDA progenitors to comply with good manufacturing practice (GMP) guidelines based on our clinical-grade human embryonic stem cell (hESC) line. KEY FINDINGS: The resulting mDA progenitors demonstrated robust differentiation and functional properties in vitro. Moreover, cryopreserved mDA progenitors were transplanted into 6-hydroxydopamine-lesioned rats, leading to functional recovery. SIGNIFICANCE: We demonstrate that our optimized protocol using a clinical hESC line is suitable for generating clinical-grade mDA progenitors and provides the ground work for future translational applications.

Neuroglial components of brain lesions may provide new therapeutic strategies for multiple sclerosis.

Multiple sclerosis (MS) is a chronic autoimmune and demyelinating disease of the central nervous system (CNS) which leads to focal demyelinated lesions in the brain and spinal cord. Failure of remyelination contributes to chronic disability in young adults. Characterization of events occurring during the demyelination and remyelination processes and those of which subsequently limit remyelination or contribute to demyelination can provide the possibility of new therapies development for MS. Most of the currently available therapies and investigations modulate immune responses and mediators. Since most therapeutic strategies have unsatisfied outcomes, developing new therapies that enhance brain lesion repair is a priority. A close look at cellular and chemical components of MS lesions will pave the way to a better understanding of lesions pathology and will provide possible opportunities for repair strategies and targeted pharmacotherapy. This review summarizes the lesion components and features, particularly the detrimental elements, and discusses the possibility of suggesting new potential targets as therapies for demyelinating diseases like MS.

Time-resolved Small-RNA Sequencing Identifies MicroRNAs Critical for Formation of Embryonic Stem Cells from the Inner Cell Mass of Mouse Embryos.

Cells of the inner cell mass (ICM) acquire a unique ability for unlimited self-renewal during transition into embryonic stem cells (ESCs) in vitro, while preserving their natural multi-lineage differentiation potential. Several different pathways have been identified to play roles in ESC formation but the function of non-coding RNAs in this process is poorly understood. Here, we describe several microRNAs (miRNAs) that are crucial for efficient generation of mouse ESCs from ICMs. Using small-RNA sequencing, we characterize dynamic changes in miRNA expression profiles during outgrowth of ICMs in a high-resolution, time-course dependent manner. We report several waves of miRNA transcription during ESC formation, to which miRNAs from the imprinted Dlk1-Dio3 locus contribute extensively. In silico analyses followed by functional investigations reveal that Dlk1-Dio3 locus-embedded miRNAs (miR-541-5p, miR-410-3p, and miR-381-3p), miR-183-5p, and miR-302b-3p promote, while miR-212-5p and let-7d-3p inhibit ESC formation. Collectively, these findings offer new mechanistic insights into the role of miRNAs during ESC derivation.

Decellularized Lung Extracellular Matrix Scaffold Promotes Human Embryonic Stem Cell Differentiation towards Alveolar Progenitors.

OBJECTIVE: Efficient production of functional and mature alveolar epithelial is a major challenge for developing any cell replacement therapy for lung degenerative diseases. The extracellular matrix (ECM) pro-vides a dynamic environment and mediates cellular responses during development and maintenance of tissue functions. The decellularized ECM (dECM) which retains its native-like structure and bio-chemical composition can provide the induction of embryonic stem cell (ESC) differentiation toward the tissue-specific lineages during in vitro culture. Therefore, the aim of this study was to evaluate the effect of sheep lung dECM-derived scaffold on differentiation and further maturation of ESC-derived lung progenitor cells. MATERIALS AND METHODS: This study was an experimental study. In the first step, a sheep lung was decellularized to achieve dECM scaffolds and hydrogels. Afterwards, the obtained dECM scaffold was evaluated for collagen and glycosaminoglycan contents, DNA quantification, and its ultrastructure. Next, the three experimental groups: i. Sheep lung dECM-derived scaffold, ii. Sheep lung dECM-derived hydrogel, and iii. Fibronectin-coated plates were compared in their abilities to induce further differentiation of human embryonic stem cells (hESCs)-derived definitive endoderm (DE) into lung progenitor cells. The comparison was evaluated by immuno-staining and real-time polymerase chain reaction (PCR) assessments. RESULTS: We found that the dECM-derived scaffold preserved its composition and native porous structures while lacking nuclei and intact cells. All experimental groups displayed lung progenitor cell differen-tiation as revealed by the RNA and protein expression of NKX2.1, P63 and CK5. DE cells differenti-ated on dECM-derived scaffold and dECMderived hydrogel showed significant upregulation of SOX9 gene expression, a marker of the distal airway epithelium. DE cells differentiated on the dECM-derived scaffold compared to the two other groups, showed enhanced expression of SFTPC (type 2 alveolar epithelial [AT2] cell marker), FOXJ1 (ciliated cell marker), and MUC5A (secretory cell marker) genes. CONCLUSION: Overall, our results suggest that dECM-derived scaffold improves the differentiation of DE cells towards lung alveolar progenitor cells in comparison with dECM-derived hydrogel and fibronectin-coated plates.

Allogenic mesenchymal stromal cells and their extracellular vesicles in COVID-19 induced ARDS: a randomized controlled trial.

BACKGROUND AND AIMS: The main causes of death in patients with severe Coronavirus disease-2019 (COVID-19) are acute respiratory distress syndrome (ARDS) and multiorgan failure caused by a severe inflammatory cascade. Novel treatment strategies, such as stem-cell-based therapy and their derivatives can be used to relieve inflammation in these cases. In this study, we aimed to evaluate the safety and efficacy of therapy using mesenchymal stromal cells (MSCs) and their derived extracellular vesicles in COVID-19 patients. MATERIALS AND METHODS: COVID-19 patients with ARDS were included in this study and allocated into two study and control groups using block randomization. While all patients received recommended treatment based on guidelines from the national advisory committee for COVID-19 pandemic, the two intervention groups received two consecutive injections of MSCs (100 × 106 cells) or one dose of MSCs (100 × 106 cells) followed by one dose of MSC-derived extracellular vesicles (EVs). Patients were assessed for safety and efficacy by evaluating clinical symptoms, laboratory parameters, and inflammatory markers at baseline and 48 h after the second intervention. RESULTS: A total number of 43 patients (the MSC alone group = 11, MSC plus EV group = 8, and control group = 24) were included in the final analysis. Mortality was reported in three patients in the MSC alone group (RR: 0.49; 95% CI 0.14-1.11; P = 0.08); zero patient in the MSC plus EV group (RR: 0.08; 95% CI 0.005-1.26; P = 0.07) and eight patients in the control group. MSC infusion was associated with a decrease in inflammatory cytokines such as IL-6 (P = 0.015), TNF-α (P = 0.034), IFN-γ (P = 0.024), and CRP (P = 0.041). CONCLUSION: MSCs and their extracellular vesicles can significantly reduce the serum levels of inflammatory markers in COVID-19 patients, with no serious adverse events. Trial registration IRCT, IRCT registration number: IRCT20200217046526N2. Registered 13th April 2020, http://www.irct.ir/trial/47073 .

Clonal mesenchymal stem cell-derived extracellular vesicles improve mouse model of weight drop-induced traumatic brain injury through reducing cistauosis and apoptosis.

OBJECTIVE: Traumatic brain injury (TBI) is a major risk factor for disabilities globally with no effective treatment thus far. Recently, homogenous population of clonal mesenchymal stem cells (cMSC) and their derived extracellular vesicles (cMSC-EVs) have been proposed as a promising TBI treatment strategy. We herein investigated possible therapeutic effect of cMSC-EVs in TBI treatment and the underlying mechanisms considering cis p-tau as an early hallmark of TBI. METHODS: We examined the EVs morphology, size distribution, marker expression, and uptake. Moreover, the EVs neuroprotective effects were studied in both in-vitro and in-vivo model. We also examined the anti-cis p-tau antibody-loading characteristics of the EVs. We treated TBI mouse model with EVs; prepared from cMSC-conditioned media. TBI mice were given cMSC-EVs intravenously and their cognitive functions were analyzed two months of the treatment. We employed immunoblot analysis to study the underlying molecular mechanisms. RESULTS: We observed a profound cMSC-EVs uptake by primary cultured neurons. We found a remarkable neuroprotective effect of cMSC-EVs upon nutritional deprivation stress. Furthermore, cMSC-EVs were effectively loaded with an anti-cis p-tau antibody. There was a significant improvement in cognitive function in TBI animal models treated with cMSC-EVs compared to the saline-treated group. There was a decreased cis p-tau and cleaved caspase3 as well as increased p-PI3K in all treated animals. CONCLUSIONS: The results revealed that cMSC-EVs efficiently improved animal behaviors after TBI by reducing cistauosis and apoptosis. Moreover, the EVs can be employed as an effective strategy for antibody delivery during passive immunotherapy.

The constitutively active pSMAD2/3 relatively improves the proliferation of chicken primordial germ cells.

In many multicellular organisms, mature gametes originate from primordial germ cells (PGCs). Improvements in the culture of PGCs are important not only for developmental biology research, but also for preserving endangered species, and for genome editing and transgenic animal technologies. SMAD2/3 appear to be powerful regulators of gene expression; however, their potential positive impact on the regulation of PGC proliferation has not been taken into consideration. Here, the effect of TGF-ß signaling as the upstream activator of SMAD2/3 transcription factors was evaluated on chicken PGCs' proliferation. For this, chicken PGCs at stages 26-28 Hamburger-Hamilton were obtained from the embryonic gonadal regions and cultured on different feeders or feeder-free substrates. The results showed that TGF-ß signaling agonists (IDE1 and Activin-A) improved PGC proliferation to some extent while treatment with SB431542, the antagonist of TGF-ß, disrupted PGCs' proliferation. However, the transfection of PGCs with constitutively active SMAD2/3 (SMAD2/3CA) resulted in improved PGC proliferation for more than 5 weeks. The results confirmed the interactions between overexpressed SMAD2/3CA and pluripotency-associated genes NANOG, OCT4, and SOX2. According to the results, the application of SMAD2/3CA could represent a step toward achieving an efficient expansion of avian PGCs.

Comparison of Ultrasound-Guided Percutaneous and Open Surgery Approaches in The Animal Model of Tumor Necrosis Factor-Alpha-Induced Disc Degeneration.

OBJECTIVE: Animal models provide a deeper understanding about various complications and better demonstrate the effect of therapeutic approaches. One of the issues in the low back pain (LBP) model is the invasiveness of the procedure and it does not mimic actual disease conditions in humans. The purpose of the present study was to compare the ultrasound-guided (US-guided) percutaneous approach with the open-surgery method in the tumor necrosis factor-alpha (TNF-α)-induced disc degeneration model for the first time to showcase the advantages of this recently developed, minimally invasive method. MATERIALS AND METHODS: In this experimental study, eight male rabbits were divided into two groups (open-surgery and US-guided). Relevant discs were punctured by two approaches and TNF-α was injected into them. Magnetic resonance imaging (MRI) was performed to assess the disc height index (DHI) at all stages. Also morphological changes (annulus fibrosus, nucleus pulposus) were evaluated by assessing Pfirrmann grade and histological evaluation (Hematoxylin and Eosin). RESULTS: The findings indicated targeted discs became degenerated after six weeks. DHI in both groups was significantly reduced (P<0.0001), however the difference was not significant between the two groups. In the open-surgery group, osteophyte formation was seen at six and eighteen weeks after the puncture. Pfirrmann grading revealed significant differences between injured and adjacent uninjured discs (P<0.0001). The US-guided method indicated significantly fewer signs of degeneration after six (P=0.0110) and eighteen (P=0.0328) weeks. Histological scoring showed significantly lower degeneration in the US-guided group (P=0.0039). CONCLUSION: The US-guided method developed a milder grade condition and such a model better mimics the chronic characteristics of LBP and the procedure is more ethically accepted. Therefore, the US-guided method could be a merit approach for future research in this domain as a safe, practical and low-cost method.

Homogenous subpopulation of human mesenchymal stem cells and their extracellular vesicles restore function of endometrium in an experimental rat model of Asherman syndrome.

BACKGROUND: Asherman syndrome (AS), or intrauterine adhesions, is a main cause of infertility in reproductive age women after endometrial injury. Mesenchymal stem cells (MSCs) and their extracellular vesicles (EVs) are promising candidates for therapies that repair damaged endometria. However, concerns about their efficacy are attributed to heterogeneity of the cell populations and EVs. A homogenous population of MSCs and effective EV subpopulation are needed to develop potentially promising therapeutic options in regenerative medicine. METHODS: AS model was induced by mechanical injury in adult rat uteri. Then, the animals were treated immediately with homogeneous population of human bone marrow-derived clonal MSCs (cMSCs), heterogenous parental MSCs (hMSCs), or cMSCs-derived EV subpopulations (EV20K and EV110K). The animals were sacrificed two weeks post-treatment and uterine horns were collected. The sections were taken, and hematoxylin-eosin was used to examine the repair of endometrial structure. Fibrosis was measured by Masson's trichrome staining and α-SMA and cell proliferation by Ki67 immunostaining. The function of the uteri was explored by the result of mating trial test. Expression changes of TNFα, IL-10, VEGF, and LIF were assayed by ELISA. RESULTS: Histological analysis indicated fewer glands, thinner endometria, increased fibrotic areas, and decreased proliferation of epithelial and stroma of the uteri in the treated compared with intact and sham-operated animals. However, these parameters improved after transplantation of both types of cMSCs and hMSCs and/or both cryopreserved EVs subpopulations. The cMSCs demonstrated more successful implantation of the embryos in comparison with hMSCs. The tracing of the transplanted cMSCs and EVs showed that they migrated and localized in the uteri. Protein expression analysis results demonstrated downregulation of proinflammatory factor TNFα and upregulation of anti-inflammatory cytokine IL-10, and endometrial receptivity cytokines VEGF and LIF in cMSC- and EV20K-treated animals. CONCLUSION: Transplantation of MSCs and EVs contributed to endometrial repair and restoration of reproductive function, likely by inhibition of excessive fibrosis and inflammation, enhancement of endometrial cell proliferation, and regulation of molecular markers related to endometrial receptivity. Compared to classical hMSCs, cMSCs were more efficient than hMSCs in restoration of reproductive function. Moreover, EV20K is more cost-effective and feasible for prevention of AS in comparison with conventional EVs (EV110K).