Krüppel-like factor 10 protects against metabolic dysfunction-associated steatohepatitis by regulating HNF4α-mediated metabolic pathways.

BACKGROUND: Krüppel-like factor 10 (KLF10), a zinc finger transcription factor, plays a pivotal role in modulating TGF-ß-mediated cellular processes such as growth, apoptosis, and differentiation. Recent studies have implicated KLF10 in regulating lipid metabolism and glucose homeostasis. This study aimed to elucidate the precise role of hepatic KLF10 in developing metabolic dysfunction-associated steatohepatitis (MASH) in diet-induced obese mice. METHODS: We investigated hepatic KLF10 expression under metabolic stress and the effects of overexpression or ablation of hepatic KLF10 on MASH development and lipidemia. We also determined whether hepatocyte nuclear factor 4α (HNF4α) mediated the metabolic effects of KLF10. RESULTS: Hepatic KLF10 was downregulated in MASH patients and genetically or diet-induced obese mice. AAV8-mediated overexpression of KLF10 in hepatocytes prevented Western diet-induced hypercholesterolemia and steatohepatitis, whereas inactivation of hepatocyte KLF10 aggravated Western diet-induced steatohepatitis. Mechanistically, KLF10 reduced hepatic triglyceride and free fatty acid levels by inducing lipolysis and fatty acid oxidation and inhibiting lipogenesis, and reducing hepatic cholesterol levels by promoting bile acid synthesis. KLF10 highly induced HNF4α expression by directly binding to its promoter. The beneficial effect of KLF10 on MASH development was abolished in mice lacking hepatocyte HNF4α. In addition, the inactivation of KLF10 in hepatic stellate cells exacerbated Western diet-induced liver fibrosis by activating the TGF-ß/SMAD2/3 pathway. CONCLUSIONS: Our data collectively suggest that the transcription factor KLF10 plays a hepatoprotective role in MASH development by inducing HNF4α. Targeting hepatic KLF10 may offer a promising strategy for treating MASH.

Hepatic Klf10-Fh1 axis promotes exercise-mediated amelioration of NASH in mice.

Exercise is an effective non-pharmacological strategy for the treatment of nonalcoholic steatohepatitis (NASH), but the underlying mechanism needs further investigation. Kruppel-like factor 10 (Klf10) is a transcriptional factor that is expressed in multiple tissues including liver, whose role in NASH is not well defined. In our study, exercise induces hepatic Klf10 expression through the cAMP/PKA/CREB pathway. Hepatocyte-specific knockout of Klf10 (Klf10LKO) increases lipid accumulation, cell death, inflammation and fibrosis in NASH diet-fed mice and reduces the protective effects of treadmill exercise against NASH, while hepatocyte-specific overexpression of Klf10 (Klf10LTG) works in concert with exercise to reduce NASH in mice. Mechanistically, Klf10 promotes the expression of fumarate hydratase 1 (Fh1), thereby reducing fumarate accumulation in hepatocytes. This decreases the trimethyl (me3) levels of histone 3 lysine 4 (H3K4me3) on lipogenic genes promoters to attenuate lipogenesis, thus ameliorating free fatty acids (FFAs)-induced hepatocytes steatosis, apoptosis, insulin resistance and blunting dysfunctional hepatocytes-mediated activation of macrophages and hepatic stellate cells. Therefore, by regulating the Fh1/fumarate/H3K4me3 pathway, Klf10 acts as a downstream effector of exercise to combat NASH.

KLF10/CBS increases the sensitivity of gastric carcinoma cells to methionine restriction by promoting sulfur transfer pathway.

Gastric cancer metastasis is a major cause of poor prognosis. Our previous research showed that methionine restriction (MR) lowers the invasiveness and motility of gastric carcinoma. In this study, we investigated the particular mechanisms of MR on gastric carcinoma metastasis. In vitro, gastric carcinoma cells (AGS, SNU-5, MKN7, KATO III, SNU-1, and MKN45) were grown in an MR medium for 24 h. In vivo, BALB/c mice were given a methionine-free (Met-) diet. Transwell assays were used to investigate cell invasion and migration. The amounts of Krüppel like factor 10 (KLF10) and cystathionine ß-synthase (CBS) were determined using quantitative real-time PCR and Western blot. To determine the relationship between KLF10 and CBS, chromatin immunoprecipitation and a dual-luciferase reporter experiment were used. Hematoxylin-eosin staining was used to detect lung metastasis. Liquid chromatography-mass spectrometry was used to determine cystathionine content. MR therapy had varying effects on the invasion and migration of gastric carcinoma cells AGS, SNU-5, MKN7, KATO III, SNU-1, and MKN45. KLF10 was highly expressed in AGS cells but poorly expressed in KATO III cells. KLF10 improved MR's ability to prevent gastric carcinoma cell invasion and migration. In addition, KLF10 may interact with CBS, facilitating transcription. Further detection revealed that inhibiting the KLF10/CBS-mediated trans-sulfur pathway lowered Met-'s inhibitory effect on lung metastasis development. KLF10 transcription activated CBS, accelerated the trans-sulfur pathway, and increased gastric carcinoma cells' susceptibility to MR.

CircITGA7 regulates malignant phenotypes in bladder cancer cells via targeting miR-330-3p/KLF10 axis.

Bladder cancer (BCa) is one of the common malignancies. Circular RNAs (circRNAs) play regulatory roles in cancer progression. CircITGA7 is a circRNA generated from several exons of ITGA7. The potential role of circITGA7 in BCa remains unknown and needs to be explored. Quantitative real time polymerase chain reaction (qRT-PCR) was used to assess circITGA7 and miR-330-3p expression in BCa tissues and cell lines. Kaplan-Meier analysis was used to evaluate the overall survival of these BCa patients. The biological function of circITGA7 was examined by overexpression of circITGA7 using CCK-8, EdU, wound-healing, and Transwell assays. Xenograft assay was performed to further validate the in vitro results. To explore the mechanism of circITGA7, luciferase reporter, RNA pull-down, fluorescence in situ hybridization (FISH) assays were employed to examine the binding interaction among circITGA7, miR-330-3p and kruppel-like factor 10 (KLF10). Western blot was used to study the protein levels of KLF10.CircITGA7 was downregulated in BCa tissues and cell lines and indicated longer overall survival. Moreover, circITGA7 restricted cell proliferation, migration and invasion of BCa through negatively regulating miR-330-3p. The in vivo model showed that circITGA7 influenced the tumor growth. Besides, the overexpression of miR-330-3p promoted cell progression by directly targeting KLF10. Mechanistically, circITGA7 inhibited BCa progression by activating KLF10 via targeting miR-330-3p.CircITGA7 alleviates BCa cell progression via circITGA7/hsa-miR-330-3p/KLF10 axis, which may provide novel therapeutic targets for BCa.

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.

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 ß (TGFß) signaling, and TGFß 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 TGFß signaling.

KLF10 Inhibits TGF-ß-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-ß)/SMAD signaling. Although Krüppel-like-factor (KLF) 10 is an early TGF-ß-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-ß treatment, whereas ATF3 expression showed delayed induction. KLF10 knockdown in LX-2 cells enhanced TGF-ß-mediated activation, as evidenced by elevated fibrogenic protein levels. Further mechanistic studies revealed that KLF10 knockdown promoted TGF-ß signaling and upregulated ATF3 expression. Conversely, KLF10 overexpression suppressed TGF-ß-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-ß-treated LX-2 cells. Collectively, our findings suggest that KLF10 acts as a negative regulator of the TGF-ß 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.

A TGF-ß/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-ß), 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-ß. ChIP-based binding studies demonstrated direct binding to Trim63, a known wasting-associated atrogene. Taken together, we report a critical role for the TGF-ß/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 knockdown negatively regulates CTRP3 to improve OGD/R-induced brain microvascular endothelial cell injury and barrier dysfunction through Nrf2/HO-1 signaling pathway.

Ischemic stroke seriously endangers human health and even death. This study aimed to investigate the role of KLF10/CTRP3 in oxygen-glucose deprivation/reperfusion (OGD/R)-induced brain microvascular endothelial cells injury, as well as the regulatory effects of the Nrf2/HO-1 signaling pathway. OGD/R-induced human microvascular endothelial cells (hBMECs) were used to simulate the model of cerebral ischemia-reperfusion (I/R) injury. The expression of KLF10/CTRP3 in OGD/R-induced hBMECs as well as the transfection efficiency were all detected by RT-qPCR and western blot. The interaction of KLF10 and CTRP3 was confirmed by dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP). The viability, apoptosis and endothelial permeability of OGD/R-induced hBMECs was detected by CCK-8, TUNEL and FITC-Dextran assay kit. The capacity of cell migration was assessed by wound healing assay. The expression of apoptosis related proteins, oxidative stress levels and tight junction proteins was also detected. As a result, the expression of KLF10 was increased in OGD/R-induced hBMECs and downregulation of KLF10 could promote the viability, migration and suppress the apoptosis, oxidative stress and endothelial permeability by downregulating the expression of caspase 3, Bax, cleaved PARP, ROS, MDA, and upregulating the expression of Bcl-2, SOD, GSH-Px, ZO-1, occludin, claudin-5. Nrf2/HO-1 signaling pathway was inhibited in OGD/R-induced hBMECs, which was activated by downregulation of KLF10. KLF10 was demonstrated to be combined with CTRP3 and KLF10 inhibited transcription of CTRP3 in hBMECs. The above changes affected by downregulation of KLF10 could be reversed by the interference with CTRP3. In conclusion, KLF10 knockdown improved OGD/R-induced brain microvascular endothelial cell injury and barrier dysfunction through the activation of Nrf2/HO-1 signaling pathway, which was weakened by the downregulation of CTRP3.

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 TGFß 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.

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.

KLF10 deficiency in CD4+ T cells promotes atherosclerosis progression by altering macrophage dynamics.

BACKGROUND AND AIMS: Accumulating evidence supports a critical role for CD4+ T cells as drivers and modifiers of the chronic inflammatory response in atherosclerosis. Effector T cells have pro-atherogenic properties, whereas CD4+ regulatory T cells (Tregs) exert suppressive activity in atherosclerosis through increased secretion of inhibitory cytokines such as transforming growth factor-ß or interleukin-10. In addition, Tregs have been shown to suppress inflammatory macrophages and promote the resolution of atherosclerosis plaques. Impaired Treg numbers and function have been associated with atherosclerosis plaque development. However, the underlying mechanisms remain unclear. METHODS AND RESULTS: Here, we investigated a cell-autonomous role of a transcription factor, Krüppel-like factor 10 (KLF10), in CD4+ T cells in regulating atherosclerosis progression. Using CD4+ T-cell-specific KLF10 knockout (TKO) mice, we identified exaggerated plaque progression due to defects in immunosuppressive functions of Tregs on macrophages. TKO mice exhibited increased lesion size as well as higher CD4+ T cells and macrophage content compared to WT mice. TKO plaques also showed increased necrotic cores along with defective macrophage efferocytosis. In contrast, adoptive cellular therapy using WT Tregs abrogated the accelerated lesion progression and deleterious effects in TKO mice. Intriguingly, RNA-seq analyses of TKO lesions revealed increased chemotaxis and cell proliferation, and reduced phagocytosis compared to WT lesions. Mechanistically, TKO-Tregs impaired the efferocytosis capacity of macrophages in vitro and promoted a pro-inflammatory macrophage phenotype via increased IFN-γ and decreased TGF-ß secretion. CONCLUSIONS: Taken together, these findings establish a critical role for KLF10 in regulating CD4+ Treg-macrophage interactions and atherosclerosis.

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.

Serum and Soleus Metabolomics Signature of Klf10 Knockout Mice to Identify Potential Biomarkers.

The transcription factor Krüppel-like factor 10 (Klf10), also known as Tieg1 for TGFß (Inducible Early Gene-1) is known to control numerous genes in many cell types that are involved in various key biological processes (differentiation, proliferation, apoptosis, inflammation), including cell metabolism and human disease. In skeletal muscle, particularly in the soleus, deletion of the Klf10 gene (Klf10 KO) resulted in ultrastructure fiber disorganization and mitochondrial metabolism deficiencies, characterized by muscular hypertrophy. To determine the metabolic profile related to loss of Klf10 expression, we analyzed blood and soleus tissue using UHPLC-Mass Spectrometry. Metabolomics analyses on both serum and soleus revealed profound differences between wild-type (WT) and KO animals. Klf10 deficient mice exhibited alterations in metabolites associated with energetic metabolism. Additionally, chemical classes of aromatic and amino-acid compounds were disrupted, together with Krebs cycle intermediates, lipids and phospholipids. From variable importance in projection (VIP) analyses, the Warburg effect, citric acid cycle, gluconeogenesis and transfer of acetyl groups into mitochondria appeared to be possible pathways involved in the metabolic alterations observed in Klf10 KO mice. These studies have revealed essential roles for Klf10 in regulating multiple metabolic pathways whose alterations may underlie the observed skeletal muscle defects as well as other diseases.

KLF10 Functions as an Independent Prognosis Factor for Gastric Cancer.

Background and Objectives: Kruppel-like factor 10 (KLF10) participates in the tumorigenesis of several human cancers by binding to the GC-rich region within the promoter regions of specific genes. KLF10 is downregulated in human cancers. However, the role of KLF10 in gastric cancer formation remains unclear. Materials and Methods: In this study, we performed immunohistochemical staining for KLF10 expression in 121 gastric cancer sections. Results: The loss of KLF10 expression was correlated with advanced stages and T status. Kaplan-Meier analysis revealed that patients with higher KLF10 levels had longer overall survival than those with lower KLF10 levels. Univariate analysis revealed that in patients with gastric cancer, advanced stages and low KLF10 levels were associated with survival. Multivariate analysis indicated that age, gender, advanced stages, and KLF10 expression were independent prognostic factors of the survival of patients with gastric cancer. After adjusting for age, gender, and stage, KLF10 expression was also found to be an independent prognostic factor in the survival of patients with gastric cancer. Conclusion: Our results collectively suggested that KLF10 may play a critical role in gastric cancer formation and is an independent prognosis factor of gastric cancer.

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.

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.

Knockout of KLF10 Ameliorated Diabetic Renal Fibrosis via Downregulation of DKK-1.

Diabetes-induced chronic kidney disease leads to mortality and morbidity and thus poses a great health burden worldwide. Krüppel-like factor 10 (KLF10), a zinc finger-containing transcription factor, regulates numerous cellular functions, such as proliferation, differentiation, and apoptosis. In this study, we explored the effects of KLF10 on diabetes-induced renal disease by using a KLF10 knockout mice model. Knockout of KLF10 obviously diminished diabetes-induced tumor growth factor-ß (TGF-ß), fibronectin, and type IV collagen expression, as evidenced by immunohistochemical staining. KLF10 knockout also repressed the expression of Dickkopf-1 (DKK-1) and phosphorylated ß-catenin in diabetic mice, as evidenced by immunohistochemical staining and Western blot analysis. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that significantly decreased type IV collagen, fibronectin, and DKK-1 existed in KLF10 knockout diabetic mice compared with control diabetic mice. Moreover, knockout of KLF10 reduced the renal fibrosis, as shown by Masson's Trichrome analysis. Overall, the results indicate that depletion of KLF10 ameliorated diabetic renal fibrosis via the downregulation of DKK-1 expression and inhibited TGF-ß1 and phosphorylated ß-catenin expression. Our findings suggest that KLF10 may be a promising therapeutic choice for the treatment of diabetes-induced renal fibrosis.

KLF10 promotes nonalcoholic steatohepatitis progression through transcriptional activation of zDHHC7.

Nonalcoholic steatohepatitis (NASH), characterized by hepatic steatosis, inflammation, and liver injury, has become a leading cause of end-stage liver diseases and liver transplantation. Krüppel-like factors 10 (KLF10) is a Cys2/His2 zinc finger transcription factor that regulates cell growth, apoptosis, and differentiation. However, whether it plays a role in the development and progression of NASH remains poorly understood. In the present study, we found that KLF10 expression was selectively upregulated in the mouse models and human patients with NASH, compared with simple steatosis (NAFL). Gain- and loss-of function studies demonstrated that hepatocyte-specific overexpression of KLF10 aggravated, whereas its depletion alleviated diet-induced NASH pathogenesis in mice. Mechanistically, transcriptomic analysis and subsequent functional experiments showed that KLF10 promotes hepatic lipid accumulation and inflammation through the palmitoylation and plasma membrane localization of fatty acid translocase CD36 via transcriptionally activation of zDHHC7. Indeed, both expression of zDHHC7 and palmitoylation of CD36 are required for the pathogenic roles of KLF10 in NASH development. Thus, our results identify an important role for KLF10 in NAFL-to-NASH progression through zDHHC7-mediated CD36 palmitoylation.

Perivascular Fibrosis Is Mediated by a KLF10-IL-9 Signaling Axis in CD4+ T Cells.

BACKGROUND: Perivascular fibrosis, characterized by increased amount of connective tissue around vessels, is a hallmark for vascular disease. Ang II (angiotensin II) contributes to vascular disease and end-organ damage via promoting T-cell activation. Despite recent data suggesting the role of T cells in the progression of perivascular fibrosis, the underlying mechanisms are poorly understood. METHODS: TF (transcription factor) profiling was performed in peripheral blood mononuclear cells of hypertensive patients. CD4-targeted KLF10 (Kruppel like factor 10)-deficient (Klf10fl/flCD4Cre+; [TKO]) and CD4-Cre (Klf10+/+CD4Cre+; [Cre]) control mice were subjected to Ang II infusion. End point characterization included cardiac echocardiography, aortic imaging, multiorgan histology, flow cytometry, cytokine analysis, aorta and fibroblast transcriptomic analysis, and aortic single-cell RNA-sequencing. RESULTS: TF profiling identified increased KLF10 expression in hypertensive human subjects and in CD4+ T cells in Ang II-treated mice. TKO mice showed enhanced perivascular fibrosis, but not interstitial fibrosis, in aorta, heart, and kidney in response to Ang II, accompanied by alterations in global longitudinal strain, arterial stiffness, and kidney function compared with Cre control mice. However, blood pressure was unchanged between the 2 groups. Mechanistically, KLF10 bound to the IL (interleukin)-9 promoter and interacted with HDAC1 (histone deacetylase 1) inhibit IL-9 transcription. Increased IL-9 in TKO mice induced fibroblast intracellular calcium mobilization, fibroblast activation, and differentiation and increased production of collagen and extracellular matrix, thereby promoting the progression of perivascular fibrosis and impairing target organ function. Remarkably, injection of anti-IL9 antibodies reversed perivascular fibrosis in Ang II-infused TKO mice and C57BL/6 mice. Single-cell RNA-sequencing revealed fibroblast heterogeneity with activated signatures associated with robust ECM (extracellular matrix) and perivascular fibrosis in Ang II-treated TKO mice. CONCLUSIONS: CD4+ T cell deficiency of Klf10 exacerbated perivascular fibrosis and multi-organ dysfunction in response to Ang II via upregulation of IL-9. Klf10 or IL-9 in T cells might represent novel therapeutic targets for treatment of vascular or fibrotic diseases.