Bone Marrow-derived Cells Research Articles

Synthesis and Biological Activity of Tetracyclic Dispiro Core Derivatives of Natural Products Dispirocochlearoids A-C.

Natural products dispirocochlearoids A-C, which are meroterpenoids derived from Ganoderma fungi, feature a 6/6/5/6/6/6 ring system and exhibit selective COX-2 inhibitory activity. Herein, the concise total synthesis of the tetracyclic core structure of dispirocochlearoids A-C was achieved through an aldol reaction/cyclization/deprotection/cyclization cascade sequence. A series of simplified tetracyclic analogues was successfully constructed and their anti-inflammatory activity was further explored, with several tetracyclic analogues (such as compound 8ab) exhibiting strong inhibitory activity against IL-1β expression in lipopolysaccharide-stimulated bone marrow-derived macrophage cells (IC50 = 2.8 μM).

Impact of Porosity and Stiffness of 3D Printed Polycaprolactone Scaffolds on Osteogenic Differentiation of Human Mesenchymal Stromal Cells and Activation of Dendritic Cells.

Despite the potential of extrusion-based printing of thermoplastic polymers in bone tissue engineering, the inherent nonporous stiff nature of the printed filaments may elicit immune responses that influence bone regeneration. In this study, bone scaffolds made of polycaprolactone (PCL) filaments with different internal microporosity and stiffness was 3D-printed. It was achieved by combining three fabrication techniques, salt leaching and 3D printing at either low or high temperatures (LT/HT) with or without nonsolvent induced phase separation (NIPS). Printing PCL at HT resulted in stiff scaffolds (modulus of elasticity (E): 403 ± 19 MPa and strain: 6.6 ± 0.1%), while NIPS-based printing at LT produced less stiff and highly flexible scaffolds (E: 53 ± 10 MPa and strain: 435 ± 105%). Moreover, the introduction of porosity by salt leaching in the printed filaments significantly changed the mechanical properties and degradation rate of the scaffolds. Furthermore, this study aimed to show how these variations influence proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBMSC) and the maturation and activation of human monocyte-derived dendritic cells (Mo-DC). The cytocompatibility of the printed scaffolds was confirmed by live-dead imaging, metabolic activity measurement, and the continuous proliferation of hBMSC over 14 days. While all scaffolds facilitated the expression of osteogenic markers (RUNX2 and Collagen I) from hBMSC as detected through immunofluorescence staining, the variation in porosity and stiffness notably influenced the early and late mineralization. Furthermore, the flexible LT scaffolds, with porosity induced by NIPS and salt leaching, stimulated Mo-DC to adopt a pro-inflammatory phenotype marked by a significant increase in the expression of IL1B and TNF genes, alongside decreased expression of anti-inflammatory markers, IL10 and TGF1B. Altogether, the results of the current study demonstrate the importance of tailoring porosity and stiffness of PCL scaffolds to direct their biological performance toward a more immune-mediated bone healing process.

Equine bone marrow-derived mesenchymal stromal cells reduce established S. aureus and E. coli biofilm matrix in vitro.

Biofilms reduce antibiotic efficacy and lead to complications and mortality in human and equine patients with orthopedic infections. Equine bone marrow-derived mesenchymal stromal cells (MSC) kill planktonic bacteria and prevent biofilm formation, but their ability to disrupt established orthopedic biofilms is unknown. Our objective was to evaluate the ability of MSC to reduce established S. aureus or E. coli biofilms in vitro. We hypothesized that MSC would reduce biofilm matrix and colony-forming units (CFU) compared to no treatment and that MSC combined with the antibiotic, amikacin sulfate, would reduce these components more than MSC or amikacin alone. MSC were isolated from 5 adult Thoroughbred horses in antibiotic-free medium. 24-hour S. aureus or E. coli biofilms were co-cultured in triplicate for 24 or 48 hours in a transwell plate system: untreated (negative) control, 30 μg/mL amikacin, 1 x 106 passage 3 MSC, and MSC with 30 μg/mL amikacin. Treated biofilms were photographed and biofilm area quantified digitally. Biomass was quantified via crystal violet staining, and CFU quantified following enzymatic digestion. Data were analyzed using mixed model ANOVA with Tukey post-hoc comparisons (p < 0.05). MSC significantly reduced S. aureus biofilms at both timepoints and E. coli biofilm area at 48 hours compared to untreated controls. MSC with amikacin significantly reduced S. aureus biofilms versus amikacin and E. coli biofilms versus MSC at 48 hours. MSC significantly reduced S. aureus biomass at both timepoints and reduced S. aureus CFU at 48 hours versus untreated controls. MSC with amikacin significantly reduced S. aureus biomass versus amikacin at 24 hours and S. aureus and E. coli CFU versus MSC at both timepoints. MSC primarily disrupted the biofilm matrix but performed differently on S. aureus versus E. coli. Evaluation of biofilm-MSC interactions, MSC dose, and treatment time are warranted prior to testing in vivo.

Conditional over-expression of heme-oxygenase 1 in myelomonocytic cells reduces AngII-induced hypertension and vascular inflammation in mice

Abstract Background Systemic arterial Hypertension is one of the most important risk factor responsible for morbidity and mortality world-wide. Angiotensin II (Ang II), a potent vasoconstrictor and key player in the renin-angiotensin-aldosterone system (RAAS) is responsible for vascular dysfunction, inflammation, and tissue damage. Heme oxygenase-1 (HO-1) overexpression may confer antioxidant and anti-inflammatory properties in Ang II-induced hypertension through its action on heme catabolism, generating carbon monoxide (CO), ferritin and biliverdin/bilirubin by the action of biliverdin reductase A (BLVRA). Methods and results Male 9–12-weeks-old HO-1indxLySMCre/wt and LySMCre/wt mice were infused with AngII (1mgAngII/Day/Kg) for 7 days to induce hypertension and compared to sham treatment. Blood pressure monitoring by tail-cuff method, and endothelium-dependent vasodilator studies via organ chamber system using acetylcholine (ACh) in isolated aortic segments (~4 mm), revealed that overexpression of HO-1 in myeloid cells resulted in decreased systolic blood pressure and improved endothelial function in AngII-infused HO-1indxLySMCre/wt mice compared to controls. Concurrently, increased BLVRA expression in liver tissue and elevated plasma bilirubin levels were detected by transcriptome analysis and high-performance liquid chromatography, respectively. These results were supported by a reduction in the expression of inducible cytokines and cell adhesion molecules (CAMs) in the aorta, assessed using qPCR. Bone marrow transplant experiments demonstrated that bone marrow from LysMcre mice in HO-1indxLySMCre/wt mice abrogated the protective effect of HO-1, resulting in endothelial damage and increased blood pressure, potentially due to decreased liver BLVRA expression and the accumulation of bone marrow-derived cells in the vessel wall in response to AngII. Additionally, adeno-associated viral vector (AAV) transfection targeting specifically BLVRA activity in liver lead to an increase in blood pressure values and worse endothelium relaxation, in parallel with higher oxidative stress and the blood neutrophils concentration, as assessed in whole blood by using oxidative burst method and blood count system respectively. Conclusion The overexpression of HO-1 in myeloid cells confers anti-inflammatory protection in AngII-induced arterial hypertension in mice. Myeloid cells bone marrow-derived overexpressing HO-1 regulate the differentiation and infiltration of pro-inflammatory immune cells in the vasculature. BLVRA expression and bilirubin levels downstream of HO-1 play a critical role in protecting against vascular damage by reducing leukocyte infiltration.

The effect of empagliflozin on circulating endothelial progenitor cells in patients with diabetes and stable coronary artery disease.

Diabetes mellitus (DM) is associated with premature atherosclerotic disease, coronary artery disease (CAD) and chronic heart failure (HF), leading to increased morbidity and mortality. Sodium-Glucose Co-transporter 2 Inhibitors (SGLT2i) exhibit cardioprotective benefits beyond glucose lowering, reducing the risk of major cardiovascular events (MACE) and HF hospitalizations in patients with DM and CAD. Endothelial progenitor cells (EPCs) are bone marrow-derived cells involved in vascular repair, mobilized in response to vascular injury. The number and function of circulating EPCs (cEPCs) are negatively affected by cardiovascular risk factors, including DM. This study aimed to examine the response of cEPCs to SGLT2i treatment in DM patients with stable CAD. A prospective single-center study included patients with DM and stable CAD who were started on an SGLT2i (empagliflozin). Peripheral blood samples were collected at baseline, 1 month, and 3 months to evaluate cEPC levels and function by flow cytometry, immunohistochemistry and MTT assays. Eighteen patients were included in the study (median age 73, (IQR 69, 77) years, 67% male). After 1 month of treatment with empagliflozin, there was no significant change in cEPCs level or function. However, following 3 months of treatment, a significant increase was observed both in cell levels (CD34(+)/VEGFR-2(+): from 0.49% (IQR 0.32, 0.64) to 1.58% (IQR 0.93, 1.82), p = 0.0006; CD133(+)/VEGFR-2(+): from 0.38% (IQR 0.27, 0.6) to 0.82% (IQR 0.7, 1.95), p = 0.0001) and in cell function (from 0.25 CFUs (IQR 0, 0.5) at baseline, to 2 CFUs (IQR 1, 2) at 3 months, p = 0.0012). Empagliflozin treatment in patients with DM and stable CAD increases cEPC levels and function, implying a cardioprotective mechanism. These findings highlight the potential of SGLT2i in treating cardiovascular diseases, warranting further research to explore these effects and their long-term implications.

Impact of proNGF/NGF-NGFR-axis on the regulation of arterial remodelling

Abstract Background Peripheral blood mononuclear cells (MNCs) contribute to the pathogenesis of arteriosclerosis. Nerve growth factor receptor (NGFR) is present in peripheral blood and the ischemic coronary artery. NGFR transduces neurotrophin signals towards cell survival or apoptosis in different cell types dependent on coupling co-receptors. However, the role of NGFR-positive (NGFR+) MNCs in arterial remodelling is unknown. Purpose To investigate the functional mechanisms under which NGFR+ MNCs are involved in arterial remodelling. Methods Adult C57BL/6J male NGFR-wild-type (WT) or -bone marrow (BM)-specific (KO) mice were subjected to unilateral carotid artery ligation. The ligated and the opposite-sided, sham-operated arteries were assessed by immunohistology and gene expression analysis using a PCR on day 28. Also, human NGFR+ MNCs from a healthy volunteer were sorted using fluorescence-activated cell sorting and characterised using RNA sequencing. The cell apoptosis (AnnexinV+7AAD-) and chemotaxis in response to the ligands, NGF and its precursor proNGF, were assessed using flow cytometry and a Transwell migration. Results In WT mice, BM-derived NGFR+ cells accumulated in the neointima after ligation. The neointimal area was significantly greater in the BM-specific depletion of NGFR than in WT mice. NGFR+ cells in the neointima exhibited apoptosis (TUNEL+ and cleaved caspase-3+) accompanied by promoted F4/80+ macrophage and anti-inflammatory IL-10. By contrast, in the BM-specific NGFR-KO model, non-BM-derived SMCs increased in the neointima with augmented proliferation, and the accumulation of BM-derived cells and the expression of IL-10 were decreased. The expressions of proNGF/NGF and inflammatory cytokines, including IL-6, were not changed in a ligated artery, irrespective of NGFR+ depletion. Human NGFR+ MNCs expressed TrkB, TrkC, and sortilin co-receptors but not macrophage markers. Human NGFR+ MNCs, but not NGFR- MNCs, co-cultured with artery SMCs were susceptible to apoptosis in response to proNGF. Additionally, PDGF stimulated proNGF/NGF expression in SMCs, and proNGF/NGF did not affect the proliferation of SMCs in vitro. Furthermore, NGFR+ MNCs, but not NGFR- MNCs, increased migration toward NGF and did not show chemotaxis toward proNGF. Conclusions These data imply that local NGF might draw NGFR+ MNCs to the injured artery, in which proNGF induces NGFR+ MNCs apoptosis. Apoptotic NGFR+ cells promoted macrophage chemotaxis to resolve inflammation and decrease neointimal formation. Thus, we propose the proNGF/NGF-NGFR axis as potentially contributing to the suppression of arterial remodelling.

Exploring the Impact of In Vitro-Transcribed mRNA Impurities on Cellular Responses.

Advances in mRNA technology have enabled mRNA-based therapies to enter a new era of medicine. Such therapies benefit from a single, standardized in vitro transcription (IVT) manufacturing process applicable to a wide range of targets. This process includes several downstream purification steps, which aim to eliminate impurities that potentially affect safety and efficacy. However, it is not fully understood which impurities are the most critical; hence, some efforts are still needed to establish the correlation between RNA impurities and their role in limiting therapeutic efficacy. To study this relationship, we produced in vitro-transcribed mRNAs using several bacteriophage T7 RNA polymerases, including one wild-type and four engineered variants. Important attributes of the mRNA such as integrity, purity, and functional activity were then measured using advanced physicochemical and cellular assays. For impurities including abortive transcripts, mRNAs containing partial poly(A) tails, and double-stranded (ds)RNA byproducts, structure-function relationships have been established by tracking cellular responses (i.e., protein expression, reactogenicity) in multiple cell models. By varying the T7 RNA polymerase, different levels of sense-antisense dsRNA byproducts were measured by mass photometry, contributing directly to immunological reactogenicity in bone marrow-derived dendritic cells. T7 RNA polymerase differences with regard to short (<20 nucleotides) 3'-loopback dsRNA byproducts were also further investigated using native mass spectrometry by precisely resolving these impurities at the nucleotide level. Overall, this study highlights the importance of developing sensitive and advanced analytical methods to characterize IVT mRNA impurities and understand their interaction with cellular machinery in order to ensure quality control of RNA-based therapies.

Retraction Note: Therapeutic potential of non-adherent BM-derived mesenchymal stem cells in tissue regeneration.

Retraction Note: Therapeutic potential of non-adherent BM-derived mesenchymal stem cells in tissue regeneration.

In Vivo Differentiation of Endogenous Bone Marrow-Derived Cells into Insulin-Producing Cells Using Four Soluble Factors.

Four soluble factors-putrescine, glucosamine, nicotinamide, and signal transducer and activator of transcription 3 (STAT3) inhibitor BP-1-102-were shown to differentiate bone marrow mononucleated cells (BMNCs) into functional insulin-producing cells (IPCs) in vitro. Transplantation of these IPCs improved hyperglycemia in diabetic mice. However, the role of endogenous BMNC regeneration in this effect was unclear. This study aimed to evaluate the effect of these factors on in vivo BMNC differentiation into IPCs in diabetic mice. Mice were orally administered the factors for 5 days, twice at 2-week intervals, and monitored for 45-55 days. Glucose tolerance, glucose-stimulated insulin secretion, and pancreatic insulin content were measured. Chimeric mice harboring BMNCs from insulin promoter luciferase/green fluorescent protein (GFP) transgenic mice were used to track endogenous BMNC fate. These factors lowered blood glucose levels, improved glucose tolerance, and enhanced insulin secretion. Immunostaining confirmed IPCs in the pancreas, showing the potential of these factors to induce β-cell regeneration and improve diabetes treatment.

The renoprotective efficacy and safety of genetically-engineered human bone marrow-derived mesenchymal stromal cells expressing anti-fibrotic cargo

BackgroundKidney fibrosis is a hallmark of chronic kidney disease (CKD) and compromises the viability of transplanted human bone marrow-derived mesenchymal stromal cells (BM-MSCs). Hence, BM-MSCs were genetically-engineered to express the anti-fibrotic and renoprotective hormone, human relaxin-2 (RLX) and green fluorescent protein (BM-MSCs-eRLX + GFP), which enabled BM-MSCs-eRLX + GFP delivery via a single intravenous injection.MethodsBM-MSCs were lentiviral-transduced with human relaxin-2 cDNA and GFP, under a eukaryotic translation elongation factor-1α promoter (BM-MSCs-eRLX + GFP) or GFP alone (BM-MSCs-eGFP). The ability of BM-MSCs-eRLX + GFP to differentiate, proliferate, migrate, produce RLX and cytokines was evaluated in vitro, whilst BM-MSC-eRLX + GFP vs BM-MSCs-eGFP homing to the injured kidney and renoprotective effects were evaluated in preclinical models of ischemia reperfusion injury (IRI) and high salt (HS)-induced hypertensive CKD in vivo. The long-term safety of BM-MSCs-RLX + GFP was also determined 9-months after treatment cessation in vivo.ResultsWhen cultured for 3- or 7-days in vitro, 1 × 106 BM-MSCs-eRLX + GFP produced therapeutic RLX levels, and secreted an enhanced but finely-tuned cytokine profile without compromising their proliferation or differentiation capacity compared to naïve BM-MSCs. BM-MSCs-eRLX + GFP were identified in the kidney 2-weeks post-administration and retained the therapeutic effects of RLX in vivo. 1–2 × 106 BM-MSCs-eRLX + GFP attenuated the IRI- or therapeutically abrogated the HS-induced tubular epithelial damage and interstitial fibrosis, and significantly reduced the HS-induced hypertension, glomerulosclerosis and proteinuria. This was to an equivalent extent as RLX and BM-MSCs administered separately but to a broader extent than BM-MSCs-eGFP or the angiotensin-converting enzyme inhibitor, perindopril. Additionally, these renoprotective effects of BM-MSCs-eRLX + GFP were maintained in the presence of perindopril co-treatment, highlighting their suitability as adjunct therapies to ACE inhibition. Importantly, no major long-term adverse effects of BM-MSCs-eRLX + GFP were observed.ConclusionsBM-MSCs-eRLX + GFP produced greater renoprotective and therapeutic efficacy over that of BM-MSCs-eGFP or ACE inhibition, and may represent a novel and safe treatment option for acute kidney injury and hypertensive CKD.

Enhanced immunomodulatory properties of ovalbumin through transglutaminase and tyrosinase/caffeic acid-catalyzed crosslinking plus galactomannan conjugation alleviates allergic asthma

Ovalbumin (OVA) is the primary allergenic protein, associated with T helper 2 (Th2)-mediated allergy reactions. Here, we studied OVA’s conformational structure, digestibility, and allergenic potency upon galactomannan (Man) conjugation along with transglutaminase-catalyzed crosslinking (TG-Man/OVA) and tyrosinase/caffeic acid-catalyzed crosslinking (Tyr-Man/OVA). Enzymatic glycosylation altered OVA’s conformation and enhanced the gastrointestinal digestibility. Stimulation of bone marrow-derived dendritic cells (BMDCs) with enzymatically glycosylated OVA reduced the expression of CD40, CD80, CD86 and MHC class II molecules. Furthermore, glycosylated OVA increased IL-10 production while suppressing proinflammatory cytokine production in BMDCs. In an OVA-induced mouse asthma model, TG-Man/OVA and Tyr-Man/OVA upregulated IFN-γ and IL-10 expression and downregulated IL-4, IL-5, and IL-13 in lungs. Crosslinked OVA diminished infiltrated cells in bronchoalveolar lavage fluid and lung and attenuated eosinophilic airway inflammation. These findings offer valuable insights into the development of a novel product with improved hypoallergenic and immunomodulatory properties and hold promise in attenuating allergic diseases.

Insights on the Characteristics and Therapeutic Potential of Mesenchymal Stem Cell-derived Exosomes for Mitigation of Alzheimer's Disease's Pathogenicity: A Systematic Review.

Alzheimer's disease (AD) remains a progressive neurodegenerative disease with no cure. Treatment of AD relies on administering drugs that only subside the symptoms. In recent studies, mesenchymal stem cell (MSC)-exosomes have been marked to possess therapeutic potential for treating AD. This study aims to systematically review and analyse findings that focus on the isolation, characterisation, and sources of MSC-derived exosomes used to unravel the therapeutic potential of these exosomes targeting AD using in vitro and in vivo models. It is hypothesised that MSC-exosomes exhibit high therapeutic potential for AD treatment by exerting various modes of action. PubMed, Scopus, and Medline were used to find relevant published works from January 2016 until December 2020, using assigned keywords including "Alzheimer's disease", "secretome", and "exosomes". Only research articles meeting the predefined inclusion/exclusion criteria were selected and analysed. The risk of bias was assessed using the Office of Health Assessment and Translation tool (OHAT). A total of 17 eligible in vivo and in vitro studies were included in this review. Bone marrow-derived stem cells (BMSCs) were the most used source for exosome isolation, even though studies on exosomes from adipose-derived stem cells (ADSCs) and human umbilical cord stem cells (HUCSCs) provide more information on the characteristics. When the risk of bias was assessed, the studies presented various levels of biases. Notably, the in vitro and in vivo studies revealed neuroprotective properties of MSC-exosomes through different modes of action to alleviate AD pathology. Our review discovered that most MSC exosomes could degrade Aβ plaques, enhance neurogenesis, extenuate neuroinflammatory response through microglial activation, regulate apoptosis and reduce oxidative stress. Delivery of exosomal micro-RNAs was also found to reduce neuroinflammation. Findings from this review provided convincing systematic evidence highlighting the therapeutic properties of MSC-derived exosomes as a prospective source for cell-free (acellular) therapy in treating AD.

Targeting Bone Tumours with 45S5 Bioactive Glass.

Despite advances in treatment modalities, bone tumour therapies still face significant challenges. Severe side effects of conventional approaches, such as chemo- and radiation therapy, result in poor survival rates and high tumour recurrence rates, which are the most common issues that need to be improved upon. The aim of this study was to evaluate the therapeutic properties of 45S5 bioactive glass (BG) for targeting bone tumours. The viability of the cells derived from osteosarcoma, chondrosarcoma, and giant cell tumours was significantly reduced in the presence of 45S5-BG. In contrast, the viability of non-malignant osteoblast-like cells, chondrocytes, and bone marrow-derived stromal cells was not or only slightly affected. While alterations to the particle surface induced by heat treatment, acid etching, or incubation in a simulated body fluid had only minor effects on cytotoxicity, reducing the particle size or sintering the material significantly improved the cytotoxic effect of 45S5-BG. Further, using a chicken chorioallantoic membrane assay, the co-transplantation of 45S5-BG resulted in a significant reduction in tumour formation in vivo. Given the known positive effects of BGs on bone regeneration, our findings suggest that 45S5-BG holds great potential for the development of new and effective bone tumour therapies, with minimal side effects on non-malignant cells and simultaneous contribution to bone healing.

DNA Methylation Negatively Regulates Gene Expression of Key Cytokines Secreted by BMMCs Recognizing FMDV-VLPs

Virus-like particles (VLPs) have been studied and used as vaccines to control foot-and-mouth disease (FMD). Mast cells (MCs) express various pattern recognition receptors that recognize pathogens and secrete numerous cytokines to initiate and modulate immune responses. Our previous study showed that bone marrow-derived mast cells (BMMCs) can recognize foot-and-mouth disease virus-like particles (FMDV-VLPs) to differentially express various cytokines and that histone acetylation can regulate the cytokines secreted during BMMC recognition of FMDV-VLPs. To demonstrate the role of DNA methylation in this response process, BMMCs that recognize FMDV-VLPs were treated with azacytidine (5-AZA), an inhibitor of DNA methylation transferase. We prepared FMDV-VLPs as described previously and cultured the BMMCs. The transcription and expression of key cytokines and transcription factors were determined using real-time quantitative PCR (RT-qPCR) and Western blotting. Results showed that pre-treatment with AZA resulted in the increased transcription and expression of tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-13, and IL-10, while the changes in IL-13 transcription and IL-6 expression were irrelevant to mannose receptors (MRs). Furthermore, analysis of the transcription factors indicated that both the transcription and expression of nuclear factor-kappa B (NF-κB) increased significantly in the AZA pre-treated group, indicating that DNA methylation may also regulate NF-κB expression to modulate TNF-α, IL-13, and IL-6. However, pre-treatment with AZA did not alter the expression of microphthalmia-associated transcription factor (MITF) or GATA-2. All the data demonstrate that DNA methylation negatively regulates the transcription and expression of TNF-α, IL-13, IL-10, and IL-6 secreted by recognizing FMDV-VLPs. These results provide new ideas for the mast cell-based design of more effective vaccine adjuvants and targeted therapies in the future.

Mesenchymal stromal cell therapy (REGENACIP®), a promising treatment option in chronic limb threatening ischemia - a narrative review.

Chronic Limb Threatening Ischemia (CLTI) is a challenging clinical problem associated with high morbidity and mortality. Endovascular interventions have been the cornerstone of treatment whenever possible. It is estimated that CLTI represents < 10% of all Peripheral Artery Disease patients, yet 50% of the patients end up either with a major amputation of the lower limbs or die of cardiovascular causes within one year period, especially in those with unsuccessful revascularization or "no-option" CLTI. Cell-based therapeutics, especially bone marrow-derived mesenchymal stromal cells have emerged as a potential, promising, and novel alternate therapeutic modality in the management of CLTI, bolstered with positive results in numerous research, including randomized and nonrandomized trials. REGENACIP® is one such BM-MSC therapy approved by Central Drugs Standard Control Organization in India for the management of "no-option" Atherosclerotic Peripheral Arterial disease / Buerger's disease patients with established critical limb ischemia in Rutherford Grade III-5 or III-6, not eligible for or have failed traditional revascularization treatment, with rest pain and / or ulcers in the affected limb. The current review aims to deliberate upon the various aspects of CLTI and clinical benefits of REGENACIP® therein.

Engineered Tendon-Fibrocartilage-Bone Composite With Mechanical Stimulation for Augmentation of Rotator Cuff Repair: A Study Using an In Vivo Canine Model With a 6-Month Follow-up.

Rotator cuff repair augmentation using biological materials has become popular in clinical practice to reduce the high retear rates associated with traditional repair techniques. Tissue engineering approaches, such as engineered tendon-fibrocartilage-bone composite (TFBC), have shown promise in enhancing the biological healing of rotator cuff tears in animals. However, previous studies have provided limited long-term data on TFBC repair outcomes. The effect of mechanical stimulation on TFBC has not been explored extensively. To evaluate functional outcomes after rotator cuff repair with engineered TFBC subjected to mechanical stimulation in a 6-month follow-up using a canine in vivo model. Controlled laboratory study. A total of 40 canines with an acute infraspinatus (ISP) tendon transection model were randomly allocated to 4 groups (n =10): (1) unilateral ISP tendon undergoing suture repair only (control surgery); (2) augmentation with engineered TFBC alone (TFBC); (3) augmentation with engineered TFBC and bone marrow-derived stem cells (BMSCs) (TFBC+C); and (4) augmentation with engineered TFBC and BMSCs, as well as mechanical stimulation (TFBC+C+M). Outcome measures-including biomechanical evaluations such as failure strength, stiffness, failure mode, gross appearance, ISP tendon and muscle morphological assessment, and histological analysis-were performed 6 months after surgery. As shown in the mechanical test, the TFBC+C+M group exhibited higher failure strength compared with other repair techniques. The most common failure mode was avulsion fracture in the TFBC+C+M group, but tendon-bone junction rupture was observed predominantly in different groups. Engineered TFBC with mechanical stimulation showed over 70% relative failure strength compared with normal ISP, and the other groups showed about 50% relative failure strength. Histological analysis revealed less fat infiltration and closer-to-normal muscle fiber structure in the mechanical stimulation group. This study provides evidence that mechanical stimulation of engineered TFBC promotes rotator cuff regeneration, thus supporting its potential for rotator cuff repair augmentation. This study provides valuable evidence supporting the use of a novel tissue-engineered material (TFBC) in rotator cuff repair and paves the way for advancements in the field of rotator cuff regeneration.

Bothrops atrox snake venom decreased MHC-II and CD86 expression in bone marrow-derived dendritic cells

The effect of Bothrops atrox venom (BaV) on the maturation of bone marrow-derived dendritic cells (BMDCs) from mice was investigated, with a focus on selected cell markers, TAP1 expression, and the release of pro-inflammatory cytokines during this process. The objective was to evaluate BaV's impact on dendritic cell (DC) function, as DCs are pivotal in antigen presentation and responsible for initiating the immune response mediated by naïve T cells, as well as regulating the immune system. Bone marrow cells were obtained from Swiss mice, and hematopoietic precursors were differentiated into BMDCs using GM-CSF and IL-4. On the 7th day, BaV and LPS were introduced into the culture, and the cells were analyzed 24 h later. BaV's ability to stimulate BMDC maturation was assessed through the analysis of surface marker expression. The findings demonstrated that BMDCs are highly influenced by culture environment factors, such as GM-CSF and IL-4, and are sensitive to additional stimuli like LPS and BaV. Mature DCs exhibited elevated levels of critical markers for T cell activation, such as MHC-II, CD80, and CD86, displaying specific phenotypic characteristics. However, the observed reduction in MHC-II and CD86 expression following BaV exposure suggests a substantial impact on the immunological activation capacity of these cells, potentially interfering with the adaptive immune response. Furthermore, the selective release of cytokines, such as IL-6, but not TNF-α or IL-1β, indicates differentiated modulation of inflammatory responses by DCs under various stimulation conditions.

P-type pilus PapG protein elicits toll-like receptor 2-mediated immune activation during cancer immunotherapy.

The immune activation ability of FimH, an adhesion protein in pili of Escherichia coli (E. coli), has been recently reported. However, studies on the immune activity of PapG, another major pili terminal protein, have not been well explored. In this study, the immune stimulatory effect of purified recombinant PapG was evaluated. PapG treatment promoted dramatic changes in dendritic morphology of the bone marrow-derived dendritic cells (BMDCs) and induced upregulation of co-stimulatory molecule levels, major histocompatibility complex (MHC) I and II expression, and pro-inflammatory cytokine production in BMDCs. To identify the stimulatory receptor of PapG, an in silico study was performed. PapG exhibited strong binding affinity with murine toll-like receptor 2 (TLR2). In addition, PapG-induced activation of splenic DC and its subsets was unsuccessful in TLR2-knock out mice. Combination of PapG and ovalbumin (OVA) elicited OVA-specific T cell proliferation and cytokine production and cytotoxicity that consequently promoted anti-cancer immune responses against OVA-expressing B16 melanoma. Furthermore, PapG treatment induced activation of peripheral blood DCs and its subsets in humans in a TLR2 dependent manner. PapG-stimulated human conventional DC2 promoted syngeneic T cell proliferation and activation. The findings of this study demonstrated that PapG could be a useful immune stimulator for immunotherapy against cancer.

Dynamic glycolytic reprogramming effects on dendritic cells in pancreatic ductal adenocarcinoma

BackgroundPancreatic ductal adenocarcinoma tumors exhibit resistance to chemotherapy, targeted therapies, and even immunotherapy. Dendritic cells use glucose to support their effector functions and play a key role in anti-tumor immunity by promoting cytotoxic CD8+ T cell activity. However, the effects of glucose and lactate levels on dendritic cells in pancreatic ductal adenocarcinoma are unclear. In this study, we aimed to clarify how glucose and lactate can impact the dendritic cell antigen-presenting function and elucidate the relevant mechanisms.MethodsGlycolytic activity and immune cell infiltration in pancreatic ductal adenocarcinoma were evaluated using patient-derived organoids and resected specimens. Cell lines with increased or decreased glycolysis were established from KPC mice. Flow cytometry and single-cell RNA sequencing were used to evaluate the impacts on the tumor microenvironment. The effects of glucose and lactate on the bone marrow-derived dendritic cell antigen-presenting function were detected by flow cytometry.ResultsThe pancreatic ductal adenocarcinoma tumor microenvironment exhibited low glucose and high lactate concentrations from varying levels of glycolytic activity in cancer cells. In mouse transplantation models, tumors with increased glycolysis showed enhanced myeloid-derived suppressor cell infiltration and reduced dendritic cell and CD8+ T cell infiltration, whereas tumors with decreased glycolysis displayed the opposite trends. In three-dimensional co-culture, increased glycolysis in cancer cells suppressed the antigen-presenting function of bone marrow-derived dendritic cells. In addition, low-glucose and high-lactate media inhibited the antigen-presenting and mitochondrial functions of bone marrow-derived dendritic cells.ConclusionsOur study demonstrates the impact of dynamic glycolytic reprogramming on the composition of immune cells in the tumor microenvironment of pancreatic ductal adenocarcinoma, especially on the antigen-presenting function of dendritic cells.

Distinctive Immune Signatures Driven by Structural Alterations in Desmuramylpeptide NOD2 Agonists.

Herein we report on the design, synthesis and biological evaluation of a series of nucleotide-binding oligomerization-domain-containing protein 2 (NOD2) desmuramylpeptide agonists. The structural prerequisites that shape both physicochemical and immunomodulatory profiles of desmuramylpeptide NOD2 agonists have been delineated. Within this context, we identified 3, a butyrylated desmuramylpeptide, as a potent in vitro NOD2 agonist (EC50 = 4.6 nM), exhibiting an almost 17-fold enhancement in potency compared to its unsubstituted counterpart 1 (EC50 = 77.0 nM). The novel set of desmuramylpeptides demonstrate unique in vitro immunomodulatory activities. They elicited cytokine production in peripheral blood mononuclear cells (PBMCs), both alone and in conjunction with lipopolysaccharide (LPS). The spermine-decorated 32 also stimulated the LPS-induced cytotoxic activity (2.95-fold) of PBMCs against K562 cancer cells. Notably, the cholesterol-conjugate 26 displayed anti-inflammatory actions, highlighted by its capacity to convert the inflammatory monocyte subset into an anti-inflammatory phenotype. Finally, the eicosapentaenoylated derivative 23 augmented antigen presentation by mouse bone marrow-derived dendritic cells (BMDCs), thus highlighting its potential as a vaccine adjuvant.