HOX genes in stem cells: Maintaining cellular identity and regulation of differentiation

Recent advances of physiochemical cues on surfaces for directing cell fates

Surface modification plays an essential role in dictating cell behavior and fate, as it creates a microenvironment that profoundly influences cell attachment, migration, proliferation, and differentiation. This review aims to the intricate interplay of culture surface properties, including topography, stiffness, charge, and chemical modifications, demonstrating their profound impact on cell destiny. We explore the nuanced responses of cells to varying surface topographies, from nano- to microscale features, elucidating the influence of geometric patterns and roughness. We also investigate the impact of substrate stiffness, highlighting the way cells perceive and respond to mechanical cues mimicking their native environments. The role of surface charge is examined, revealing how electrostatic interactions influence cell adhesion, signaling, and cell fate decisions. Finally, we delve into the diverse effects of chemical modifications, including the presentation of bioactive molecules, growth factors, and extracellular matrix (ECM) components, demonstrating their ability to guide cell behavior and stimulate specific cellular responses. This review offers comprehensive insights into the important role of surface properties in shaping cell fate, offering promising avenues for developing sophisticated cell culture platforms for applications in drug discovery, regenerative medicine, and fundamental research.

Parallel and convergent dynamics in the evolution of primary breast and lung adenocarcinomas

Cancer development requires an evolutionary transformation from mammalian cells fully regulated by and integrated into multicellular tissue to cancer cells  that, as single cell protists, are individually subject to Darwinian selection. Through genetic and epigenetic mechanisms of inheritance, the evolving cancer phenotype must acquire independence from host controls, downregulate differentiated functions that benefit the host but not individual cells, and generate phenotypic traits that increase fitness in the context of the selection forces within the local microenvironment. Here, we investigate this  evolutionary transition in breast (BRCA) and lung (LUAD, without EGFR, KRAS or BRAF driver mutations) adenocarcinomas using bulk mutation and expression data from the TCGA database. We define evolution selection for genes and molecular pathways based on 1) changes in gene expression compared to normal tissue, and 2) significantly larger or smaller observed mutation rates compared to those expected based on the gene size. We find BRCA and LUAD disable different genes and gene pathways associated with tissue-specific signaling and differentiated functions but promote common molecular pathways associated with cell cycle, cell-cell interactions, cytoskeleton, voltage gated ion channels, and microenvironmental niche construction. Thus, tissue-specific parallel evolution in early cancer development is followed by convergence to a common cancer phenotype.

Enhance the therapeutic efficacy of human umbilical cord-derived mesenchymal stem cells in prevention of acute graft-versus-host disease through CRISPLD2 modulation

BACKGROUND

Acute graft-versus-host disease (aGVHD) remains a major life-threatening complication of allogeneic haematopoietic cell transplantation (allo-HSCT), often limiting the therapeutic efficacy of allo-HSCT. Recent studies have suggested that mesenchymal stem cells (MSCs) may be beneficial for the treatment of aGVHD. However, the therapeutic potential of MSCs is often negatively impacted by their heterogeneity.

METHODS

To investigate MSCs heterogeneity, we conducted single-cell transcriptomic analysis of human umbilical cord-derived MSCs (HUC-MSCs) and identified key feature genes that distinguish MSCs subpopulations. The function of the newly discovered biomarker CRISPLD2 was also explored. We engineered human umbilical cord-derived MSCs (HUC-MSCs) to overexpress the CRISPLD2 gene using lentiviral vectors. The downstream regulatory effects of CRISPLD2 overexpression were assessed through bulk RNA sequencing. Additionally, we evaluated its impact on cellular senescence using Western blotting and β-galactosidase (SA-β-gal) staining. The immunoregulatory capability of HUC-MSCs was tested through coculture experiments with T cells and liver organoids in vitro. Mitochondrial function was analysed via flow cytometry and electron microscopy. The in vivo therapeutic effects of HUC-MSCs on aGVHD were evaluated using an aGVHD murine model. The graft-versus-leukaemia (GVL) effect was measured via the inoculation of luciferase-positive A20 cells, and tumour growth was monitored via bioluminescence imaging.

RESULTS

Our findings indicated that the CRISPLD2 gene is heterogeneously expressed in HUC-MSCs subsets characterized by stemness and immunosuppressive properties. Transcriptomic analysis revealed that CRISPLD2 overexpression suppressed calcium ion binding and G protein-coupled receptor signalling. In vitro studies demonstrated a marked increase in IL-10 secretion, which enhanced T-cell suppression in CRISPLD2-modified HUC-MSCs. The in vivo results demonstrated that transfusion of CRISPLD2-overexpressing HUC-MSCs ameliorated aGVHD while maintaining GVL activity. Mechanistically, CRISPLD2 overexpression overcomes the mitochondrial damage mediated by extracellular ATP and LPS in HUC-MSCs by inhibiting P2Y11 receptor signalling, thereby preserving their stemness and IL-10-mediated immunosuppressive functions.

CONCLUSIONS

Our study revealed that CRISPLD2 is a novel marker for identifying HUC-MSCs subpopulation with enhanced immunosuppressive functions. CRISPLD2 overexpression enhances the immunosuppressive function of HUC-MSCs by inhibiting P2Y11 receptor signalling. Targeting CRISPLD2 is a promising strategy to improve the therapeutic efficacy of HUC-MSCs in aGVHD while maintaining GVL activity.

DNA-guided transcription factor interactions extend human gene regulatory code

In the same way that the mRNA-binding specificities of transfer RNAs define the genetic code, the DNA-binding specificities of transcription factors (TFs) form the molecular basis of the gene regulatory code1,2. The human gene regulatory code is much more complex than the genetic code, in particular because there are more than 1,600 TFs that commonly interact with each other. TF-TF interactions are required for specifying cell fate and executing cell-type-specific transcriptional programs. Despite this, the landscape of interactions between DNA-bound TFs is poorly defined. Here we map the biochemical interactions between DNA-bound TFs using CAP-SELEX, a method that can simultaneously identify individual TF binding preferences, TF-TF interactions and the DNA sequences that are bound by the interacting complexes. A screen of more than 58,000 TF-TF pairs identified 2,198 interacting TF pairs, 1,329 of which preferentially bound to their motifs arranged in a distinct spacing and/or orientation. We also discovered 1,131 TF-TF composite motifs that were markedly different from the motifs of the individual TFs. In total, we estimate that the screen identified between 18% and 47% of all human TF-TF motifs. The novel composite motifs we found were enriched in cell-type-specific elements, active in vivo and more likely to be formed between developmentally co-expressed TFs. Furthermore, TFs that define embryonic axes commonly interacted with different TFs and bound to distinct motifs, explaining how TFs with a similar specificity can define distinct cell types along developmental axes.

The HOX Gene Family's Role as Prognostic and Diagnostic Biomarkers in Hematological and Solid Tumors

The HOX gene family encodes for regulatory transcription factors that play a crucial role in embryogenesis and differentiation of adult cells. This highly conserved family of genes consists of thirty-nine genes in humans that are located in four clusters, A-D, on different chromosomes. While early studies on the HOX gene family have been focused on embryonic development and its related disorders, research has shifted to examine aberrant expression of HOX genes and the subsequent implication in cancer prediction and progression. Due to their role of encoding master regulatory transcription factors, the abnormal expression of HOX genes has been shown to affect all stages of tumorigenesis and metastasis. This review highlights the novel role of the HOX family's clinical relevance as both prognostic and diagnostic biomarkers in hematological and solid tumors.

Innovative Approaches in Knee Osteoarthritis Treatment: A Comprehensive Review of Bone Marrow-Derived Products

Knee osteoarthritis (OA) is a chronic articular disease characterized by the progressive degeneration of cartilage and bone tissue, leading to the appearance of subchondral cysts, osteophyte formation, and synovial inflammation. Conventional treatments consist of non-steroidal anti-inflammatory drugs (NSAIDs), analgesics, and glucocorticoids. However, the prolonged use of these drugs causes adverse effects. NSAIDs, for instance, are known to be nephrotoxic, increasing the damage to articular cartilage. New therapies capable of accelerating the process of tissue regeneration and repair are being discussed, such as the use of orthobiologics that are naturally found in the body and obtained through minimally invasive collection and/or laboratory manipulations. Bone marrow aspirate (BMA) and bone marrow aspirate concentrate (BMAC) are both rich in hematopoietic stem cells, mesenchymal stem cells (MSCs), and growth factors (GFs) that can be used in the healing process due to their anabolic and anti-inflammatory effects. The aim of this literature review is to assess the efficacy of BMA and BMAC in the treatment of knee OA based on the favorable results that researchers have obtained with the use of both orthobiologics envisaging an accelerated healing process and the prevention of OA progression.

Comprehensive analysis of mesenchymal cells reveals a dysregulated TGF-β/WNT/HOXB7 axis in patients with myelofibrosis

Despite the advances in the understanding and treatment of myeloproliferative neoplasm (MPN), the disease remains incurable with the risk of evolution to acute myeloid leukemia or myelofibrosis (MF). Unfortunately, the evolution of the disease to MF remains poorly understood, impeding preventive and therapeutic options. Recent studies in solid tumor microenvironment and organ fibrosis have shed instrumental insights on their respective pathogenesis and drug resistance, yet such precise data are lacking in MPN. In this study, through a patient sample-driven transcriptomic and epigenetic description of the MF microenvironment landscape and cell-based analyses, we identify homeobox B7 (HOXB7) overexpression and more precisely a potentially novel TGF-β/WNT/HOXB7 pathway as associated to a pro-fibrotic and pro-osteoblastic biased differentiation of mesenchymal stromal cells (MSCs). Using gene-based and chemical inhibition of this pathway, we reversed the abnormal phenotype of MSCs from patients with MF, providing the MPN field a potentially novel target to prevent and manage evolution to MF.

HOXD1 inhibits lung adenocarcinoma progression and is regulated by DNA methylation

The homeobox (HOX) gene family encodes a number of highly conserved transcription factors and serves a crucial role in embryonic development and tumorigenesis. Homeobox D1 (HOXD1) is a member of the HOX family, whose biological functions in lung cancer are currently unclear. The University of Alabama at Birmingham Cancer data analysis Portal of HOXD1 expression patterns demonstrated that HOXD1 was downregulated in lung adenocarcinoma (LUAD) patient samples compared with adjacent normal tissue. Western blotting analysis demonstrated low HOXD1 protein expression levels in lung LUAD cell lines. The Kaplan‑Meier plotter database demonstrated that reduced HOXD1 expression levels in LUAD correlated with poorer overall survival. Meanwhile, an in vitro study showed that HOXD1 overexpression suppressed LUAD cell proliferation, migration and invasion. In a mouse tumor model, upregulated HOXD1 was demonstrated to inhibit tumor growth. In addition, targeted bisulfite sequencing and chromatin immunoprecipitation assays demonstrated that DNA hypermethylation occurred in the promoter region of the HOXD1 gene and was associated with the action of DNA methyltransferases. Moreover, upregulated HOXD1 served as a transcriptional factor and increased the transcriptional expression of bone morphogenic protein (BMP)2 and BMP6. Taken together, the dysregulation of HOXD1 mediated by DNA methylation inhibited the initiation and progression of LUAD by regulating the expression of BMP2/BMP6.

An unexpected role of IL10 in mesoderm induction and differentiation from pluripotent stem cells: Implications in zebrafish angiogenic sprouting, vascular organoid development, and therapeutic angiogenesis

Mesoderm induction is a crucial step for vascular cell specification, vascular development and vasculogenesis. However, the cellular and molecular mechanisms underlying mesoderm induction remain elusive. In the present study, a chemically-defined differentiation protocol was used to induce mesoderm formation and generate functional vascular cells including smooth muscle cells (SMCs) and endothelial cells (ECs) from human induced pluripotent stem cells (hiPSCs). Zebrafish larvae were used to detect an in vivo function of interleukin 10 (IL10) in mesoderm formation and vascular development. A three dimensional approach was used to create hiPSC-derived blood vessel organoid (BVO) and explore a potential impact of IL10 on BVO formation. A murine model hind limb ischemia was applied to investigate a therapeutic potential of hiPSC-derived cells treated with or without IL10 during differentiation. We found that IL10 was significantly and specifically up-regulated during mesoderm stage of vascular differentiation. IL10 addition in mesoderm induction media dramatically increased mesoderm induction and vascular cell generation from hiPSCs, whereas an opposite effect was observed with IL10 inhibition. Mechanistic studies revealed that IL10 promotes mesoderm formation and vascular cell differentiation by activating signal transducer and activator of transcription 3 signal pathway. Functional studies with an in vivo model system confirmed that knockdown of IL10 using morpholino antisense oligonucleotides in zebrafish larvae caused defective mesoderm formation, angiogenic sprouting and vascular development. Additionally, our data also show IL10 promotes blood vessel organoid development and enhances vasculogenesis and angiogenesis. Importantly, we demonstrate that IL10 treatment during mesoderm induction stage enhances blood flow perfusion recovery and increases vasculogenesis and therapeutic angiogenesis after hind limb ischemia. Our data, therefore, demonstrate a regulatory role for IL10 in mesoderm formation from hiPSCs and during zebrafish vascular development, providing novel insights into mesoderm induction and vascular cell specifications.

Genome-wide association study reveals the underlying regulatory mechanisms of red blood traits in Anadara granosa

BACKGROUND

Anadara granosa, commonly known as the blood clam, exhibits the unusual characteristic of having red blood among invertebrates. There is significant individual variation in blood color intensity among blood clams; individuals with vibrant red blood are deemed healthier and exhibit stronger stress resistance. However, the molecular basis underlying these red blood traits (RBTs) remains poorly understood.

RESULTS

In this study, we performed genome-wide association studies (GWAS) in a population of 300 A. granosa individuals, focusing on RBTs as measured by hemoglobin concentration (HC), total hemocyte count (THC), and heme concentration (HEME). Our analysis identified 18 single nucleotide polymorphisms (SNPs) correlated with RBTs, subsequently selected 117 candidate genes within a 100 kb flanking region of these SNPs, potentially involved in the RBTs of A. granosa. Moreover, we discovered two haplotype blocks specifically associated with THC and HEME. Further analysis revealed eight genes (Septin7, Hox5, Cbfa2t3, Avpr1b, Hhex, Eif2ak3, Glrk, and Rpl35a) that significantly influence RBTs. Notably, a heterozygous A/T mutation in the 3'UTR of Cbfa2t3 was found to promote blood cell proliferation. These genes suggest that the hematopoietic function plays a significant role in the variability of RBTs in A. granosa.

CONCLUSIONS

Our findings reveal a conservation of the regulatory mechanisms of RBTs between blood clams and vertebrates. The results not only provide a scientific basis for selective breeding in blood clams, but also offer deeper insights into the evolutionary mechanisms of RBTs in invertebrates.

Hoxc10-mediated 'positional memory' regulates cartilage formation subsequent to femoral heterotopic grafting

The Hox gene plays a crucial role in the bone development, determining their structure and morphology. Limb bone grafts expressing Hox positive genes are commonly used for free transplantation to repair Hox negative mandibular critical bone defects. However, the specific role of original Hox genes in newly formed bone during the cross-layer bone grafting healing process remains unexplored. Our findings demonstrate that femurs ectopically grafted into the mandibular environment retained a significant ability to differentiate into cartilage and form cartilaginous callus, which may be a key factor contributing to differences in bone graft healing. Hoxc10, an embryonic layer-specific genes, regulates cartilage formation during bone healing. Mechanistically, we observed Hoxc10 retention in co-cultured femoral BMSCs. Knocking out Hoxc10 narrows the bone gap and reduces cartilage formation. In summary, we reveal Hoxc10's 'positional memory' after adult cross-layer bone graft, influencing the outcomes of autologous bone graft.

Role of homeobox genes in cancer: immune system interactions, long non-coding RNAs, and tumor progression

The intricate interplay between Homeobox genes, long non-coding RNAs (lncRNAs), and the development of malignancies represents a rapidly expanding area of research. Specific discernible lncRNAs have been discovered to adeptly regulate HOX gene expression in the context of cancer, providing fresh insights into the molecular mechanisms that govern cancer development and progression. An in-depth comprehension of these intricate associations may pave the way for innovative therapeutic strategies in cancer treatment. The HOX gene family is garnering increasing attention due to its involvement in immune system regulation, interaction with long non-coding RNAs, and tumor progression. Although initially recognized for its crucial role in embryonic development, this comprehensive exploration of the world of HOX genes contributes to our understanding of their diverse functions, potentially leading to immunology, developmental biology, and cancer research discoveries. Thus, the primary objective of this review is to delve into these aspects of HOX gene biology in greater detail, shedding light on their complex functions and potential therapeutic applications.

The Potential Links between lncRNAs and Drug Tolerance in Lung Adenocarcinoma

Lung cancer patients treated with targeted therapies frequently respond well but invariably relapse due to the development of drug resistance. Drug resistance is in part mediated by a subset of cancer cells termed "drug-tolerant persisters" (DTPs), which enter a dormant, slow-cycling state that enables them to survive drug exposure. DTPs also exhibit stem cell-like characteristics, broad epigenetic reprogramming, altered metabolism, and a mutagenic phenotype mediated by adaptive mutability. While several studies have characterised the transcriptional changes that lead to the altered phenotypes exhibited in DTPs, these studies have focused predominantly on protein coding changes. As long non-coding RNAs (lncRNAs) are also implicated in the phenotypes altered in DTPs, it is likely that they play a role in the biology of drug tolerance. In this review, we outline how lncRNAs may contribute to the key characteristics of DTPs, their potential roles in tolerance to targeted therapies, and the emergence of genetic resistance in lung adenocarcinoma.

Engrailed 2 serves as a master regulator of the super-enhancer in the TNC gene locus in non-small cell lung cancer

Engrailed 2 (EN2) is a homeodomain-containing protein that is dysregulated in many types of cancer. However, the role of EN2 in non-small cell lung cancer (NSCLC) and the mechanism underlying its biological function are largely unclear. Here, we showed that EN2 played an oncogenic function in NSCLC and greatly enhanced the malignant phenotype of NSCLC cells. Meanwhile, EN2 was able to boost the expression of a well-studied oncogenic Tenascin-C (TNC) gene, which in turn activated the AKT signaling pathway. Interestingly, we found that EN2 directly bound to the super-enhancer (SE) region in the TNC locus. The histone marker H3K27ac was also enriched in the region, indicating the activation of the SE. Treatment of the cells with JQ1, an inhibitor of SE activity, abrogated the effect of EN2 on the expression of TNC and phosphorylation of AKT-Ser473. Collectively, our work unveils a novel mode of EN2 function, in which EN2 governs the SE in the TNC locus, consequently activating the oncogenic TNC-AKT axis in NSCLC.

HOXA9 Regulome and Pharmacological Interventions in Leukemia

HOXA9, an important transcription factor (TF) in hematopoiesis, is aberrantly expressed in numerous cases of both acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) and is a strong indicator of poor prognosis in patients. HOXA9 is a proto-oncogene which is both sufficient and necessary for leukemia transformation. HOXA9 expression in leukemia correlates with patient survival outcomes and response to therapy. Chromosomal transformations (such as NUP98-HOXA9), mutations, epigenetic dysregulation (e.g., MLL- MENIN -LEDGF complex or DOT1L/KMT4), transcription factors (such as USF1/USF2), and noncoding RNA (such as HOTTIP and HOTAIR) regulate HOXA9 mRNA and protein during leukemia. HOXA9 regulates survival, self-renewal, and progenitor cell cycle through several of its downstream target TFs including LMO2, antiapoptotic BCL2, SOX4, and receptor tyrosine kinase FLT3 and STAT5. This dynamic and multilayered HOXA9 regulome provides new therapeutic opportunities, including inhibitors targeting DOT1L/KMT4, MENIN, NPM1, and ENL proteins. Recent findings also suggest that HOXA9 maintains leukemia by actively repressing myeloid differentiation genes. This chapter summarizes the recent advances understanding biochemical mechanisms underlying HOXA9-mediated leukemogenesis, the clinical significance of its abnormal expression, and pharmacological approaches to treat HOXA9-driven leukemia.

Phosphodiesterase 4 activity uniquely regulates ciliary cAMP-dependent 3T3-L1 adipogenesis

Recent evidence indicates that the presence of a primary cilium (PC), and of selective cAMP signaling within this smallest of organelles, promotes adipogenic differentiation of 3T3-L1 preadipocytes incubated in media supplemented with either a natural (docosahexaenoic acid, DHA), or a synthetic (TUG-891), free fatty acid receptor 4 (FFAR4) agonist. Indeed, in this earlier work, activation of ciliary FFAR4 in 3T3-L1 cells was correlated with selective increases in PC cAMP and adipogenesis in these cells. However, this study was silent on the role of local PC cAMP phosphodiesterases (PDEs)-mediated events in regulating these adipogenic responses and on the identity of cAMP PDEs that could regulate the "pool" of ciliary cAMP accessed by FFAR4 agonists. In this context, we have identified the PDEs expressed by 3T3-L1 preadipocytes and showed that of these, only PDE4 inhibition promotes FFAR4-mediated adipogenesis. We propose that this work will identify more selective therapeutic targets through which to control adipogenesis, and perhaps the differentiation of other stem cells in which ciliary cAMP is critical.

Constructing the pharyngula: Connecting the primary axial tissues of the head with the posterior axial tissues of the tail

The pharyngula stage of vertebrate development is characterized by stereotypical arrangement of ectoderm, mesoderm, and neural tissues from the anterior spinal cord to the posterior, yet unformed tail. While early embryologists over-emphasized the similarity between vertebrate embryos at the pharyngula stage, there is clearly a common architecture upon which subsequent developmental programs generate diverse cranial structures and epithelial appendages such as fins, limbs, gills, and tails. The pharyngula stage is preceded by two morphogenetic events: gastrulation and neurulation, which establish common shared structures despite the occurrence of cellular processes that are distinct to each of the species. Even along the body axis of a singular organism, structures with seemingly uniform phenotypic characteristics at the pharyngula stage have been established by different processes. We focus our review on the processes underlying integration of posterior axial tissue formation with the primary axial tissues that creates the structures laid out in the pharyngula. Single cell sequencing and novel gene targeting technologies have provided us with new insights into the differences between the processes that form the anterior and posterior axis, but it is still unclear how these processes are integrated to create a seamless body. We suggest that the primary and posterior axial tissues in vertebrates form through distinct mechanisms and that the transition between these mechanisms occur at different locations along the anterior-posterior axis. Filling gaps that remain in our understanding of this transition could resolve ongoing problems in organoid culture and regeneration.

Progress in the treatment of neonatal hypoxic-ischemic encephalopathy with umbilical cord blood mononuclear cells

Neonatal hypoxic-ischemic encephalopathy (HIE) is a common disease among newborns, which is a leading cause of neonatal death and permanent neurological sequelae. Therapeutic hypothermia (TH) is the only method for the treatment of HIE that has been recognized effective clinically at home and abroad, but the efficacy is limited. Recent research suggests that the cord blood-derived mononuclear cells (CB-MNCs), which the refer to blood cells containing one nucleus in the cord blood, exert anti-oxidative, anti-inflammatory, anti-apoptotic effects and play a neuroprotective role in HIE. This review focuses on safety and efficacy, the route of administration, dose, timing and combination treatment of CB-MNCs in HIE.

Comparative computational analysis to distinguish mesenchymal stem cells from fibroblasts

Introduction

Mesenchymal stem cells (MSCs) are considered to be the most promising stem cell type for cell-based therapies in regenerative medicine. Based on their potential to home to diseased body sites following a therapeutically application, these cells could (i) differentiate then into organ-specific cell types to locally restore injured cells or, most prominently, (ii) foster tissue regeneration including immune modulations more indirectly by secretion of protective growth factors and cytokines. As tissue-resident stem cells of mesenchymal origin, these cells are morphologically and even molecularly- at least concerning the classical marker genes- indistinguishable from similar lineage cells, particularly fibroblasts.

Methods

Here we used microarray-based gene expression and global DNA methylation analyses as well as accompanying computational tools in order to specify differences between MSCs and fibroblasts, to further unravel potential identity genes and to highlight MSC signaling pathways with regard to their trophic and immunosuppressive action.

Results

We identified 1352 differentially expressed genes, of which in the MSCs there is a strong signature for e.g., KRAS signaling, known to play essential role in stemness maintenance, regulation of coagulation and complement being decisive for resolving inflammatory processes, as well as of wound healing particularly important for their regenerative capacity. Genes upregulated in fibroblasts addressed predominately transcription and biosynthetic processes and mapped morphological features of the tissue. Concerning the cellular identity, we specified the already known HOX code for MSCs, established a potential HOX code for fibroblasts, and linked certain HOX genes to functional cell-type-specific properties. Accompanied methylation profiles revealed numerous regions, especially in HOX genes, being differentially methylated, which might provide additional biomarker potential.

Discussion

Conclusively, transcriptomic together with epigenetic signatures can be successfully be used for the definition (cellular identity) of MSCs versus fibroblasts as well as for the determination of the superior functional properties of MSCs, such as their immunomodulatory potential.

Effects of HOXC8 on the Proliferation and Differentiation of Porcine Preadipocytes

Transcription factor Homeobox C8 (HOXC8) is identified as a white adipose gene as revealed by expression profile analysis in fat tissues. However, the specific role of HOXC8 in fat accumulation remains to be identified. This study was designed to reveal the effects of HOXC8 on preadipocyte proliferation and differentiation. We first make clear that the expression of HOXC8 is associated with fat contents in muscles, highlighting a role of HOXC8 in fat accumulation. Next, it is demonstrated that HOXC8 promotes the proliferation and differentiation of preadipocytes through gain- and loss-of-function assays in primary cultured porcine preadipocytes. Then, mechanisms underlying the regulation of HOXC8 on preadipocyte proliferation and differentiation are identified with RNA sequencing, and a number of differentially expressed genes (DEGs) in response to HOXC8 knockdown are identified. The top GO (Gene Ontology) terms enriched by DEGs involved in proliferation and differentiation, respectively, are identical. IL-17 signaling pathway is the common one significantly enriched by DEGs involved in preadipocyte proliferation and differentiation, respectively, indicating its importance in mediating fat accumulation regulated by HOXC8. Additionally, we find that the inhibition of proliferation is one of the main processes during preadipocyte differentiation. The results will contribue to further revealing the mechanisms underlying fat accumulation regulated by HOXC8.