Identification of a novel TGF-beta-regulated gene encoding a putative zinc finger protein in human osteoblasts

Peripheral blood mononuclear cell transcriptomic trajectories reveal dynamic regulation of inflammatory actors in delirium

Delirium is a neurologic syndrome characterized by inattention and cognitive impairment frequently encountered in the medically ill. Peripheral inflammation is a key trigger of delirium, but the patient-specific immune responses associated with delirium development and resolution are unknown. This retrospective cohort study of prospectively collected biospecimens examines RNA sequencing from peripheral blood mononuclear cells of adults hospitalized for COVID-19 to better understand patient-specific factors associated with delirium (n = 64). Longitudinal transcriptomic analyses highlight persistent immune dysregulation in delirium, marked by increasing expression trajectories of genes linked to innate immune pathways, including complement activation, cytokine production, and monocyte/macrophage recruitment. Genes involved adaptive immunity showed a declining trajectory over time in patients with delirium. Although corticosteroid treatment suppressed some aspects of immune hyperactivation, aberrant responses contributing to delirium were exacerbated. Delirium resolution was characterized by normalization of key transcripts such as CCL2 and innate immune markers. Novel associations with delirium were found in genes related to stress granule assembly and DUSP2 and KLF10, which mediate T-cell responses. These findings provide insights into the peripheral immune responses accompanying delirium and their modulation by corticosteroids. Future trials targeting aberrant inflammatory responses may mitigate the severe outcomes associated with delirium due to COVID19.

Klf10 Regulates the Emergence of Glial Phenotypes During Hypothalamic Development

Glial cells play a pivotal role in the Central Nervous System (CNS), constituting most brain cells. Gliogenesis, crucial in CNS development, occurs after neurogenesis. In the hypothalamus, glial progenitors first generate oligodendrocytes and later astrocytes. However, the precise molecular mechanisms governing the emergence of glial lineages in the developing hypothalamus remain incompletely understood. This study reveals the pivotal role of the transcription factor KLF10 in regulating the emergence of both astrocyte and oligodendrocyte lineages during embryonic hypothalamic development. Through transcriptomic and bioinformatic analyses, we identified novel KLF10 putative target genes, which play important roles in the differentiation of neurons, astrocytes, and oligodendrocytes. Notably, in the absence of KLF10, there is an increase in the oligodendrocyte population, while the astrocyte population decreases in the embryonic hypothalamus. Strikingly, this decline in the number of astrocytes persists into adulthood, indicating that the absence of KLF10 leads to an extended period of oligodendrocyte emergence while delaying the appearance of astrocytes. Our findings also unveil a novel signaling pathway for Klf10 gene expression regulation. We demonstrate that Klf10 is a target of CREB and that its expression is upregulated via the BDNF-p38-CREB pathway. Thus, we postulate that KLF10 is an integral part of the hypothalamic developmental program that ensures the correct timing for glial phenotypes' generation. Importantly, we propose that the Klf10-/- mouse model represents a valuable tool for investigating the impact of reduced astrocyte and microglia populations in the homeostasis of the adult hypothalamus.

KLF10 Induced by Hypothermic Machine Perfusion Alleviates Renal Inflammation Through BIRC2 /Noncanonical NF-κB Pathway

BACKGROUND

Hypothermic machine perfusion (HMP) is becoming the main preservation method for donation after circulatory death (DCD) kidneys. It can provide continuous flow and form shear stress (SS) upon endothelial cells (ECs), thereby regulating EC injury. Krüppel-like factor 10 (KLF10) has been shown to lessen vascular damage. However, how SS and KLF10 impact HMP-regulated injury is unclear.

METHODS

In this study, we investigated the influences of KLF10 on HMP in animal models and human renal biopsy and explored how SS affected KLF10 expression in a parallel-plate flow chamber system. Chromatin Immunoprecipitation sequencing and luciferase assay were performed to seek the target genes of KLF10. The influences of KLF10 on HMP-regulated injury were investigated by transfecting si-KLF10 adeno-associated virus serotype 9 into rat kidneys. The molecular expression was examined using immunofluorescence staining, Western blotting, and quantitative polymerase chain reaction.

RESULTS

Our results show KLF10 expression was augmented in human, rabbit, and rat DCD kidneys after HMP. HMP improved ECs and tubule injury and attenuated inflammation; however, the knockdown of KLF10 reversed this effect. SS regulated KLF10 expression in ECs by affecting F-actin, and KLF10 could maintain ECs homeostasis. Chromatin Immunoprecipitation sequencing and luciferase assay revealed that baculoviral inhibitor of apoptosis protein repeat-containing 2 ( BIRC2 ) is a target gene of KLF10. Furthermore, BIRC2 linked to nuclear factor kappa B (NF-κB)-inducing kinase, induced NF-κB)-inducing kinase ubiquitination, and resulted in inhibiting the noncanonical NF-κB pathway.

CONCLUSIONS

SS can mediate KLF10 expression, whereas HMP can protect against warm ischemic injury by reducing inflammation via KLF10/BIRC2/noncanonical NF-κB pathway. Therefore, KLF10 might be a novel target for improving DCD kidney quality.

Roles of SP/KLF transcription factors in odontoblast differentiation: From development to diseases

OBJECTIVES

A zinc-finger transcription factor family comprising specificity proteins (SPs) and Krüppel-like factor proteins (KLFs) plays an important role in dentin development and regeneration. However, a systematic regulatory network involving SPs/KLFs in odontoblast differentiation has not yet been described. This review examined the expression patterns of SP/KLF gene family members and their current known functions and mechanisms in odontoblast differentiation, and discussed prospective research directions for further exploration of mechanisms involving the SP/KLF gene family in dentin development.

MATERIALS AND METHODS

Relevant literature on SP/KLF gene family members and dentin development was acquired from PubMed and Web of Science.

RESULTS

We discuss the expression patterns, functions, and related mechanisms of eight members of the SP/KLF gene family in dentin development and genetic disorders with dental problems. We also summarize current knowledge about their complementary or synergistic actions. Finally, we propose future research directions for investigating the mechanisms of dentin development.

CONCLUSIONS

The SP/KLF gene family plays a vital role in tooth development. Studying the complex complementary or synergistic interactions between SPs/KLFs is helpful for understanding the process of odontoblast differentiation. Applications of single-cell and spatial multi-omics may provide a more complete investigation of the mechanism involved in dentin development.

KLF10: a point of convergence in cancer cachexia

PURPOSE OF THE REVIEW

Cancer-associated cachexia is a wasting syndrome entailing loss in body mass and a shortened life expectancy. There is currently no effective treatment to abrogate this syndrome, which leads to 20-30% of deaths in patients with cancer. While there have been advancements in defining signaling factors/pathways in cancer-induced muscle wasting, targeting the same in the clinic has not been as successful. Krüppel-like factor 10 (KLF10), a transcription factor implicated in muscle regulation, is regulated by the transforming growth factor-beta signaling pathway. This review proposes KLF10 as a potential convergence point of diverse signaling pathways involved in muscle wasting.

RECENT FINDINGS

KLF10 was discovered as a target of transforming growth factor-beta decades ago but more recently it has been shown that deletion of KLF10 rescues cancer-induced muscle wasting. Moreover, KLF10 has also been shown to bind key atrophy genes associated with muscle atrophy in vitro .

SUMMARY

There is an elevated need to explore targets in cachexia, which will successfully translate into the clinic. Investigating a convergence point downstream of multiple signaling pathways might hold promise in developing effective therapies for cachexia.

KLF transcription factors in bone diseases

Krüppel-like factors (KLFs) are crucial in the development of bone disease. They are a family of zinc finger transcription factors that are unusual in containing three highly conserved zinc finger structural domains interacting with DNA. It has been discovered that it engages in various cell functions, including proliferation, apoptosis, autophagy, stemness, invasion and migration, and is crucial for the development of human tissues. In recent years, the role of KLFs in bone physiology and pathology has received adequate attention. In addition to regulating the normal growth and development of the musculoskeletal system, KLFs participate in the pathological process of the bones and joints and are intimately linked to several skeletal illnesses, such as osteoarthritis (OA), rheumatoid arthritis (RA), osteoporosis (OP) and osteosarcoma (OS). Consequently, targeting KLFs has emerged as a promising therapeutic approach for an array of bone disorders. In this review, we summarize the current literature on the importance of KLFs in the emergence and regulation of bone illnesses, with a particular emphasis on the pertinent mechanisms by which KLFs regulate skeletal diseases. We also discuss the need for KLFs-based medication-targeted treatment. These endeavours offer new perspectives on the use of KLFs in bone disorders and provide prognostic biomarkers, therapeutic targets and possible drug candidates for bone diseases.

Multiscale analysis of Klf10's impact on the passive mechanical properties of murine skeletal muscle

Skeletal muscle is a hierarchical structure composed of multiple organizational scales. A major challenge in the biomechanical evaluation of muscle relates to the difficulty in evaluating the experimental mechanical properties at the different organizational levels of the same tissue. Indeed, the ability to integrate mechanical properties evaluated at various levels will allow for improved assessment of the entire tissue, leading to a better understanding of how changes at each level evolve over time and/or impact tissue function, especially in the case of muscle diseases. Therefore, the purpose of this study was to analyze a genetically engineered mouse model (Klf10 KO: Krüppel-Like Factor 10 knockout) with known skeletal muscle defects to compare the mechanical properties with wild-type (WT) controls at the three main muscle scales: the macroscopic (whole muscle), microscopic (fiber) and submicron (myofibril) levels. Passive mechanical tests (ramp, relaxation) were performed on two types of skeletal muscle (soleus and extensor digitorum longus (EDL)). Results of the present study revealed muscle-type specific behaviors in both genotypes only at the microscopic scale. Interestingly, loss of Klf10 expression resulted in increased passive properties in the soleus but decreased passive properties in the EDL compared to WT controls. At the submicron scale, no changes were observed between WT and Klf10 KO myofibrils for either muscle; these results demonstrate that the passive property differences observed at the microscopic scale (fiber) are not caused by sarcomere intrinsic alterations but instead must originate outside the sarcomeres, likely in the collagen-based extracellular matrix. The macroscopic scale revealed similar passive mechanical properties between WT and Klf10 KO hindlimb muscles. The present study has allowed for a better understanding of the role of Klf10 on the passive mechanical properties of skeletal muscle and has provided reference data to the literature which could be used by the community for muscle multiscale modeling.

New Insights into the Role of KLF10 in Tissue Fibrosis

Fibrosis, characterized by excessive extracellular matrix accumulation, disrupts normal tissue architecture, causes organ dysfunction, and contributes to numerous chronic diseases. This review focuses on Krüppel-like factor 10 (KLF10), a transcription factor significantly induced by transforming growth factor-β (TGF-β), and its role in fibrosis pathogenesis and progression across various tissues. KLF10, initially identified as TGF-β-inducible early gene-1 (TIEG1), is involved in key biological processes including cell proliferation, differentiation, apoptosis, and immune responses. Our analysis investigated KLF10 gene and protein structures, interaction partners, and context-dependent functions in fibrotic diseases. This review highlights recent findings that underscore KLF10 interaction with pivotal signaling pathways, such as TGF-β, and the modulation of gene expression in fibrotic tissues. We examined the dual role of KLF10 in promoting and inhibiting fibrosis depending on tissue type and fibrotic context. This review also discusses the therapeutic potential of targeting KLF10 in fibrotic diseases, based on its regulatory role in key pathogenic mechanisms. By consolidating current research, this review aims to enhance the understanding of the multifaceted role of KLF10 in fibrosis and stimulate further research into its potential as a therapeutic target in combating fibrotic diseases.

Klf10 is involved in extracellular matrix calcification of chondrocytes alleviating chondrocyte senescence

Osteoarthritis (OA) is a chronic degenerative disease resulting joint disability and pain. Accumulating evidences suggest that chondrocyte extracellular matrix calcification plays an important role in the development of OA. Here, we showed that Krüppel-like factor 10 (Klf10) was involved in the regulation of chondrocyte extracellular matrix calcification by regulating the expression of Frizzled9. Knockdown of Klf10 attenuated TBHP induced calcification and reduced calcium content in chondrocytes. Restoring extracellular matrix calcification of chondrocytes could aggravate chondrocyte senescence. Destabilization of a medial meniscus (DMM) mouse model of OA, in vivo experiments revealed that knockdown Klf10 improved the calcification of articular cartilage and ameliorated articular cartilage degeneration. These findings suggested that knockdown Klf10 inhibited extracellular matrix calcification-related changes in chondrocytes and alleviated chondrocyte senescence.

Loss of Krüppel-like factor-10 facilitates the development of chemical-induced liver cancer in mice

BACKGROUND

Krüppel-like factor 10 (KLF10) is involved in a positive feedback loop that regulates transforming growth factor β (TGFβ) signaling, and TGFβ plays an important role in the pathogenesis of liver disease. Here, we investigated whether KLF10 deletion affects the development of liver fibrosis and hepatocellular carcinoma (HCC).

METHODS

We induced KLF10 deletion in C57BL/6 mice. Liver fibrosis was induced by feeding a diet high in fat and sucrose (high-fat diet [HFD]), whereas HCC was produced by intraperitoneal administration of N-diethylnitrosamine (DEN). An in vitro experiment was performed to evaluate the role of KLF10 in the cancer microenvironment using Hep3B and LX2 cells. An immunohistochemical study of KLF10 expression was performed using human HCC samples from 60 patients who had undergone liver resection.

RESULTS

KLF10 deletion resulted in an increased DEN-induced HCC burden with significant upregulation of SMAD2, although loss of KLF10 did not alter HFD-induced liver fibrosis. DEN-treated mice with KLF10 deletion exhibited increased levels of mesenchymal markers (N-cadherin and SNAI2) and tumor metastasis markers (matrix metalloproteinases 2 and 9). KLF10 depletion in Hep3B and LX2 cells using siRNA was associated with increased invasiveness. Compared with co-culture of KLF10-preserved Hep3B cells and KLF10-intact LX2 cells, co-culture of KLF10-preserved Hep3B cells and KLF10-depleted LX2 cells resulted in significantly enhanced invasion. Low KLF10 expression in resected human HCC specimens was associated with poor survival.

CONCLUSION

The results of this study suggest that loss of KLF10 facilitates liver cancer development with alteration in TGFβ signaling.

Krüppel-like Factor 10 as a Prognostic and Predictive Biomarker of Radiotherapy in Pancreatic Adenocarcinoma

The prognosis of pancreatic adenocarcinoma (PDAC) remains poor, with a 5-year survival rate of 12%. Although radiotherapy is effective for the locoregional control of PDAC, it does not have survival benefits compared with systemic chemotherapy. Most patients with localized PDAC develop distant metastasis shortly after diagnosis. Upfront chemotherapy has been suggested so that patients with localized PDAC with early distant metastasis do not have to undergo radical local therapy. Several potential tissue markers have been identified for selecting patients who may benefit from local radiotherapy, thereby prolonging their survival. This review summarizes these biomarkers including SMAD4, which is significantly associated with PDAC failure patterns and survival. In particular, Krüppel-like factor 10 (KLF10) is an early response transcription factor of transforming growth factor (TGF)-β. Unlike TGF-β in advanced cancers, KLF10 loss in two-thirds of patients with PDAC was associated with rapid distant metastasis and radioresistance; thus, KLF10 can serve as a predictive and therapeutic marker for PDAC. For patients with resectable PDAC, a combination of KLF10 and SMAD4 expression in tumor tissues may help select those who may benefit the most from additional radiotherapy. Future trials should consider upfront systemic therapy or include molecular biomarker-enriched patients without early distant metastasis.

TGF-β1 activates neutrophil signaling and gene expression but not migration

Tumor-associated neutrophils are found in many types of cancer and are often reported to contribute to negative outcomes. The presence of transforming growth factor-beta (TGF-β) in the tumor microenvironment reportedly contributes to the skewing of neutrophils to a more pro-tumor phenotype. The effects of TGF-β on neutrophil signaling and migration are, however, unclear. We sought to characterize TGF-β signaling in both primary human neutrophils and the neutrophil-like cell line HL-60 and determine whether it directly induces neutrophil migration. We found that TGF-β1 does not induce neutrophil chemotaxis in transwell or underagarose migration assays. TGF-β1 does activate canonical signaling through SMAD3 and noncanonical signaling through ERK1/2 in neutrophils in a time- and dose-dependent manner. Additionally, TGF-β1 present in the tumor-conditioned media (TCM) of invasive breast cancer cells results in SMAD3 activation. We discovered that TCM induces neutrophils to secrete leukotriene B4 (LTB4), which is a lipid mediator important for amplifying the range of neutrophil recruitment. However, TGF-β1 alone does not induce secretion of LTB4. RNA-sequencing revealed that TGF-β1 and TCM alter gene expression in HL-60 cells, including the mRNA levels of the pro-tumor oncostatin M (OSM) and vascular endothelial growth factor A (VEGFA). These new insights into the role and impact of TGF-β1 on neutrophil signaling, migration, and gene expression have significant implications in the understanding of the changes in neutrophils that occur in the tumor microenvironment.

A TGF-β/KLF10 signaling axis regulates atrophy-associated genes to induce muscle wasting in pancreatic cancer

Cancer cachexia, and its associated complications, represent a large and currently untreatable roadblock to effective cancer management. Many potential therapies have been proposed and tested-including appetite stimulants, targeted cytokine blockers, and nutritional supplementation-yet highly effective therapies are lacking. Innovative approaches to treating cancer cachexia are needed. Members of the Kruppel-like factor (KLF) family play wide-ranging and important roles in the development, maintenance, and metabolism of skeletal muscle. Within the KLF family, we identified KLF10 upregulation in a multitude of wasting contexts-including in pancreatic, lung, and colon cancer mouse models as well as in human patients. We subsequently interrogated loss-of-function of KLF10 as a potential strategy to mitigate cancer associated muscle wasting. In vivo studies leveraging orthotopic implantation of pancreas cancer cells into wild-type and KLF10 KO mice revealed significant preservation of lean mass and robust suppression of pro-atrophy muscle-specific ubiquitin ligases Trim63 and Fbxo32, as well as other factors implicated in atrophy, calcium signaling, and autophagy. Bioinformatics analyses identified Transforming growth factor beta (TGF-β), a known inducer of KLF10 and cachexia promoting factor, as a key upstream regulator of KLF10. We provide direct in vivo evidence that KLF10 KO mice are resistant to the atrophic effects of TGF-β. ChIP-based binding studies demonstrated direct binding to Trim63, a known wasting-associated atrogene. Taken together, we report a critical role for the TGF-β/KLF10 axis in the etiology of pancreatic cancer-associated muscle wasting and highlight the utility of targeting KLF10 as a strategy to prevent muscle wasting and limit cancer-associated cachexia.

KLF10 Inhibits TGF-β-Mediated Activation of Hepatic Stellate Cells via Suppression of ATF3 Expression

Liver fibrosis is a progressive and debilitating condition characterized by the excessive deposition of extracellular matrix proteins. Stellate cell activation, a major contributor to fibrogenesis, is influenced by Transforming growth factor (TGF-β)/SMAD signaling. Although Krüppel-like-factor (KLF) 10 is an early TGF-β-inducible gene, its specific role in hepatic stellate cell activation remains unclear. Our previous study demonstrated that KLF10 knockout mice develop severe liver fibrosis when fed a high-sucrose diet. Based on these findings, we aimed to identify potential target molecules involved in liver fibrosis and investigate the mechanisms underlying the KLF10 modulation of hepatic stellate cell activation. By RNA sequencing analysis of liver tissues from KLF10 knockout mice with severe liver fibrosis induced by a high-sucrose diet, we identified ATF3 as a potential target gene regulated by KLF10. In LX-2 cells, an immortalized human hepatic stellate cell line, KLF10 expression was induced early after TGF-β treatment, whereas ATF3 expression showed delayed induction. KLF10 knockdown in LX-2 cells enhanced TGF-β-mediated activation, as evidenced by elevated fibrogenic protein levels. Further mechanistic studies revealed that KLF10 knockdown promoted TGF-β signaling and upregulated ATF3 expression. Conversely, KLF10 overexpression suppressed TGF-β-mediated activation and downregulated ATF3 expression. Furthermore, treatment with the chemical chaperone 4-PBA attenuated siKLF10-mediated upregulation of ATF3 and fibrogenic responses in TGF-β-treated LX-2 cells. Collectively, our findings suggest that KLF10 acts as a negative regulator of the TGF-β signaling pathway, exerting suppressive effects on hepatic stellate cell activation and fibrogenesis through modulation of ATF3 expression. These results highlight the potential therapeutic implications of targeting the KLF10-ATF3 axis in liver fibrosis treatment.

TGF-β1 activates neutrophil signaling and gene expression but not migration

Tumor-associated neutrophils are found in many types of cancer and are often reported to contribute to negative outcomes. The presence of transforming growth factor-beta (TGF-β) in the tumor microenvironment reportedly contributes to the skewing of neutrophils to a more pro-tumor phenotype. The effects of TGF-β on neutrophil signaling and migration are, however, unclear. We sought to characterize TGF-β signaling in both primary human neutrophils and the neutrophil-like cell line HL-60 and determine whether it directly induces neutrophil migration. We found that TGF-β1 does not induce neutrophil chemotaxis in transwell or underagarose migration assays. TGF-β1 does activate canonical signaling through SMAD3 and noncanonical signaling through ERK1/2 in neutrophils in a time-and dose-dependent manner. Additionally, TGF-β1 present in the tumor-conditioned media (TCM) of invasive breast cancer cells results in SMAD3 activation. We discovered that TCM induces neutrophils to secrete leukotriene B 4 (LTB 4 ), which is a lipid mediator important for amplifying the range of neutrophil recruitment. However, TGF-β1 alone does not induce secretion of LTB 4 . RNA-sequencing revealed that TGF-β1 and TCM alter gene expression in HL-60 cells, including the mRNA levels of the pro-tumor oncostatin M ( OSM ) and vascular endothelial growth factor A ( VEGFA ). These new insights into the role and impact of TGF-β1 on neutrophil signaling, migration, and gene expression have significant implications in the understanding of the changes in neutrophils that occur in the tumor microenvironment.

Krüppel-like factor 10 (KLF10) as a critical signaling mediator: Versatile functions in physiological and pathophysiological processes

Krüppel-like factor 10 (KLF10), also known as TGFβ-inducible early gene-1 (TIEG1), was first found in human osteoblasts. Early studies show that KLF10 plays an important role in osteogenic differentiation. Through decades of research, KLF10 has been found to have complex functions in many different cell types, and its expression and function is regulated in multiple ways. As a downstream factor of transforming growth factor β (TGFβ)/SMAD signaling, KLF10 is involved in various biological functions, including glucose and lipid metabolism in liver and adipose tissue, the maintenance of mitochondrial structure and function of the skeletal muscle, cell proliferation and apoptosis, and plays roles in multiple disease processes, such as nonalcoholic steatohepatitis (NASH) and tumor. Besides, KLF10 shows gender-dependent difference of regulation and function in many aspects. In this review, the biological functions of KLF10 and its roles in disease states is updated and discussed, which would provide new insights into the functional roles of KLF10 and a clearer view of potential therapeutic strategies by targeting KLF10.

Identification of actionable targets for breast cancer intervention using a diversity outbred mouse model

HER2-targeted therapy has improved breast cancer survival, but treatment resistance and disease prevention remain major challenges. Genes that enable HER2/Neu oncogenesis are the next intervention targets. A bioinformatics discovery platform of HER2/Neu-expressing Diversity Outbred (DO) F1 Mice was established to identify cancer-enabling genes. Quantitative Trait Loci (QTL) associated with onset ages and growth rates of spontaneous mammary tumors were sought. Twenty-six genes in 3 QTL contain sequence variations unique to the genetic backgrounds that are linked to aggressive tumors and 21 genes are associated with human breast cancer survival. Concurrent identification of TSC22D3, a transcription factor, and its target gene LILRB4, a myeloid cell checkpoint receptor, suggests an immune axis for regulation, or intervention, of disease. We also investigated TIEG1 gene that impedes tumor immunity but suppresses tumor growth. Although not an actionable target, TIEG1 study revealed genetic regulation of tumor progression, forming the basis of the genetics-based discovery platform.

Downregulation of KLF10 contributes to the regeneration of survived renal tubular cells in cisplatin-induced acute kidney injury via ZBTB7A-KLF10-PTEN axis

Acute kidney injury (AKI) is a common clinical dysfunction with complicated pathophysiology and limited therapeutic methods. Renal tubular injury and the following regeneration process play a vital role in the course of AKI, but the underlining molecular mechanism remains unclear. In this study, network-based analysis of online transcriptional data of human kidney found that KLF10 was closely related to renal function, tubular injury and regeneration in various renal diseases. Three classical mouse models confirmed the downregulation of KLF10 in AKI and its correlation with tubular regeneration and AKI outcome. The 3D renal tubular model in vitro and fluorescent visualization system of cellular proliferation were constructed to show that KLF10 declined in survived cells but increased during tubular formation or conquering proliferative impediment. Furthermore, overexpression of KLF10 significantly inhibited, whereas knockdown of KLF10 extremely promoted the capacity of proliferation, injury repairing and lumen-formation of renal tubular cells. In mechanism, PTEN/AKT pathway were validated as the downstream of KLF10 and participated in its regulation of tubular regeneration. By adopting proteomic mass spectrum and dual-luciferase reporter assay, ZBTB7A were found to be the upstream transcription factor of KLF10. Our findings suggest that downregulation of KLF10 positively contributed to tubular regeneration in cisplatin induced acute kidney injury via ZBTB7A-KLF10-PTEN axis, which gives insight into the novel therapeutic and diagnostical target of AKI.

Inhibition of Klf10 Attenuates Oxidative Stress-Induced Senescence of Chondrocytes via Modulating Mitophagy

Osteoarthritis (OA) is the most prevalent degenerative joint disease in the elderly. Accumulation of evidence has suggested that chondrocyte senescence plays a significant role in OA development. Here, we show that Krüppel-like factor 10 (Klf10), also named TGFβ inducible early gene-1 (TIEG1), is involved in the pathology of chondrocyte senescence. Knocking down the Klf10 in chondrocytes attenuated the tert-butyl hydroperoxide (TBHP)-induced senescence, inhibited generation of reactive oxygen species (ROS), and maintained mitochondrial homeostasis by activating mitophagy. These findings suggested that knocking down Klf10 inhibited senescence-related changes in chondrocytes and improved cartilage homeostasis, indicating that Klf10 may be a therapeutic target for protecting cartilage against OA.

Kruppel-like Factors in Skeletal Physiology and Pathologies

Kruppel-like factors (KLFs) belong to a large group of zinc finger-containing transcription factors with amino acid sequences resembling the Drosophila gap gene Krüppel. Since the first report of molecular cloning of the KLF family gene, the number of KLFs has increased rapidly. Currently, 17 murine and human KLFs are known to play crucial roles in the regulation of transcription, cell proliferation, cellular differentiation, stem cell maintenance, and tissue and organ pathogenesis. Recent evidence has shown that many KLF family molecules affect skeletal cells and regulate their differentiation and function. This review summarizes the current understanding of the unique roles of each KLF in skeletal cells during normal development and skeletal pathologies.

LINC00629, a KLF10-responsive lncRNA, promotes the anticancer effects of apigenin by decreasing Mcl1 stability in oral squamous cell carcinoma

Apigenin, a naturally occurring flavonoid, is known to exhibit antitumor activity in many cancers. However, the regulatory mechanism of apigenin and the long noncoding RNAs (lncRNAs) altered upon apigenin treatment in oral squamous cell carcinoma (OSCC) remain unclear. In this study, we found that LINC00629 was significantly upregulated in response to apigenin treatment. Upregulated LINC00629 enhanced the growth-suppressive and proapoptotic effects of apigenin on OSCC cells by interacting with Mcl1 and facilitating its degradation. Subsequently, our data indicated that KLF10, an important transcription factor, directly bound to the promoter of LINC00629, facilitating its transcription and contributing to apigenin-induced LINC00629 expression. Collectively, these results suggest that the KLF10-LINC00629-Mcl1 axis plays an important role in the anticancer effects of apigenin.

Expression and Prognostic Role of CXCL1 Gene in Colorectal Adenocarcinoma

In this manuscript, we have extensively examined expression and prognosis of CXCL1 gene in colorectal adenocarcinoma (COAD) using different cases of colorectal adenocarcinoma and tissues. To verify this, protein and mRNA expressions of cxcl1 were identified through RT-PCR and immunohistochemistry in 30 cases of colorectal adenocarcinoma and adjacent tissues, which were surgically resected from January to July 2021 in our hospital, and relationship between CXCL1 mRNA and clinicopathological features and protein expression was analyzed. CXCL 1 mRNA in COAD carcinoma's expression was considerably higher than in the adjacent normal intestine. At the same time, CXCL 1 diagnostic receiver operating characteristic (ROC) curve had preferably higher value of the diagnostic for area under curve (AUC) = 0.912, 95%, COAD (P < 0.001, CI = 0.825–0.969). We have observed that CXCL1 gene was closely linked with preoperative CEA level (P=0.007) and gross tumor typing (P=0.039). Finally, we have concluded that that CXCL1 can be a possible biomarker for stress prognosis and diagnosis.

Klf10 favors Mycobacterium tuberculosis survival by impairing IFN-γ production and preventing macrophages reprograming to macropinocytosis

Mycobacterium tuberculosis has developed diverse mechanisms to survive inside phagocytic cells, such as macrophages. Phagocytosis is a key process in eliminating invading pathogens; thus, M. tuberculosis efficiently disrupts phagosome maturation to ensure infection. However, inflammatory cytokines produced by macrophages in response to early M. tuberculosis infection are key to promoting bacterial clarification. IFN-γ enhances M. tuberculosis engulfment and destruction by reprogramming macrophages from phagocytosis to macropinocytosis. Here, we show that the transcription factor Krüppel-like factor 10 (Klf10) plays a positive role in M. tuberculosis survival and infection by negatively modulating IFN-γ levels. Naïve Klf10-deficient macrophages produce more IFN-γ upon stimulation than wild-type macrophages, thus enhancing bacterial uptake and bactericidal activity achieved by macropinocytosis. Moreover, Klf10⁻^/ ⁻ macrophages showed cytoplasmic distribution of coronin 1 correlated with increased pseudopod count and length. In agreement with these observations, Klf10⁻^/ ⁻ mice showed improved bacterial clearance from the lungs and increased viability. Altogether, our data indicate that Klf10 plays a critical role in M. tuberculosis survival by preventing macrophage reprogramming from phagocytosis to macropinocytosis by negatively regulating IFN-γ production upon macrophage infection.

Zebrafish Klf11b is Required to Maintain Cell Viability by Inhibiting p53-Mediated Apoptosis

Krüppel-like factor 10 (KLF10) regulates various cellular functions, such as proliferation, differentiation and apoptosis, as well as the homeostasis of several types of tissue. In the present study, we attempted a loss-of-function analysis of zebrafish Klf11a and Klf11b, which constitute human KLF10 homologs. Embryos injected with klf11b-morpholino (MO) showed developmental retardation and cell death, whereas klf11a-MO-injected embryos showed normal development. In klf11b-MO-injected embryos, a dramatic increase in the amount of zebrafish p53 mRNA might be the cause of the increase in that of bax. The degree of apoptosis decreased in the klf11b-MO and p53-MO co-injected embryos. These findings imply that KLF10 is a negative regulator of p53-dependent transcription, suggesting that the KLF10/p53 complex may play an important role in apoptosis for maintenance of tissue homeostasis during embryonic development.

The effect of insulin and kruppel like factor 10 on osteoblasts in the dental implant osseointegration in diabetes mellitus patients

Diabetes mellitus, metabolic disease, is characterized by chronic hyperglycemia. Patients with diabetes mellitus are susceptible to infection and therefore have a higher prevalence and progression rate of periodontal disease. We aimed to study the effect of insulin and kruppel like factor 10 (KLF10) on osteoblasts proliferation and differentiation, and expression of bone metabolism-related molecules and related signaling pathway molecules of AKT serine/threonine kinase 1 (AKT) and nuclear factor kappa B subunit 1 (NF-κB) through in vitro experiments, which can provide theoretical basis for the dental implant osseointegration in diabetic patients. The osteoblasts (hFOB 1.19 cells) were subdivided into KLF10 gene over expression group, KLF10 gene knockdown group, and KLF10 gene knockdown + insulin treatment group. CCK-8 and ELISA were, respectively, used for analysis of cell proliferation and differentiation. In vitro experiments were applied to detect the mRNA and protein expression of bone metabolism-related molecules, respectively. GSE178351 dataset and GSE156993 dataset were utilized to explore the expression of KLF10 in periodontitis. In osteoblasts, insulin treatment increased the expression of KLF10. Insulin and KLF10 could reduce the proliferation and differentiation of osteoblasts. Knockdown of KLF10 could increase the expression of bone metabolism-related molecules and activate AKT and NF-κB pathways, whereas insulin reversed this effect. KLF10 was up-regulated in both patients with periodontitis and type 2 diabetes mellitus with periodontitis. It is assumed that knockdown of KLF10 in insulin resistance may promote osteoblasts differentiation and dental implant osseointegration in diabetic patients.

Deciphering the Role of Klf10 in the Cerebellum

Recent studies have demonstrated a new role for Klf10, a Krüppel-like transcription factor, in skeletal muscle, specifically relating to mitochondrial function. Thus, it was of interest to analyze additional tissues that are highly reliant on optimal mitochondrial function such as the cerebellum and to decipher the role of Klf10 in the functional and structural properties of this brain region. In vivo (magnetic resonance imaging and localized spectroscopy, behavior analysis) and in vitro (histology, spectroscopy analysis, enzymatic activity) techniques were applied to comprehensively assess the cerebellum of wild type (WT) and Klf10 knockout (KO) mice. Histology analysis and assessment of locomotion revealed no significant difference in Klf10 KO mice. Diffusion and texture results obtained using MRI revealed structural changes in KO mice characterized as defects in the organization of axons. These modifications may be explained by differences in the levels of specific metabolites (myo-inositol, lactate) within the KO cerebellum. Loss of Klf10 expression also led to changes in mitochondrial activity as reflected by a significant increase in the activity of citrate synthase, complexes I and IV. In summary, this study has provided evidence that Klf10 plays an important role in energy production and mitochondrial function in the cerebellum.

Aryl hydrocarbon receptor and Krüppel like factor 10 mediate a transcriptional axis modulating immune homeostasis in mosquitoes

Immune responses require delicate controls to maintain homeostasis while executing effective defense. Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor. The Krüppel-like factor 10 (KLF10) is a C2H2 zinc-finger containing transcription factor. The functions of mosquito AhR and KLF10 have not been characterized. Here we show that AhR and KLF10 constitute a transcriptional axis to modulate immune responses in mosquito Anopheles gambiae. The manipulation of AhR activities via agonists or antagonists repressed or enhanced the mosquito antibacterial immunity, respectively. KLF10 was recognized as one of the AhR target genes in the context. Phenotypically, silencing KLF10 reversed the immune suppression caused by the AhR agonist. The transcriptome comparison revealed that silencing AhR and KLF10 plus challenge altered the expression of 2245 genes in the same way. The results suggest that KLF10 is downstream of AhR in a transcriptional network responsible for immunomodulation. This AhR–KLF10 axis regulates a set of genes involved in metabolism and circadian rhythms in the context. The axis was required to suppress the adverse effect caused by the overactivation of the immune pathway IMD via the inhibitor gene Caspar silencing without a bacterial challenge. These results demonstrate that the AhR–KLF10 axis mediates an immunoregulatory transcriptional network as a negative loop to maintain immune homeostasis.

TGF-β/SMAD Pathway Is Modulated by miR-26b-5p: Another Piece in the Puzzle of Chronic Lymphocytic Leukemia Progression

Simple Summary

TGF-β is a key immunoregulatory pathway that can limit the proliferation of B-lymphocytes. Chronic lymphocytic leukemia (CLL) has been historically conceptualized as a neoplasm characterized by accumulation of mature B cells escaping programmed cell death and undergoing cell-cycle arrest in the G0/G1 phase. However, new evidence indicates that tumor expansion is in fact a dynamic process in which cell proliferation also plays an important role. In general, cancers progress by the emergence of subclones with genomic aberrations distinct from the initial tumor. Often, these subclones are selected for advantages in cell survival and/or growth. Here, we provide novel evidence to explain, at least in part, the origins of CLL progression in a subgroup of patients with a poor clinical outcome. In this cohort, the immunoregulatory pathway TGF-β/SMAD is modulated by miR-26b-5p and the impairment of this axis bypasses cell cycle arrest in CLL cells facilitating disease progression.

Abstract

Clinical and molecular heterogeneity are hallmarks of chronic lymphocytic leukemia (CLL), a neoplasm characterized by accumulation of mature and clonal long-lived CD5 + B-lymphocytes. Mutational status of the IgHV gene of leukemic clones is a powerful prognostic tool in CLL, and it is well established that unmutated CLLs (U-CLLs) have worse evolution than mutated cases. Nevertheless, progression and treatment requirement of patients can evolve independently from the mutational status. Microenvironment signaling or epigenetic changes partially explain this different behavior. Thus, we think that detailed characterization of the miRNAs landscape from patients with different clinical evolution could facilitate the understanding of this heterogeneity. Since miRNAs are key players in leukemia pathogenesis and evolution, we aim to better characterize different CLL behaviors by comparing the miRNome of clinically progressive U-CLLs vs. stable U-CLLs. Our data show up-regulation of miR-26b-5p, miR-106b-5p, and miR-142-5p in progressive cases and indicate a key role for miR-26b-5p during CLL progression. Specifically, up-regulation of miR-26b-5p in CLL cells blocks TGF-β/SMAD pathway by down-modulation of SMAD-4, resulting in lower expression of p21^−Cip1 kinase inhibitor and higher expression of c-Myc oncogene. This work describes a new molecular mechanism linking CLL progression with TGF-β modulation and proposes an alternative strategy to explore in CLL therapy.

Characterization of Accessible Chromatin Regions in Cattle Rumen Epithelial Tissue during Weaning

Weaning in ruminants is characterized by the transition from a milk-based diet to a solid diet, which drives a critical gastrointestinal tract transformation. Understanding the regulatory control of this transformation during weaning can help to identify strategies to improve rumen health. This study aimed to identify regions of accessible chromatin in rumen epithelial tissue in pre- and post-weaning calves and investigate differentially accessible regions (DARs) to uncover regulatory elements in cattle rumen development using the ATAC-seq approach. A total of 126,071 peaks were identified, covering 1.15% of the cattle genome. From these accessible regions, 2766 DARs were discovered. Gene ontology enrichment resulted in GO terms related to the cell adhesion, anchoring junction, growth, cell migration, motility, and morphogenesis. In addition, putative regulatory canonical pathways were identified (TGFβ, integrin-linked kinase, integrin signaling, and regulation of the epithelial–mesenchymal transition). Canonical pathways integrated with co-expression results showed that TGFβ and ILK signaling pathways play essential roles in rumen development through the regulation of cellular adhesions. In this study, DARs during weaning were identified, revealing enhancers, transcription factors, and candidate target genes that represent potential biomarkers for the bovine rumen development, which will serve as a molecular tool for rumen development studies.

Mesenchymal stem cells: A comprehensive methods for odontoblastic induction

BACKGROUND

In the area of oral and maxillofacial surgery, regenerative endodontics aims to present alternative options to conventional treatment strategies. With continuous advances in regenerative medicine, the source of cells used for pulp tissue regeneration is not only limited to mesenchymal stem cells as the non-mesenchymal stem cells have shown capabilities too. In this review, we are systematically assessing the recent findings on odontoblastic differentiation induction with scaffold and non-scaffold approaches.

METHODS

A comprehensive search was conducted in Pubmed, and Scopus, and relevant studies published between 2015 and 2020 were selected following the PRISMA guideline. The main inclusion criteria were that articles must be revolving on method for osteoblast differentiation in vitro study. Therefore, in vivo and human or animal clinical studies were excluded. The search outcomes identified all articles containing the word "odontoblast", "differentiation", and "mesenchymal stem cell".

RESULTS

The literature search identified 99 related studies, but only 11 articles met the inclusion criteria. These include 5 odontoblastic differentiation induction with scaffold, 6 inductions without scaffolds. The data collected were characterised into two main categories: type of cells undergo odontoblastic differentiation, and odontoblastic differentiation techniques using scaffolds or non-scaffold.

CONCLUSION

Based on the data analysis, the scaffold-based odontoblastic induction method seems to be a better option compared to the non-scaffold method. In addition of that, the combination of growth factors in scaffold-based methods could possibly enhance the differentiation. Thus, further detailed studies are still required to understand the mechanism and the way to enhance odontoblastic differentiation.

Krüppel-like factor 10 regulates the contractile properties of skeletal muscle fibers in mice

INTRODUCTION/AIMS

Klf10 is a member of the Krüppel-like family of transcription factors, which is implicated in mediating muscle structure (fiber size, organization of the sarcomere), muscle metabolic activity (respiratory chain), and passive force. The aim of this study was to further characterize the roles of Klf10 in the contractile properties of skeletal muscle fibers.

METHODS

Fifty-two single fibers were extracted from female wild-type (WT) and Klf10 knockout (KO) oxidative (soleus) and glycolytic (extensor digitorum longus [EDL]) skinned muscles. Each fiber was immersed successively in relaxing (R), washing (W), and activating (A) solutions. Calcium was included in the activating solution to induce a maximum contraction of the fiber. The maximum force (F_max ) was measured and normalized to the cross-sectional area to obtain the maximum stress (Stress_max ). After a steady state in contraction was reached, a quick stretch-release was performed; the force at the maximum stretch (F_stretch ) was measured and the stiffness was assessed.

RESULTS

Deletion of the Klf10 gene induced changes in the contractile parameters (F_max , Stress_max , Stiffness), which were lower and higher for soleus and EDL fibers compared with littermates, respectively. These measurements also revealed changes in the proportion and resistance of attached cross-bridges.

DISCUSSION

Klf10 plays a major role in the homeostasis of the contractile behavior of skeletal muscle fibers in a muscle fiber type-specific manner. These findings further implicate important roles for Klf10 in skeletal muscle function and shed new light on understanding the molecular processes regulating the contractility of skeletal muscle fibers.

KLF10 integrates circadian timing and sugar signaling to coordinate hepatic metabolism

The mammalian circadian timing system and metabolism are highly interconnected, and disruption of this coupling is associated with negative health outcomes. Krüppel-like factors (KLFs) are transcription factors that govern metabolic homeostasis in various organs. Many KLFs show a circadian expression in the liver. Here, we show that the loss of the clock-controlled KLF10 in hepatocytes results in extensive reprogramming of the mouse liver circadian transcriptome, which in turn alters the temporal coordination of pathways associated with energy metabolism. We also show that glucose and fructose induce Klf10, which helps mitigate glucose intolerance and hepatic steatosis in mice challenged with a sugar beverage. Functional genomics further reveal that KLF10 target genes are primarily involved in central carbon metabolism. Together, these findings show that in the liver KLF10 integrates circadian timing and sugar metabolism-related signaling, and serves as a transcriptional brake that protects against the deleterious effects of increased sugar consumption.

A stress-responsive miRNA regulates BMP signaling to maintain tissue homeostasis

Adult organisms must sense and adapt to environmental fluctuations. In high-turnover tissues such as the intestine, these adaptive responses require rapid changes in gene expression that, in turn, likely involve posttranscriptional gene control. However, intestinal-tissue-specific microRNA (miRNA)-mediated regulatory pathways remain unexplored. Here, we report the role of an intestinal-specific miRNA, miR-958, that non-cell autonomously regulates stem cell numbers during tissue homeostasis and regeneration in the Drosophila adult midgut. We identify its downstream target cabut, the Drosophila ortholog of mammalian KLF10/11 transcription factors, which mediates this miR-958 function by promoting paracrine enterocyte-to-stem-cell bone morphogenetic protein (BMP) signaling. We also show that mature miR-958 levels transiently decrease in response to stress and that this decrease is required for proper stem cell expansion during tissue regeneration. In summary, we have identified a posttranscriptional mechanism that modulates BMP signaling activity within Drosophila adult intestinal tissue during both normal homeostasis and tissue regeneration to regulate intestinal stem cell numbers.

Krüppel like factor 10 prevents intervertebral disc degeneration via TGF-β signaling pathway both in vitro and in vivo

Background

Krüppel like factor 10 (KLF10), which is also known as TGF-β Inducible Early Gene-1 (TIEG1), plays a crucial role in regulating cell proliferation, cell apoptosis and inflammatory reaction in human carcinoma cells. Moreover, KLF10 knockout in mice leads to severe defects associated with muscle, skeleton and heart etc. However, the function of KLF10 in intervertebral disc degeneration (IVDD) has not been reported yet.

Methods

The relationship between KLF10 and IVDD were investigated in nucleus pulposus (NP) tissues from human and rats. The role of KLF10 in NP cells was explored via loss or gain of function experiments. IVDD rat models were constructed through needle puncture and the effects of KLF10 in IVDD model of rats were investigated via intradiscal injection of KLF10.

Results

We first found that KLF10 was lowly expressed in degenerative NP tissues and the level of KLF10 showed negative correlation with the disc grades of IVDD patients. Loss or gain of function experiments demonstrated that KLF10 could inhibit apoptosis and enhance migration and proliferation of IL-1β induced NP cells. And KLF10 overexpression reduced extracellular matrix (ECM) degeneration and enhanced ECM synthesis, whereas knockdown of KLF10 resulted in adverse effects. These positive effects of KLF10 could be reversed by the inhibition of TGF-β signaling pathway. In vivo, KLF10 overexpression alleviated IVDD.

Conclusions

This is the first study to reveal that KLF10 was dysregulated in IVDD and overexpressed KLF10 could alleviate IVDD by regulating TGF-β signaling pathway both in vitro and in vivo, which were involved in prohibiting apoptosis, promoting proliferation and migration of NP cells.The translational potential of this article: Overexpression of KLF10 might be an effective therapeutic strategy in the treatment of IVDD.

The Krüppel-like factor Cabut has cell cycle regulatory properties similar to E2F1

Using a gain-of-function screen in Drosophila, we identified the Krüppel-like factor Cabut (Cbt) as a positive regulator of cell cycle gene expression and cell proliferation. Enforced cbt expression is sufficient to induce an extra cell division in the differentiating fly wing or eye, and also promotes intestinal stem cell divisions in the adult gut. Although inappropriate cell proliferation also results from forced expression of the E2f1 transcription factor or its target, Cyclin E, Cbt does not increase E2F1 or Cyclin E activity. Instead, Cbt regulates a large set of E2F1 target genes independently of E2F1, and our data suggest that Cbt acts via distinct binding sites in target gene promoters. Although Cbt was not required for cell proliferation during wing or eye development, Cbt is required for normal intestinal stem cell divisions in the midgut, which expresses E2F1 at relatively low levels. The E2F1-like functions of Cbt identify a distinct mechanism for cell cycle regulation that may be important in certain normal cell cycles, or in cells that cycle inappropriately, such as cancer cells.

The basal transcriptional activity of the murine Klf10 gene is regulated by the transcriptional factor JunB

BACKGROUND

Krüppel-like factor 10 (KLF10) belongs to the Sp1-like transcription factor family, which plays an important role in many directions, e.g., cell proliferation, apoptosis, and differentiation. Its 5' upstream regions are conserved across mammalian species. However, the regulatory mechanism has not been elucidated yet.

OBJECTIVE

Nonetheless the basal transcriptional regulation mechanisms of these regions are unknown. Here, we characterized it which is indispensable for the basal transcription of the Klf10 gene.

METHODS

Seven deletions of 5' upstream DNA fragments from the 10 kb mKlf10 genomic DNA were produced by PCR and cloned into the upstream of the luciferase (Luc) reporter gene in the pGL3 basic plasmid.

RESULT

The luciferase reporter assay showed that the DNA sequence at positions from -101 to +68 was required for a principle activity in the promoter of mKlf10 gene, in which transcriptional factor binding motifs, one JunB and two Sp1 sites, are included. Mutations at the sequence of JunB motif, but not at the two Sp1, abrogated the promoter activity completely, suggesting the indispensable role of JunB site for basal transcription of mKlf10 gene. Moreover, electrophoretic mobility and supershift assays (EMSA) uncovered that JunB protein bound to this region specifically.

CONCLUSION

Taken together, our study revealed that the JunB but not Sp1 at mKlf10 promoter functions as a positive basic factor for the transcriptional activity of the gene.

Deletion of KLF10 Leads to Stress-Induced Liver Fibrosis upon High Sucrose Feeding

Liver fibrosis is a consequence of chronic liver injury associated with chronic viral infection, alcohol abuse, and nonalcoholic fatty liver. The evidence from clinical and animal studies indicates that transforming growth factor-β (TGF-β) signaling is associated with the development of liver fibrosis. Krüppel-like factor 10 (KLF10) is a transcription factor that plays a significant role in TGF-β-mediated cell growth, apoptosis, and differentiation. In recent studies, it has been reported to be associated with glucose homeostasis and insulin resistance. In the present study, we investigated the role of KLF10 in the progression of liver disease upon a high-sucrose diet (HSD) in mice. Wild type (WT) and Klf10 knockout (KO) mice were fed either a control chow diet or HSD (50% sucrose) for eight weeks. Klf10 KO mice exhibited significant hepatic steatosis, inflammation, and liver injury upon HSD feeding, whereas the WT mice exhibited mild hepatic steatosis with no apparent liver injury. The livers of HSD-fed Klf10 KO mice demonstrated significantly increased endoplasmic reticulum stress, oxidative stress, and proinflammatory cytokines. Klf10 deletion led to the development of sucrose-induced hepatocyte cell death both in vivo and in vitro. Moreover, it significantly increased fibrogenic gene expression and collagen accumulation in the liver. Increased liver fibrosis was accompanied by increased phosphorylation and nuclear localization of Smad3. Here, we demonstrate that HSD-fed mice develop a severe liver injury in the absence of KLF10 due to the hyperactivation of the endoplasmic reticulum stress response and CCAAT/enhance-binding protein homologous protein (CHOP)-mediated apoptosis of hepatocytes. The current study suggests that KLF10 plays a protective role against the progression of hepatic steatosis into liver fibrosis in a lipogenic state.

KLF10 Deficiency in CD4+ T Cells Triggers Obesity, Insulin Resistance, and Fatty Liver

CD4+ T cells regulate inflammation and metabolism in obesity. An imbalance of CD4+ T regulatory cells (Tregs) is critical in the development of insulin resistance and diabetes. Although cytokine control of this process is well understood, transcriptional regulation is not. KLF10, a member of the Kruppel-like transcription factor family, is an emerging regulator of immune cell function. We generated CD4+-T-cell-specific KLF10 knockout (TKO) mice and identified a predisposition to obesity, insulin resistance, and fatty liver due to defects of CD4+ Treg mobilization to liver and adipose tissue depots and decreased transforming growth factor β3 (TGF-β3) release in vitro and in vivo. Adoptive transfer of wild-type CD4+ Tregs fully rescued obesity, insulin resistance, and fatty liver. Mechanistically, TKO Tregs exhibit reduced mitochondrial respiration and glycolysis, phosphatidylinositol 3-kinase (PI3K)-Akt-mTOR signaling, and consequently impaired chemotactic properties. Collectively, our study identifies CD4+ T cell KLF10 as an essential regulator of obesity and insulin resistance by altering Treg metabolism and mobilization.

High Expression of KLF10 Is Associated with Favorable Survival in Patients with Oral Squamous Cell Carcinoma

BACKGROUND AND OBJECTIVES

Krüppel-like transcription factor 10 (KLF10) plays a vital role in regulating cell proliferation, including the anti-proliferative process, activation of apoptosis, and differentiation control. KLF10 may also act as a protective factor against oral cancer. We studied the impact of KLF10 expression on the clinical outcomes of oral cancer patients to identify its role as a prognostic factor in oral cancer.

MATERIALS AND METHODS

KLF10 immunoreactivity was analyzed by immunohistochemical (IHC) stain analysis in 286 cancer specimens from primary oral cancer patients. The prognostic value of KLF10 on overall survival was determined by Kaplan-Meier analysis and the Cox proportional hazard model.

RESULTS

High KLF10 expression was significantly associated with male gender and betel quid chewing. The 5-year survival rate was greater for patients with high KLF10 expression than for those with low KLF10 expression (62.5% vs. 51.3%, respectively; p = 0.005), and multivariate analyses showed that high KLF10 expression was the only independent factor correlated with greater overall patient survival. The significant correlation between high KLF10 expression and a higher 5-year survival rate was observed in certain subgroups of clinical parameters, including female gender, non-smokers, cancer stage T1, and cancer stage N0.

CONCLUSIONS

KLF10 expression, detected by IHC staining, could be an independent prognostic marker for oral cancer patients.

Kruppel-like factor 10 protects against acute viral myocarditis by negatively regulating cardiac MCP-1 expression

Viral myocarditis (VMC) is a cardiac disease associated with myocardial inflammation and injury induced by virus infection. Cardiomyocytes have recently been regarded as key players in eliciting and modulating inflammation within the myocardium. Kruppel-like factor 10 (KLF10) is a crucial regulator of various pathological processes and plays different roles in a variety of diseases. However, its role in VMC induced by coxsackievirus B3 (CVB3) infection remains unknown. In this study, we report that cardiac KLF10 confers enhanced protection against viral myocarditis. We found that KLF10 expression was downregulated upon CVB3 infection. KLF10 deficiency enhanced cardiac viral replication and aggravated VMC progress. Bone marrow chimera experiments indicated that KLF10 expression in nonhematopoietic cells was involved in the pathogenesis of VMC. We further identified MCP-1 as a novel target of KLF10 in cardiomyocytes, and KLF10 cooperated with histone deacetylase 1 (HDAC1) to negatively regulate MCP-1 expression by binding its promoter, leading to activation of MCP-1 transcription and recruitment of Ly6C^high monocytes/macrophages into the myocardium. This novel mechanism of MCP-1 regulation by KLF10 might provide new insights into the pathogenesis of VMC and a potential therapeutic target for VMC.

KLF10 is a modulatory factor of chondrocyte hypertrophy in developing skeleton

To define the functional role of Krüppel-like factor (KLF) 10 as a modulator of chondrocyte hypertrophy in developing skeleton, the developmental features in the long bone of KLF10 knockout (KO) mice were investigated and the mesenchymal stem cells (MSCs) from KLF10 KO mice were characterized regarding chondrogenesis and osteogenesis. Delayed long bone growth and delayed formation of primary ossification center were observed in an early embryonic stage in KLF10 KO mouse along with very low Indian hedgehog expression in epiphyseal plate. While the chondrogenic potential of mouse MSCs from KLF10 KO mice appeared normal or slight decreased, hypertrophy and osteogenesis were extensively suppressed. These findings suggest that KLF10 is a mediator of chondrocyte hypertrophy in developing skeleton, and that suppression of KLF10 may be employed as a new strategy for preventing hypertrophy in cartilage regeneration using MSCs.

A KDM6A-KLF10 reinforcing feedback mechanism aggravates diabetic podocyte dysfunction

Diabetic nephropathy is the leading cause of end‐stage renal disease. Although dysfunction of podocytes, also termed glomerular visceral epithelial cells, is critically associated with diabetic nephropathy, the mechanism underlying podocyte dysfunction still remains obscure. Here, we identify that KDM6A, a histone lysine demethylase, reinforces diabetic podocyte dysfunction by creating a positive feedback loop through up‐regulation of its downstream target KLF10. Overexpression of KLF10 in podocytes not only represses multiple podocyte‐specific markers including nephrin, but also conversely increases KDM6A expression. We further show that KLF10 inhibits nephrin expression by directly binding to the gene promoter together with the recruitment of methyltransferase Dnmt1. Importantly, inactivation or knockout of either KDM6A or KLF10 in mice significantly suppresses diabetes‐induced proteinuria and kidney injury. Consistent with the notion, we also show that levels of both KDM6A and KLF10 proteins or mRNAs are substantially elevated in kidney tissues or in urinary exosomes of human diabetic nephropathy patients as compared with control subjects. Our findings therefore suggest that targeting the KDM6A–KLF10 feedback loop may be beneficial to attenuate diabetes‐induced kidney injury.

circRNA circFUT8 Upregulates Krüpple-like Factor 10 to Inhibit the Metastasis of Bladder Cancer via Sponging miR-570-3p

Circular RNAs (circRNAs) are broad and diverse endogenous non-coding RNAs. Emerging evidence has revealed that circRNAs play pivotal roles in cancers, regulating the gene expression by acting as a microRNA (miRNA) sponge. However, the biological functions of circRNAs in bladder cancer (BCa) remain largely unknown. In this study, we identified an altered circRNA, termed circFUT8, by screening RNA sequencing data generated from three BCa tissues and matched adjacent normal bladder tissues. Quantitative real-time PCR analysis demonstrated that circFUT8 was downregulated in BCa tissues and correlated with patients' prognosis, histological grade, and lymph node (LN) metastasis. Functionally, gain- and loss-of-function assays indicated that circFUT8 inhibited the migration and invasion of BCa cell lines in vitro and LN metastasis in vivo. Mechanistically, circFUT8 directly bound to miR-570-3p and partially abrogated its oncogenic role, and miR-570-3p could suppress the expression of tumor suppressor gene Krüpple-like factor 10 (KLF10) by binding its 3' untranslated region (3' UTR). Moreover, we found that circFUT8 promoted the expression of KLF10 by competitively sponging miR-570-3p. In conclusion, circFUT8 functions as a tumor suppressor in BCa cells by targeting the miR-570-3p/KLF10 axis and may serve as a potential biomarker and therapeutic target for the management of BCa patients with LN metastasis.

Novel role of Tieg1 in muscle metabolism and mitochondrial oxidative capacities

AIM

Tieg1 is involved in multiple signalling pathways, human diseases, and is highly expressed in muscle where its functions are poorly understood.

METHODS

We have utilized Tieg1 knockout (KO) mice to identify novel and important roles for this transcription factor in regulating muscle ultrastructure, metabolism and mitochondrial functions in the soleus and extensor digitorum longus (EDL) muscles. RNA sequencing, immunoblotting, transmission electron microscopy, MRI, NMR, histochemical and mitochondrial function assays were performed.

RESULTS

Loss of Tieg1 expression resulted in altered sarcomere organization and a significant decrease in mitochondrial number. Histochemical analyses demonstrated an absence of succinate dehydrogenase staining and a decrease in cytochrome c oxidase (COX) enzyme activity in KO soleus with similar, but diminished, effects in the EDL. Decreased complex I, COX and citrate synthase (CS) activities were detected in the soleus muscle of KO mice indicating altered mitochondrial function. Complex I activity was also diminished in KO EDL. Significant decreases in CS and respiratory chain complex activities were identified in KO soleus. ¹ H-NMR spectra revealed no significant metabolic difference between wild-type and KO muscles. However, ³¹ P spectra revealed a significant decrease in phosphocreatine and ATPγ. Altered expression of 279 genes, many of which play roles in mitochondrial and muscle function, were identified in KO soleus muscle. Ultimately, all of these changes resulted in an exercise intolerance phenotype in Tieg1 KO mice.

CONCLUSION

Our findings have implicated novel roles for Tieg1 in muscle including regulation of gene expression, metabolic activity and organization of tissue ultrastructure. This muscle phenotype resembles diseases associated with exercise intolerance and myopathies of unknown consequence.

Sclerostin antibody treatment rescues the osteopenic bone phenotype of TGFβ inducible early gene-1 knockout female mice

Deletion of TGFβ inducible early gene-1 (TIEG) in mice results in an osteopenic phenotype that exists only in female animals. Molecular analyses on female TIEG knockout (KO) mouse bones identified increased expression of sclerostin, an effect that was confirmed at the protein level in serum. Sclerostin antibody (Scl-Ab) therapy has been shown to elicit bone beneficial effects in multiple animal model systems and human clinical trials. For these reasons, we hypothesized that Scl-Ab therapy would reverse the low bone mass phenotype of female TIEG KO mice. In this study, wildtype (WT) and TIEG KO female mice were randomized to either vehicle control (Veh, n = 12/group) or Scl-Ab therapy (10 mg/kg, 1×/wk, s.c.; n = 12/group) and treated for 6 weeks. Following treatment, bone imaging analyses revealed that Scl-Ab therapy significantly increased cancellous and cortical bone in the femur of both WT and TIEG KO mice. Similar effects also occurred in the vertebra of both WT and TIEG KO animals. Additionally, histomorphometric analyses revealed that Scl-Ab therapy resulted in increased osteoblast perimeter/bone perimeter in both WT and TIEG KO animals, with a concomitant increase in P1NP, a serum marker of bone formation. In contrast, osteoclast perimeter/bone perimeter and CTX-1 serum levels were unaffected by Scl-Ab therapy, irrespective of mouse genotype. Overall, our findings demonstrate that Scl-Ab therapy elicits potent bone-forming effects in both WT and TIEG KO mice and effectively increases bone mass in female TIEG KO mice.

The Use of Genetically Engineered Mouse Models for Studying the Function of Mutated Driver Genes in Pancreatic Cancer

Pancreatic cancer is often treatment-resistant, with the emerging standard of care, gemcitabine, affording only a few months of incrementally-deteriorating survival. Reflecting on the history of failed clinical trials, genetically engineered mouse models (GEMMs) in oncology research provides the inspiration to discover new treatments for pancreatic cancer that come from better knowledge of pathogenesis mechanisms, not only of the derangements in and consequently acquired capabilities of the cancer cells, but also in the aberrant microenvironment that becomes established to support, sustain, and enhance neoplastic progression. On the other hand, the existing mutational profile of pancreatic cancer guides our understanding of the disease, but leaves many important questions of pancreatic cancer biology unanswered. Over the past decade, a series of transgenic and gene knockout mouse modes have been produced that develop pancreatic cancers with features reflective of metastatic pancreatic ductal adenocarcinoma (PDAC) in humans. Animal models of PDAC are likely to be essential to understanding the genetics and biology of the disease and may provide the foundation for advances in early diagnosis and treatment.

miR-892b Inhibits Hypertrophy by Targeting KLF10 in the Chondrogenesis of Mesenchymal Stem Cells

We investigated the functional role of miR-892b as a novel inhibitor of chondrocyte hypertrophy during TGF-β-mediated chondrogenesis of human mesenchymal stem cells (hMSCs). The expression of miR-892b during TGF-β-mediated chondrogenesis of hMSCs and the effects of miR-892b overexpression on chondrogenic and hypertrophic marker genes in the chondrogenesis of hMSCs were investigated. Targets of miR-892b were identified and verified by overexpression of synthetic miRNA mimics and luciferase assays. Cross-talk between Kruppel-like factor 10 (KLF10) and Indian hedgehog (Ihh) was investigated using KLF10 knockdown (KD). miR-892b enhanced chondrogenic makers and suppressed hypertrophy in hMSC chondrogenesis, mimicking parathyroid hormone-related peptide (PTHrP). KLF10, a transcription factor and miR-892b target, directly regulated Ihh promoter activity. Like miR-892b, KLF10 KD enhanced hMSC chondrogenesis and inhibited hypertrophy. Our findings suggest a key role of miR-892b in targeting the KLF10-Ihh axis as a regulator of hypertrophy in TGF-β-mediated chondrogenesis of hMSCs and provide a novel strategy for preventing hypertrophy in chondrogenesis from MSCs.

Development of a novel multiphysical approach for the characterization of mechanical properties of musculotendinous tissues

At present, there is a lack of well-validated protocols that allow for the analysis of the mechanical properties of muscle and tendon tissues. Further, there are no reports regarding characterization of mouse skeletal muscle and tendon mechanical properties in vivo using elastography thereby limiting the ability to monitor changes in these tissues during disease progression or response to therapy. Therefore, we sought to develop novel protocols for the characterization of mechanical properties in musculotendinous tissues using atomic force microscopy (AFM) and ultrasound elastography. Given that TIEG1 knockout (KO) mice exhibit well characterized defects in the mechanical properties of skeletal muscle and tendon tissue, we have chosen to use this model system in the present study. Using TIEG1 knockout and wild-type mice, we have devised an AFM protocol that does not rely on the use of glue or chemical agents for muscle and tendon fiber immobilization during acquisition of transversal cartographies of elasticity and topography. Additionally, since AFM cannot be employed on live animals, we have also developed an ultrasound elastography protocol using a new linear transducer, SLH20-6 (resolution: 38 µm, footprint: 2.38 cm), to characterize the musculotendinous system in vivo. This protocol allows for the identification of changes in muscle and tendon elasticities. Such innovative technological approaches have no equivalent to date, promise to accelerate our understanding of musculotendinous mechanical properties and have numerous research and clinical applications.

Transforming growth factor-β in pancreatic diseases: Mechanisms and therapeutic potential

Pancreatic diseases, such as acute pancreatitis, chronic pancreatitis, and pancreatic cancer, are common gastrointestinal diseases resulting in the development of local and systemic complications with a high risk of death. Numerous studies have examined pancreatic diseases over the past few decades; however, the pathogenesis remains unclear, and there is a lack of effective treatment options. Recently, emerging evidence has suggested that transforming growth factor beta (TGF-β) exerts controversial functions in apoptosis, inflammatory responses, and carcinogenesis, indicating its complex role in the pathogenesis of pancreas-associated disease. Therefore, a further understanding of relevant TGF-β signalling will provide new ideas and potential therapeutic targets for preventing disease progression. This is the first systematic review of recent data from animal and human clinical studies focusing on TGF-β signalling in pancreas damage and diseases. This information may aid in the development of therapeutic agents for regulating TGF-β in this pathology to prevent or treat pancreatic diseases.