Stable Stem Research Articles

Immuno‐Isolation Strategy with Tacrolimus‐Loaded Nanofilm Promotes Stable Stem Cell‐Based Cartilage Regeneration

AbstractBone marrow stem cells (BMSCs)‐engineered cartilage (BEC) shows promise for clinically repairing cartilage defects. However, when implanted in immunocompetent large animals, BEC becomes susceptible to ossification due to inflammatory infiltration. To address this, a nanofilm isolation approach is developed to enhance BEC's chondrogenic stability. Tacrolimus (FK506), known for its immunosuppressive effect, is integrated into adipic dihydrazide (ADH)‐modified hyaluronic acid (HA), creating an acid‐responsive macromolecular prodrug called FK506@HA‐ADH. This prodrug is then blended with poly(lactic‐co‐glycolic acid) (PLGA) to form electrospun FK506@HA/PLGA nanofilm. Goat‐derived BMSCs are induced in vitro to form BEC, which is enclosed within the FK506@HA/PLGA nanofilm and subcutaneously implanted in autologous goats. The nanofilm acted as a physical barrier, preventing immunocyte infiltration. Additionally, in response to the acidic environment triggered by inflammation and the gradual degradation of PLGA, the FK506@HA‐ADH prodrug is cleaved, releasing FK506 as needed. The released FK506 effectively countered inflammatory cytokines and promoted cartilaginous maturity. These combined mechanisms significantly inhibited BEC hypertrophy and improved its chondrogenic stability within an immunocompetent goat model. This nanofilm‐based isolation strategy established an immunosuppressive niche, successfully preventing endochondral ossification and promoting stable cartilage formation in BEC. These advancements are crucial for translating stem cell‐based therapies into clinical use for cartilage repair.

Sphere fibrations over highly connected manifolds

AbstractWe construct sphere fibrations over ‐connected ‐manifolds such that the total space is a connected sum of sphere products. More precisely, for even, we construct fibrations , where is a ‐connected ‐dimensional Poincaré duality complex that satisfies , in a localised category of spaces. The construction of the fibration is proved for , where the prime 2, and the primes that occur as torsion in are inverted. In specific cases, by either assuming is small, or assuming is large we can reduce the number of primes that need to be inverted. Integral results are obtained for or 4, and if is bigger than the number of cyclic summands in the stable stem , we obtain results after inverting 2. Finally, we prove some applications for fibrations over , and for looped configuration spaces.

Productive Poplar Genotypes Exhibited Temporally Stable Low Stem Embolism Resistance and Hydraulic Resistance Segmentation at the Stem-Leaf Transition.

Breeding tree genotypes that are both productive and drought-resistant is a primary goal in forestry. However, the relationships between plant hydraulics and yield at the genotype level, and their temporal stabilities, remain unclear. We selected six poplar genotypes from I-101 (Populus alba) × 84 K (P. alba × Popolus tremula var. glandulosa) for experiments in the first and fourth years after planting in a common garden. Measurements included stem embolism resistance, shoot hydraulic resistance and its partitioning between stems and leaves, vessel- and pit-level anatomy, leaf carbon acquisition capacity, carbon allocation to leaves, and aboveground biomass (yield proxy). Significant genetic variations in hydraulic properties and yield were found among genotypes in both years. Productive genotypes had wide vessels, large thin pit membranes, small pit apertures, and shallow pit chambers. Hydraulic resistance was negatively correlated with yield, enabling high stomatal conductance and assimilation rates. Productive genotypes allocated less aboveground carbon and hydraulic resistance to leaves. Temporally stable trade-offs between stem embolism resistance and yield, and between hydraulic segmentation and yield, were identified. These findings highlight the tight link between hydraulic function and yield and suggest that stable trade-offs may challenge breeding poplar genotypes that are both productive and drought-resistant.

Core-shell structured nanomembrane with sequential immune and vascular isolation effects followed by chondrogenic induction to promote stable stem cell-based subcutaneous cartilage regeneration in large animals

Bone marrow stem cell (BMSC)-regenerated cartilage (BRC) shows promising prospects for clinically repairing cartilage defects. However, when subcutaneously implanted into immunocompetent large animals, BRC is prone to ossification due to vascular invasion and inflammatory infiltration, compromising its chondrogenic stability. To address this challenge, we developed a core–shell structured KGN/Gel@Cur/PLCL nanomembrane using coaxial electrospinning technology to enhance the chondrogenic stability of BRC in subcutaneous niche. The shell layer comprises curcumin (Cur), known for its potent immunomodulatory and anti-angiogenic effects, and poly(L-lactide-co-caprolactone) (PLCL). The core layer comprises Kartogenin (KGN), a recognized chondrogenic inducer, and gelatin (Gel). This nanomembrane encapsulated BRCs induced from goat BMSCs in vitro and was subcutaneously implanted into autologous goats. The nanomembrane’s physical barrier and Cur release from the shell layer prevented vascular invasion and inflammatory infiltration. Additionally, KGN release from the core layer maintained the BRC’s chondrogenic phenotype and promoted cartilage maturation. These combined mechanisms significantly inhibited BRC ossification and preserved its chondrogenic stability. chondrogenic phenotype and promoted cartilage maturation. These combined mechanisms significantly inhibited BRC ossification and maintained its chondrogenic stability. Overall, this study highlights the effectiveness of the core–shell structured KGN/Gel@Cur/PLCL nanomembrane in providing sequential immune and vascular isolation, followed with chondrogenic induction, to prevent BRC ossification and preserve the chondrogenic stability of subcutaneously implanted BRC in large animal. This is crucial for the clinical translation of stem cell therapy into subcutaneous cartilage repair.

Establishment of porcine embryonic stem cells in simplified serum free media and feeder free expansion

BackgroundThe establishment of stable porcine embryonic stem cells (pESCs) can contribute to basic and biomedical research, including comparative developmental biology, as well as assessing the safety of stem cell-based therapies. Despite these advantages, most pESCs obtained from in vitro blastocysts require complex media and feeder layers, making routine use, genetic modification, and differentiation into specific cell types difficult. We aimed to establish pESCs with a single cell-passage ability, high proliferative potency, and stable in long-term culture from in vitro-derived blastocysts using a simplified serum-free medium.MethodsWe evaluated the establishment efficiency of pESCs from in vitro blastocysts using various basal media (DMEM/F10 (1:1), DMEM/F12, and a-MEM) and factors (FGF2, IWR-1, CHIR99021, and WH-4-023). The pluripotency and self-renewal capacity of the established pESCs were analyzed under feeder or feeder-free conditions. Ultimately, we developed a simplified culture medium (FIW) composed of FGF2, IWR-1, and WH-4-023 under serum-free conditions.ResultsThe pESC-FIW lines were capable of single-cell passaging with short cell doubling times and expressed the pluripotency markers POU5F1, SOX2, and NANOG, as well as cell surface markers SSEA1, SSEA4, and TRA-1-60. pESC-FIW showed a stable proliferation rate and normal karyotype, even after 50 passages. Transcriptome analysis revealed that pESC-FIW were similar to reported pESC maintained in complex media and showed gastrulating epiblast cell characteristics. pESC-FIW were maintained for multiple passages under feeder-free conditions on fibronectin-coated plates using mTeSR™, a commercial medium used for feeder-free culture, exhibiting characteristics similar to those observed under feeder conditions.ConclusionsThese results indicated that inhibition of WNT and SRC was sufficient to establish pESCs capable of single-cell passaging and feeder-free expansion under serum-free conditions. The easy maintenance of pESCs facilitates their application in gene editing technology for agriculture and biomedicine, as well as lineage commitment studies.

Generation of a human SLC12A3 knock-in human induced pluripotent stem cell line (CMCi014-A-82) using CRISPR-Cas9 system

Gitelman’s disease is caused by a genetic mutation in the solute carrier family 12 member 3 (SLC12A3) gene, which encodes the sodium chloride cotransporter. In this study, we generated a stable human induced pluripotent stem cell (hiPSC) line, WTC11-SLC12A3 (CMCi014-A-82), by knocking in the entire SLC12A3 gene at the SHS231 locus in healthy wild-type control hiPSCs (WTC11). We verified that WTC11-SLC12A3 expressed pluripotency markers and exhibited normal stem cell morphology. Furthermore, this cell line maintains a normal karyotype and can differentiate into the three germ layers. Therefore, this cell line may provide a basis for gene therapy for Gitelman’s disease.

Improved constructs for bait RNA display in a bacterial three-hybrid assay.

We have previously developed a transcription-based bacterial three-hybrid (B3H) assay as a genetic approach to probe RNA-protein interactions inside of E. coli cells. This system offers a straightforward path to identify and assess the consequences of mutations in RBPs with molecular phenotypes of interest. One limiting factor in detecting RNA-protein interactions in the B3H assay is RNA misfolding arising from incorrect base-pair interactions with neighboring RNA sequences in a hybrid RNA. To support correct folding of hybrid bait RNAs, we have explored the use of a highly stable stem ("GC clamp") to isolate regions of a hybrid RNA as discrete folding units. In this work, we introduce new bait RNA constructs to 1) insulate the folding of individual components of the hybrid RNA with GC clamps and 2) express bait RNAs that do not encode their own intrinsic terminator. We find that short GC clamps (5 or 7 bp long) are more effective than a longer 13bp GC clamp in the B3H assay. These new constructs increase the number of Hfq-sRNA and -5'UTR interactions that are detectable in the B3H system and improve the signal-to-noise ratio of many of these interactions. We therefore recommend the use of constructs containing short GC clamps for the expression of future B3H bait RNAs. With these new constructs, a broader range of RNA-protein interactions are detectable in the B3H assay, expanding the utility and impact of this genetic tool as a platform to search for and interrogate mechanisms of additional RNA-protein interactions.

Evolving trends in stem cell therapy: an emerging and promising approach against various diseases

Stem cell therapy is growing in popularity as a form of regenerative medicine with the capacity to treat a wide range of ailments. Stem cells exhibit the ability to differentiate into a diverse array of cell types within the organism due to their undifferentiated state. These cell sources include bone marrow, induced pluripotent stem cells, and umbilical cord tissue 1. Significant advancements in clinical applications and fundamental research of stem cells in regenerative medicine and other domains have occurred in recent years, motivating individuals to delve deeper into the study of stem cells. Stem cells, owing to their virtually limitless capacity for self-renewal, offer vast potential for advancements in the treatment of various diseases and human organ damage. Stem cell-related technologies for induction and isolation are relatively developed in the field of stem cell research, and numerous stable stem cell lines have been constructed with outstanding results 2. This editorial will delve into the latest advancements in stem cell therapy, shedding light on key developments, their clinical applications, and the promising future prospects.

Generation and characterisation of scalable and stable human pluripotent stem cell-derived microvascular-like endothelial cells for cardiac applications

Coronary microvascular disease (CMD) and its progression towards major adverse coronary events pose a significant health challenge. Accurate in vitro investigation of CMD requires a robust cell model that faithfully represents the cells within the cardiac microvasculature. Human pluripotent stem cell-derived endothelial cells (hPSC-ECs) offer great potential; however, they are traditionally derived via differentiation protocols that are not readily scalable and are not specified towards the microvasculature. Here, we report the development and comprehensive characterisation of a scalable 3D protocol enabling the generation of phenotypically stable cardiac hPSC-microvascular-like ECs (hPSC-CMVECs) and cardiac pericyte-like cells. These were derived by growing vascular organoids within 3D stirred tank bioreactors and subjecting the emerging 3D hPSC-ECs to high-concentration VEGF-A treatment (3DV). Not only did this promote phenotypic stability of the 3DV hPSC-ECs; single cell-RNA sequencing (scRNA-seq) revealed the pronounced expression of cardiac endothelial- and microvascular-associated genes. Further, the generated mural cells attained from the vascular organoid exhibited markers characteristic of cardiac pericytes. Thus, we present a suitable cell model for investigating the cardiac microvasculature as well as the endothelial-dependent and -independent mechanisms of CMD. Moreover, owing to their phenotypic stability, cardiac specificity, and high angiogenic potential, the cells described within would also be well suited for cardiac tissue engineering applications.

A placebo-controlled, crossover trial to investigate the efficacy of tiotropium bromide or placebo added to usual care in stable symptomatic post-hematopoietic stem cell transplantation (HSCT) bronchiolitis obliterans syndrome (BOS)

BackgroundDespite the fundamental progress in hematopoietic stem cell transplant, this treatment is also associated with complications. Graft-versus-host disease is a possible complication of HSCT. Bronchiolitis obliterans syndrome (BOS) is the pulmonary form of this syndrome. Due to the high morbidity and mortality rate of BOS, various studies have been conducted in the field of drug therapy for this syndrome, although no standard treatment has yet been proposed. According to the hypotheses about the similarities between BOS and chronic obstructive pulmonary disease, the idea of using tiotropium bromide as a bronchodilator has been proposed.Method/designA randomized, double-blind, placebo-controlled, and crossover clinical trial is being conducted to evaluate the efficacy of tiotropium in patients with BOS. A total of 20 patients with BOS were randomly assigned (1:1) to receive a once-daily inhaled capsule of either tiotropium bromide (KP-Tiova Rotacaps 18 mcg, Cipla, India) or placebo for 1 month. Patients will receive tiotropium bromide or placebo Revolizer added to usual standard care. Measurements will include spirometry and a 6-min walking test.Ethics/disseminationThis study was approved by the Research Ethics Committees of Imam Khomeini Hospital Complex, Tehran University of Medical Science. Recruitment started in September 2022, with 20 patients randomized. The treatment follow-up of participants with tiotropium is currently ongoing and is due to finish in April 2024. The authors will disseminate the findings in peer-reviewed publications, conferences, and seminar presentations.Trial registrationIranian Registry of Clinical Trial (IRCT) IRCT20200415047080N3. Registered on 2022–07-12, 1401/04/21.

Molecular dynamics in multidimensional space explains how mutations affect the association path of neomycin to a riboswitch

Riboswitches are messenger RNA (mRNA) fragments binding specific small molecules to regulate gene expression. A synthetic N1 riboswitch, inserted into yeast mRNA controls the translation of a reporter gene in response to neomycin. However, its regulatory activity is sensitive to single-point RNA mutations, even those distant from the neomycin binding site. While the association paths of neomycin to N1 and its variants remain unknown, recent fluorescence kinetic experiments indicate a two-step process driven by conformational selection. This raises the question of which step is affected by mutations. To address this, we performed all-atom two-dimensional replica-exchange molecular dynamics simulations for N1 and U14C, U14C[Formula: see text], U15A, and A17G mutants, ensuring extensive conformational sampling of both RNA and neomycin. The obtained neomycin association and binding paths, along with multidimensional free-energy profiles, revealed a two-step binding mechanism, consisting of conformational selection and induced fit. Neomycin binds to a preformed N1 conformation upon identifying a stable upper stem and U-turn motif in the riboswitch hairpin. However, the positioning of neomycin in the binding site occurs at different RNA-neomycin distances for each mutant, which may explain their different regulatory activities. The subsequent induced fit arises from the interactions of the neomycin's N3 amino group with RNA, causing the G9 backbone to rearrange. In the A17G mutant, the critical C6-A17/G17 stacking forms at a closer RNA-neomycin distance compared to N1. These findings together with estimated binding free energies coincide with experiments and elucidate why the A17G mutation decreases and U15A enhances N1 activity in response to neomycin.

Generation of a human embryonic stem cell line (SMUDHe010-A-1A) carrying Brainbow cassette in the AAVS1 gene by CRISPR/Cas9-mediated homologous recombination

Tracking single-cell lineages and their phenotypes longitudinally would help us better study skin development. Brainbow multicolor labeling approach is a genetic cell-labeling technique that tracks individual cells or analyzes cell lineages during development. Hence, we generated a stable Cre-inducible rainbow reporter human embryonic stem cell line (Named SMUDHe010-A-1A) by inserting the fluorescent protein gene (nGFP, YFP, RFP and CFP) at AAVS1 safe harbor locus using CRISPR/Cas9 technology. We verified that SMUDHe010-A-1A expressed the pluripotency markers and showed normal stem cell morphology. Furthermore, SMUDHe010-A-1A preserves normal karyotype and the ability to differentiate toward three germ layers. So the SMUDHe010-A-1A is effective for identifying and track cell populations.

Tau depletion in human neurons mitigates Aβ-driven toxicity

Alzheimer’s disease (AD) is an age-related neurodegenerative condition and the most common type of dementia, characterised by pathological accumulation of extracellular plaques and intracellular neurofibrillary tangles that mainly consist of amyloid-β (Aβ) and hyperphosphorylated tau aggregates, respectively. Previous studies in mouse models with a targeted knock-out of the microtubule-associated protein tau (Mapt) gene demonstrated that Aβ-driven toxicity is tau-dependent. However, human cellular models with chronic tau lowering remain unexplored. In this study, we generated stable tau-depleted human induced pluripotent stem cell (iPSC) isogenic panels from two healthy individuals using CRISPR-Cas9 technology. We then differentiated these iPSCs into cortical neurons in vitro in co-culture with primary rat cortical astrocytes before conducting electrophysiological and imaging experiments for a wide range of disease-relevant phenotypes. Both AD brain derived and recombinant Aβ were used in this study to elicit toxic responses from the iPSC-derived cortical neurons. We showed that tau depletion in human iPSC-derived cortical neurons caused considerable reductions in neuronal activity without affecting synaptic density. We also observed neurite outgrowth impairments in two of the tau-depleted lines used. Finally, tau depletion protected neurons from adverse effects by mitigating the impact of exogenous Aβ-induced hyperactivity, deficits in retrograde axonal transport of mitochondria, and neurodegeneration. Our study established stable human iPSC isogenic panels with chronic tau depletion from two healthy individuals. Cortical neurons derived from these iPSC lines showed that tau is essential in Aβ-driven hyperactivity, axonal transport deficits, and neurodegeneration, consistent with studies conducted in Mapt−/− mouse models. These findings highlight the protective effects of chronic tau lowering strategies in AD pathogenesis and reinforce the potential in clinical settings. The tau-depleted human iPSC models can now be applied at scale to investigate the involvement of tau in disease-relevant pathways and cell types.

Regulation of spermatogonial stem cell differentiation by Sertoli cells-derived exosomes through paracrine and autocrine signaling.

In the orchestrated environment of the testicular niche, the equilibrium between self-renewal and differentiation of spermatogonial stem cells (SSCs) is meticulously maintained, ensuring a stable stem cell reserve and robust spermatogenesis. Within this milieu, extracellular vesicles, specifically exosomes, have emerged as critical conveyors of intercellular communication. Despite their recognized significance, the implications of testicular exosomes in modulating SSC fate remain incompletely characterized. Given the fundamental support and regulatory influence of Sertoli cells (SCs) on SSCs, we were compelled to explore the role of SC-derived exosomes (SC-EXOs) in the SSC-testicular niche. Our investigation hinged on the hypothesis that SC-EXOs, secreted by SCs from the testes of 5-day-old mice-a developmental juncture marking the onset of SSC differentiation-participate in the regulation of this process. We discovered that exposure to SC-EXOs resulted in an upsurge of PLZF, MVH, and STRA8 expression in SSC cultures, concomitant with a diminution of ID4 and GFRA1 levels. Intriguingly, obstructing exosomal communication in a SC-SSC coculture system with the exosome inhibitor GW4869 attenuated SSC differentiation, suggesting that SC-EXOs may modulate this process via paracrine signaling. Further scrutiny revealed the presence of miR-493-5p within SC-EXOs, which suppresses Gdnf mRNA in SCs to indirectly restrain SSC differentiation through the modulation of GDNF expression-an indication of autocrine regulation. Collectively, our findings illuminate the complex regulatory schema by which SC-EXOs affect SSC differentiation, offering novel perspectives and laying the groundwork for future preclinical and clinical investigations.

Generation of three-dimensional meat-like tissue from stable pig epiblast stem cells

Cultured meat production has emerged as a breakthrough technology for the global food industry with the potential to reduce challenges associated with environmental sustainability, global public health, animal welfare, and competition for food between humans and animals. The muscle stem cell lines currently used for cultured meat cannot be passaged in vitro for extended periods of time. Here, we develop a directional differentiation system of porcine pre-gastrulation epiblast stem cells (pgEpiSCs) with stable cellular features and achieve serum-free myogenic differentiation of the pgEpiSCs. We show that the pgEpiSCs-derived skeletal muscle progenitor cells and skeletal muscle fibers have typical muscle cell characteristics and display skeletal muscle transcriptional features during myogenic differentiation. Importantly, we establish a three-dimensional differentiation system for shaping cultured tissue by screening plant-based edible scaffolds of non-animal origin, followed by the generation of pgEpiSCs-derived cultured meat. These advances provide a technical approach for the development of cultured meat.

Scalable and stable human pluripotent stem cell-derived microvascular-like endothelial cells for cardiac regeneration and disease modelling applications

Abstract Introduction The microvasculature is a vital constituent of the adult human vasculature 1. Cardiac tissue engineering, in vitro models of cardiac remodelling and regeneration, and disease models of the microvasculature would benefit from the inclusion of well-characterised, phenotypically stable microvascular-like endothelial cells (ECs) that could be generated at scale without xenogeneic reagents. Primary microvascular ECs have been utilised for such applications however, they are susceptible to passaging-induced senescence². Moreover, alternative solutions including current protocols for the derivation of human pluripotent stem cell-derived ECs (hPSC-ECs) generate cells with a heterogenous vascular identity that often transdifferentiate into non-EC lineages³. Purpose The purpose of this study was to create a 3D, xenogeneic-free differentiation protocol that yielded stable hPSC-derived microvascular-like ECs (hPSC-MVECs) at scale. Methods Endothelial differentiation of hPSCs was conducted in 2D adherent monolayers and within stirred 3D bioreactors for 12 days. Thereafter, CD31pos ECs were isolated via fluorescence-activated cell sorting (FACS) and cultured for a further 14 days. Gene expression analysis of hPSCs undergoing 2D and 3D differentiation was evaluated via RT-qPCR. The day 26 hPSC-ECs were treated with VEGFA (0 – 50 ng/ml) for a further 7 days and evaluated for CD31 expression via high-content image analysis. The angiogenic profiles of 2D-, 3D-, and 3D-hPSC-ECs cultured in high concentration VEGFA (herein, 3D+V), relative to primary Human Cardiac Microvascular Endothelial Cells (HMVEC-Cs) was assessed using the Proteome Profiler Human Angiogenesis Array. Transcriptomic analysis of these EC populations was subsequently conducted via single-cell RNA sequencing (scRNA-seq). Results Complex vascular clusters emerged by day 12 of the 3D differentiation protocol (fig. 1). The emergent 3D hPSC-ECs had a comparable expression of PECAM1 and CDH5 relative to 2D-derived hPSC-ECs however, VEGFA expression was significantly reduced (P<0.01, fig. 2A). VEGFA treatment at 50 ng/ml yielded phenotypically stable hPSC-ECs (3D+V, fig. 2B). Principal component analysis of the angiogenic factors assayed for revealed 3D+V hPSC-ECs clustered with HMVEC-Cs (fig. 2C). scRNA-seq identified a subset of 3D-derived hPSC-ECs expressing genes associated with microvascular vessels (GMFG, PLVAP), capillary ECs (RGCC, GLUL), and angiogenic tip cells (ESM1, HSPG2). Conclusion The scalable and xenogeneic-free 3D protocol outlined within allows for the attainment of hPSC-derived microvascular-like ECs with high angiogenic potential. The absence of Matrigel enhances the translational capacity of the hPSC-MVECs arising from this protocol that could now be derived from patient-specific hPSC lines for evaluation in pre-clinical models of post-myocardial infarction cardiac regeneration or for in vivo models of cardiac remodelling and microvasculature disease.

M/F-theory as Mf-theory

In the quest for mathematical foundations of M-theory, the Hypothesis H that fluxes are quantized in Cohomotopy theory, implies, on flat but possibly singular spacetimes, that M-brane charges locally organize into equivariant homotopy groups of spheres. Here, we show how this leads to a correspondence between phenomena conjectured in M-theory and fundamental mathematical concepts/results in stable homotopy, generalized cohomology and Cobordism theory [Formula: see text] : — stems of homotopy groups correspond to charges of probe [Formula: see text]-branes near black [Formula: see text]-branes; — stabilization within a stem is the boundary-bulk transition; — the Adams d-invariant measures [Formula: see text]-flux; — trivialization of the d-invariant corresponds to [Formula: see text]-flux; — refined Toda brackets measure [Formula: see text]-flux; — the refined Adams e-invariant sees the [Formula: see text]-charge lattice; — vanishing Adams e-invariant implies consistent global [Formula: see text]-fields; — Conner–Floyd’s e-invariant is the [Formula: see text]-flux seen in the Green–Schwarz mechanism; — the Hopf invariant is the M2-brane Page charge ([Formula: see text]-flux); — the Pontrjagin–Thom theorem associates the polarized brane worldvolumes sourcing all these charges. In particular, spontaneous K3-reductions with 24 branes are singled out from first principles : — Cobordism in the third stable stem witnesses spontaneous KK-compactification on K3-surfaces; — the order of the third stable stem implies the 24 NS5/D7-branes in M/F-theory on K3. Finally, complex-oriented cohomology emerges from Hypothesis H, connecting it to all previous proposals for brane charge quantization in the chromatic tower: K-theory, elliptic cohomology, etc. : — quaternionic orientations correspond to unit [Formula: see text]-fluxes near M2-branes; — complex orientations lift these unit [Formula: see text]-fluxes to heterotic M-theory with heterotic line bundles. In fact, we find quaternionic/complex Ravenel-orientations bounded in dimension; and we find the bound to be 10, as befits spacetime dimension [Formula: see text].

Periprosthetic fractures after shoulder arthroplasty: a systematic review.

The goal of this study was to review available literature on periprosthetic shoulder fractures to evaluate epidemiology, risk factors and support clinical decision-making regarding diagnostics, preoperative planning, and treatment options. Two authors cross-checked the PubMed and Web of Science medical databases. The inclusion criteria were as follows: original human studies published in English, with the timeframe not limited, and the following keywords were used: 'periprosthetic shoulder fracture,' 'total shoulder arthroplasty periprosthetic fractures,' 'total shoulder arthroplasty fracture,' and 'total shoulder replacement periprosthetic fracture.' Seventy articles were included in the review. All articles were retrieved using the aforementioned criteria. The fracture rate associated with total shoulder arthroplasty varied between 0 and 47.6%. Risk factors for periprosthetic fractures were female gender, body mass index < 25 kg/m2, smoking, rheumatoid arthritis, and Parkinson's disease. The most commonly used classification is the Wright and Coefield classification. Periprosthetic fractures can be treated both, conservatively and operatively. Periprosthetic fracture frequency after shoulder arthroplasty ranges from 0 to 47.6%. The most common location of the fracture is the humerus and most commonly occurs intraoperatively. The most important factor influencing treatment is stem stability. Fractures with stem instability require revision arthroplasty with stem replacement. Fractures with a stable stem depending on the location, displacement and bone stock quality can be treated both conservatively and operatively. For internal fixation plates with cables and screws are most commonly used.

Pluripotency and embryonic lineage genes expression in the presence of small molecule inhibitors of FGF, TGFβ and GSK3 during pre-implantation development of goat embryos

Generating stable livestock pluripotent stem cells (PSCs) can be used for complex genome editing, cellular agriculture, gamete generation, regenerative medicine and in vitro breeding schemes. Over the past decade, significant progress has been made in characterizing pluripotency markers for livestock species. In this study, we investigated embryo development and gene expression of the core pluripotency triad (OCT4, NANOG, SOX2) and cell lineage commitment markers (REX1, CDX2, GATA4) in the presence of three small molecules and their combination [PD0325901 (FGF inhibitor), SB431542 (TGFβ inhibitor), and CHIR99021 (GSK3B inhibitor)] from day 2–7 post-insemination in goat.Significant reduction in rate of blastocyst formation was observed when SB was used along with PD or CHIR and their three combinations had more sever effect. SB and CHIR decreased the expression of SOX2 while increasing the GATA4 expression. PD decrease the relative expression of NANOG, OCT4 and GATA4, while increased the expression of REX1. Among the combination of two molecules, only SB + CHIR combination significantly decreased the expression of GATA4, while the combination of the three molecules significantly decreases the expression of NANOG, SOX2 and CDX2.According to these results, the inhibition of the FGF signaling pathway, by PD may lead to blocking the hypoblast formation as observed by reduction of GATA4. OCT4 and NANOG expressions did not show signs of maintenance pluripotency. GATA4, NANOG and OCT4 in the PD group were downregulated and REX1 as EPI-marker was upregulated thus REX1 may be considered as a marker of EPI/ICM in goat.

Establishment of a Coilia nasus Spermatogonial Stem Cell Line Capable of Spermatogenesis In Vitro.

The process by which spermatogonial stem cells (SSCs) continuously go through mitosis, meiosis, and differentiation to produce gametes that transmit genetic information is known as spermatogenesis. Recapitulation of spermatogenesis in vitro is hindered by the challenge of collecting spermatogonial stem cells under long-term in vitro culture conditions. Coilia nasus is a commercially valuable anadromous migrant fish found in the Yangtze River in China. In the past few decades, exploitation and a deteriorating ecological environment have nearly caused the extinction of C. nasus's natural resources. In the present study, we established a stable spermatogonial stem cell line (CnSSC) from the gonadal tissue of the endangered species C. nasus. The cell line continued to proliferate and maintain stable cell morphology, a normal diploid karyotype, and gene expression patterns after more than one year of cell culture (>80 passages). Additionally, CnSSC cells could successfully differentiate into sperm cells through a coculture system. Therefore, the establishment of endangered species spermatogonial stem cell lines is a model for studying spermatogenesis in vitro and a feasible way to preserve germplasm resources.