The Novel Secreted Adipokine WNT1-inducible Signaling Pathway Protein 2 (WISP2) Is a Mesenchymal Cell Activator of Canonical WNT

The Impact of Resident Adipose Tissue Macrophages on Adipocyte Homeostasis and Dedifferentiation

Obesity is concurrent with immunological dysregulation, resulting in chronic low-grade inflammation and cellular dysfunction. In pancreatic islets, this loss of function has been correlated with mature β-cells dedifferentiating into a precursor-like state through constant exposure to inflammatory stressors. As mature adipocytes likewise have the capability to dedifferentiate in vitro and in vivo, we wanted to analyze this cellular change in relation to adipose tissue (AT) inflammation and adipose tissue macrophage (ATM) activity. Using our organotypic AT explant culture method combined with a double-reporter mouse model for labeling ATMs and mature adipocytes, we were able to visualize and quantify dedifferentiated fat (DFAT) cells in AT explants. Preliminary testing showed increased dedifferentiation after tamoxifen (TAM) stimulation, making TAM-dependent lineage-tracing models unsuitable for quantification of naturally occurring DFAT cells. The regulatory role of ATMs in adipocyte dedifferentiation was shown through macrophage depletion using Plexxicon 5622 or clodronate liposomes, which significantly increased DFAT cell levels. Subsequent bulk RNA sequencing of macrophage-depleted explants revealed enrichment of the tumor necrosis factor α (TNFα) signaling pathway as well as downregulation of associated genes. Direct stimulation with TNFα decreased adipocyte dedifferentiation, while application of a TNFα-neutralizing antibody did not significantly alter DFAT cell levels. Our findings suggest a regulatory role of resident ATMs in maintaining the mature adipocyte phenotype and preventing excessive adipocyte dedifferentiation. The specific regulatory pathways as well as the impact that DFAT cells might have on ATMs, and vice versa, are subject to further investigation.

CCN5/WISP2 serum levels in patients with coronary artery disease and type 2 diabetes and its correlation with inflammation and insulin resistance; a machine learning approach

Introduction

Studies have shown various effects of CCN5/WISP2 on metabolic pathways, yet no prior investigation has established a link between its serum levels and CAD and/or T2DM. Therefore, this study seeks to explore the relation between CCN5 and the risk factor of CAD and/or diabetes, in comparison to individuals with good health, marking a pioneering endeavor in this field.

Methods

This case-control study investigates serum levels of CCN5, TNF-α, IL-6, adiponectin, and fasting insulin in a population of 160 individuals recruited into four equal groups (T2DM, CAD, CAD-T2DM, and healthy controls). Statistical tests comprise Chi-square tests, ANOVA, Spearman correlation, and logistic regression. ROC curves were used to represent the diagnostic potential of CCN5. Disease states are predicted by machine learning algorithms: Decision Tree, Gradient Boosted Trees, Random Forest, Naïve Bayes, and KNN. These models' performance was evaluated by various metrics, all of which were ensured to be robust by applying 10-fold cross-validation. Analyses were done in SPSS and GraphPad Prism and RapidMiner software.

Results

The CAD, T2DM, and CAD-T2DM groups had significantly higher CCN5 concentrations compared to the healthy control group (CAD: 336.87 ± 107.36 ng/mL, T2DM: 367.46 ± 102.15 ng/mL, CAD-T2DM: 404.68 ± 108.15 ng/mL, control: 205.62 ± 63.34 ng/mL; P < 0.001). A positive and significant correlation was observed between CCN5 and cytokines (IL-6 and TNF-α) in all patient groups (P < 0.05). Multinomial logistic regression analysis indicated a significant association between CCN5 and T2DM-CAD, T2DM, and CAD conditions (P < 0.001) even after adjusting for gender, BMI, and age (P < 0.001). Regarding the machine learning models, the Naïve Bayes model showed the best performance for classifying cases of T2DM, achieving an AUC value of 0.938±0.066. For predicting CAD, the Random Forest classifier achieved the highest AUC value of 0.994±0.020. In the case of CAD-T2DM prediction, the Naïve Bayes model demonstrated the highest AUC of 0.981±0.059, along with an Accuracy of 97.50 % ± 7.91 % and an F-measure of 96.67 % ± 10.54 %.

Conclusion

Our study has revealed, for the first time, a positive connection between CCN5 serum levels and the risk of developing T2DM and CAD. Nonetheless, more research is needed to ascertain whether CCN5 can serve as a predictive marker.

DCLK1 mediated cooperative acceleration of EMT by avian leukosis virus subgroup J and Marek's disease virus via the Wnt/β-catenin pathway promotes tumor metastasis

Co-infection with oncogenic retrovirus and herpesvirus significantly facilitates tumor metastasis in human and animals. Co-infection with avian leukosis virus subgroup J (ALV-J) and Marek's disease virus (MDV), which are typical oncogenic retrovirus and herpesvirus, respectively, leads to enhanced oncogenicity and accelerated tumor formation, resulting in increased mortality of affected chickens. Previously, we found that ALV-J and MDV cooperatively promoted tumor metastasis. However, the molecular mechanism remains elusive. Here, we found that doublecortin-like kinase 1 (DCLK1) mediated cooperative acceleration of epithelial-mesenchymal transition (EMT) by ALV-J and MDV promoted tumor metastasis. Mechanistically, DCLK1 induced EMT via activating Wnt/β-catenin pathway by interacting with β-catenin, thereby cooperatively promoting tumor metastasis. Initially, we screened and found that DCLK1 was a potential mediator for the cooperative activation of EMT by ALV-J and MDV, and enhanced cell proliferation, migration, and invasion. Subsequently, we revealed that DCLK1 physically interacted with β-catenin to promote the formation of the β-catenin-TCF4 complex, inducing transcription of the Wnt target gene, c-Myc, promoting EMT by increasing the expression of N-cadherin, Vimentin, and Snail, and decreasing the expression of E-cadherin. Taken together, we discovered that jointly activated DCLK1 by ALV-J and MDV accelerated cell proliferation, migration and invasion, and ultimately activated EMT, paving the way for tumor metastasis. This study elucidated the molecular mechanism underlying cooperative metastasis induced by co-infection with retrovirus and herpesvirus.

IMPORTANCE

Tumor metastasis, a complex phenomenon in which tumor cells spread to new organs, is one of the greatest challenges in cancer research and is the leading cause of cancer-induced death. Numerous studies have shown that oncoviruses and their encoded proteins significantly affect metastasis, especially the EMT process. ALV-J and MDV are classic tumorigenic retrovirus and herpesvirus, respectively. We found that ALV-J and MDV synergistically promoted EMT. Further, we identified the tumor stem cell marker DCLK1 in ALV-J and MDV co-infected cells. DCLK1 directly interacted with β-catenin, promoting the formation of the β-catenin-TCF4 complex. This interaction activated the Wnt/β-catenin pathway, thereby inducing EMT and paving the way for synergistic tumor metastasis. Exploring the molecular mechanisms by which ALV-J and MDV cooperate during EMT will contribute to our understanding of tumor progression and metastasis. This study provides new insights into the cooperative induced tumor metastasis by retroviruses and herpesviruses.

Insights into the molecular changes of adipocyte dedifferentiation and its future research opportunities

Recent studies have challenged the traditional belief that mature fat cells are irreversibly differentiated and revealed they can dedifferentiate into fibroblast-like cells known as dedifferentiated fat (DFAT) cells. Resembling pluripotent stem cells, DFAT cells hold great potential as a cell source for stem cell therapy. However, there is limited understanding of the specific changes that occur following adipocyte dedifferentiation and the detailed regulation of this process. This review explores the epigenetic, genetic, and phenotypic alterations associated with DFAT cell dedifferentiation, identifies potential targets for clinical regulation and discusses the current applications and challenges in the field of DFAT cell research.

hnRNPA1 promotes the metastasis and proliferation of gastric cancer cells through WISP2-guided Wnt/β-catenin signaling pathway

The main cause of gastric cancer (GC)-related death is due to malignant cell unregulated distant metastasis and proliferation. Heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) has been shown to play an important role in carcinogenesis and the development of metastasis in several tumors. However, its downstream regulatory mechanism in GC is not well defined. Our study aims to investigate the function and regulatory mechanism of hnRNPA1 in GC. We analyzed the differential expression of hnRNPA1 in gastric cancer and paired adjacent normal tissues in the TCGA database. Kaplan-Meier analysis was employed for survival assessment. The expressions of hnRNPA1 in GC cells were measured by qRT-PCR and Western blot. Transwell assay, CCK8 and colony formation assay were used to detect the effect of hnRNPA1 on the metastasis and proliferation ability of GC cells. Additionally, Western blotting was performed to examine the expression of proteins related to the Wnt/β-catenin signaling pathway as well as epithelial-mesenchymal transition (EMT), while further investigations were carried out to explore potential regulatory mechanisms. The results showed that hnRNPA1 was highly expressed differentially in GC over normal gastric tissue. Knocking down hnRNPA1 inhibited the metastasis and proliferation of human gastric cancer cells. Overexpression of hnRNPA1 significantly enhanced the metastatic potential and proliferative capacity of human GC cells. Further mechanism exploration revealed that knocking down hnRNPA1 inhibited the Wnt/β-catenin signaling pathway and WNT1 inducible signaling pathway protein-2 (WISP2), an activator of the Wnt/β-catenin signaling pathway. Whereas overexpression of hnRNPA1 had the opposite effects. Our results demonstrated that hnRNPA1 promoted metastasis and proliferation of GC cells by activating Wnt/β-catenin signaling pathway via WISP2. hnRNPA1 may serve as a potential biomarker and novel therapeutic targets for GC.

17β-Estradiol (E2) Activates Matrix Mineralization through Genomic/Nongenomic Pathways in MC3T3-E1 Cells

Estrogen plays an important role in osteoporosis prevention. We herein report the possible novel signaling pathway of 17β-estradiol (E2) in the matrix mineralization of MC3T3-E1, an osteoblast-like cell line. In the culture media-containing stripped serum, in which small lipophilic molecules such as steroid hormones including E2 were depleted, matrix mineralization was significantly reduced. However, the E2 treatment induced this. The E2 effects were suppressed by ICI182,780, the estrogen receptor (ER)α, and the ERβ antagonist, as well as their mRNA knockdown, whereas Raloxifene, an inhibitor of estrogen-induced transcription, and G15, a G-protein-coupled estrogen receptor (GPER) 1 inhibitor, had little or no effect. Furthermore, the E2-activated matrix mineralization was disrupted by PMA, a PKC activator, and SB202190, a p38 MAPK inhibitor, but not by wortmannin, a PI3K inhibitor. Matrix mineralization was also induced by the culture media from the E2-stimulated cell culture. This effect was hindered by PMA or heat treatment, but not by SB202190. These results indicate that E2 activates the p38 MAPK pathway via ERs independently from actions in the nucleus. Such activation may cause the secretion of certain signaling molecule(s), which inhibit the PKC pathway. Our study provides a novel pathway of E2 action that could be a therapeutic target to activate matrix mineralization under various diseases, including osteoporosis.

ITIH5 inhibits proliferation, adipogenic differentiation, and secretion of inflammatory cytokines of human adipose stem cells-A new key in treating obesity?

Inter-α-trypsin inhibitor heavy chain 5 (ITIH5) is widely expressed in the human body, and it is detected to be particularly abundant in adipose tissue. ITIH5 expression is increased in people with obesity compared to lean persons and is decreased by diet-induced weight loss. This suggests that ITIH5 may be involved in the development of adiposity and clinical metabolic variables, although its exact function remains unknown. We measured the protein concentration of ITIH5 in adipose samples from patients undergoing abdominoplasty and tested for correlation with the subjects' BMI as well as inflammatory mediators. We stimulated human adipose stem cells (ASCs) with recombinant (r)ITIH5 protein and tested for an effect on proliferation, differentiation, and immunosuppressive properties when the cells were exposed to an artificial inflammatory environment. We found positive correlations between ITIH5 levels and the BMI (p < .001) as well as concentrations of inflammatory cytokines (TNF-α, IL-6, and MCP-1) in adipose tissue (p < .01). Application of the rITIH5 protein inhibited both proliferation (p < .001) and differentiation of ASCs. Especially, the development of mature adipocytes was reduced by over 50%. Moreover, rITIH5 decreased the release of IL-6 and MCP-1 when the cells were exposed to TNF-α and IL-1β (p < .001). Our data suggest that ITIH5 is an adipokine that is increasingly released during human adipose tissue development, acting as a regulator that inhibits proliferation and adipogenic differentiation of ASCs. ITIH5 thus presents itself as a positive regulator of adipose tissue homeostasis, possibly protecting against both hyperplasia and hypertrophy of adipose tissue and the associated chronic inflammation.

SNHG3/WISP2 Axis Promotes Hela Cell Migration and Invasion via Activating Wnt/β-Catenin Signaling

BACKGROUND/AIM

Cervical cancer (CC) poses a significant threat to women's health and has a relatively poor prognosis due to local invasion and metastasis. It is, therefore, crucial to elucidate the molecular mechanisms of CC metastasis. SNHG3 has been implicated in various tumor metastasis processes, but its involvement in CC has not been thoroughly studied. Our study aimed to investigate the role of SNHG3 in metastasis and elucidate its underlying mechanisms in CC.

MATERIALS AND METHODS

LncRNA SNHG3 expression in CC tissues was analyzed using TCGA and GSE27469 databases. Normal cervical epithelial cells and CC cell lines were used to detect mRNA expression of SNHG3 via quantitative reverse transcription polymerase chain reaction (qRT-PCR). With RNA interference (RNAi) technology, antisense oligonucleotides (ASO) can act on HeLa cells to knockdown target gene expression. The influence of SNHG3 on cell migration and invasion were determined by wound healing and transwell assays. Transcriptome sequencing (RNA-seq) was used to seek abnormally expressed genes between SNHG3 knockdown cells and control cells. The expressions of epithelial-mesenchymal transition (EMT) and Wnt/β-catenin signaling related proteins were detected using western blot.

RESULTS

SNHG3 was obviously up-regulated in CC tissues and cell lines, and ectopic expression of SNHG3 was associated with lymph node metastasis of CC. Knockdown of SNHG3 significantly inhibited cell migration and invasion in CC. Further molecular mechanism studies showed that SNHG3 knockdown could down-regulate the expression of WNT1 Inducible Signaling Pathway Protein 2 (WISP2) so as to inhibit the activation of the Wnt/β-catenin signaling pathway, and regulated the expression of EMT-related markers, that promoted the protein expression of E-cadherin, as well as decreased the expression of N-cadherin and vimentin.

CONCLUSION

SNHG3 appears to exert a pro-metastatic effect in CC, as evidenced by inhibition of cell migration and invasion upon SNHG3 knockdown. EMT also appears to be attenuated. Of interest is the down-regulation of WISP2 following SNHG3 knockdown leads to the inactivation of the Wnt/β-catenin signaling pathway.

Accumulation of 4-Hydroxynonenal Characterizes Diabetic Fat and Modulates Adipogenic Differentiation of Adipose Precursor Cells

Redox imbalance in fat tissue appears to be causative of impaired glucose homeostasis. This "proof-of-concept" study investigated whether the peroxidation by-product of polyunsaturated n-6 fatty acids, namely 4-hydroxynonenal (4-HNE), is formed by, and accumulates in, the adipose tissue (AT) of obese patients with type 2 diabetes (OBT2D) as compared with lean, nondiabetic control subjects (CTRL). Moreover, we studied the effects of 4-HNE on the cell viability and adipogenic differentiation of adipose-derived stem cells (ASCs). Protein-HNE adducts in subcutaneous abdominal AT (SCAAT) biopsies from seven OBT2D and seven CTRL subjects were assessed using Western blot. The effects of 4-HNE were then studied in primary cultures of ASCs, focusing on cell viability, adipogenic differentiation, and the "canonical" Wnt and MAPK signaling pathways. When compared with the controls, the OBT2D patients displayed increased HNE-protein adducts in the SCAAT. The exposure of ASCs to 4-HNE fostered ROS production and led to a time- and concentration-dependent decrease in cell viability. Notably, at concentrations that did not affect cell viability (1 μM), 4-HNE hampered adipogenic ASCs' differentiation through a timely-regulated activation of the Wnt/β-catenin, p38MAPK, ERK1/2- and JNK-mediated pathways. These "hypothesis-generating" data suggest that the increased accumulation of 4-HNE in the SCAAT of obese patients with type 2 diabetes may detrimentally affect adipose precursor cell differentiation, possibly contributing to the obesity-associated derangement of glucose homeostasis.

Magneto-mechanical stimulation modulates osteocyte fate via the ECM-integrin-CSK axis and wnt pathway

Osteocytes are the mechano-sensors of bones. Large gradient high-static magnetic fields (LG-HMFs) produce stable, high-precision, and non-attenuation mechanical forces. We discovered that magnetic forces opposite to gravity inhibited MLO-Y4 osteocyte proliferation and viability by inducing structural damage and apoptosis. In contrast, magnetic force loading in the same direction as that of gravity promoted the proliferation and inhibited apoptosis of MLO-Y4 osteocytes. Differentially expressed gene (DEG) analysis after magnetic force stimulation indicated that the ECM-integrin-CSK axis responded most significantly to mechanical signals. Wisp2 was the most significant DEG between the 12 T upward and downward groups, showing the highest correlation with the Wnt pathway according to the STRING protein interaction database. Explaining the cellular and molecular mechanisms by which mechanical stimuli influence bone remodeling is currently the focus of osteocyte-related research. Our findings provide insights into the effects of LG-HMFs on bone cells, which have further implications in clinical practice.

Single-cell RNA-seq reveals intratumoral heterogeneity in osteosarcoma patients: A review

While primary bone malignancies make up just 0.2% of all cancers, osteosarcoma (OS) is the third most common cancer in adolescents. Due to its highly complex and heterogeneous tumor microenvironment (TME), OS has proven difficult to treat. There has been little to no improvement in therapy for this disease over the last 40 years. Even the recent success of immunotherapies in other blood-borne and solid malignancies has not translated to OS. With frequent recurrence and lung metastases continuing to pose a challenge in the clinic, recent advancements in molecular profiling, such as single-cell RNA sequencing (scRNA-seq), have proven useful in identifying novel biomarkers of OS tumors while providing new insight into this TME that could potentially lead to new therapeutic options. This review combines the analyses of over 150,000 cells from 18 lesions ranging from primary, recurrent, and metastatic OS lesions, revealing distinct cellular populations and gene signatures that exist between them. Here, we detail these previous findings and ultimately convey the intratumoral heterogeneity that exists within OS tumor specimens.

Domestic cat embryos reveal unique transcriptomes of developing incisor, canine, and premolar teeth

Division of the dentition into morphologically distinct classes of teeth (incisors, canines, premolars, and molars) and the acquisition of tribosphenic molars facilitated precise occlusion between the teeth early in mammal evolution. Despite the evolutionary and ecological importance of distinct classes of teeth with unique cusp, crest, and basin morphologies, relatively little is known about the genetic basis for the development of different tooth classes within the embryo. Here we investigated genetic differences between developing deciduous incisor, canine, and premolar teeth in the domestic cat (Felis catus), which we propose to be a new model for tooth development. We examined differences in both developmental timing and crown morphology between the three tooth classes. Using RNA sequencing of early bell stage tooth germs, we showed that each of the three deciduous tooth classes possess a unique transcriptional profile. Three notable groups of genes emerged from our differential expression analysis; genes involved in the extracellular matrix (ECM), Wnt pathway signaling, and members of multiple homeobox gene families (Lhx, Dlx, Alx, and Nkx). Our results suggest that ECM genes may play a previously under-appreciated role in shaping the surface of the tooth crown during development. Differential regulation of these genes likely underlies differences in tooth crown shape and size, although subtle temporal differences in development between the tooth germs could also be responsible. This study provides foundational data for future experiments to examine the function of these candidate genes in tooth development to directly test their potential effects on crown morphology.

Comprehensive bioinformatics analysis reveals biomarkers of DNA methylation-related genes in varicose veins

Background: Patients with Varicose veins (VV) show no obvious symptoms in the early stages, and it is a common and frequent clinical condition. DNA methylation plays a key role in VV by regulating gene expression. However, the molecular mechanism underlying methylation regulation in VV remains unclear. Methods: The mRNA and methylation data of VV and normal samples were obtained from the Gene Expression Omnibus (GEO) database. Methylation-Regulated Genes (MRGs) between VV and normal samples were crossed with VV-associated genes (VVGs) obtained by weighted gene co-expression network analysis (WGCNA) to obtain VV-associated MRGs (VV-MRGs). Their ability to predict disease was assessed using receiver operating characteristic (ROC) curves. Biomarkers were then screened using a random forest model (RF), support vector machine model (SVM), and generalized linear model (GLM). Next, gene set enrichment analysis (GSEA) was performed to explore the functions of biomarkers. Furthermore, we also predicted their drug targets, and constructed a competing endogenous RNAs (ceRNA) network and a drug target network. Finally, we verified their mRNA expression using quantitative real-time polymerase chain reaction (qRT-PCR). Results: Total three VV-MRGs, namely Wnt1-inducible signaling pathway protein 2 (WISP2), Cysteine-rich intestinal protein 1 (CRIP1), and Odd-skipped related 1 (OSR1) were identified by VVGs and MRGs overlapping. The area under the curves (AUCs) of the ROC curves for these three VV-MRGs were greater than 0.8. RF was confirmed as the optimal diagnostic model, and WISP2, CRIP1, and OSR1 were regarded as biomarkers. GSEA showed that WISP2, CRIP1, and OSR1 were associated with oxidative phosphorylation, extracellular matrix (ECM), and respiratory system functions. Furthermore, we found that lncRNA MIR17HG can regulate OSR1 by binding to hsa-miR-21-5p and that PAX2 might treat VV by targeting OSR1. Finally, qRT-PCR results showed that the mRNA expression of the three genes was consistent with the results of the datasets. Conclusion: This study identified WISP2, CRIP1, and OSR1 as biomarkers of VV through comprehensive bioinformatics analysis, and preliminary explored the DNA methylation-related molecular mechanism in VV, which might be important for VV diagnosis and exploration of potential molecular mechanisms.

WISP-2 modulates the induction of inflammatory mediators and cartilage catabolism in chondrocytes

Wnt-1 inducible signaling pathway protein 2 (WISP-2/CCN5) is a recently identified adipokine that has been described as an important mediator of canonical Wnt activation in adipogenic precursor cells. In osteoarthritis (OA), the most common form of arthritis, chondrocytes exhibit aberrant and increased production of pro-inflammatory mediators and matrix degrading enzymes such as IL-1β and MMP-13. Although recent evidence suggests a role for Wnt signaling in OA physiopathology, little is known about the involvement of WISP-2 in cartilage degradation. In the present study, we determined the expression of WISP-2 in healthy and OA human chondrocytes. WISP-2 expression is modulated along chondrocyte differentiation and downregulated at the onset of hypertrophy by inflammatory mediators. We also investigated the effect of WISP-2 on cartilage catabolism and performed WISP-2 loss-of-function experiments using RNA interference technology in human T/C-28a2 immortalized chondrocytes. We demonstrated that recombinant human WISP-2 protein reduced IL-1β-mediated chondrocyte catabolism, that IL-1β and WNT/b-catenin signaling pathways are involved in rhWISP-2 protein and IL-1β effects in human chondrocytes, and that WISP-2 has a regulatory role in attenuating the catabolic effects of IL-1β in chondrocytes. Gene silencing of WISP-2 increased the induction of the catabolic markers MMP-13 and ADAMTS-5 and the inflammatory mediators IL-6 and IL-8 triggered by IL-1β in human primary OA chondrocytes in a Wnt/β-catenin dependent manner. In conclusion, here we have shown for the first time that WISP-2 may have relevant roles in modulating the turnover of extracellular matrix in the cartilage and that its downregulation may detrimentally alter the inflammatory environment in OA cartilage. We also proved the participation of Wnt/β-catenin signaling pathway in these processes. Thus, targeting WISP-2 might represent a potential therapeutical approach for degenerative and/or inflammatory diseases of musculoskeletal system, such as osteoarthritis.

Multi-omic rejuvenation of human cells by maturation phase transient reprogramming

Ageing is the gradual decline in organismal fitness that occurs over time leading to tissue dysfunction and disease. At the cellular level, ageing is associated with reduced function, altered gene expression and a perturbed epigenome. Recent work has demonstrated that the epigenome is already rejuvenated by the maturation phase of somatic cell reprogramming, which suggests full reprogramming is not required to reverse ageing of somatic cells. Here we have developed the first "maturation phase transient reprogramming" (MPTR) method, where reprogramming factors are selectively expressed until this rejuvenation point then withdrawn. Applying MPTR to dermal fibroblasts from middle-aged donors, we found that cells temporarily lose and then reacquire their fibroblast identity, possibly as a result of epigenetic memory at enhancers and/or persistent expression of some fibroblast genes. Excitingly, our method substantially rejuvenated multiple cellular attributes including the transcriptome, which was rejuvenated by around 30 years as measured by a novel transcriptome clock. The epigenome was rejuvenated to a similar extent, including H3K9me3 levels and the DNA methylation ageing clock. The magnitude of rejuvenation instigated by MPTR appears substantially greater than that achieved in previous transient reprogramming protocols. In addition, MPTR fibroblasts produced youthful levels of collagen proteins, and showed partial functional rejuvenation of their migration speed. Finally, our work suggests that optimal time windows exist for rejuvenating the transcriptome and the epigenome. Overall, we demonstrate that it is possible to separate rejuvenation from complete pluripotency reprogramming, which should facilitate the discovery of novel anti-ageing genes and therapies.

Identification and analysis of novel endometriosis biomarkers via integrative bioinformatics

Endometriosis is a gynecological disease prevalent in women of reproductive age, and it is characterized by the ectopic presence and growth of the eutopic endometrium. The pathophysiology and diagnostic biomarkers of endometriosis have not yet been comprehensively determined. To discover molecular markers and pathways underlying the pathogenesis of endometriosis, we identified differentially expressed genes (DEGs) in three Gene Expression Omnibus microarray datasets (GSE11691, GSE23339, and GSE7305) and performed gene set enrichment analysis (GSEA) and protein-protein interaction (PPI) network analyses. We also validated the identified genes via immunohistochemical analysis of tissues obtained from patients with endometriosis or healthy volunteers. A total of 118 DEGs (79 upregulated and 39 downregulated) were detected in each dataset with a lower (fold change) FC cutoff (log2|FC| > 1), and 17 DEGs (11 upregulated and six downregulated) with a higher FC cutoff (log2|FC| > 2). KEGG and GO functional analyses revealed enrichment of signaling pathways associated with inflammation, complement activation, cell adhesion, and extracellular matrix in endometriotic tissues. Upregulation of seven genes (C7, CFH, FZD7, LY96, PDLIM3, PTGIS, and WISP2) out of 17 was validated via comparison with external gene sets, and protein expression of four genes (LY96, PDLIM3, PTGIS, and WISP2) was further analyzed by immunohistochemistry and western blot analysis. Based on these results, we suggest that TLR4/NF-κB and Wnt/frizzled signaling pathways, as well as estrogen receptors, regulate the progression of endometriosis. These pathways may be therapeutic and diagnostic targets for endometriosis.

Potential key factors involved in regulating adipocyte dedifferentiation

Adipocytes are the key constituents of adipose tissue, and their de-differentiation process has been widely observed in physiological and pathological conditions. For obese people, the promotion of adipocyte de-differentiation or maintenance of an undifferentiated state of adipocytes may help to improve their metabolic condition. Thus, understanding the regulatory mechanisms of adipocyte de-differentiation is necessary for treating metabolic diseases. Attractively, in addition to intracellular signals regulating adipocyte de-differentiation, external factors such as temperature and pressure also affect adipocyte de-differentiation. In this review, we summarize the recent progress in the field and discuss the regulatory roles and mechanisms of involved endogenous and exogenous factors during the process of de-differentiation.

EH Domain-Containing 2 Deficiency Restricts Adipose Tissue Expansion and Impairs Lipolysis in Primary Inguinal Adipocytes

Lipid uptake can be facilitated via caveolae, specific plasma membrane invaginations abundantly expressed in adipocytes. The dynamin-related protein EH domain-containing 2 (EHD2) stabilizes caveolae at the cell surface. Here, we have examined the importance of EHD2 for lipid handling using primary adipocytes isolated from EHD2 knockout (Ehd2^−/−) C57BL6/N mice. Following high-fat diet (HFD) feeding, we found a clear impairment of epididymal, but not inguinal, adipose tissue expansion in Ehd2^−/− compared with Ehd2^+/+ (WT) mice. Cell size distribution analysis revealed that Ehd2^−/− mice had a lower proportion of small adipocytes, and an accumulation of medium-sized adipocytes in both epididymal and inguinal adipose tissue. Further, PPARγ activity, FABP4 and caveolin-1 expression were decreased in adipocytes isolated from Ehd2^−/− mice. Inguinal adipocytes isolated from Ehd2^−/− mice displayed reduced lipolysis in response to beta adrenergic receptor agonist, which was associated with reduced phosphorylation of perilipin-1 and hormone sensitive lipase (HSL). This impairment could not be rescued using a cAMP analog, indicating that impaired lipolysis in Ehd2^−/− primary adipocytes likely occurs at the level of, or downstream of, protein kinase A (PKA). Altogether, these findings pinpoint the importance of EHD2 for maintained intracellular lipid metabolism, and emphasize differences in mechanisms regulating lipid handling in various adipose-tissue depots.

Dual roles of WISP2 in the progression of hepatocellular carcinoma: implications of the fibroblast infiltration into the tumor microenvironment

The dismal outcome of hepatocellular carcinoma (HCC) patients is attributable to high frequency of metastasis and. Identification of effective biomarkers is a key strategy to inform prognosis and improve survival. Previous studies reported inconsistent roles of WISP2 in carcinogenesis, while the role of WISP2 in HCC progression also remains unclear. In this study, we confirmed that WISP2 was downregulated in HCC tissues, and WISP2 was acting as a protective factor, especially in patients without alcohol intake using multiple online datasets. In addition, we reported that upregulation of WISP2 in HCC was related to inhibition of the malignant phenotype in vitro, but these alterations were not observed in vivo. WISP2 also negatively correlated with tumour purity, and increased infiltration of fibroblasts promoted malignant progression in HCC tissues. The enhanced infiltration ability of fibroblasts was related to upregulated HMGB1 after overexpression of WISP2 in HCC. The findings shed light on the anticancer role of WISP2, and HMGB1 is one of the key factors involved in the inhibition of the efficiency of WISP2 through reducing the tumour purity with fibroblast infiltration.

Wnt Signaling Pathway Proteins in Scar, Hypertrophic Scar, and Keloid: Evidence for a Continuum?

Hypertrophic scars and keloids are fibroproliferative lesions characterized by excessive collagen deposition. It is unclear whether these entities represent distinct disorders or share a common pathogenesis and the molecular underpinnings of these lesions are poorly understood. Accumulating evidence suggests that the Wnt signaling pathway is a key regulator of wound healing. In this study, tissue microarray was used to evaluate the protein expression profile for Wnt3a, phosphorylated glycogen synthase kinase 3 alpha (pGSK-3α), WNT1-inducible-signaling pathway protein 1 (WISP1), and WISP2 in normal skin, scars, hypertrophic scars, and keloids. Analysis revealed significantly increased fibroblast expression of pGSK-3α in scars (27.2%), hypertrophic scars (30.4%), and keloids (57.3%) compared with normal skin (16.4%) (all differences statistically significant; P < 0.01). Analysis of WISP2 showed 94% of fibroblasts in normal skin expressing WISP2 and significantly decreased expression in scars (46.8%), hypertrophic scars (27.0%), and keloids (61.3%) (all differences statistically significant; P < 0.01). The parallel patterns of expression of pGSK-3α and WISP2 in scars and hypertrophic scars and significantly increased expression in keloids may support the notion that keloids are a truly distinct fibrosing disorder and may provide further evidence for targeting the Wnt signaling pathway in the treatment of keloids.

CCN proteins in the musculoskeletal system: current understanding and challenges in physiology and pathology

The acronym for the CCN family was recently revised to represent “cellular communication network”. These six, small, cysteine-enriched and evolutionarily conserved proteins are secreted matricellular proteins, that convey and modulate intercellular communication by interacting with structural proteins, signalling factors and cell surface receptors. Their role in the development and physiology of musculoskeletal system, constituted by connective tissues where cells are interspersed in the cellular matrix, has been broadly studied. Previous research has highlighted a crucial balance of CCN proteins in mesenchymal stem cell commitment and a pivotal role for CCN1, CCN2 and their alter ego CCN3 in chondrogenesis and osteogenesis; CCN4 plays a minor role and the role of CCN5 and CCN6 is still unclear. CCN proteins also participate in osteoclastogenesis and myogenesis. In adult life, CCN proteins serve as mechanosensory proteins in the musculoskeletal system providing a steady response to environmental stimuli and participating in fracture healing. Substantial evidence also supports the involvement of CCN proteins in inflammatory pathologies, such as osteoarthritis and rheumatoid arthritis, as well as in cancers affecting the musculoskeletal system and bone metastasis. These matricellular proteins indeed show involvement in inflammation and cancer, thus representing intriguing therapeutic targets. This review discusses the current understanding of CCN proteins in the musculoskeletal system as well as the controversies and challenges associated with their multiple and complex roles, and it aims to link the dispersed knowledge in an effort to stimulate and guide readers to an area that the writers consider to have significant impact and relevant potentialities.

Molecular characterisation of osteoblasts from bone obtained from people of Polynesian and European ancestry undergoing joint replacement surgery

Population studies in Aotearoa New Zealand found higher bone mineral density and lower rate of hip fracture in people of Polynesian ancestry compared to Europeans. We hypothesised that differences in osteoblast proliferation and differentiation contribute to the differences in bone properties between the two groups. Osteoblasts were cultured from bone samples obtained from 30 people of Polynesian ancestry and 25 Europeans who had joint replacement surgeries for osteoarthritis. The fraction of cells in S-phase was determined by flow cytometry, and gene expression was analysed by microarray and real-time PCR. We found no differences in the fraction of osteoblasts in S-phase between the groups. Global gene expression analysis identified 79 differentially expressed genes (fold change > 2, FDR P < 0.1). Analysis of selected genes by real-time PCR found higher expression of COL1A1 and KRT34 in Polynesians, whereas BGLAP, DKK1, NOV, CDH13, EFHD1 and EFNB2 were higher in Europeans (P ≤ 0.01). Osteoblasts from European donors had higher levels of late differentiation markers and genes encoding proteins that inhibit the Wnt signalling pathway. This variability may contribute to the differences in bone properties between people of Polynesian and European ancestry that had been determined in previous studies.

Single-cell RNA landscape of intratumoral heterogeneity and immunosuppressive microenvironment in advanced osteosarcoma

Osteosarcoma is the most frequent primary bone tumor with poor prognosis. Through RNA-sequencing of 100,987 individual cells from 7 primary, 2 recurrent, and 2 lung metastatic osteosarcoma lesions, 11 major cell clusters are identified based on unbiased clustering of gene expression profiles and canonical markers. The transcriptomic properties, regulators and dynamics of osteosarcoma malignant cells together with their tumor microenvironment particularly stromal and immune cells are characterized. The transdifferentiation of malignant osteoblastic cells from malignant chondroblastic cells is revealed by analyses of inferred copy-number variation and trajectory. A proinflammatory FABP4+ macrophages infiltration is noticed in lung metastatic osteosarcoma lesions. Lower osteoclasts infiltration is observed in chondroblastic, recurrent and lung metastatic osteosarcoma lesions compared to primary osteoblastic osteosarcoma lesions. Importantly, TIGIT blockade enhances the cytotoxicity effects of the primary CD3+ T cells with high proportion of TIGIT+ cells against osteosarcoma. These results present a single-cell atlas, explore intratumor heterogeneity, and provide potential therapeutic targets for osteosarcoma.

Adipose Morphology: a Critical Factor in Regulation of Human Metabolic Diseases and Adipose Tissue Dysfunction

Emerging evidence highlights that dysfunction of adipose tissue contributes to impaired insulin sensitivity and systemic metabolic deterioration in obese state. Of note, adipocyte hypertrophy serves as a critical event which associates closely with adipose dysfunction. An increase in cell size exacerbates hypoxia and inflammation as well as excessive collagen deposition, finally leading to metabolic dysregulation. Specific mechanisms of adipocyte hypertrophy include dysregulated differentiation and maturation of preadipocytes, enlargement of lipid droplets, and abnormal adipocyte osmolarity sensors. Also, weight loss therapies exert profound influence on adipocyte size. Here, we summarize the critical role of adipocyte hypertrophy in the development of metabolic disturbances. Future studies are required to establish a standard criterion of size measurement to better clarify the impact of adipocyte hypertrophy on changes in metabolic homeostasis.

WISP-2 expression induced by Teriparatide treatment affects in vitro osteoblast differentiation and improves in vivo osteogenesis

The Osteocyte, recognized as a major orchestrator of osteoblast and osteoclast activity, is the most important key player during bone remodeling processes. Imbalances occurring during bone remodeling, caused by hormone perturbations or by mechanical loading alterations, can induce bone pathologies such as osteoporosis. Recently, the active fraction of parathormone, PTH (1-34) or Teriparatide (TPTD), was chosen as election treatment for osteoporosis. The effect of such therapy is dependent on the temporal manner of administration. The molecular reasons why the type of administration regimen is so critical for the fate of bone remodeling are numerous and not yet well known. Our study attempts to analyze diverse signaling pathways directly activated in osteocytes upon TPTD treatment. By means of gene array analysis, we found many molecules upregulated or downregulated in osteocytes. Later, we paid attention to Wisp-2, a protein involved in the Wnt pathway, that is secreted by MLO-Y4 cells and increases upon TPTD treatment and that is able to positively influence the early phases of osteogenic differentiation. We also confirmed the pro osteogenic property of Wisp-2 during mesenchymal stem cell differentiation into the preliminary osteoblast phenotype. The same results were confirmed with an in vivo approach confirming a remarkable Wisp-2 expression in metaphyseal trabecular bone. These results highlighted the anabolic roles unrolled by osteocytes in controlling the action of neighboring cells, suggesting that the perturbation of certain signaling cascades, such as the Wnt pathway, is crucial for the positive regulation of bone formation.

An Approach towards a GMP Compliant In-Vitro Expansion of Human Adipose Stem Cells for Autologous Therapies

Human Adipose Tissue Stem Cells (hASCs) are a valuable source of cells for clinical applications (e.g., treatment of acute myocardial infarction and inflammatory diseases), especially in the field of regenerative medicine. However, for autologous (patient-specific) and allogeneic (off-the-shelf) hASC-based therapies, in-vitro expansion is necessary prior to the clinical application in order to achieve the required cell numbers. Safe, reproducible and economic in-vitro expansion of hASCs for autologous therapies is more problematic because the cell material changes for each treatment. Moreover, cell material is normally isolated from non-healthy or older patients, which further complicates successful in-vitro expansion. Hence, the goal of this study was to perform cell expansion studies with hASCs isolated from two different patients/donors (i.e., different ages and health statuses) under xeno- and serum-free conditions in static, planar (2D) and dynamically mixed (3D) cultivation systems. Our primary aim was I) to compare donor variability under in-vitro conditions and II) to develop and establish an unstructured, segregated growth model as a proof-of-concept study. Maximum cell densities of between 0.49 and 0.65 × 10⁵ hASCs/cm² were achieved for both donors in 2D and 3D cultivation systems. Cell growth under static and dynamically mixed conditions was comparable, which demonstrated that hydrodynamic stresses (P/V = 0.63 W/m³, τ_nt = 4.96 × 10⁻³ Pa) acting at N_s1u (49 rpm for 10 g/L) did not negatively affect cell growth, even under serum-free conditions. However, donor-dependent differences in the cell size were found, which resulted in significantly different maximum cell densities for each of the two donors. In both cases, stemness was well maintained under static 2D and dynamic 3D conditions, as long as the cells were not hyperconfluent. The optimal point for cell harvesting was identified as between cell densities of 0.41 and 0.56 × 10⁵ hASCs/cm² (end of exponential growth phase). The growth model delivered reliable predictions for cell growth, substrate consumption and metabolite production in both types of cultivation systems. Therefore, the model can be used as a basis for future investigations in order to develop a robust MC-based hASC production process for autologous therapies.

Mandibular undifferentiated pleomorphic sarcoma: Molecular analysis of a primary cell population

Background

Undifferentiated pleomorphic sarcomas are one of the most common subtypes of soft tissue sarcomas. These are aggressive mesenchymal tumors and are devoid of the major known biomarkers except vimentin. Our objective was to establish and characterize a primary cell population from a mandibular UPS specimen.

Methods

The tumor was surgically removed from the right mandible of a 24‐year‐old male with IRB approved signed consent. Tumor was dissected, cultured ex vivo, and a cell population, MUPS‐1, were isolated from outgrowths. Gene and protein expression profiles of both the primary tumor and the derived there from cells were obtained by quantitative RT‐PCR and immunohistochemistry and included markers of epithelial, endothelial, and mesenchymal differentiation. To better define potential biomarkers, MUPS‐1 cells were additionally characterized by RNA sequencing analysis.

Results

Pathological analysis of primary tumor tissue revealed a sarcoma demonstrating multiple pathways of differentiation simultaneously with myxoid, fibrous, and osseous tissue. The isolated cells had a spindle cell‐like morphology, were maintained in culture for greater than 20 passages, and formed colonies in soft agar indicating tumorigenicity. The cells, similar to the primary tumor, were strongly positive for vimentin and moderately expressed alkaline phosphatase. RNA‐seq analysis revealed the tumor over‐expressed several genes compared to normal tissue, including components of the Notch signaling pathway, NOTCH3 and JAG1.

Conclusions

We have successfully established an undifferentiated pleomorphic sarcoma cell population, which will provide a valuable resource for studying fundamental processes and potentially serving as a platform for exploring therapeutic strategies for sarcomas.

Silencing of lncRNA 6030408B16RIK prevents ultrafiltration failure in peritoneal dialysis via microRNA-326-3p-mediated WISP2 down-regulation

Continuous exposure to peritoneal dialysis (PD) fluid results in peritoneal fibrosis and ultimately causes ultrafiltration failure. Noncoding RNAs, including long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), have been reported to participate in ultrafiltration failure in PD. Therefore, our study aimed to investigate the mechanism of lncRNA 6030408B16RIK in association with miR-326-3p in ultrafiltration failure in PD. Peritoneal tissues were collected from uremic patients with or without PD. A uremic rat model with PD was first established by 5/6 nephrectomy. The relationship between lncRNA 6030408B16RIK, miR-326-3p and WISP2 was identified using luciferase reporter, RNA pull-down and RIP assays. After ectopic expression and depletion treatments in cells, expression of α-SMA, phosphorylated β-catenin, FSP1, E-cadherin and Vimentin was evaluated by RT-qPCR and Western blot analyses, and Collagen III and CD31 expression by immunohistochemistry. Ultrafiltration volume and glucose transport capacity were assessed by the peritoneal equilibration test. Expression of lncRNA 6030408B16RIK and WISP2 was up-regulated and miR-326-3p expression was poor in peritoneal tissues of uremic PD patients and model rats. LncRNA 6030408B16RIK competitively bound to miR-326-3p and then elevated WISP2 expression. Silencing of lncRNA 6030408B16RIK and WISP2 or overexpression of miR-326-3p was shown to decrease the expression of α-SMA, phosphorylated β-catenin, FSP1, Vimentin, Collagen III and CD31, while reducing glucose transport capacity and increasing E-cadherin expression and ultrafiltration volume in uremic PD rats. In summary, lncRNA 6030408B16RIK silencing exerts an anti-fibrotic effect on uremic PD rats with ultrafiltration failure by inactivating the WISP2-dependent Wnt/β-catenin pathway via miR-326-3p.

A Novel Mechanism of bta-miR-210 in Bovine Early Intramuscular Adipogenesis

Intramuscular fat (IMF) is one of the major factors determining beef quality. IMF formation is influenced by multiple conditions including genetic background, age and nutrition. In our previous investigation, bta-miR-210 was found to be increased during adipogenesis using miRNA-seq. In this study, we validated the upregulation of bta-miR-210 in platelet-derived growth factor receptor α positive (PDGFRα⁺) progenitor cells during adipogenic differentiation in vitro. To investigate its role in adipogenesis, bta-miR-210 mimics were introduced into progenitor cells, which resulted in enhanced intracellular lipid accumulation. Accordingly, the expression of adipocyte-specific genes significantly increased in the bta-miR-210 mimic group compared to that in the negative control group (p < 0.01). Dual-luciferase reporter assays revealed that WISP2 is a target of bta-miR-210. WISP2 knockdown enhanced adipogenesis. In conclusion, bta-miR-210 positively regulates the adipogenesis of PDGFRα⁺ cells derived from bovine fetal muscle by targeting WISP2.

Loss of Wasl improves pancreatic cancer outcome

Several studies have suggested an oncogenic role for the neural Wiskott-Aldrich syndrome protein (N-WASP, encoded by the Wasl gene), but thus far, little is known about its function in pancreatic ductal adenocarcinoma (PDAC). In this study, we performed in silico analysis of WASL expression in PDAC patients and found a correlation between low WASL expression and prolonged survival. To clarify the role of Wasl in pancreatic carcinogenesis, we used 2 oncogenic Kras-based PDAC mouse models with pancreas-specific Wasl deletion. In line with human data, both mouse models had an increased survival benefit due to either impaired tumor development in the presence of the tumor suppressor Trp53 or the delayed tumor progression and senescent phenotype upon genetic ablation of Trp53. Mechanistically, loss of Wasl resulted in cell-autonomous senescence through displacement of the N-WASP binding partners WASP-interacting protein (WIP) and p120ctn; vesicular accumulation of GSK3β, as well as YAP1 and phosphorylated β-catenin, which are components of the destruction complex; and upregulation of Cdkn1a(p21), a master regulator of senescence. Our findings, thus, indicate that Wasl functions in an oncogenic manner in PDAC by promoting the deregulation of the p120-catenin/β-catenin/p21 pathway. Therefore, strategies to reduce N-WASP activity might improve the survival outcomes of PDAC patients.

WISP-2, an upregulated gene in hip cartilage from the DDH model rats, induces chondrocyte apoptosis through PPARγ in vitro

Chondrocyte apoptosis plays an important role in the developmental dysplasia of the hip (DDH) development. It has been found that WNT1 inducible signaling pathway protein 2 (WISP-2) and peroxisome proliferator-activated receptor γ (PPARγ) are involved in cell apoptosis. In this study, we performed the straight-leg swaddling DDH rat model and we found that cartilage degradation and chondrocyte apoptosis were remarkably increased in DDH rats in vivo. Moreover, we found that WISP-2 was upregulated in hip acetabular cartilage of DDH rats compared to control rats. Next, the effects of WISP-2 on chondrocyte apoptosis and its possible underlying mechanism were examined in vitro. The lentivirus-mediated gain- and loss-of-function experiments of WISP-2 and peroxisome proliferator-activated receptor γ (PPARγ) for cell viability and apoptosis were performed in primary rat chondrocytes. The results showed that the overexpression of WISP-2 induced chondrocyte apoptosis, and knockdown of WISP-2 could suppress the chondrocyte apoptosis induced by advanced glycation end products (AGE). Additionally, WISP-2 could negatively regulate the expression of PPARγ in chondrocytes. Moreover, the knockdown of PPARγ promoted chondrocyte apoptosis and overexpression of PPARγ abated the increased apoptosis and decreased cell viability of chondrocytes induced by WISP-2. This study demonstrated that WISP-2 might contribute to chondrocyte apoptosis of hip acetabular cartilage through regulating PPARγ expression and activation, which may play an important role in the development of DDH.

Serial Xenotransplantation in NSG Mice Promotes a Hybrid Epithelial/Mesenchymal Gene Expression Signature and Stemness in Rhabdomyosarcoma Cells

Serial xenotransplantation of sorted cancer cells in immunodeficient mice remains the most complex test of cancer stem cell (CSC) phenotype. However, we have demonstrated in various sarcomas that putative CSC surface markers fail to identify CSCs, thereby impeding the isolation of CSCs for subsequent analyses. Here, we utilized serial xenotransplantation of unsorted rhabdomyosarcoma cells in NOD/SCID gamma (NSG) mice as a proof-of-principle platform to investigate the molecular signature of CSCs. Indeed, serial xenotransplantation steadily enriched for rhabdomyosarcoma stem-like cells characterized by enhanced aldehyde dehydrogenase activity and increased colony and sphere formation capacity in vitro. Although the expression of core pluripotency factors (SOX2, OCT4, NANOG) and common CSC markers (CD133, ABCG2, nestin) was maintained over the passages in mice, gene expression profiling revealed gradual changes in several stemness regulators and genes linked with undifferentiated myogenic precursors, e.g., SOX4, PAX3, MIR145, and CDH15. Moreover, we identified the induction of a hybrid epithelial/mesenchymal gene expression signature that was associated with the increase in CSC number. In total, 60 genes related to epithelial or mesenchymal traits were significantly altered upon serial xenotransplantation. In silico survival analysis based on the identified potential stemness-associated genes demonstrated that serial xenotransplantation of unsorted rhabdomyosarcoma cells in NSG mice might be a useful tool for the unbiased enrichment of CSCs and the identification of novel CSC-specific targets. Using this approach, we provide evidence for a recently proposed link between the hybrid epithelial/mesenchymal phenotype and cancer stemness.

A Cellular Taxonomy of the Bone Marrow Stroma in Homeostasis and Leukemia

Stroma is a poorly defined non-parenchymal component of virtually every organ with key roles in organ development, homeostasis, and repair. Studies of the bone marrow stroma have defined individual populations in the stem cell niche regulating hematopoietic regeneration and capable of initiating leukemia. Here, we use single-cell RNA sequencing (scRNA-seq) to define a cellular taxonomy of the mouse bone marrow stroma and its perturbation by malignancy. We identified seventeen stromal subsets expressing distinct hematopoietic regulatory genes spanning new fibroblastic and osteoblastic subpopulations including distinct osteoblast differentiation trajectories. Emerging acute myeloid leukemia impaired mesenchymal osteogenic differentiation and reduced regulatory molecules necessary for normal hematopoiesis. These data suggest that tissue stroma responds to malignant cells by disadvantaging normal parenchymal cells. Our taxonomy of the stromal compartment provides a comprehensive bone marrow cell census and experimental support for cancer cell crosstalk with specific stromal elements to impair normal tissue function and thereby enable emergent cancer.

Adipose Tissue Dysfunction as Determinant of Obesity-Associated Metabolic Complications

Obesity is a critical risk factor for the development of type 2 diabetes (T2D), and its prevalence is rising worldwide. White adipose tissue (WAT) has a crucial role in regulating systemic energy homeostasis. Adipose tissue expands by a combination of an increase in adipocyte size (hypertrophy) and number (hyperplasia). The recruitment and differentiation of adipose precursor cells in the subcutaneous adipose tissue (SAT), rather than merely inflating the cells, would be protective from the obesity-associated metabolic complications. In metabolically unhealthy obesity, the storage capacity of SAT, the largest WAT depot, is limited, and further caloric overload leads to the fat accumulation in ectopic tissues (e.g., liver, skeletal muscle, and heart) and in the visceral adipose depots, an event commonly defined as “lipotoxicity.” Excessive ectopic lipid accumulation leads to local inflammation and insulin resistance (IR). Indeed, overnutrition triggers uncontrolled inflammatory responses in WAT, leading to chronic low-grade inflammation, therefore fostering the progression of IR. This review summarizes the current knowledge on WAT dysfunction in obesity and its associated metabolic abnormalities, such as IR. A better understanding of the mechanisms regulating adipose tissue expansion in obesity is required for the development of future therapeutic approaches in obesity-associated metabolic complications.

Osteoblast-Derived Vesicle Protein Content Is Temporally Regulated During Osteogenesis: Implications for Regenerative Therapies

Osteoblast-derived extracellular vesicles (EV) are a collection of secreted (sEVs) and matrix-bound nanoparticles that function as foci for mineral nucleation and accumulation. Due to the fact sEVs can be isolated directly from the culture medium of mineralizing osteoblasts, there is growing interest their application regenerative medicine. However, at present therapeutic advancements are hindered by a lack of understanding of their precise temporal contribution to matrix mineralization. This study advances current knowledge by temporally aligning sEV profile and protein content with mineralization status. sEVs were isolated from mineralizing primary osteoblasts over a period of 1, 2, and 3 weeks. Bimodal particle distributions were observed (weeks 1 and 3: 44 and 164 nm; week 2: 59 and 220 nm), indicating a heterogeneous population with dimensions characteristic of exosome- (44 and 59 nm) and microvesicle-like (164 and 220 nm) particles. Proteomic characterization by liquid chromatography tandem-mass spectrometry (LC-MS/MS) revealed a declining correlation in EV-localized proteins as mineralization advanced, with Pearson correlation-coefficients of 0.79 (week 1 vs. 2), 0.6 (2 vs. 3) and 0.46 (1 vs. 3), respectively. Principal component analysis (PCA) further highlighted a time-dependent divergence in protein content as mineralization advanced. The most significant variations were observed at week 3, with a significant (p < 0.05) decline in particle concentration, visual evidence of EV rupture and enhanced mineralization. A total of 116 vesicle-localized proteins were significantly upregulated at week 3 (56% non-specifically, 19% relative to week 1, 25% relative to week 2). Gene ontology enrichment analysis of these proteins highlighted overrepresentation of genes associated with matrix organization. Of note, increased presence of phospholipid-binding and calcium channeling annexin proteins (A2, A5, and A6) indicative of progressive variations in the nucleational capacity of vesicles, as well as interaction with the surrounding ECM. We demonstrate sEV-mediated mineralization is dynamic process with variations in vesicle morphology and protein content having a potential influence on developmental changes matrix organization. These findings have implications for the selection and application of EVs for regenerative applications.

EHD2 regulates adipocyte function and is enriched at cell surface-associated lipid droplets in primary human adipocytes

Adipocytes play a central role in energy balance, and dysfunctional adipose tissue severely affects systemic energy homeostasis. The ATPase EH domain–containing 2 (EHD2) has previously been shown to regulate caveolae, plasma membrane-specific domains that are involved in lipid uptake and signal transduction. Here, we investigated the role of EHD2 in adipocyte function. We demonstrate that EHD2 protein expression is highly up-regulated at the onset of triglyceride accumulation during adipocyte differentiation. Small interfering RNA–mediated EHD2 silencing affected the differentiation process and impaired insulin sensitivity, lipid storage capacity, and lipolysis. Fluorescence imaging revealed localization of EHD2 to caveolae, close to cell surface–associated lipid droplets in primary human adipocytes. These lipid droplets stained positive for glycerol transporter aquaporin 7 and phosphorylated perilipin-1 following adrenergic stimulation. Further, EHD2 overexpression in human adipocytes increased the lipolytic signaling and suppressed the activity of transcription factor PPARγ. Overall, these data suggest that EHD2 plays a key role for adipocyte function.

Impaired Adipogenesis and Dysfunctional Adipose Tissue in Human Hypertrophic Obesity

The subcutaneous adipose tissue (SAT) is the largest and best storage site for excess lipids. However, it has a limited ability to expand by recruiting and/or differentiating available precursor cells. When inadequate, this leads to a hypertrophic expansion of the cells with increased inflammation, insulin resistance, and a dysfunctional prolipolytic tissue. Epi-/genetic factors regulate SAT adipogenesis and genetic predisposition for type 2 diabetes is associated with markers of an impaired SAT adipogenesis and development of hypertrophic obesity also in nonobese individuals. We here review mechanisms for the adipose precursor cells to enter adipogenesis, emphasizing the role of bone morphogenetic protein-4 (BMP-4) and its endogenous antagonist gremlin-1, which is increased in hypertrophic SAT in humans. Gremlin-1 is a secreted and a likely important mechanism for the impaired SAT adipogenesis in hypertrophic obesity. Transiently increasing BMP-4 enhances adipogenic commitment of the precursor cells while maintained BMP-4 signaling during differentiation induces a beige/brown oxidative phenotype in both human and murine adipose cells. Adipose tissue growth and development also requires increased angiogenesis, and BMP-4, as a proangiogenic molecule, may also be an important feedback regulator of this. Hypertrophic obesity is also associated with increased lipolysis. Reduced lipid storage and increased release of FFA by hypertrophic SAT are important mechanisms for the accumulation of ectopic fat in the liver and other places promoting insulin resistance. Taken together, the limited expansion and storage capacity of SAT is a major driver of the obesity-associated metabolic complications.

CCN5 knockout mice exhibit lipotoxic cardiomyopathy with mild obesity and diabetes

Obesity is associated with various human disorders, such as type 2 diabetes, cardiovascular diseases, hypertension, and cancers. In this study, we observed that knockout (KO) of CCN5, which encodes a matricellular protein, caused mild obesity in mice. The CCN5 KO mice also exhibited mild diabetes characterized by high fasting glucose levels and impaired insulin and glucose tolerances. Cardiac hypertrophy, ectopic lipid accumulation, and impaired lipid metabolism in hearts were observed in the CCN5 KO mice, as determined using histology, quantitative RT-PCR, and western blotting. Fibrosis was significantly greater in hearts from the CCN5 KO mice both in interstitial and perivascular regions, which was accompanied by higher expression of pro-fibrotic and pro-inflammatory genes. Both systolic and diastolic functions were significantly impaired in hearts from the CCN5 KO mice, as assessed using echocardiography. Taken together, these results indicate that CCN5 KO leads to lipotoxic cardiomyopathy with mild obesity and diabetes in mice.

EFFECTS OF BODY WEIGHT REDUCTION ON ARTERIAL STIFFNESS AND ENDOTHELIAL FUNCTION AFTER BARIATRIC SURGERY IN MORBIDLY OBESE PATIENTS: A 4-YEAR CLINICAL STUDY

OBJECTIVE

To determine the long-term effect of weight loss on arterial stiffness, metabolic parameters in morbidly obese patients who underwent laparoscopic adjustable gastric banding (LAGB).

SUBJECTS

Forty-eight morbidly obese Caucasian subjects underwent LAGB from January 2009 to January 2010 and completed 4 years follow-up.

MEASUREMENTS

Patients were evaluated for body mass index (BMI), waist circumference, arterial blood pressure (BP), metabolic factors: leptin, adiponectin, glucose, glycated haemoglobin (HbA1c), insulin. Endothelial function - evaluated as reactive hyperemic index (RHI). Arterial stiffness - determined by cardio - ankle vascular index (CAVI).

RESULTS

Average BMI decreased from 46.48±7.06 kg/m2 to 39.78±7.36 kg/m2 (1year, p<0.001) and 37.29±7.49 kg/m2 (4years, p=0.012). The systolic BP and heart rate reduction were observed after the 4 years. Changes in cardiovascular parameters were accompanied by waist circumference reduction and improvement of glucose metabolism,reduction of insulin, HbA1c, leptin, C-reactive protein values. However, there were statistically significant increases in CAVI 6.58±1.77m/s vs. 7.03±2.00 m/s (p=0.014) at 1 year, but not significant 7.12±2.19 (p=0.153) after 4 years. Endothelial changes were observed only in diabetic patients one year after LAGB 2.18±0.57 vs. 1.86±0.34 (p=0.021) vs. 2.05±0.42 (p=0.086).

CONCLUSION

Weight reduction induced by LAGB was associated with changes in body weight and metabolic parameters, but it was no improvement on endothelial function and arterial stiffness.

CCN5/WISP2 and metabolic diseases

Obesity and type 2 diabetes increase worldwide at an epidemic rate. It is expected that by the year 2030 around 500 million people will have diabetes; predominantly type 2 diabetes. The CCN family of proteins has become of interest in both metabolic and other common human diseases because of their effects on mesenchymal stem cell (MSCs) proliferation and differentiation as well as being important regulators of fibrosis. We here review current knowledge of the WNT1 inducible signaling pathway protein 2 (CCN5/WISP2). It has been shown to be an important regulator of both these processes through effects on both the canonical WNT and the TGFβ pathways. It is also under normal regulation by the adipogenic commitment factor BMP4, in contrast to conventional canonical WNT ligands, and allows MSCs to undergo normal adipose cell differentiation. CCN5/WISP2 is highly expressed in, and secreted by, MSCs and is an important regulator of MSCs growth. In a transgenic mouse model overexpressing CCN5/WISP2 in the adipose tissue, we have shown that it is secreted and circulating in the blood, the mice develop hypercellular white and brown adipose tissue, have increased lean body mass and enlarged hypercellular hearts. Obese transgenic mice had improved insulin sensitivity. Interestingly, the anti-fibrotic effect of CCN5/WISP2 is protective against heart failure by inhibition of the TGFβ pathway. Understanding how CCN5/WISP2 is regulated and signals is important and may be useful for developing new treatment strategies in obesity and metabolic diseases and it can also be a target in regenerative medicine.

Characterization of bone morphology in CCN5/WISP5 knockout mice

CCN5/WISP2 is part of the CCN family of matricellular proteins, but is distinct in that it lacks the C-terminal (CT) domain. Although CCN5 has been shown to impact cell proliferation and differentiation in vitro, its role in vivo is unclear. We therefore generated mice using ES cells developed by the Knockout Mouse Project (KOMP) in which exons 2-5, which encode the all of the conserved protein coding regions, are replaced by a lacZ cassette. Ccn5 ^LacZ/LacZ mice were viable and apparently normal. Based on previous studies showing that CCN5 impacts osteoblast proliferation and differentiation, we performed an analysis of adult bone phenotype. LacZ expression was examined in adult bone, and was found to be strong within the periosteum, but not in trabecular bone or bone marrow. Micro-CT analysis revealed no apparent changes in bone mineral density (BMD) or bone tissue volume (BV/TV) in Ccn5 ^LacZ/LacZ mice. These studies indicate that CCN5 is not required for normal bone formation, but they do not rule out a role in mechanotransduction or repair processes. The availability of Ccn5 ^LacZ mice enables studies of CCN5 expression and function in multiple tissues.

Amplification of Adipogenic Commitment by VSTM2A

Despite progress in our comprehension of the mechanisms regulating adipose tissue development, the nature of the factors that functionally characterize adipose precursors is still elusive. Defining the early steps regulating adipocyte development is needed for the generation of tools to control adipose tissue size and function. Here, we report the discovery of V-set and transmembrane domain containing 2A (VSTM2A) as a protein expressed and secreted by committed preadipocytes. VSTM2A expression is elevated in the early phases of adipogenesis in vitro and adipose tissue development in vivo. We show that VSTM2A-producing cells associate with the vasculature and express the common surface markers of adipocyte progenitors. Overexpression of VSTM2A induces adipogenesis, whereas its depletion impairs this process. VSTM2A controls preadipocyte determination at least in part by modulating BMP signaling and PPARγ2 activation. We propose a model in which VSTM2A is produced to preserve and amplify the adipogenic capability of adipose precursors.

Wisp2 disruption represses Cxcr4 expression and inhibits BMSCs homing to injured liver

Liver regeneration/repair is a compensatory regrowth following acute liver failure, and bone marrow-derived mesenchyme stem cell (BMSC) transplantation is an effective therapy that promotes liver regeneration/repair. Wnt1 inducible signaling pathway protein 2 (Wisp2) is highly expressed in BMSCs, however, its function remains unclear. In this work, we used clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein -9 nuclease (CRISPR/Cas9) genome editing technology to knockdown Wisp2 in BMSCs, and these modified cells were then transplanted into rats which were induced by the 2-AAF/PH. By linking the expression of Cas9 to green fluorescent protein (GFP), we tracked BMSCs in the rats. Disruption of Wisp2 inhibited the homing of BMSCs to injured liver and aggravated liver damage as indicated by remarkably high levels of ALT and AST. Moreover, the key factor in BMSC transplantation, C-X-C chemokine receptor type 4 (Cxcr4), was down-regulated in the Wisp2 depleted BMSCs and had a lower expression in the livers of the corresponding rats. By tracing the GFP marker, more BMSCs were observed to differentiate into CD31 positive endothelial cells in the functional Wisp2 cells but less in the Wisp2 gene disrupted cells. In summary, Wisp2 promotes the homing of BMSCs through Cxcr4 related signaling during liver repair in rats.

Effective tumor immunity to melanoma mediated by B16F10 cancer stem cell vaccine

Although tumor vaccines have been considered a promising immunotherapy approach, therapeutic tumor vaccines are mostly disappointing in the clinic due to vaccine weak immunogenicity. Cancer stem cells (CSCs) may broaden the antigenic breadth and effectively induce the immune responses against autologous cancer cells. Here we report on the development of the B16F10 CD133⁺CD44⁺CSCs (B16F10 CSCs) vaccine to induce tumor immunity to melanoma in mice. Efficacy of against melanoma was evaluated by analysis of tumor growth and mouse survival. Immunogenicity was assessed by ELISA and flow cytometric assays, including serum cytokines, cytotoxic activity of NK cells and splenocytes in the immunized mice. The results showed that the B16F10 CSC vaccine resulted in tumor shrinkage and mouse lifespan extension. The cytotoxic activity and IFN-γ level were significantly increased in mice immunized with B16F10 CSC vaccine compared with the mice immunized with control vaccines. Additionally, New York esophageal squamous cell carcinoma-1, an efficient tumor associated antigen over-expressed by B16F10 CSCs, was markedly reduced in expression in melanoma tissue, suggesting decrease of CSC subpopulation due to B16F10 CSC vaccination. Collectively, the findings may represent a new powerful approach for treatment of melanoma by B16F10 CSC vaccination.

CDK5 Regulatory Subunit-Associated Protein 1-like 1 Negatively Regulates Adipocyte Differentiation through Activation of Wnt Signaling Pathway

CDK5 Regulatory Subunit-Associated Protein 1-like 1 (CDKAL1) was identified as a susceptibility gene for type 2 diabetes and body mass index in genome-wide association studies. Although it was reported that CDKAL1 is a methylthiotransferase essential for tRNA^Lys(UUU) and faithful translation of proinsulin generated in pancreatic β cells, the role of CDKAL1 in adipocytes has not been understood well. In this study, we found that CDKAL1 is expressed in adipose tissue and its expression is increased during differentiation. Stable overexpression of CDKAL1, however, inhibited adipocyte differentiation of 3T3-L1 cells, whereas knockdown of CDKAL1 promoted differentiation. CDKAL1 increased protein levels of β-catenin and its active unphosphorylated form in the nucleus, thereby promoting Wnt target gene expression, suggesting that CDKAL1 activated the Wnt/β-catenin pathway—a well-characterized inhibitory regulator of adipocyte differentiation. Mutant experiments show that conserved cysteine residues of Fe-S clusters of CDKAL1 are essential for its anti-adipogenic action. Our results identify CDKAL1 as novel negative regulator of adipocyte differentiation and provide insights into the link between CDKAL1 and metabolic diseases such as type 2 diabetes and obesity.

WISP1/CCN4 inhibits adipocyte differentiation through repression of PPARγ activity

WISP1 (Wnt1-inducible signaling pathway protein-1, also known as CCN4) is a member of the CCN family able to mediate cell growth, transformation and survival in a tissue-specific manner. Here, we report that WISP1 expression was highly increased in preadipocytes and decreased during adipocyte differentiation. Moreover, we observed an increase in WISP1 gene expression in adipose tissue from both diet-induced and leptin-deficient ob/ob obese mice, suggesting that WISP1 could be involved in the pathophysiological onset of obesity. Interestingly, overexpression of WISP1 in 3T3-F442A cells prevented adipocyte differentiation via downregulation of peroxisome proliferator-activated receptor (PPARγ) transcriptional activity thereby attenuating the expression of adipogenic markers. Conversely, silencing of WISP1 enhanced adipocyte differentiation. We further show that the inactivation of PPARγ transcriptional activity was mediated, at least in part, by a direct physical association between WISP1 and PPARγ, followed by proteasome-dependent degradation of PPARγ. These results suggest for the first time that WISP1 interacts with PPARγ and that this interaction results in the inhibition of PPARγ activity. Taken together our results suggest that WISP1 functions as a negative regulator of adipogenesis.

Systemic and Local Adipose Tissue in Knee Osteoarthritis

Osteoarthritis is a common chronic joint disorder affecting older people. The knee is the major joint affected. The symptoms of osteoarthritis include limited range of motion, joint swelling, and pain causing disability. There are no disease modifying drugs available, and treatments are mainly focused on pain management. Total knee replacement performed at the end stage of the disease is considered the only cure available. It has been found that obese people have an increased risk to develop not only knee but also hand osteoarthritis. This supports the concept that adipose tissue might be related to osteoarthritis not only through overloading. As matter of fact, obesity induces a low grade systemic inflammatory state characterized by the production and secretion of several adipocytokines that may have a role in osteoarthritis development. Furthermore, hypertension, impaired glucose, and lipid metabolism, which are comorbidities associated with obesity, have been shown to alter the joint tissue homeostasis. Moreover, infrapatellar fat pad in the knee has been demonstrated to be a local source of adipocytokines and potentially contribute to osteoarthritis pathogenesis. Here, we discuss the role of systemic and local adipose tissue in knee osteoarthritis. J. Cell. Physiol. 232: 1971-1978, 2017. © 2016 Wiley Periodicals, Inc.

Overexpressing the novel autocrine/endocrine adipokine WISP2 induces hyperplasia of the heart, white and brown adipose tissues and prevents insulin resistance

WISP2 is a novel adipokine, most highly expressed in the adipose tissue and primarily in undifferentiated mesenchymal cells. As a secreted protein, it is an autocrine/paracrine activator of canonical WNT signaling and, as an intracellular protein, it helps to maintain precursor cells undifferentiated. To examine effects of increased WISP2 in vivo, we generated an aP2-WISP2 transgenic (Tg) mouse. These mice had increased serum levels of WISP2, increased lean body mass and whole body energy expenditure, hyperplastic brown/white adipose tissues and larger hyperplastic hearts. Obese Tg mice remained insulin sensitive, had increased glucose uptake by adipose cells and skeletal muscle in vivo and ex vivo, increased GLUT4, increased ChREBP and markers of adipose tissue lipogenesis. Serum levels of the novel fatty acid esters of hydroxy fatty acids (FAHFAs) were increased and transplantation of Tg adipose tissue improved glucose tolerance in recipient mice supporting a role of secreted FAHFAs. The growth-promoting effect of WISP2 was shown by increased BrdU incorporation in vivo and Tg serum increased mesenchymal precursor cell proliferation in vitro. In contrast to conventional canonical WNT ligands, WISP2 expression was inhibited by BMP4 thereby allowing normal induction of adipogenesis. WISP2 is a novel secreted regulator of mesenchymal tissue cellularity.

Blockade to pathological remodeling of infarcted heart tissue using a porcupine antagonist

The secreted Wnt signaling molecules are essential to the coordination of cell-fate decision making in multicellular organisms. In adult animals, the secreted Wnt proteins are critical for tissue regeneration and frequently contribute to cancer. Small molecules that disable the Wnt acyltransferase Porcupine (Porcn) are candidate anticancer agents in clinical testing. Here we have systematically assessed the effects of the Porcn inhibitor (WNT-974) on the regeneration of several tissue types to identify potentially unwanted chemical effects that could limit the therapeutic utility of such agents. An unanticipated observation from these studies is proregenerative responses in heart muscle induced by systemic chemical suppression of Wnt signaling. Using in vitro cultures of several cell types found in the heart, we delineate the Wnt signaling apparatus supporting an antiregenerative transcriptional program that includes a subunit of the nonfibrillar collagen VI. Similar to observations seen in animals exposed to WNT-974, deletion of the collagen VI subunit, COL6A1, has been shown to decrease aberrant remodeling and fibrosis in infarcted heart tissue. We demonstrate that WNT-974 can improve the recovery of heart function after left anterior descending coronary artery ligation by mitigating adverse remodeling of infarcted tissue. Injured heart tissue exposed to WNT-974 exhibits decreased scarring and reduced Col6 production. Our findings support the development of Porcn inhibitors as antifibrotic agents that could be exploited to promote heart repair following injury.