TGF-β Family Signaling in Embryonic and Somatic Stem-Cell Renewal and Differentiation

TSP50 Attenuates DSS-Induced Colitis by Regulating TGF-β Signaling Mediated Maintenance of Intestinal Mucosal Barrier Integrity

The integrity of the intestinal mucosal barrier is crucial for protecting the intestinal epithelium against invasion by commensal bacteria and pathogens, thereby combating colitis. The investigation revealed that the absence of TSP50 compromised the integrity of the intestinal mucosal barrier in murine subjects. This disruption facilitated direct contact between intestinal bacteria and the intestinal epithelium, thereby increasing susceptibility to colitis. Mechanistic analysis indicated that TSP50 deficiency in intestinal stem cells (ISCs) triggered aberrant activation of the TGF-β signaling pathway and impeded the differentiation of goblet cells in mice, leading to impairment of mucosal permeability. By inhibiting the TGF-β pathway, the functionality of the intestinal mucosal barrier is successfully restored and mitigated colitis in TSP50-deficient mice. In conclusion, TSP50 played a crucial role in maintaining the intestinal mucosal barrier function and exhibited the preventive effect against the development of colitis by regulating the TGF-β signaling pathway.

Phenotypic sorting of individual male and female intersex Cherax quadricarinatus and analysis of molecular differences in the gonadal transcriptome

Cherax quadricarinatus exhibit sexual dimorphism, with males outpacing females in size specification and growth rate. However, there is limited understanding of the molecular mechanisms underlying sex determination and sex differentiation in crustaceans. To study the differences between intersex individuals and normal individuals, this study counted the proportion of intersex individuals in the natural population, collected the proportion of 7 different phenotypes in 200 intersex individuals, and observed the differences in tissue sections. RNA-seq was used to study the different changes in the transcriptome of normal and intersex gonads. The results showed that: the percentage of intersex in the natural population was 1.5 %, and the percentage of different types of intersex ranged from 0.5 % to 22.5 %; the sections revealed that the development of normal ovaries was stagnant at the primary oocyte stage when intersex individuals with ovaries were present; We screened for pathways and genes that may be associated with gonadal development and sex, including ovarian steroid synthesis, estrogen signaling pathway, oocyte meiosis, progesterone-mediated oocyte maturation, etc. Relevant genes including tra2a, dmrta2, ccnb2, foxl2, and smad4. This study provides an important molecular basis for sex determination, sex-controlled breeding, and unisex breeding in red crayfish.

Asymmetric division of stem cells and its cancer relevance

Asymmetric division is a fundamental process for generating cell diversity and maintaining the stem cell population. During asymmetric division, proteins, organelles, and even RNA are distributed unequally between the two daughter cells, determining their distinct cell fates. The mechanisms orchestrating this process are extremely complex. Dysregulation of asymmetric division can potentially trigger cancer progression. Cancer stem cells, in particular, undergo asymmetric division, leading to intra-tumoral heterogeneity, which contributes to treatment refractoriness. In this review, we delve into the cellular and molecular mechanisms that govern asymmetric division and explore its relevance to tumorigenesis.

Mesenchymal stem cells (MSCs) from the mouse bone marrow show differential expression of interferon regulatory factors IRF-1 and IRF-2

BACKGROUND

Interferon regulatory factors (IRF-1 and IRF-2) are transcription factors widely implicated in various cellular processes, including regulation of inflammatory responses to pathogens, cell proliferation, oncogenesis, differentiation, autophagy, and apoptosis.

METHODS

We have studied the expression of IRF-1, IRF-2 mRNAs by RT-PCR, cellular localization of the proteins by immunofluorescence, and expression of mRNAs of genes regulated by IRF-1, IRF-2 by RT-PCR in mouse bone marrow cells (BMCs) and mesenchymal stem cells (MSCs).

RESULTS

Higher level of IRF-1 mRNA was observed in BMCs and MSCs compared to that of IRF-2. Similarly, differential expression of IRF-1 and IRF-2 proteins was observed in BMCs and MSCs. IRF-1 was predominantly localized in the cytoplasm, whereas IRF-2 was localized in the nuclei of BMCs. MSCs showed nucleo-cytoplasmic distribution of IRF-1 and nuclear localization of IRF-2. Constitutive expression of IRF-1 and IRF-2 target genes: monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), cyclooxygenase-2 (COX-2), matrix metalloproteinase-9 (MMP-9), and caspase-1 was observed in both BMCs and MSCs. MSCs showed constitutive expression of the pluripotency-associated factors, Oct3/4 and Sox-2. Lipopolysaccharide (LPS)-treatment of MSCs induced prominent cellular localization of IRF-1 and IRF-2.

CONCLUSIONS

Our results suggest that IRF-1 and IRF-2 exhibit differential expression of their mRNAs and subcellular localization of the proteins in BMCs and MSCs. These cells also show differential levels of constitutive expression of IRF-1 and IRF-2 target genes. This may regulate immune-responsive properties of BMCs and MSCs through IRF-1, IRF-2-dependent gene expression and protein-protein interaction. Regulating IRF-1 and IRF-2 may be helpful for immunomodulatory functions of MSCs for cell therapy and regenerative medicine.

Comparison of Four Protocols for In Vitro Differentiation of Human Embryonic Stem Cells into Trophoblast Lineages by BMP4 and Dual Inhibition of Activin/Nodal and FGF2 Signaling

Human embryonic stem cells (hESCs) cultured in media containing bone morphogenic protein 4 (BMP4; B) differentiate into trophoblast-like cells. Supplementing media with inhibitors of activin/nodal signaling (A83-01) and of fibroblast growth factor 2 (PD173074) suppresses mesoderm and endoderm formation and improves specification of trophoblast-like lineages, but with variable effectiveness. We compared differentiation in four BMP4-containing media: mTeSR1-BMP4 only, mTeSR1-BAP, basal medium with BAP (basal-BAP), and a newly defined medium, E7-BAP. These media variably drive early differentiation towards trophoblast-like lineages with upregulation of early trophoblast markers CDX2 and KRT7 and downregulation of pluripotency markers (OCT4 and NANOG). As expected, based on differences between media in FGF2 and its inhibitors, downregulation of mesendoderm marker EOMES was variable between media. By day 7, only hESCs grown in E7-BAP or basal-BAP expressed HLA-G protein, indicating the presence of cells with extravillous trophoblast characteristics. Expression of HLA-G and other differentiation markers (hCG, KRT7, and GCM1) was highest in basal-BAP, suggesting a faster differentiation in this medium, but those cultures were more inhomogeneous and still expressed some endodermal and pluripotency markers. In E7-BAP, HLA-G expression increased later and was lower. There was also a low but maintained expression of some C19MC miRNAs, with more CpG hypomethylation of the ELF5 promoter, suggesting that E7-BAP cultures differentiate slower along the trophoblast lineage. We conclude that while all protocols drive differentiation into trophoblast lineages with varying efficiency, they have advantages and disadvantages that must be considered when selecting a protocol for specific experiments.

Mutual regulation of TGFβ-induced oncogenic EMT, cell cycle progression and the DDR

TGFβ signaling and the DNA damage response (DDR) are two cellular toolboxes with a strong impact on cancer biology. While TGFβ as a pleiotropic cytokine affects essentially all hallmarks of cancer, the multifunctional DDR mostly orchestrates cell cycle progression, DNA repair, chromatin remodeling and cell death. One oncogenic effect of TGFβ is the partial activation of epithelial-to-mesenchymal transition (EMT), conferring invasiveness, cellular plasticity and resistance to various noxae. Several reports show that both individual networks as well as their interface affect chemo-/radiotherapies. However, the underlying mechanisms remain poorly resolved. EMT often correlates with TGFβ-induced slowing of proliferation, yet numerous studies demonstrate that particularly the co-activated EMT transcription factors counteract anti-proliferative signaling in a partially non-redundant manner. Collectively, evidence piled up over decades underscore a multifaceted, reciprocal inter-connection of TGFβ signaling / EMT with the DDR / cell cycle progression, which we will discuss here. Altogether, we conclude that full cell cycle arrest is barely compatible with the propagation of oncogenic EMT traits and further propose that 'EMT-linked DDR plasticity' is a crucial, yet intricate facet of malignancy, decisively affecting metastasis formation and therapy resistance.

Helicobacter pylori-activated fibroblasts as a silent partner in gastric cancer development

The discovery of Helicobacter pylori (Hp) infection of gastric mucosa leading to active chronic gastritis, gastroduodenal ulcers, and MALT lymphoma laid the groundwork for understanding of the general relationship between chronic infection, inflammation, and cancer. Nevertheless, this sequence of events is still far from full understanding with new players and mediators being constantly identified. Originally, the Hp virulence factors affecting mainly gastric epithelium were proposed to contribute considerably to gastric inflammation, ulceration, and cancer. Furthermore, it has been shown that Hp possesses the ability to penetrate the mucus layer and directly interact with stroma components including fibroblasts and myofibroblasts. These cells, which are the source of biophysical and biochemical signals providing the proper balance between cell proliferation and differentiation within gastric epithelial stem cell compartment, when exposed to Hp, can convert into cancer-associated fibroblast (CAF) phenotype. The crosstalk between fibroblasts and myofibroblasts with gastric epithelial cells including stem/progenitor cell niche involves several pathways mediated by non-coding RNAs, Wnt, BMP, TGF-β, and Notch signaling ligands. The current review concentrates on the consequences of Hp-induced increase in gastric fibroblast and myofibroblast number, and their activation towards CAFs with the emphasis to the altered communication between mesenchymal and epithelial cell compartment, which may lead to inflammation, epithelial stem cell overproliferation, disturbed differentiation, and gradual gastric cancer development. Thus, Hp-activated fibroblasts may constitute the target for anti-cancer treatment and, importantly, for the pharmacotherapies diminishing their activation particularly at the early stages of Hp infection.

Transcriptional and open chromatin analysis of bovine skeletal muscle development by single-cell sequencing

Skeletal muscle is a complex heterogeneous tissue and characterizing its cellular heterogeneity and transcriptional and epigenetic signatures are important for understanding the details of its ontogeny. In our study, we applied scRNA-seq and scATAC-seq to investigate the cell types, molecular features, transcriptional and epigenetic regulation, and patterns of developing bovine skeletal muscle from gestational, lactational and adult stages. Detailed molecular analyses were used to dissect cellular heterogeneity, and we deduced the differentiation trajectory of myogenic cells and uncovered their dynamic gene expression profiles. SCENIC analysis was performed to demonstrate key regulons during cell fate decisions. We explored the future expression states of these heterogeneous cells by RNA velocity analysis and found extensive networks of intercellular communication using the toolkit CellChat. Moreover, the transcriptomic and chromatin accessibility modalities were confirmed to be highly concordant, and integrative analysis of chromatin accessibility and gene expression revealed key transcriptional regulators acting during myogenesis. In bovine skeletal muscle, by scRNA-seq and scATAC-seq analysis, different cell types such as adipocytes, endothelial cells, fibroblasts, lymphocytes, monocytes, pericyte cells and eight skeletal myogenic subpopulations were identified at the three developmental stages. The pseudotime trajectory exhibited a distinct sequential ordering for these myogenic subpopulations and eight distinct gene clusters were observed according to their expression pattern. Moreover, specifically expressed TFs (such as MSC, MYF5, MYOD1, FOXP3, ESRRA, BACH1, SIX2 and ATF4) associated with muscle development were predicted, and likely future transcriptional states of individual cells and the developmental dynamics of differentiation among neighbouring cells were predicted. CellChat analysis on the scRNA-seq data set then classified many ligand-receptor pairs among these cell clusters, which were further categorized into significant signalling pathways, including BMP, IGF, WNT, MSTN, ANGPTL, TGFB, TNF, VEGF and FGF. Finally, scRNA-seq and scATAC-seq results were successfully integrated to reveal a series of specifically expressed TFs that are likely to be candidates for the promotion of cell fate transition during bovine skeletal muscle development. Overall, our results outline a single-cell dynamic chromatin/transcriptional landscape for normal bovine skeletal muscle development; these provide an important resource for understanding the structure and function of mammalian skeletal muscle, which will promote research into its biology.

Functional Characterization of Transforming Growth Factor-β Signaling in Dasatinib Resistance and Pre-BCR+ Acute Lymphoblastic Leukemia

The multi-kinase inhibitor dasatinib has been implicated to be effective in pre-B-cell receptor (pre-BCR)-positive acute lymphoblastic leukemia (ALL) expressing the E2A-PBX1 fusion oncoprotein. The TGFβ signaling pathway is involved in a wide variety of cellular processes, including embryonic development and cell homeostasis, and it can have dual roles in cancer: suppressing tumor growth at early stages and mediating tumor progression at later stages. In this study, we identified the upregulation of the TGFβ signaling pathway in our previously generated human dasatinib-resistant pre-BCR+/E2A-PBX1+ ALL cells using global transcriptomic analysis. We confirm the upregulation of the TGFβ pathway member SMAD3 at the transcriptional and translational levels in dasatinib-resistant pre-BCR+/E2A-PBX1+ ALL cells. Hence, dasatinib blocks, at least partially, TGFβ-induced SMAD3 phosphorylation in several B-cell precursor (BCP) ALL cell lines as well as in dasatinib-resistant pre-BCR+/E2A-PBX1+ ALL cells. Activation of the TGFβ signaling pathway by TGF-β1 leads to growth inhibition by cell cycle arrest at the G0/G1 stage, increase in apoptosis and transcriptional changes of SMAD-targeted genes, e.g. c-MYC downregulation, in pre-BCR+/E2A-PBX1+ ALL cells. These results provide a better understanding about the role that the TGFβ signaling pathway plays in leukemogenesis of BCP-ALL as well as in secondary drug resistance to dasatinib.

ASH2L regulates postnatal neurogenesis through Onecut2-mediated inhibition of TGF-β signaling pathway

The ability of neural stem/progenitor cells (NSPCs) to proliferate and differentiate is required through different stages of neurogenesis. Disturbance in the regulation of neurogenesis causes many neurological diseases, such as intellectual disability, autism, and schizophrenia. However, the intrinsic mechanisms of this regulation in neurogenesis remain poorly understood. Here, we report that Ash2l (Absent, small or homeotic discs-like 2), one core component of a multimeric histone methyltransferase complex, is essential for NSPC fate determination during postnatal neurogenesis. Deletion of Ash2l in NSPCs impairs their capacity for proliferation and differentiation, leading to simplified dendritic arbors in adult-born hippocampal neurons and deficits in cognitive abilities. RNA sequencing data reveal that Ash2l primarily regulates cell fate specification and neuron commitment. Furthermore, we identified Onecut2, a major downstream target of ASH2L characterized by bivalent histone modifications, and demonstrated that constitutive expression of Onecut2 restores defective proliferation and differentiation of NSPCs in adult Ash2l-deficient mice. Importantly, we identified that Onecut2 modulates TGF-β signaling in NSPCs and that treatment with a TGF-β inhibitor rectifies the phenotype of Ash2l-deficient NSPCs. Collectively, our findings reveal the ASH2L-Onecut2-TGF-β signaling axis that mediates postnatal neurogenesis to maintain proper forebrain function.

miR-140-5p attenuates hepatic fibrosis by directly targeting TGFβR1

OBJECTIVE

To explore the protective effect and related mechanism of miR-140-5p on liver fibrosis by interfering with TGF-β/Smad signaling pathway.

METHODS

Liver fibrosis mice models were established by intraperitoneal injection of CCL4. Hematoxylin and eosin (HE) staining was used to detect the structural and morphological changes of the liver. Masson staining was used to detect collagen deposition. Human hepatic stellate cells (HSCs, LX-2) were transfected with miR-140-5p mimic or inhibitor then treated with TGF-β1. The qRT-PCR and Western blotting was used to detect the expression of related molecules. The luciferase reporter assay was used to identify the target of miR-140-5p.

RESULTS

Our results indicated that miR-140-5p expression was downregulated in fibrotic liver tissues of model mice and LX-2 cells treated with TGF-β1. The overexpression of miR-140-5p decreased the expression of collagen1(COL1) and α-smooth muscle actin(α-SMA), inhibited the phosphorylation of Smad-2/3 (pSmad-2/3) in LX-2 cells. Conversely, the knockdown of miR-140-5p upregulated COL1 and α-SMA expression, increased Smad-2/3 phosphorylation. A dual-luciferase reporter assay showed that TGFβR1 was a target gene of miR-140-5p. The overexpression of miR-140-5p suppressed TGFβR1 expression in LX-2 cells. Additionally, knockdown of TGFβR1 decreased the expression of COL1 and α-SMA. Conversely, the overexpression of TGFβR1 reversed the inhibitory effect of miR-140-5p upregulation on expression of COL1 and α-SMA.

CONCLUSION

miR-140-5p bound to TGFβR1 mRNA 3'-untranslated region(3'UTR) and inhibited the expression of TGFβR1, pSmad-2/3, COL1 and α-SMA, thereby exerting a potential therapeutic effect on hepatic fibrosis.

Human cortical spheroids with a high diversity of innately developing brain cell types

BACKGROUND

Three-dimensional (3D) human brain spheroids are instrumental to study central nervous system (CNS) development and (dys)function. Yet, in current brain spheroid models the limited variety of cell types hampers an integrated exploration of CNS (disease) mechanisms.

METHODS

Here we report a 5-month culture protocol that reproducibly generates H9 embryonic stem cell-derived human cortical spheroids (hCSs) with a large cell-type variety.

RESULTS

We established the presence of not only neuroectoderm-derived neural progenitor populations, mature excitatory and inhibitory neurons, astrocytes and oligodendrocyte (precursor) cells, but also mesoderm-derived microglia and endothelial cell populations in the hCSs via RNA-sequencing, qPCR, immunocytochemistry and transmission electron microscopy. Transcriptomic analysis revealed resemblance between the 5-months-old hCSs and dorsal frontal rather than inferior regions of human fetal brains of 19-26 weeks of gestational age. Pro-inflammatory stimulation of the generated hCSs induced a neuroinflammatory response, offering a proof-of-principle of the applicability of the spheroids.

CONCLUSIONS

Our protocol provides a 3D human brain cell model containing a wide variety of innately developing neuroectoderm- as well as mesoderm-derived cell types, furnishing a versatile platform for comprehensive examination of intercellular CNS communication and neurological disease mechanisms.

The effect of crocin and losartan on TGF-β gene expression and histopathology of kidney tissue in a rat model of diabetic nephropathy

Objective

Diabetic nephropathy is one of the most common microvascular complications of diabetes mellitus that finally leads to complete loss of kidney function. Therefore, this study aimed to evaluate the effect of crocin and losartan on TGF-β gene expression and histopathology of kidney tissue in a rat model of diabetic nephropathy.

Materials and Methods

Forty male Wistar rats were randomly divided into five groups (n=8): Untreated control, Diabetic (D), D + crocin, D + losartan, and D + losartan + crocin. Induction of diabetes was performed using streptozotocin (50 mg/kg/ Intraperitoneal injection). At the end of the eight-week period, the rats were sacrificed. Spectrophotometry measured serum glucose, urea, creatinine, and uric acid levels. Microalbumin and creatinine levels were measured in 24-hour urine. Real-time PCR was used to determine the relative expression of the TGF-β gene in kidney tissue. Renal tissue histopathology was also examined.

Results

The results showed that hyperglycemia increased biochemical factors associated with diabetes, TGF-β gene expression, and kidney damage. Separate treatment with crocin and losartan led to a decrease in renal function factors and TGF-β gene expression and improved kidney damage.

Conclusion

Our results showed that crocin could improve kidney function in diabetic conditions. In addition, we showed that crocin increases the effectiveness of losartan. Consequently, we suggest that crocin in combination with chemical drugs can be a potential therapeutic agent for diabetes and its complications. Nonetheless, human studies are needed to make firm findings.

Mutual regulation between glycosylation and transforming growth factor-β isoforms signaling pathway

Transforming growth factor-beta (TGF-β) superfamily members orchestrate a wide breadth of biological processes. Through Sma and Mad (Smad)-related dependent or noncanonical pathways, TGF-β members involve in the occurrence and development of many diseases such as cancers, fibrosis, autoimmune diseases, cardiovascular diseases and brain diseases. Glycosylation is one kind of the most common posttranslational modifications on proteins or lipids. Abnormal protein glycosylation can lead to protein malfunction and biological process disorder, thereby causing serious diseases. Previously, researchers commonly make comprehensive systematic overviews on the roles of TGF-β signaling in a specific disease or biological process. In recent years, more and more evidences associate glycosylation modification with TGF-β signaling pathway, and we can no longer disengage and ignore the roles of glycosylation from TGF-β signaling to make investigation. In this review, we provide an overview of current findings involved in glycosylation within TGF-βs and theirs receptors, and the interaction effects between glycosylation and TGF-β subfamily signaling, concluding that there is an intricate mutual regulation between glycosylation and TGF-β signaling, hoping to present the glycosylation regulatory patterns that concealed in TGF-βs signaling pathways.

TGFβ3, dibutyryl cAMP and a notch inhibitor modulate phenotype late in stem cell-derived dopaminergic neuron maturation

The generation of midbrain dopaminergic neurons (mDAs) from pluripotent stem cells (hPSC) holds much promise for both disease modelling studies and as a cell therapy for Parkinson's disease (PD). Generally, dopaminergic neuron differentiation paradigms rely on inhibition of smad signalling for neural induction followed by hedgehog signalling and an elevation of β-catenin to drive dopaminergic differentiation. Post-patterning, differentiating dopaminergic neuron cultures are permitted time for maturation after which the success of these differentiation paradigms is usually defined by expression of tyrosine hydroxylase (TH), the rate limiting enzyme in the synthesis of dopamine. However, during maturation, culture media is often supplemented with additives to promote neuron survival and or promote cell differentiation. These additives include dibutyryl cyclic adenosine monophosphate (dbcAMP), transforming growth factor β3 (TGFβ3) and or the γ-secretase inhibitor (DAPT). While these factors are routinely added to cultures, their impact upon pluripotent stem cell-derived mDA phenotype is largely unclear. In this study, we differentiate pluripotent stem cells toward a dopaminergic phenotype and investigate how the omission of dbcAMP, TGFβ3 or DAPT, late in maturation, affects the regulation of multiple dopaminergic neuron phenotype markers. We now show that the removal of dbcAMP or TGFβ3 significantly and distinctly impacts multiple markers of the mDA phenotype (FOXA2, EN1, EN2, FOXA2, SOX6), while commonly increasing both MSX2 and NEUROD1 and reducing expression of both tyrosine hydroxylase and WNT5A. Removing DAPT significantly impacted MSX2, OTX2, EN1, and KCNJ6. In the absence of any stressful stimuli, we suggest that these culture additives should be viewed as mDA phenotype-modifying, rather than neuroprotective. We also suggest that their addition to cultures is likely to confound the interpretation of both transplantation and disease modelling studies.

The Integrator complex desensitizes cellular response to TGF-β/BMP signaling

Maintenance of stem cells requires the concerted actions of niche-derived signals and stem cell-intrinsic factors. Although Decapentaplegic (Dpp), a Drosophila bone morphogenetic protein (BMP) molecule, can act as a long-range morphogen, its function is spatially limited to the germline stem cell niche in the germarium. We show here that Integrator, a complex known to be involved in RNA polymerase II (RNAPII)-mediated transcriptional regulation in the nucleus, promotes germline differentiation by restricting niche-derived Dpp/BMP activity in the cytoplasm. Further results show that Integrator works in various developmental contexts to desensitize the cellular response to Dpp/BMP signaling during Drosophila development. Mechanistically, our results show that Integrator forms a multi-subunit complex with the type I receptor Thickveins (Tkv) and other Dpp/BMP signaling components and acts in a negative feedback loop to promote Tkv turnover independent of its transcriptional activity. Similarly, human Integrator subunits bind transforming growth factor β (TGF-β)/BMP signaling components and antagonize their activity, suggesting a conserved role of Integrator across metazoans.

Pathogenicity of Plesiomonas shigelloides causing mass mortalities of largemouth bass (Micropterus salmoides) and its induced host immune response

The outbreak of mass mortality of M. salmoides occurred in an aquaculture farm in Jiangsu province of China, showing signs of skin ulceration and haemorrhages. The bacteria were isolated from diseased largemouth bass, and identified as Plesiomonas shigelloides based on morphological, physiological and biochemical features, as well as 16S rRNA gene sequence analysis. The pathogenicity of P. shigelloides was determined by challenge experiments, and the median lethal dosage (LD₅₀) of the isolate NJS1 for M. salmoides was calculated as 1.6 × 10⁵ CFU/mL at 7 d post-infection. Histopathological analysis revealed that extensive necrosis, vacuolization and inflammation were presented in the kidney, liver and gill of the diseased fish. Detection of virulence-related genes showed that P. shigelloides NJS1 was positive for astA, astB, astD, astE, actP and 6 ahpA. Additionally, the host defensive response of M. salmoides infected by P. shigelloides was analyzed by quantitive real-time PCR (qRT-PCR), and the results showed that the expression levels of Cas3, Hep1, HIF, IgM, IL15 and TGF were significantly up-regulated in head kidney, liver and spleen in different hours post-infection, which revealed varying expression profiles and clear transcriptional activation of immune related genes. The results suggested that P. shigelloides was an etiological element in the mass mortalities of M. salmoides and this study provided deeper insights for the pathogenesis and host defensive system in P. shigelloides invasion.

Protein tyrosine phosphatase PTPN2 regulates TGF-β signaling through Smad4 dephosphorylation

Transforming Growth Factor beta (TGF-β) is a multifunctional cytokine that regulates cell proliferation, differentiation, and apoptosis. Dysregulation of the TGF-β signaling is one of the major mechanisms underlying tumor progression. We have previously reported that anaplastic lymphoma kinase (ALK) phosphorylates Smad4 at Tyr95, which compromises the DNA-binding ability of Smad4 and thus renders ALK-positive cancer cells resistant to TGF-β tumor-suppressive action. In this study, we demonstrated that tyrosine phosphatase PTPN2 positively regulated TGF-β signaling through dephosphorylating Smad4 at the Tyr95 site. Both in vitro and cell-based assays revealed that PTPN2 bound to and dephosphorylated Smad4, thereby preserving the DNA-binding ability of Smad4. Furthermore, overexpression of PTPN2 restored TGF-β transcriptional and growth inhibitory responses in ALK-positive cancer cells. Consistently, Spermidine, an activator of PTPN2, also promoted TGF-β-induced gene expression, apoptosis, and anti-proliferation effect. Taken together, we revealed that PTPN2 functioned as a tumor suppressor to antagonize the inhibitory effect of tyrosine phosphorylation of Smad4 and to ensure the proper TGF-β growth inhibitory signaling in cancer cells.

The role of erythrocytes and erythroid progenitor cells in tumors

In the current research context of precision treatment of malignant tumors, the advantages of immunotherapy are unmatched by conventional antitumor therapy, which can prolong progression-free survival and overall survival. The search for new targets and novel combination therapies can improve the efficacy of immunotherapy and reduce adverse effects. Since current research targets for immunotherapy mainly focus on lymphocytes, little research has been done on erythrocytes. Nucleated erythroid precursor stem cells have been discovered to play an essential role in tumor progression. Researchers are exploring new targets and therapeutic approaches for immunotherapy from the perspective of erythroid progenitor cells (EPCs). Recent studies have shown that different subtypes of EPCs have specific surface markers and distinct biological roles in tumor immunity. CD45⁺ EPCs are potent myeloid-derived suppressor cell-like immunosuppressants that reduce the patient's antitumor immune response. CD45^- EPCs promote tumor invasion and metastasis by secreting artemin. A specific type of EPC also promotes angiogenesis and provides radiation protection. Therefore, EPCs may be involved in tumor growth, infiltration, and metastasis. It may also be an important cause of anti-angiogenesis and immunotherapy resistance. This review summarizes recent research advances in erythropoiesis, EPC features, and their impacts and processes on tumors.

SIN3-HDAC complex-associated factor, a chromatin remodelling gene located in the 12p amplicon, is a potential germ cell tumour-specific oncogene

A genetic hallmark of malignant germ cell tumours (GCTs) is isochromosome 12p, but oncogenes located in 12p that are specifically expressed in GCT have not yet been identified. SIN3-HDAC complex-associated factor (SINHCAF) is a subunit of the Sin3/histone deacetylase (HDAC) complex, and it defines a Sin3a-Hdac complex variant that is required for the self-renewal of mouse embryonic stem cells. This study demonstrated that SINHCAF is expressed in a vast majority of malignant GCTs and is rarely expressed in somatic malignancy. Fluorescence in situ hybridisation revealed SINHCAF amplification in malignant GCTs. SINHCAF silencing using shRNA reduced anchorage-dependent cell proliferation and tumoursphere formation and inhibited tumour cell migration and invasion in GCT cell lines. Moreover, in the GCT cell line NTERA2/D1, SINHCAF silencing inhibited the expression of genes associated with embryonic stem cells and induced the expression of genes associated with neuronal and white fat cell differentiation. Compared with somatic cell lines, GCT cell lines were more susceptible to HDAC inhibitor treatment. Thus, we identified SINHCAF to be a potential oncogene located in the amplicon of chromosome 12p and showed that SINHCAF was specifically expressed in malignant GCTs. HDAC inhibitor treatment may counteract the oncogenic activity of SINHCAF and is a promising therapeutic approach for GCTs. © 2022 The Pathological Society of Great Britain and Ireland.

The role of BMP4 in adipose-derived stem cell differentiation: A minireview

Bone morphogenetic protein 4 (BMP4) is a member of the transforming growth factor beta (TGF-β) superfamily of cytokines responsible for stem cells’ commitment to differentiation, proliferation, and maturation. To date, various studies have utilized BMP4 as a chemical inducer for in vitro differentiation of human mesenchymal stem cells (MSCs) based on its potential. BMP4 drives in vitro differentiation of ADSC via TGF-β signaling pathway by interactions with BMP receptors leading to the activation of smad-dependent and smad-independent pathways. The BMP4 signaling pathways are regulated by intracellular and extracellular BMP4 antagonists. Extracellular BMP4 antagonist prevents interaction between BMP4 ligand to its receptors, while intracellular BMP4 antagonist shutdowns the smad-dependent pathways through multiple mechanisms. BMP4 proved as one of the popular differentiation factors to induce ADSC differentiation into cell from mesodermal origin. However, addition of all-trans retinoic acid is also needed in trans-differentiation of ADSC into ectodermal lineage cells. Suggesting that both BMP4 and RA signaling pathways may be necessary to be activated for in vitro trans-differentiation of ADSC.

Recombinant production of growth factors for application in cell culture

Culturing eukaryotic cells has widespread applications in research and industry, including the emerging field of cell-cultured meat production colloquially referred to as “cellular agriculture”. These applications are often restricted by the high cost of growth medium necessary for cell growth. Mitogenic protein growth factors (GFs) are essential components of growth medium and account for upwards of 90% of the total costs. Here, we present a set of expression constructs and a simplified protocol for recombinant production of functionally active GFs, including FGF2, IGF1, PDGF-BB, and TGF-β1 in Escherichia coli. Using this E. coli expression system, we produced soluble GF orthologs from species including bovine, chicken, and salmon. Bioactivity analysis revealed orthologs with improved performance compared to commercially available alternatives. We estimated that the production cost of GFs using our methodology will significantly reduce the cost of cell culture medium, facilitating low-cost protocols tailored for cultured meat production and tissue engineering.

•

Developed methodology for low-cost production of soluble, bioactive GFs

•

Purified GFs were active on NIH-3T3 and bovine satellite cells

•

Some GF orthologs outperformed commercially sourced GFs

•

Production of GFs using these methods can foster significant cost savings

Specificity of TGF-β1 signal designated by LRRC33 and integrin αVβ8

Myeloid lineage cells present the latent form of transforming growth factor-β1 (L-TGF-β1) to the membrane using an anchor protein LRRC33. Integrin α_Vβ₈ activates extracellular L-TGF-β1 to trigger the downstream signaling functions. However, the mechanism designating the specificity of TGF-β1 presentation and activation remains incompletely understood. Here, we report cryo-EM structures of human L-TGF-β1/LRRC33 and integrin α_Vβ₈/L-TGF-β1 complexes. Combined with biochemical and cell-based analyses, we demonstrate that LRRC33 only presents L-TGF-β1 but not the -β2 or -β3 isoforms due to difference of key residues on the growth factor domains. Moreover, we reveal a 2:2 binding mode of integrin α_Vβ₈ and L-TGF-β1, which shows higher avidity and more efficient L-TGF-β1 activation than previously reported 1:2 binding mode. We also uncover that the disulfide-linked loop of the integrin subunit β₈ determines its exquisite affinity to L-TGF-β1. Together, our findings provide important insights into the specificity of TGF-β1 signaling achieved by LRRC33 and integrin α_Vβ₈.

Inhibition of Epithelial-Mesenchymal Transition Maintains Stemness in Human Amniotic Epithelial Cells

Human amniotic epithelial cells (hAECs), which are a type of placental stem cell, express stem cell marker genes and are capable of differentiating into all three germ layers under appropriate culture conditions. hAECs are known to undergo TGF-β-dependent epithelial-mesenchymal transition (EMT); however, the impact of EMT on the stemness or differentiation of hAECs has not yet been determined. Here, we first confirmed that hAECs undergo EMT immediately after starting primary culture. Comprehensive transcriptome analysis using RNA-seq revealed that inhibition of TGF-β-dependent EMT maintained the expression of stemness-related genes, including NANOG and POU5F1, in hAECs. Moreover, the maintenance of stemness did not affect the nontumorigenic characteristics of hAECs. We showed for the first time that TGF-β-dependent EMT negatively affected the stemness of hAECs, providing novel insight into cellular processes of placental stem cells.

TGF-β Superfamily Signaling in the Eye: Implications for Ocular Pathologies

The TGF-β signaling pathway plays a crucial role in several key aspects of development and tissue homeostasis. TGF-β ligands and their mediators have been shown to be important regulators of ocular physiology and their dysregulation has been described in several eye pathologies. TGF-β signaling participates in regulating several key developmental processes in the eye, including angiogenesis and neurogenesis. Inadequate TGF-β signaling has been associated with defective angiogenesis, vascular barrier function, unfavorable inflammatory responses, and tissue fibrosis. In addition, experimental models of corneal neovascularization, diabetic retinopathy, proliferative vitreoretinopathy, glaucoma, or corneal injury suggest that aberrant TGF-β signaling may contribute to the pathological features of these conditions, showing the potential of modulating TGF-β signaling to treat eye diseases. This review highlights the key roles of TGF-β family members in ocular physiology and in eye diseases, and reviews approaches targeting the TGF-β signaling as potential treatment options.

Pathobiology of the Klotho Antiaging Protein and Therapeutic Considerations

The α-Klotho protein (henceforth denoted Klotho) has antiaging properties, as first observed in mice homozygous for a hypomorphic Klotho gene (kl/kl). These mice have a shortened lifespan, stunted growth, renal disease, hyperphosphatemia, hypercalcemia, vascular calcification, cardiac hypertrophy, hypertension, pulmonary disease, cognitive impairment, multi-organ atrophy and fibrosis. Overexpression of Klotho has opposite effects, extending lifespan. In humans, Klotho levels decline with age, chronic kidney disease, diabetes, Alzheimer’s disease and other conditions. Low Klotho levels correlate with an increase in the death rate from all causes. Klotho acts either as an obligate coreceptor for fibroblast growth factor 23 (FGF23), or as a soluble pleiotropic endocrine hormone (s-Klotho). It is mainly produced in the kidneys, but also in the brain, pancreas and other tissues. On renal tubular-cell membranes, it associates with FGF receptors to bind FGF23. Produced in bones, FGF23 regulates renal excretion of phosphate (phosphaturic effect) and vitamin D metabolism. Lack of Klotho or FGF23 results in hyperphosphatemia and hypervitaminosis D. With age, human renal function often deteriorates, lowering Klotho levels. This appears to promote age-related pathology. Remarkably, Klotho inhibits four pathways that have been linked to aging in various ways: Transforming growth factor β (TGF-β), insulin-like growth factor 1 (IGF-1), Wnt and NF-κB. These can induce cellular senescence, apoptosis, inflammation, immune dysfunction, fibrosis and neoplasia. Furthermore, Klotho increases cell-protective antioxidant enzymes through Nrf2 and FoxO. In accord, preclinical Klotho therapy ameliorated renal, cardiovascular, diabetes-related and neurodegenerative diseases, as well as cancer. s-Klotho protein injection was effective, but requires further investigation. Several drugs enhance circulating Klotho levels, and some cross the blood-brain barrier to potentially act in the brain. In clinical trials, increased Klotho was noted with renin-angiotensin system inhibitors (losartan, valsartan), a statin (fluvastatin), mTOR inhibitors (rapamycin, everolimus), vitamin D and pentoxifylline. In preclinical work, antidiabetic drugs (metformin, GLP-1-based, GABA, PPAR-γ agonists) also enhanced Klotho. Several traditional medicines and/or nutraceuticals increased Klotho in rodents, including astaxanthin, curcumin, ginseng, ligustilide and resveratrol. Notably, exercise and sport activity increased Klotho. This review addresses molecular, physiological and therapeutic aspects of Klotho.

Glucocorticoid signaling and regulatory T cells cooperate to maintain the hair-follicle stem-cell niche

Maintenance of tissue homeostasis is dependent on the communication between stem cells and supporting cells in the same niche. Regulatory T cells (Treg cells) are emerging as a critical component of the stem-cell niche for supporting their differentiation. How Treg cells sense dynamic signals in this microenvironment and communicate with stem cells is mostly unknown. In the present study, by using hair follicles (HFs) to study Treg cell-stem cell crosstalk, we show an unrecognized function of the steroid hormone glucocorticoid in instructing skin-resident Treg cells to facilitate HF stem-cell (HFSC) activation and HF regeneration. Ablation of the glucocorticoid receptor (GR) in Treg cells blocks hair regeneration without affecting immune homeostasis. Mechanistically, GR and Foxp3 cooperate in Treg cells to induce transforming growth factor β3 (TGF-β3), which activates Smad2/3 in HFSCs and facilitates HFSC proliferation. The present study identifies crosstalk between Treg cells and HFSCs mediated by the GR-TGF-β3 axis, highlighting a possible means of manipulating Treg cells to support tissue regeneration.

The Role of Transforming Growth Factor Beta in Joint Homeostasis and Cartilage Regeneration

Transforming growth factor-beta (TGF-β) is an important regulator of joint homeostasis, of which dysregulation is closely associated with the development of osteoarthritis (OA). In normal conditions, its biological functions in a joint environment are joint protective, but it can be dramatically altered in different contexts, making its therapeutic application a challenge. However, with the deeper insights into the TGF-β functions, it has been proven that TGF-β augments cartilage regeneration by chondrocytes, and differentiates both the precursor cells of chondrocytes and stem cells into cartilage-generating chondrocytes. Following documentation of the therapeutic efficacy of chondrocytes augmented by TGF-β in the last decade, there is an ongoing phase III clinical trial examining the therapeutic efficacy of a mixture of allogeneic chondrocytes and TGF-β-overexpressing cells. To prepare cartilage-restoring chondrocytes from induced pluripotent stem cells (iPSCs), the stem cells are differentiated mainly using TGF-β with some other growth factors. Of note, clinical trials evaluating the therapeutic efficacy of iPSCs for OA are scheduled this year. Mesenchymal stromal stem cells (MSCs) have inherent limitations in that they differentiate into the osteochondral pathway, resulting in the production of poor-quality cartilage. Despite the established essential role of TGF-β in chondrogenic differentiation of MSCs, whether the coordinated use of TGF-β in MSC-based therapy for degenerated cartilage is effective is unknown. We herein reviewed the general characteristics and mechanism of action of TGF-β in a joint environment. Furthermore, we discussed the core interaction of TGF-β with principal cells of OA cell-based therapies, the chondrocytes, MSCs, and iPSCs. Impact Statement Transforming growth factor-beta (TGF-β) has been widely used as a core regulator to improve or formulate therapeutic regenerative cells for degenerative joints. It differentiates stem cells into chondrocytes and improves the chondrogenic potential of differentiated chondrocytes. Herein, we discussed the overall characteristics of TGF-β and reviewed the comprehension and utilization of TGF-β in cell-based therapy for degenerative joint disease.

MASTL is enriched in cancerous and pluripotent stem cells and influences OCT1/OCT4 levels

MASTL is a mitotic accelerator with an emerging role in breast cancer progression. However, the mechanisms behind its oncogenicity remain largely unknown. Here, we identify a previously unknown role and eminent expression of MASTL in stem cells. MASTL staining from a large breast cancer patient cohort indicated a significant association with β3 integrin, an established mediator of breast cancer stemness. MASTL silencing reduced OCT4 levels in human pluripotent stem cells and OCT1 in breast cancer cells. Analysis of the cell-surface proteome indicated a strong link between MASTL and the regulation of TGF-β receptor II (TGFBR2), a key modulator of TGF-β signaling. Overexpression of wild-type and kinase-dead MASTL in normal mammary epithelial cells elevated TGFBR2 levels. Conversely, MASTL depletion in breast cancer cells attenuated TGFBR2 levels and downstream signaling through SMAD3 and AKT pathways. Taken together, these results indicate that MASTL supports stemness regulators in pluripotent and cancerous stem cells.

Regulation of homeostasis and regeneration in the adult intestinal epithelium by the TGF-β superfamily

The delicate balance between the homeostatic maintenance and regenerative capacity of the intestine makes this a fascinating tissue of study. The intestinal epithelium undergoes continuous homeostatic renewal but is also exposed to a diverse array of stresses that can range from physiological processes such as digestion, to exposure to infectious agents, drugs, radiation therapy, and inflammatory stimuli. The intestinal epithelium has thus evolved to efficiently maintain and reinstate proper barrier function that is essential for intestinal integrity and function. Factors governing homeostatic epithelial turnover are well described, however, the dynamic regenerative mechanisms that occur following injury are the subject of intense ongoing investigations. The TGF-β superfamily is a key regulator of both homeostatic renewal and regenerative processes of the intestine. Here we review the roles of TGF-β and BMP on the adult intestinal epithelium during self-renewal and injury to provide a framework for understanding how this major family of morphogens can tip the scale between intestinal health and disease. This article is protected by copyright. All rights reserved.

TGFβ selects for pro-stemness over pro-invasive phenotypes during cancer cell epithelial-mesenchymal transition

Transforming growth factor β (TGFβ) induces epithelial-mesenchymal transition (EMT), which correlates with stemness and invasiveness. Mesenchymal-epithelial transition (MET) is induced by TGFβ withdrawal and correlates with metastatic colonization. Whether TGFβ promotes stemness and invasiveness simultaneously via EMT remains unclear. We established a breast cancer cell model expressing red fluorescent protein (RFP) under the E-cadherin promoter. In 2D cultures, TGFβ induced EMT, generating RFP^low cells with a mesenchymal transcriptome, and regained RFP, with an epithelial transcriptome, after MET induced by TGFβ withdrawal. RFP^low cells generated robust mammospheres, with epithelio-mesenchymal cell surface features. Mammospheres that were forced to adhere generated migratory cells, devoid of RFP, a phenotype which was inhibited by a TGFβ receptor kinase inhibitor. Further stimulation of RFP^low mammospheres with TGFβ suppressed the generation of motile cells, but enhanced mammosphere growth. Accordingly, mammary fat-pad-transplanted mammospheres, in the absence of exogenous TGFβ treatment, established lung metastases with evident MET (RFP^high cells). In contrast, TGFβ-treated mammospheres revealed high tumor-initiating capacity, but limited metastatic potential. Thus, the biological context of partial EMT and MET allows TGFβ to differentiate between pro-stemness and pro-invasive phenotypes.

Transcriptional profiling of β-2M-SPα-6+THY1+ spermatogonial stem cells in human spermatogenesis

Male infertility is responsible for approximately half of all cases of reproductive issues. Spermatogenesis originates in a small pool of spermatogonial stem cells (SSCs), which are of interest for therapy of infertility but remain not well defined in humans. Using multiparametric analysis of the side population (SP) phenotype and the α-6 integrin, THY1, and β-2 microglobulin cell markers, we identified a population of human primitive undifferentiated spermatogonia with the phenotype β-2 microglobulin (β-2M)⁻SPα-6⁺THY1⁺, which is highly enriched in stem cells. By analyzing the expression signatures of this SSC-enriched population along with other germinal progenitors, we established an exhaustive transcriptome of human spermatogenesis. Transcriptome profiling of the human β-2M⁻SPα-6⁺THY1⁺ population and comparison with the profile of mouse undifferentiated spermatogonia provide insights into the molecular networks and key transcriptional regulators regulating human SSCs, including the basic-helix-loop-helix (bHLH) transcriptional repressor HES1, which we show to be implicated in maintenance of SSCs in vitro.

•

Human β-2M⁻SPα-6⁺THY1⁺ undifferentiated spermatogonia are enriched in stem cells

•

Comparative transcriptomics analysis of human and murine spermatogonia

•

HES1 is involved in the physiology of SSCs in vitro

Measurement of activity of developmental signal transduction pathways to quantify stem cell pluripotency and phenotypically characterize differentiated cells

Important challenges in stem cell research and regenerative medicine are reliable assessment of pluripotency state and purity of differentiated cell populations. Pluripotency and differentiation are regulated and determined by activity of developmental signal transduction pathways (STPs). To date activity of these STPs could not be directly measured on a cell sample. Here we validate a novel assay platform for measurement of activity of developmental STPs (STP) for use in stem cells and stem cell derivatives. In addition to previously developed STP assays, we report development of an additional STP assay for the MAPK-AP1 pathway. Subsequently, activity of Notch, Hedgehog, TGFβ, Wnt, PI3K, MAPK-AP1, and NFκB signaling pathways was calculated from Affymetrix transcriptome data of human pluripotent embryonic (hES) and iPS cell lines under different culture conditions, organ-derived multipotent stem cells, and differentiated cell types, to generate quantitative STP activity profiles. Results show that the STP assay technology enables reliable and quantitative measurement of multiple STP activities simultaneously on any individual cell sample. Using the technology, we found that culture conditions dominantly influence the pluripotent stem cell STP activity profile, while the origin of the stem cell line was a minor variable. A pluripotency STP activity profile (Pluripotency qPAP) was defined (active PI3K, MAPK, Hedgehog, Notch, TGFβ, and NFκB pathway, inactive Wnt pathway). Differentiation of hES cells to intestinal progenitor cells resulted in an STP activity profile characterized by active PI3K, Wnt and Notch pathways, comparable to the STP activity profile measured on primary intestinal crypt stem cells. Quantitative STP activity measurement is expected to improve experimental reproducibility and standardization of pluripotent and multipotent stem cell culture/differentiation, and enable controlled manipulation of pluripotency/differentiation state using pathway targeting compounds.

Principles for the design of multicellular engineered living systems

Remarkable progress in bioengineering over the past two decades has enabled the formulation of fundamental design principles for a variety of medical and non-medical applications. These advancements have laid the foundation for building multicellular engineered living systems (M-CELS) from biological parts, forming functional modules integrated into living machines. These cognizant design principles for living systems encompass novel genetic circuit manipulation, self-assembly, cell-cell/matrix communication, and artificial tissues/organs enabled through systems biology, bioinformatics, computational biology, genetic engineering, and microfluidics. Here, we introduce design principles and a blueprint for forward production of robust and standardized M-CELS, which may undergo variable reiterations through the classic design-build-test-debug cycle. This Review provides practical and theoretical frameworks to forward-design, control, and optimize novel M-CELS. Potential applications include biopharmaceuticals, bioreactor factories, biofuels, environmental bioremediation, cellular computing, biohybrid digital technology, and experimental investigations into mechanisms of multicellular organisms normally hidden inside the "black box" of living cells.

Assessment of Mineralization, Oxidative Stress, and Inflammation Mechanisms in the Pulp of Primary Teeth

Inflammation in primary teeth (PT) is commonly associated with a lower sensibility to painful stimuli, compared to permanent teeth, and usually leads to late presentation for dental treatment. Data obtained on the molecular assessments of dental pulp and clinical examinations could guide practitioners to conduct precise diagnoses and correct treatments. The aim of our pilot study was to assess the levels of several biomarkers (e.g., mineralization, oxidative stress, and inflammation) in primary teeth. The research included 46 dental pulp specimens collected from the primary teeth of children and adolescents between the ages of 6 and 12. The experimental groups consisted of 18 samples collected from primary teeth with acute pulpitis and 15 samples from chronically inflamed pulp tissues. The control group was represented by 13 specimens acquired from clinically healthy primary teeth. The enzyme-linked immunosorbent assay (ELISA) technique was used to determine the protein expression of tumor necrosis factor-α (TNF-α), superoxide dismutase-3 (SOD-3), osteocalcin, and transforming growth factor-β1 (TGF-β1) in the lysates. Our results revealed that all of the studied parameters presented statistically significant (p ≤ 0.05) increased levels in both experimental groups compared to the control samples. Furthermore, osteocalcin presented statistically significant increased concentrations in chronically- versus acute-inflamed pulp samples (p ≤ 0.05). The studied molecules may have an influential role in acute and chronic pulp inflammation in primary teeth.

Connexin 43 Gene Ablation Does Not Alter Human Pluripotent Stem Cell Germ Lineage Specification

During embryonic germ layer development, cells communicate with each other and their environment to ensure proper lineage specification and tissue development. Connexin (Cx) proteins facilitate direct cell–cell communication through gap junction channels. While previous reports suggest that gap junctional intercellular communication may contribute to germ layer formation, there have been limited comprehensive expression analyses or genetic ablation studies on Cxs during human pluripotent stem cell (PSC) germ lineage specification. We screened the mRNA profile and protein expression patterns of select human Cx isoforms in undifferentiated human induced pluripotent stem cells (iPSCs), and after directed differentiation into the three embryonic germ lineages: ectoderm, definitive endoderm, and mesoderm. Transcript analyses by qPCR revealed upregulation of Cx45 and Cx62 in iPSC-derived ectoderm; Cx45 in mesoderm; and Cx30.3, Cx31, Cx32, Cx36, Cx37, and Cx40 in endoderm relative to control human iPSCs. Generated Cx43 (GJA1) CRISPR-Cas9 knockout iPSCs successfully differentiated into cells of all three germ layers, suggesting that Cx43 is dispensable during directed iPSC lineage specification. Furthermore, qPCR screening of select Cx transcripts in our GJA1-/- iPSCs showed no significant Cx upregulation in response to the loss of Cx43 protein. Future studies will reveal possible compensation by additional Cxs, suggesting targets for future CRISPR-Cas9 ablation studies in human iPSC lineage specification.

The DGCR8 E518K mutation found in Wilms tumors leads to a partial miRNA processing defect that alters gene expression patterns and biological processes

Wilms tumor (WT) is the most common renal tumor in childhood. We and others have previously identified oncogenic driver mutations affecting the microprocessor genes DROSHA and DGCR8 that lead to altered miRNA expression patterns. In the case of DGCR8, a single recurrent hotspot mutation (E518K) was found in the RNA binding domain. To functionally assess this mutation in vitro, we generated mouse Dgcr8-KO embryonic stem cell (mESC) lines with an inducible expression of wild-type or mutant DGCR8, mirroring the hemizygous mutant expression seen in WT. RNA-seq analysis revealed significant differences of miRNA expression profiles in DGCR8-E518K compared to DGCR8-wild-type mESCs. The E518K mutation only led to a partial rescue of the reported miRNA processing defect in Dgcr8-KO, with selectively reduced expression of numerous canonical miRNAs. Nevertheless, DGCR8-E518K retained significant activity given its ability to still process many miRNAs. Subsequent to altered miRNA levels, the expression of mRNA targets was likewise changed. Functional assays showed that DGCR8-E518K cells still have a partial proliferation and differentiation defect but were able to rescue critical biological processes in embryoid body development. The stem cell program could be shut down and all three germ layers were formed. These findings suggest that the E518K mutation leads to a partial reduction of microprocessor activity and altered specificity with selective impairment only in certain developmental contexts, apparently including nephrogenesis.

Advances in Immunotherapy and the TGF-β Resistance Pathway in Metastatic Bladder Cancer

Simple Summary

Bladder cancer accounts for a significant burden to global public health. Despite advances in therapeutics with the advent of immunotherapy, only a small subset of patients benefit from immunotherapy. In this review, we examine the evidence that suggests that the TGF-β pathway may present a resistance mechanism to immunotherapy. In addition, we present possible therapies that may overcome the TGF-β resistance pathway in the treatment of bladder cancer.

Abstract

Bladder cancer accounts for nearly 200,000 deaths worldwide yearly. Urothelial carcinoma (UC) accounts for nearly 90% of cases of bladder cancer. Cisplatin-based chemotherapy has remained the mainstay of treatment in the first-line setting for locally advanced or metastatic UC. More recently, the treatment paradigm in the second-line setting was drastically altered with the approval of several immune checkpoint inhibitors (ICIs). Given that only a small subset of patients respond to ICI, further studies have been undertaken to understand potential resistance mechanisms to ICI. One potential resistance mechanism that has been identified in the setting of metastatic UC is the TGF-β signaling pathway. Several pre-clinical and ongoing clinical trials in multiple advanced tumor types have evaluated several therapies that target the TGF-β pathway. In addition, there are ongoing and planned clinical trials combining TGF-β inhibition with ICI, which may provide a promising therapeutic approach for patients with advanced and metastatic UC.

Neural is Fundamental: Neural Stemness as the Ground State of Cell Tumorigenicity and Differentiation Potential

Tumorigenic cells are similar to neural stem cells or embryonic neural cells in regulatory networks, tumorigenicity and pluripotent differentiation potential. By integrating the evidence from developmental biology, tumor biology and evolution, I will make a detailed discussion on the observations and propose that neural stemness underlies two coupled cell properties, tumorigenicity and pluripotent differentiation potential. Neural stemness property of tumorigenic cells can hopefully integrate different observations/concepts underlying tumorigenesis. Neural stem cells and tumorigenic cells share regulatory networks; both exhibit neural stemness, tumorigenicity and pluripotent differentiation potential; both depend on expression or activation of ancestral genes; both rely primarily on aerobic glycolytic metabolism; both can differentiate into various cells/tissues that are derived from three germ layers, leading to tumor formation resembling severely disorganized or more degenerated process of embryonic tissue differentiation; both are enriched in long genes with more splice variants that provide more plastic scaffolds for cell differentiation, etc. Neural regulatory networks, which include higher levels of basic machineries of cell physiological functions and developmental programs, work concertedly to define a basic state with fast cell cycle and proliferation. This is predestined by the evolutionary advantage of neural state, the ground or initial state for multicellularity with adaptation to an ancient environment. Tumorigenesis might represent a process of restoration of neural ground state, thereby restoring a state with fast proliferation and pluripotent differentiation potential in somatic cells. Tumorigenesis and pluripotent differentiation potential might be better understood from understanding neural stemness, and cancer therapy should benefit more from targeting neural stemness.

Identification, Molecular Characterization, and Tissue Expression Profiles of Three Smad Genes from Water Buffalo (Bubalus bubalis)

Smads are involved in a variety of biological activities by mediating bone morphogenetic protein (BMP) signals. The full-length coding sequences (CDSs) of buffalo Smads 1, 4, and 5 were isolated and identified through RT-PCR in this study. Their lengths are 1398 bp, 1662 bp, and 1398 bp, respectively. In silico analysis showed that their transcriptional region structures, as well as their amino acid sequences, physicochemical characteristics, motifs, conserved domains, and three-dimensional structures of their encoded proteins are highly consistent with their counterparts in the species of Bovidae. The three Smad proteins are all hydrophilic without the signal peptides and transmembrane regions. Each of them has an MH1 domain and an MH2 domain. A nuclear localization sequence was found in the MH1 domain of buffalo Smads 1 and 5. Prediction showed that the function of the three Smads is mainly protein binding, and they can interact with BMPs and their receptors. The three genes were expressed in all 10 buffalo tissues assayed, and their expression in the mammary gland, gonad, and spleen was relatively high. The results here indicate that the three buffalo Smads may be involved in the transcriptional regulation of genes in a variety of tissues.

Pluripotent-derived Mesenchymal Stem/stromal Cells: an Overview of the Derivation Protocol Efficacies and the Differences Among the Derived Cells

Mesenchymal stem/stromal cells (MSCs) are remarkable tools for regenerative medicine. Therapeutic approaches using these cells can promote increased activity and viability in several cell types through diverse mechanisms such as paracrine and immunomodulatory activities, contributing substantially to tissue regeneration and functional recovery. However, biological samples of human MSCs, usually obtained from adult tissues, often exhibit variable behavior during in vitro culture, especially with respect to cell population heterogeneity, replicative senescence, and consequent loss of functionality. Accordingly, it is necessary to establish standard protocols to generate high-quality, stable cell cultures, for example, by using pluripotent stem cells (PSCs) in derivation protocols of MSC-like cells since PSCs maintain their characteristics consistently during culture. However, the available protocols seem to generate distinct populations of PSC-derivedMSCs (PSC-MSCs) with peculiar attributes, which do not always resemble bona fide primary MSCs. The present review addresses the developmental basis behind some of these derivation protocols, exposing the differences among them and discussing the functional properties of PSC-MSCs, shedding light on elements that may help determine standard characterizations and criteria to evaluate and define these cells.

High-throughput screening on cochlear organoids identifies VEGFR-MEK-TGFB1 signaling promoting hair cell reprogramming

Hair cell degeneration is a major cause of sensorineural hearing loss. Hair cells in mammalian cochlea do not spontaneously regenerate, posing a great challenge for restoration of hearing. Here, we establish a robust, high-throughput cochlear organoid platform that facilitates 3D expansion of cochlear progenitor cells and differentiation of hair cells in a temporally regulated manner. High-throughput screening of the FDA-approved drug library identified regorafenib, a VEGFR inhibitor, as a potent small molecule for hair cell differentiation. Regorafenib also promotes reprogramming and maturation of hair cells in both normal and neomycin-damaged cochlear explants. Mechanistically, inhibition of VEGFR suppresses TGFB1 expression via the MEK pathway and TGFB1 downregulation directly mediates the effect of regorafenib on hair cell reprogramming. Our study not only demonstrates the power of a cochlear organoid platform in high-throughput analyses of hair cell physiology but also highlights VEGFR-MEK-TGFB1 signaling crosstalk as a potential target for hair cell regeneration and hearing restoration.

•

Cochlear organoids can be derived from both LGR5+ and LGR5– supporting cells

•

HTS using cochlear organoids identifies regorafenib for hair cell differentiation

•

Regorafenib promotes hair cell reprogramming and maturation in cochlear explants

•

Regorafenib acts via a NOTCH-independent and VEGFR-MEK-TGFB1-dependent mechanism

Taking the road less traveled - the therapeutic potential of CBP/β-catenin antagonists

AREAS COVERED

This perspective discusses the challenges of targeting the Wnt signaling cascade, the safety, efficacy, and therapeutic potential of specific CBP/β-catenin antagonists and a rationale for the pleiotropic effects of CBP/β-catenin antagonists beyond Wnt signaling.

EXPERT OPINION

CBP/β-catenin antagonists can correct lineage infidelity, enhance wound healing, both normal and aberrant (e.g. fibrosis) and force the differentiation and lineage commitment of stem cells and cancer stem cells by regulating enhancer and super-enhancer coactivator occupancy. Small molecule CBP/β-catenin antagonists rebalance the equilibrium between CBP/β-catenin versus p300/β-catenin dependent transcription and may be able to treat or prevent many diseases of aging, via maintenance of our somatic stem cell pool, and regulating mitochondrial function and metabolism involved in differentiation and immune cell function.

Fibroblastic galectin-1-fostered invasion and metastasis are mediated by TGF-β1-induced epithelial-mesenchymal transition in gastric cancer

Background The gastric cancer (GC) microenvironment has important effects on biological behaviors, such as tumor cell invasion and metastasis. However, the mechanism by which the GC microenvironment promotes GC cell invasion and metastasis is unknown. The present study aimed to clarify the effects and mechanism of galectin-1 (GAL-1, encoded by LGALS1) on GC invasion and metastasis in the GC microenvironment. Methods The expression of GAL-1/ LGALS1 was determined using western blotting, immunohistochemistry, and quantitative real-time reverse transcription PCR in GC tissues. Besides, methods including stable transfection, Matrigel invasion and migration assays, and wound-healing assays in vitro; and metastasis assays in vivo, were also conducted. Results GAL-1 from cancer-associated fibroblasts (CAFs) induced the epithelial-mesenchymal transition (EMT) of GC cells though the transforming growth factor beta (TGF-β1)/ Sma- and mad-related protein (Smad) pathway, and affected the prognosis of patients with GC. The level of GAL-1 was high in CAFs, and treating MGC-803 and SGC -7901 cell line with the conditioned medium from CAFs promoted their invasion and metastasis abilities. Overexpression of LGALS1 promoted the expression of TGF-β1 and induced EMT of GC cell lines. A TGF-β1 antagonist inhibited the invasion and migration of GC cells. In vivo, overexpression of LGALS1 promoted GC growth and metastasis, and the TGF-β1 antagonist dramatically reversed these events. Conclusions These findings suggested that high expression of GAL-1 in the GC microenvironment predicts a poor prognosis in patients with GC by promoting the migration and invasion of GC cells via EMT through the TGF-β1/Smad signaling pathway. The results might provide new therapeutic targets to treat GC.

Transforming Growth Factor-β Signaling Regulates Tooth Root Dentinogenesis by Cooperation With Wnt Signaling

Proper differentiation of odontoblasts is crucial for the development of tooth roots. Previous studies have reported the osteogenic/odontogenic potential of pre-odontoblasts during root odontoblast differentiation. However, the underlying molecular pathway that orchestrates these processes remains largely unclear. In this study, ablation of transforming growth factor-β receptor type 2 (Tgfbr2) in root pre-odontoblasts resulted in abnormal formation of root osteodentin, which was associated with ectopic osteogenic differentiation of root odontoblasts. Disrupting TGF-β signaling caused upregulation of Wnt signaling characterized by increased Wnt6, Wnt10a, Tcf-1, and Axin2 expression. Interestingly, inhibiting Wnt signaling by deleting Wntless (wls) in Osteocalcin (Ocn)-Cre; Tgfbr2 ^fl/fl ; Wls ^fl/fl mice or overexpressing the Wnt antagonist Dkk1 in Ocn-Cre; Tgfbr2 ^fl/fl ; ROSA26 ^Dkk1 mice decreased ectopic osteogenic differentiation and arrested odontoblast differentiation. Our results suggest that TGF-β signaling acts with Wnt signaling to regulate root odontogenic differentiation.

Prediction and Boolean logical modelling of synergistic microRNA regulatory networks during reprogramming of male germline pluripotent stem cells

Unipotent male germline stem (GS) cells can undergo spontaneous reprogramming to germline pluripotent stem (GPS) cells during in vitro culture. In our previous study, we proposed a Boolean logical model of gene regulatory network (GRN) during reprogramming of GS cells to GPS cells. This study was designed to predict and model synergistic microRNA (miRNA) regulatory network during reprogramming of GS cells into GPS cells. The miRNAs targeting differentially expressed genes (DEGs) among GS and GPS cells were predicted by a novel Gene Ontology (GO) enrichment analysis to construct miRNA synergistic networks (MSN) and identify regulatory miRNA modules. Qualitative Boolean logical model of synergistic miRNAs and its regulated genes was then constructed by considering discrete, asynchronous, multivalued logical formalism using the GINsim modeling and simulation tools. Topology, functional and community overlap studies revealed that mmu-miR-200b-3p, mmu-miR-429-3p and mmu-miR-141-3p, mmu-miR-200a-3p and mmu-miR-200c-3p in MSN belongs to the family of miR-200/429/141 and conjectured to control the pluripotency and reprogramming by promoting Mesenchymal to Epithelial Transition (MET). Synergistic network involving mmu-miR-20b-5p, mmu-miR-20a-5p, mmu-miR-106a-5p, mmu-miR-106b-5p, and mmu-miR-17-5p were found to be essential for the maintenance of GS cells. Logical miRNA regulatory network modelling showed that synergistic miRNAs regulates the gene dynamics of MET during GS-GPS reprogramming, as confirmed by perturbation analysis. Taken together, our study predicted novel synergistic miRNAs involved in the regulation of reprogramming and pluripotency in GPS cells. The Boolean logical model of synergistic miRNAs regulatory network further confirms our previous study that gene dynamics of MET regulates GS-GPS reprogramming.

Development of luspatercept to treat ineffective erythropoiesis

Luspatercept (Reblozyl) was recently approved for treating patients with transfusion-dependent lower-risk myelodysplastic syndrome (MDS) with ring sideroblasts (RS) and/or SF3B1 mutation who were not eligible for erythropoiesis-stimulating agents (ESAs) or patients for whom those agents failed. Luspatercept acts as an activin receptor type IIB fusion protein ligand trap that targets the altered transforming growth factor beta pathway in MDS, which is associated with impaired terminal erythroid maturation. Treatment with luspatercept results in decreased SMAD signaling, which enables erythroid maturation by means of late-stage erythroblast differentiation and thus improves anemia. ESAs, the current standard first-line therapeutic option for anemic lower-risk patients with MDS, also improve red cell parameters mainly by expanding proliferation of early erythroid progenitor cells. However, erythropoietin (EPO) and its receptor (EPO-R) are also required for survival of late-stage definitive erythroid cells, and they play an essential role in promoting proliferation, survival, and appropriate timing of terminal maturation of primitive erythroid precursors. Thus, luspatercept joins the mechanism of ESAs in promoting erythroid maturation. Especially in the subgroup of MDS patients with RS, luspatercept showed high clinical activity for the treatment of anemia in the phase 2 (PACE-MDS) trial and subsequently in the phase 3 (MEDALIST) trial, which resulted in approval by both the US Food and Drug Administration and the European Medicines Agency in April 2020. Additional studies are needed to better understand the mechanism of action and pharmacodynamics of this novel agent in MDS.

Low complexity domains, condensates, and stem cell pluripotency

Biological reactions require self-assembly of factors in the complex cellular milieu. Recent evidence indicates that intrinsically disordered, low-complexity sequence domains (LCDs) found in regulatory factors mediate diverse cellular processes from gene expression to DNA repair to signal transduction, by enriching specific biomolecules in membraneless compartments or hubs that may undergo liquid-liquid phase separation (LLPS). In this review, we discuss how embryonic stem cells take advantage of LCD-driven interactions to promote cell-specific transcription, DNA damage response, and DNA repair. We propose that LCD-mediated interactions play key roles in stem cell maintenance and safeguarding genome integrity.

Reprogramming oral epithelial keratinocytes into a pluripotent phenotype for tissue regeneration

Objectives

We set out to reprogram adult somatic oral epithelial keratinocytes into pluripotent cells for regenerative dentistry.

Setting and Sample population

Immortalized murine oral keratinocyte cell (IMOK) line raised from adult mouse mucosa were cultured in vitro in our studies.

Materials and Methods

Adult murine oral epithelial keratinocytes were chronically treated with TGF‐β1 in vitro, and the expression of Oct4, Nanog, Sox2 and Nestin, as well as specific homeobox Gata and Pax gene family members were investigated.

Results

We documented the induction of stem factors linked with pluripotency and/or the maintenance and regulation of stem‐cell self‐renewal in oral epithelial keratinocytes by TGFβ1. Moreover, we discovered that this TGF‐β1‐induced increase in Oct4, Nanog, Sox2 and Nestin was inhibited by SB431542, suggesting that TGF‐β1 signals via the TGF‐βRI receptor to induce pluripotency and stemness.

Conclusions

Adult oral epithelial keratinocytes treated chronically with TGF‐β1 acquired phenotypic characteristics consistent with pluripotent stem cells, highlighting the facileness of reprogramming adult oral keratinocytes into an unlimited supply of pluripotent stem cells.