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Background: Krüppel-like factor 5 (KLF5) is recognized as a tumor mediator in multiple types of tumors. Nevertheless, whether KLF5 plays a role in gallbladder cancer (GBC) remains to be elucidated. This study aims to clarify the role of KLF5 in the proliferation, migration and angiogenesis in GBC cells. Methods: The expressions of KLF5 and platelet-derived growth factor subunit A (PDGFA) in GBC cell lines were analyzed by qRT-PCR and western blot assay. Cell proliferation was assessed utilizing the Cell Counting Kit-8 assay and EDU staining. Cell apoptosis was evaluated using flow cytometry, and apoptosis-related proteins was examined by western blotting. The migratory and invasive capabilities were evaluated utilizing wound healing and Transwell. Angiogenesis was assessed by ELISA, tube formation assay and western blot. The interaction between KLF5 and PDGFA was confirmed by ChIP assay, as well as luciferase reporter assay. Results: In this study, we discovered that the levels of KLF5 and PDGFA were upregulated in GBC cells. Silencing of KLF5 reduced the viability and suppressed the proliferation of GBC cells, as well as promoting the apoptosis. In addition, KLF5 silencing restrained the invasion and migration and angiogenesis in NOZ and GBC-SD cells. KLF5 transcription activated PDGFA expression and KLF5 was proved to bind to PDGFA promoter in NOZ cells. Following the silencing of PDGFA, the proliferation, invasion, migration, angiogenesis and apoptosis exhibited similar changes to KLF5 silencing. Additionally, PDGFA overexpression reversed the effects of KLF5 silencing on NOZ cells. Conclusion: Collectively, our results suggest that KLF5 regulates GBC cell proliferation, invasion, migration, angiogenesis, as well as apoptosis, via mediating PDGFA transcriptionally, which might provide a novel therapeutic strategy for treatment of human GBC. [ABSTRACT FROM AUTHOR]

Objectives Diabetic nephropathy (DN) is a serious consequence of diabetes that can develop through the lysophosphatidic acid axis. The purpose of this study was to determine whether the antidiabetic drug liraglutide can slow the development of diabetic kidney damage by altering the lysophosphatidic acid axis via KLF5. Methods Wistar albino rats were divided into nondiabetic and diabetic rats (resulting from an intraperitoneal streptozotocin dose of 30 mg/kg and a high-fat diet). These rats were further divided into four groups: nondiabetic control, liraglutide-treated nondiabetic, diabetic control, and liraglutide-treated diabetic. The nondiabetic and diabetic control groups received normal saline for 42 days, while the liraglutide-treated nondiabetic and diabetic groups received normal saline for 21 days, followed by a subcutaneous dose of liraglutide (200 μg/kg/day) for 21 days. Subsequently, serum levels of DN biomarkers were evaluated, and kidney tissues were histologically examined. The protein expression of PCNA, autotaxin, and KLF5 was detected. Key findings Liraglutide treatment in diabetic rats decreased DN biomarkers, histological abnormalities in kidney tissues, and the protein expression of PCNA, autotaxin, and KLF5. Conclusion Liraglutide can slow the progression of DN by modulating KLF5-related lysophosphatidic acid axis. Thus, liraglutide may be an effective treatment for preventing or mitigating diabetes-related kidney damage. [ABSTRACT FROM AUTHOR]

Objective To explore the relationship between serum Krüppel-like factor 5(KLF5) and actinin-4 with prognosis of hepatocellular carcinoma (HCC) treated with transcatheter arterial chemoembolization (TACE). Methods From March 2015 to March 2020, 130 HCC patients admitted into the Second Affiliated Hospital were collected as study subjects and divided into HCC group and 86 patients with liver cirrhosis were collected as control group. After 3 years of postoperative follow-up, HCC patients were sub-divided into survival group (n=38) and mortality group (n=92) based on their survival outcomes. ELISA was applied to detect the level of serum KLF5 and actinin-4 in each group and analyzed the correlation between serum KLF5 and actinin-4 levels. Cox regression was applied to analyze the risk factors affecting the prognostic mortality of HCC patients; Receiver operating characteristic curve(ROC) was plotted to evaluate the predictive value of serum KLF5 and actinin-4 levels for the prognostic mortality of HCC patients. Results The serum level of KLF5 and actinin-4 in the mortality group was significantly higher than those in the survival group(P＜0.05); There was a positive correlation between serum level of KLF5 and actinin-4 in HCC patients(P＜0.001); Low differentiation, staging (CNLC) stage IIIa of China liver cancer staging (CNLC), vascular invasion and elevated level of KLF5 and actinin-4 were risk factors for prognostic mortality in HCC patients(P＜0.05); The area under the curve (AUC) of serum KLF5 and actinin-4 alone and in combination for predicting mortality in HCC patients was 0.835, 0.866, and 0.936, respectively, showing a high level of combined predicting function (Zcombination-KLF5=2.792, P=0.005, Zcombination-actinin-4=2.014, P=0.044). Conclusions Serum level of KLF5 and actinin-4 l found in HCC patients has a high predictive value for prognosis.

Objective To explore the relationship between serum Krüppel-like factor 5(KLF5) and actinin-4 with prognosis of hepatocellular carcinoma (HCC) treated with transcatheter arterial chemoembolization (TACE). Methods From March 2015 to March 2020, 130 HCC patients admitted into the Second Affiliated Hospital were collected as study subjects and divided into HCC group and 86 patients with liver cirrhosis were collected as control group. After 3 years of postoperative follow-up, HCC patients were sub-divided into survival group (n=38) and mortality group (n=92) based on their survival outcomes. ELISA was applied to detect the level of serum KLF5 and actinin-4 in each group and analyzed the correlation between serum KLF5 and actinin-4 levels. Cox regression was applied to analyze the risk factors affecting the prognostic mortality of HCC patients; Receiver operating characteristic curve(ROC) was plotted to evaluate the predictive value of serum KLF5 and actinin-4 levels for the prognostic mortality of HCC patients. Results The serum level of KLF5 and actinin-4 in the mortality group was significantly higher than those in the survival group(P＜0.05); There was a positive correlation between serum level of KLF5 and actinin-4 in HCC patients(P＜0.001); Low differentiation, staging (CNLC) stage IIIa of China liver cancer staging (CNLC), vascular invasion and elevated level of KLF5 and actinin-4 were risk factors for prognostic mortality in HCC patients(P＜0.05); The area under the curve (AUC) of serum KLF5 and actinin-4 alone and in combination for predicting mortality in HCC patients was 0.835, 0.866, and 0.936, respectively, showing a high level of combined predicting function (Zcombination-KLF5=2.792, P=0.005, Zcombination-actinin-4=2.014, P=0.044). Conclusions Serum level of KLF5 and actinin-4 l found in HCC patients has a high predictive value for prognosis. [ABSTRACT FROM AUTHOR]

Objective: To explore the role of sublytic C5b -9 upregulating the transcription factor Krüppel -like factor 5 (KLF5) in promoting the production of the inflammatory cytokine interleukin-23 (IL-23) in glomerular mesangial cells (GMCs) of rats with Thy-1 nephritis (Thy-1N) . Methods: ①A rat model of Thy-1N was established and rat GMCs were cultured in vitro. The expression levels of KLF5 and IL-23 in the renal tissues of Thy-1N rats and in GMCs stimulated by sublytic C5b-9 were detected by using Western blot (WB) . ②The levels of mRNA and protein of KLF5 and IL -23 in the GMCs transfected with either a KLF5 overexpressing plasmid (pIRES2 - KLF5) or a KLF5 small interfering plasmid (shKLF5) were examined by RT - qPCR and WB. ③The full - length IL - 23 promoter luciferase reporter gene plasmid (pGL3-IL-23-FL) was transfected into GMCs, followed by stimulation with sublytic C5b-9. Alternatively, pGL3- IL -23-FL was co -transfected with either pIRES2-KLF5 or shKLF5 into GMCs, and changes in IL -23 promoter activity were measured using a luciferase reporter gene assay. ④The LV-shKLF5 and LV-shCTR lentivirus vectors were respectively perfused into rat renal tissues via the artery perfusion. After confirming that LV - shCTR could enrich in rat kidney through animal imaging system and frozen section, the Thy-1N was reproduced, and the KLF5 and IL-23 expression in the renal tissues were measured by WB. Results: ①The expressions of KLF5 and IL -23 were significantly increased in the renal tissues of Thy -1N rats and in GMCs stimulated by sublytic C5b-9, with KLF5 expression peaking slightly earlier than IL-23. ②Overexpression or knockdown of KLF5 in GMCs led to an increase or decrease in IL - 23 expression, respectively. ③ Sublytic C5b - 9 stimulation or KLF5 overexpression upregulated the activity of IL-23 promoter, while KLF5 knockdown markedly reduced the IL-23 promoter activity induced by sublytic C5b-9. ④IL-23 expression in the renal tissues of the rats treated by knocking down of renal KLF5 gene was significantly downregulated. Conclusion: In the early stage of Thy-1N in rats, sublytic C5b-9 stimulates GMCs to promote the transcription and expression of the IL-23 gene by upregulating KLF5. [ABSTRACT FROM AUTHOR]

Simple Summary: This report shows that KLF5 plays a crucial role in the progression of chronic pancreatitis to pre-neoplastic precursor lesions. Notably, the deletion of Klf5 from pancreatic acinar cells by itself or in the context of activating KRAS mutation resulted in a significant reduction in inflammatory and stromal activation and, thus, inhibition of chronic pancreatitis progression. Furthermore, this study demonstrated that KLF5 exerts its role by directly activating profibrotic and inflammatory cytokines. Using ChIP-PCR, we demonstrated that KLF5 binds directly to the Il1b, Il6, and Tgfb1 gene promoters in vitro and in vivo. Deletion of Klf5 during chronic pancreatitis development and progression resulted in a decrease of several vital chemokines, such as CCL6, CCL11, and CCL21. In summary, we showed that KLF5 regulates inflammatory and fibrotic responses during chronic pancreatitis. Chronic pancreatitis results in the formation of pancreatic intraepithelial neoplasia (PanIN) and poses a risk of developing pancreatic cancer. Our previous study demonstrated that Krüppel-like factor 5 (KLF5) is necessary for forming acinar-to-ductal metaplasia (ADM) in acute pancreatitis. Here, we investigated the role of KLF5 in response to chronic injury in the pancreas. Human tissues originating from chronic pancreatitis patients showed increased levels of epithelial KLF5. An inducible genetic model combining the deletion of Klf5 and the activation of KrasG12D mutant expression in pancreatic acinar cells together with chemically induced chronic pancreatitis was used. The chronic injury resulted in increased levels of KLF5 in both control and KrasG12D mutant mice. Furthermore, it led to numerous ADM and PanIN lesions and extensive fibrosis in the KRAS mutant mice. In contrast, pancreata with Klf5 loss (with or without KrasG12D) failed to develop ADM, PanIN, or significant fibrosis. Furthermore, the deletion of Klf5 reduced the expression level of cytokines and fibrotic components such as Il1b, Il6, Tnf, Tgfb1, Timp1, and Mmp9. Notably, using ChIP-PCR, we showed that KLF5 binds directly to the promoters of Il1b, Il6, and Tgfb1 genes. In summary, the inactivation of Klf5 inhibits ADM and PanIN formation and the development of pancreatic fibrosis. [ABSTRACT FROM AUTHOR]

The mucosal renewal, which depends on the intestinal stem cell (ISC) activity, is the foundation of mucosal repairment. Importantly, activation of reserve ISCs (rISCs) plays a vital role in initiating mucosal repair after injury. However, the underlying regulatory mechanism of rISCs activation in chickens remains unclear. In this study, immediately after lipopolysaccharide (LPS) challenge, mitochondrial morphological destruction and dysfunction appeared in the crypt, accompanied by decreased epithelial secretion (decreased Muc2 mRNA abundance and LYSOZYME protein level). However, immediately after mucosal injury, the mucosal renewal accelerated, as indicated by the increased BrdU positive rate, proliferating cell nuclear antigen (PCNA) protein level and mRNA abundance of cell cycle markers (Ccnd1, Cdk2). Concerning the ISCs activity, during the early period of injury, there appeared a reduction of active ISCs (aISCs) marker Lgr5 mRNA and protein, and an increasing of rISCs marker Hopx mRNA and protein. Strikingly, upon LPS challenge, increased mRNA transcriptional level of Krüppel-like factor 5 (Klf5) was detected in the crypt. Moreover, under LPS treatment in organoids, the KLF5 inhibitor (ML264) would decrease the mRNA and protein levels of Stat5a and Hopx, the STAT5A inhibitor (AC-4-130) would suppress the Lgr5 mRNA and protein levels. Furthermore, the Dual-Luciferase Reporter assay confirmed that, KLF5 would bind to Hopx promoter and activate the rISCs, STAT5A would trigger Lgr5 promoter and activate the aISCs. Collectively, KLF5 was upregulated during the early period of injury, further activate the rISCs directly and activate aISCs via STAT5A indirectly, thus initiate mucosal repair after injury. [ABSTRACT FROM AUTHOR]

AimsCircular RNA (circRNA) is involved in the regulation of articular cartilage degeneration induced by inflammatory factors or oxidative stress. In a previous study, we found that the expression of circStrn3 was significantly reduced in chondrocytes of osteoarthritis (OA) patients and OA mice. Therefore, the aim of this paper was to explore the role and mechanism of circStrn3 in osteoarthritis.MethodsMinus RNA sequencing, fluorescence in situ hybridization, and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression of circStrn3 in human and mouse OA cartilage tissues and chondrocytes. Chondrocytes were then stimulated to secrete exosomal miR-9-5p by cyclic tensile strain. Intra-articular injection of exosomal miR-9-5p into the model induced by destabilized medial meniscus (DMM) surgery was conducted to alleviate OA progression.ResultsTensile strain could decrease the expression of circStrn3 in chondrocytes. CircStrn3 expression was significantly decreased in human and mouse OA cartilage tissues and chondrocytes. CircStrn3 could inhibit matrix metabolism of chondrocytes through competitively ‘sponging’ miRNA-9-5p targeting Kruppel-like factor 5 (KLF5), indicating that the decrease in circStrn3 might be a protective factor in mechanical instability-induced OA. The tensile strain stimulated chondrocytes to secrete exosomal miR-9-5p. Exosomes with high miR-9-5p expression from chondrocytes could inhibit osteoblast differentiation by targeting KLF5. Intra-articular injection of exosomal miR-9-5p alleviated the progression of OA induced by destabilized medial meniscus surgery in mice.ConclusionTaken together, these results demonstrate that reduction of circStrn3 causes an increase in miR-9-5p, which acts as a protective factor in mechanical instability-induced OA, and provides a novel mechanism of communication among joint components and a potential application for the treatment of OA.Cite this article: Bone Joint Res 2023;12(1):33–45.

Peripheral artery disease (PAD) is an occlusive disease of limb arteries. Critical limb ischemia (CLI) is an advanced form of PAD that is prognostically worse in subjects with diabetes and can result in limb loss, gangrene, and death, although the underlying signaling mechanisms that contribute to its development remain poorly understood. By comparing plasma samples from diabetic humans with PAD and mouse models of PAD, we identified miR-375 to be significantly downregulated in humans and mice during progression to CLI. Overexpression of miR-375 was pro-angiogenic in endothelial cells in vitro and induced endothelial migration, proliferation, sprouting, and vascular network formation, whereas miR-375 inhibition conferred anti-angiogenic effects. Intramuscular delivery of miR-375 improved blood flow recovery to diabetic mouse hindlimbs following femoral artery ligation (FAL) and improved neovessel growth and arteriogenesis in muscle tissues. Using RNA-sequencing and prediction algorithms, Kruppel-like factor 5 (KLF5) was identified as a direct target of miR-375 and siRNA knockdown of KLF5 phenocopied the effects of miR-375 overexpression in vitro and in vivo through regulatory changes in NF-kB signaling. Together, a miR-375-KLF5-NF-kB signaling axis figures prominently as a potential therapeutic pathway in the development CLI in diabetes. [ABSTRACT FROM AUTHOR]

Abstract Background In several human cancers, Krüppel-like factor 5 (KLF5), a zinc finger transcription factor, can contribute to both tumor progression or suppression; however, the precise role of KLF5 in nasopharyngeal carcinoma (NPC) remains poorly understood. In this study, the association between KLF5 and microRNA-145-5p (miR-145-5p) in NPC cells was elucidated. Results Our results showed that KLF5 expression was up-regulated in NPC group compared to normal group. We found that KLF5 exhibited an oncogenic role in NPC cells. The upregulation of miR-145-5p inhibited the proliferation, migration, and invasion of NPC cells. It was observed that miR-145-5p could down-regulate the mRNA and protein expression of KLF5 in NPC cell lines. Additionally, the activity of focal adhesion kinase (FAK), a migration marker, was regulated by miR-145-5p and KLF5 in NPC cells. Conclusions The results of this study indicated that miR-145-5p could repress the proliferation, migration, and invasion of NPC cells via KLF5/FAK regulation, and could be a potential therapeutic target for patients with NPC.

Osteoarthritis (OA) is the most common joint disorder worldwide and a leading cause of pain and disability. However, the pathogenesis of osteoarthritis has not been elucidated. Krüppel-like factor (KLF)-5 is involved in several biological processes, including inflammation and cell differentiation, but its role in OA has not been evaluated. In this study, we investigated the role of KLF-5 in chondrocyte differentiation. KLF-5 overexpression in chondrocytes induced a loss of type II collagen expression and sulfated proteoglycan synthesis at the transcriptional and translational levels. Based on immunofluorescence staining, the ectopic expression of KLF-5 reduced type II collagen expression. In contrast, with KLF-5-transfected cells, KLF-5 siRNA transfection–induced type II expression also blocked dedifferentiation caused by the overexpression of KLF-5. In zebra fish, KLF-5 reduced the sulfated proteoglycan synthesis of ceratobranchial cartilage. Our results suggest that KLF-5 plays a pivotal role in the dedifferentiation of rabbit articular cartilage and zebra fish, providing a basis for therapeutic strategy for osteoarthritis aimed at controlling cartilage destruction. [ABSTRACT FROM AUTHOR]

Background: Krüppel-like factor 5 (KLF5) is recognized as a tumor mediator in multiple types of tumors. Nevertheless, whether KLF5 plays a role in gallbladder cancer (GBC) remains to be elucidated. This study aims to clarify the role of KLF5 in the proliferation, migration and angiogenesis in GBC cells., Methods: The expressions of KLF5 and platelet-derived growth factor subunit A (PDGFA) in GBC cell lines were analyzed by qRT-PCR and western blot assay. Cell proliferation was assessed utilizing the Cell Counting Kit-8 assay and EDU staining. Cell apoptosis was evaluated using flow cytometry, and apoptosis-related proteins was examined by western blotting. The migratory and invasive capabilities were evaluated utilizing wound healing and Transwell. Angiogenesis was assessed by ELISA, tube formation assay and western blot. The interaction between KLF5 and PDGFA was confirmed by ChIP assay, as well as luciferase reporter assay., Results: In this study, we discovered that the levels of KLF5 and PDGFA were upregulated in GBC cells. Silencing of KLF5 reduced the viability and suppressed the proliferation of GBC cells, as well as promoting the apoptosis. In addition, KLF5 silencing restrained the invasion and migration and angiogenesis in NOZ and GBC-SD cells. KLF5 transcription activated PDGFA expression and KLF5 was proved to bind to PDGFA promoter in NOZ cells. Following the silencing of PDGFA, the proliferation, invasion, migration, angiogenesis and apoptosis exhibited similar changes to KLF5 silencing. Additionally, PDGFA overexpression reversed the effects of KLF5 silencing on NOZ cells., Conclusion: Collectively, our results suggest that KLF5 regulates GBC cell proliferation, invasion, migration, angiogenesis, as well as apoptosis, via mediating PDGFA transcriptionally, which might provide a novel therapeutic strategy for treatment of human GBC., Competing Interests: Declarations. Conflict of interest: The authors declare no competing financial interests. Ethical approval: Not applicable., (© 2024. The Author(s).)

Background: Accumulated studies have demonstrated that Kruppel-like factor 5 (KLF5), a transcription factor, plays an important role in regulating cell proliferation and tissue remodeling through the expression of its downstream genes. KLF5-related factors are expected to be involved in the healing process after myocardial injury or myocardial ischemic changes, especially for the forensic diagnosis of myocardial ischemic physiopathology. Aim and Objectives: This study aimed to explore the discrimination ability and applicability of KLF5-related factors in SCD caused by MI compared with other causes of death to provide further insights into the forensic diagnosis of myocardial ischemic pathology. Materials and Methods: The relative quantification of F-Box and WD Repeat Domain Containing 7 (FBW7), KLF5, factor-binding protein (FGFBP) 1, and FGFBP2 messenger RNAs (mRNAs) in myocardial tissue samples was performed using real-time fluorescence quantitative reverse transcription polymerase chain reaction. KLF5 and FGFBP1/2 protein levels were examined using immunohistochemistry (IHC). The forensic autopsy cases (27 in total, autopsy within 72 h postmortem) included seven cases of acute myocardial infarction and 10 cases of acute myocardial ischemia. There were 10 cases in the control group, including four cases of traffic injury one case of injury by fall from height, one case of electric death, and four cases of blunt force injury. Results: Characteristic results were found in myocardial samples from three groups of deaths: KLF5 and FGFBP1 mRNA levels were significantly elevated in the infarction and ischemia groups, while FBW7 mRNA levels were significantly decreased. FBW7 is an important ubiquitin ligase that can mediate the degradation of KLF5 protein. In addition, FBW7 and FGFBP2 mRNA levels were decreased in the infarction group compared with the ischemia group. The IHC results were consistent with the observed mRNA expression patterns. Conclusions: Quantitative detection of FBW7, KLF5, FGFBP1, and FGFBP2 mRNA transcripts in myocardial tissues supports the pathophysiological study of myocardial ischemic diseases and provides molecular pathological evidence for forensic discrimination of death causes.

The epithelial–mesenchymal transition (EMT) is a differentiation process associated with fibrogenesis in diabetic nephropathy (DN). Lysophosphatidic acid (LPA) is a small, naturally occurring glycerophospholipid implicated in the pathogenesis of DN. In this study, we investigated the role of LPA/LPAR1 signaling in the EMT of tubular cells as well as the underlying mechanisms. We observed a decrease in E-cadherin and an increase in vimentin expression levels in the kidney tubules of diabetic db/db mice, and treatment with ki16425 (LPAR1/3 inhibitor) inhibited the expression of these EMT markers. Ki16425 treatment also decreased the expression levels of the fibrotic factors fibronectin and alpha-smooth muscle actin (α-SMA) in db/db mice. Similarly, we found that LPA decreased E-cadherin expression and increased vimentin expression in HK-2 cells, which was reversed by treatment with ki16425 or AM095 (LPAR1 inhibitor). In addition, the expression levels of fibronectin and α-SMA were increased by LPA, and this effect was reversed by treatment with ki16425 and AM095 or by LPAR1 knockdown. Moreover, LPA induced the expression of the transcription factor, Krüppel-like factor 5 (KLF5), which was decreased by AM095 treatment or LPAR1 knockdown. The expression levels of EMT markers and fibrotic factors induced by LPA were decreased upon KLF5 knockdown in HK-2 cells. Inhibition of the extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and serine-threonine kinase (AKT) pathways decreased LPA-induced expression of KLF5 and EMT markers. In conclusion, these data suggest that LPA contributes to the pathogenesis of diabetic nephropathy by inducing EMT and renal tubular fibrosis via regulation of KLF5 through the LPAR1. [ABSTRACT FROM AUTHOR]

ABSTRACT Krüppel-like factor 5 (KLF5) is critical in maintaining intestinal barrier function, and renal denervation (RDN) mitigates gut microbiota aberrations in rats with heart failure (HF). It is unclear whether intestinal KLF5 can be regulated by RDN and whether inhibiting intestinal KLF5 weakens the beneficial role of RDN on gut microbiota. Sprague-Dawley rats were distributed into a CG (sham transverse aortic constriction [TAC] and sham RDN), HF (induced by TAC), or RDN (underwent RDN after TAC) group or a CG.M, HF.M, or RDN.M group, which included the administration of the KLF5 inhibitor to the CG, HF, or RDN group, respectively. Transmission electron microscopy, mRNA, and protein expression of KLF5 and desmoglein 2 (DSG2) in jejunum and sequencing of the 16S rRNA gene in fecal samples were evaluated. KLF5 expression was lower in the RDN group than in the HF group (P

Background: In several human cancers, Krüppel-like factor 5 (KLF5), a zinc finger transcription factor, can contribute to both tumor progression or suppression; however, the precise role of KLF5 in nasopharyngeal carcinoma (NPC) remains poorly understood. In this study, the association between KLF5 and microRNA-145-5p (miR-145-5p) in NPC cells was elucidated. Results: Our results showed that KLF5 expression was up-regulated in NPC group compared to normal group. We found that KLF5 exhibited an oncogenic role in NPC cells. The upregulation of miR-145-5p inhibited the proliferation, migration, and invasion of NPC cells. It was observed that miR-145-5p could down-regulate the mRNA and protein expression of KLF5 in NPC cell lines. Additionally, the activity of focal adhesion kinase (FAK), a migration marker, was regulated by miR-145-5p and KLF5 in NPC cells. Conclusions: The results of this study indicated that miR-145-5p could repress the proliferation, migration, and invasion of NPC cells via KLF5/FAK regulation, and could be a potential therapeutic target for patients with NPC. [ABSTRACT FROM AUTHOR]

Myocardial infarction (MI) is a significant contributor to the development of heart failure. Histidine decarboxylase (HDC), the unique enzyme that converts l-histidine to histamine, is highly expressed in CD11b+ immature myeloid cells. However, the relationship between HDC-expressing macrophages and cardiac myofibroblasts remains to be explained. Here, we demonstrate that the GFP (green fluorescent protein)-labeled HDC+CD11b+ myeloid precursors and their descendants could differentiate into fibroblast-like cells in myocardial interstitium. Furthermore, we prove that CD11b+Ly6C+ monocytes/macrophages, but not CD11b+Ly6G+ granulocytes, are identified as the main cellular source for bone marrow-derived myofibroblast transformation, which could be regulated via histamine H1 and H2 receptor-dependent signaling pathways. Using HDC knockout mice, we find that histamine deficiency promotes myofibroblast transformation from Ly6C+ macrophages and cardiac fibrosis partly through upregulating the expression of Krüppel-like factor 5 (KLF5). Taken together, our data uncover a central role of HDC in regulating bone marrow-derived macrophage-to-myofibroblast transformation but also identify a histamine receptor (HR)-KLF5 related signaling pathway that mediates myocardial fibrosis post-MI. CD11b+Ly6C+ monocytes/macrophages are the main cellular source for bone marrow-derived myofibroblast transformation. Histamine inhibits myofibroblasts transformation via H1R and H2R-dependent signaling pathways, and ameliorates cardiac fibrosis partly through upregulating KLF5 expression. [ABSTRACT FROM AUTHOR]

Krüppel-like factors (KLFs) are DNA-binding transcriptional factors, which regulate various pathways that pertain to development, metabolism and other cellular mechanisms. KLF5 was first cloned in 1993 and by 1999, it was reported as the intestinal-enriched KLF. Beyond findings that have associated KLF5 with normal development and cancer, it has been associated with various types of cardiovascular (CV) complications and regulation of metabolic pathways in the liver, heart, adipose tissue and skeletal muscle. Specifically, increased KLF5 expression has been linked with cardiomyopathy in diabetes, end-stage heart failure, and as well as in vascular atherosclerotic lesions. In this review article, we summarize research findings about transcriptional, post-transcriptional and post-translational regulation of KLF5, as well as the role of KLF5 in the biology of cells and organs that affect cardiovascular health either directly or indirectly. Finally, we propose KLF5 inhibition as an emerging approach for cardiovascular therapeutics. [Display omitted] • Cardiomyocyte KLF5 expression is increased in diabetes and myocardial ischemia. • Vascular KLF5 is associated with atherosclerosis and vascular remodeling. • KLF5 regulates lipid metabolism in the heart, liver, WAT, and skeletal muscle. • KLF5 inhibition holds therapeutic potential for cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Objectives: Diabetic nephropathy (DN) is a serious consequence of diabetes that can develop through the lysophosphatidic acid axis. The purpose of this study was to determine whether the antidiabetic drug liraglutide can slow the development of diabetic kidney damage by altering the lysophosphatidic acid axis via KLF5., Methods: Wistar albino rats were divided into nondiabetic and diabetic rats (resulting from an intraperitoneal streptozotocin dose of 30 mg/kg and a high-fat diet). These rats were further divided into four groups: nondiabetic control, liraglutide-treated nondiabetic, diabetic control, and liraglutide-treated diabetic. The nondiabetic and diabetic control groups received normal saline for 42 days, while the liraglutide-treated nondiabetic and diabetic groups received normal saline for 21 days, followed by a subcutaneous dose of liraglutide (200 μg/kg/day) for 21 days. Subsequently, serum levels of DN biomarkers were evaluated, and kidney tissues were histologically examined. The protein expression of PCNA, autotaxin, and KLF5 was detected., Key Findings: Liraglutide treatment in diabetic rats decreased DN biomarkers, histological abnormalities in kidney tissues, and the protein expression of PCNA, autotaxin, and KLF5., Conclusion: Liraglutide can slow the progression of DN by modulating KLF5-related lysophosphatidic acid axis. Thus, liraglutide may be an effective treatment for preventing or mitigating diabetes-related kidney damage., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Royal Pharmaceutical Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: A large number of clinical trials have proved that radiotherapy is an effective strategy for treating breast cancer (BC), but radioresistance is an urgent problem to be solved. Objective: Herein, radio-tolerant BC cell lines named MDA-MB-231/R and MCF-7/R were successfully constructed, respectively, and it was shown that microRNA-125b-5p (miR-125b-5p) was lowly expressed in radio-tolerant cells, which was associated with poor prognosis of BC patients. Results: Furthermore, miR-125b-5p over expression could hinder cell proliferation and strengthen radio-sensitivity. Mechanistically, Breast Cancer 1 (BRCA1) was identified as a downstream protein target of miR-125b-5p in BC cells, and Kruppel-like factor 5 (KLF5) was identified as an upstream transcription factor involved in promoting miR-125b-5p expression. More importantly, over expression of KLF5 suppressed BC cell proliferation and increased its radiation sensitivity, which could be retained by miR-125b-5p downregulation. Conclusion: In conclusion, these findings suggested that the KLF5/miR-125b-5p/BRCA1 axis may provide new information on radiation therapy for breast cancer. [ABSTRACT FROM AUTHOR]

Long non-coding RNA (lncRNA) differentiation antagonizing non-protein coding RNA (DANCR) participates in the development of diverse cancers. Nevertheless, the impact of DANCR on cervical cancer (CC) remains largely unknown. This study aims to explore the effects of DANCR sponging microRNA-145-3p (miR-145-3p) on CC. Expression of KLF5, DANCR, miR-145-3p, and zinc finger E-box binding homeobox 1 (ZEB1) in CC and adjacent normal tissues was determined. Human CC cell lines were, respectively, treated with silenced DANCR or miR145-3p mimic/inhibitor. Then, the viability, migration, invasion, and apoptosis of CC cells were measured. The cell growth in vivo was observed as well. Chromatin immunoprecipitation assay was performed to analyze the binding of KLF5 and DANCR promoter. Interaction among DANCR, miR-145-3p, and ZEB1 was assessed. KLF5, DANCR, and ZEB1 were upregulated but miR-145-3p was downregulated in CC tissues. KLF5 activated DANCR expression and the high DANCR expression was related to tumor staging, infiltrating muscle depth and lymphatic metastasis of CC patients. Reduced DANCR or elevated miR-145-3p repressed malignant behaviors of CC cells. The tumor diameter and weight were also repressed by DANCR silencing or miR-145-3p elevation. The effect of DANCR knockdown on CC cells could be reversed by miR-145-3p inhibitor. MiR-145-3p was targeted by DANCR and ZEB1 was targeted by miR-145-3p. KLF5-induced overexpression of DANCR promotes CC progression via suppressing miR-145-3p to target ZEB1. This study may provide potential targets for CC treatment. [ABSTRACT FROM AUTHOR]

Aims: Emerging evidence suggests that the pathogenesis of osteoporosis, characterized by impaired osteogenesis, is shifting from estrogen centric to oxidative stress. Our previous studies have shown that the zinc-finger transcription factor krüppel-like factor 5 (KLF5) plays a key role in the degeneration of nucleus pulposus and cartilage. However, its role in osteoporosis remains unknown. We aimed to investigate the effect and mechanism of KLF5 on osteogenesis under oxidative stress. Results: First, KLF5 was required for osteogenesis and stimulated osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). KLF5 was hypermethylated and downregulated in ovariectomy-induced osteoporosis mice and in BMSCs treated with H2O2. Interestingly, DNA methyltransferases 3B (DNMT3B) upregulation mediated the hypermethylation of KLF5 induced by oxidative stress, thereby impairing osteogenic differentiation. The inhibition of KLF5 hypermethylation using DNMT3B siRNA or 5-AZA-2-deoxycytidine (5-AZA) protected osteogenic differentiation of BMSCs from oxidative stress. Regarding the downstream mechanism, KLF5 induced β-catenin expression. More importantly, KLF5 promoted the nuclear translocation of β-catenin, which was mediated by the armadillo repeat region of β-catenin. Consistently, oxidative stress-induced KLF5 hypermethylation inhibited osteogenic differentiation by reducing the expression and nuclear translocation of β-catenin. Innovation: We describe the novel effect and mechanism of KLF5 on osteogenesis under oxidative stress, which is linked to osteoporosis for the first time. Conclusion: Our results suggested that oxidative stress-induced hypermethylation of KLF5 mediated by DNMT3B impairs osteogenesis by diminishing the interaction with β-catenin, which is likely to contribute to osteoporosis. Targeting the hypermethylation of KLF5 might be a new strategy for the treatment of osteoporosis. Antioxid. Redox Signal. 35, 1–20. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) are aberrantly expressed in pancreatic ductal adenocarcinoma (PDAC). In the current study, we investigated how circRNA_000684 affected the progression of PDAC, and how it regulated kruppel-like factor 5 (KLF5) and microRNA (miR)-145. Differentially expressed circRNAs, miRs and genes related to PDAC as well as their targeting relationship were predicted using bioinformatics analyses. Binding relationships among circRNA_000684, miR-145 and KLF5 were verified using dual-luciferase reporter gene assay, RIP and RNA pull-down assay, respectively. The effects of circRNA_000684, miR-145, KLF5 on the malignant phenotypes of PDAC cells and human umbilical vein endothelial cell (HUVEC) angiogenesis were assessed using loss- and gain-of function experiments by CCK-8 assay, scratch test, Transwell and tube formation assays. RT-qPCR and Western blot analysis were used to determine MCM2, MMP2 and MMP9 and VEGFA expression. In addition, the roles of circRNA_000684, miR-145, and KLF5 in tumor growth were validated through in vivo experiments. Expression of CircRNA_000684 and KLF5 was upregulated, whereas miR-145 expression was downregulated in PDAC tissues and cells. CircRNA_000684 repression or miR-145 elevation inhibited the proliferation, invasion and migration of PDAC cells and HUVEC angiogenesis, as evidenced by lower levels of MCM2, MMP2 and MMP9 and VEGFA. CircRNA_000684 negatively regulated miR-145 expression, while miR-145 negatively regulated KLF5. In-vivo , circRNA_000684 elevation or miR-145 repression promoted tumor growth. Taken together, the present study provided evidence clarifying that circRNA_000684 could downregulate miR-145 expression and elevate KLF5 to promote the progression of PDAC. [ABSTRACT FROM AUTHOR]

Purpose: Vein graft failure (VGF) is an important limitation for coronary artery bypass graft (CABG) surgery. Inhibition of the excessive proliferation and migration of venous smooth muscle cells (SMCs) is an effective strategy to alleviate VGF during the CABG perioperative period. In the present study, we aimed to explore the role and potential mechanism of all-trans retinoic acid (ATRA) on preventing vein grafts stenosis. Methods: The autogenous vein grafts model was established in the right jugular artery of rabbits. Immunohistochemistry staining and western blot assays were used to detected the protein expression, while real-time PCR assay was applied for mRNAs expression detection. The interaction between proteins was identified by co-immunoprecipitation assay. The Cell Counting Kit-8 and wound-healing assays were used to investigate the role of ATRA on human umbilical vein smooth muscle cells (HUVSMCs) function. Cell cycle progression was identified by flow cytometry assay. Results: Vein graft stenosis and SMCs hyperproliferation were confirmed in vein grafts by histological and Ki-67 immunohistochemistry assays. Treatment of ATRA (10 mg/kg/day) significantly mitigated the stenosis extent of vein grafts, demonstrated by the decreased thickness of intima-media, and decreased Ki-67 expression. ATRA could repress the PDGF-bb-induced excessive proliferation and migration of HUVSMCs, which was mediated by Rb-E2F dependent cell cycle inhibition. Meanwhile, ATRA could reduce the interaction between KLF5 and RARα, thereby inhibiting the function of cis-elements of KLF5. KLF5-induced inducible nitric oxide synthase (iNOS) expression activation could be significantly inhibited by ATRA. Conclusions: These results suggested that ATRA treatment may represent an effective prevention and therapy avenue for VGF. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC) carcinogenesis and malignant transformation are intimately associated with Epstein-Barr virus (EBV) infection. A zinc-fingered transcription factor known as Krüppel-like factor 5 (KLF5) has been shown to be aberrantly expressed in a number of cancer types. However, little is known about the regulatory pathways and roles of KLF5 in EBV-positive NPC. Our study found that KLF5 expression was significantly lower in EBV-positive NPC than in EBV-negative NPC. Further investigation revealed that EBER1, which is encoded by EBV, down-regulates KLF5 via the extracellular signal-regulated kinase (ERK) signalling pathway. This down-regulation of KLF5 by EBER1 contributes to maintaining latent EBV infection in NPC. Furthermore, we uncovered the biological roles of KLF5 in NPC cells. Specifically, KLF5 may influence the cell cycle, prevent apoptosis, and encourage cell migration and proliferation - all of which have a generally pro-cancer impact. In conclusion, these findings offer novel strategies for EBV-positive NPC patients' antitumour treatment.

Accumulating literature and evidence has highlighted the cancer stem-like cell (CSC) model as a cellular mechanism responsible for the phenotypic heterogeneity observed in various types of cancers, including cervical cancer. Long non-coding RNAs (lncRNAs) have been implicated in the retention of stem cell-like traits in cancer cells. However, the role of lncRNAs in the acquisition and maintenance of CSCs in cervical cancer remains largely unknown. Hence, the current study identified that LINC00337 knockdown diminished the CSC-like properties of CD44+/CD24low/−SFCs, evidenced by a decline in the generation of tumorospheres and colonies, a reduction in multi-drug resistance gene-1 (MDR-1), Nanog, Sox2, and Oct4 expression, along with an enhancement in cell apoptosis. RNA pull-down assays and RNA immunoprecipitation revealed the role of LINC00337 as a competing endogenous RNA (ceRNA) of microRNA-145 (miR-145). Furthermore, the miR-145 mRNA target, Kruppel-like factor 5 (KLF5), was decreased in CD44+/CD24low/−SFCs upon LINC00337 knockdown. The in vitro results were reproduced in in vivo studies, which provided verification attesting that LINC00337 knockdown attenuated the tumorigenicity of CD44+/CD24low/−SFCs in nude mice. Taken together, the key findings of the current study demonstrate that LINC00337 acts as an oncogenic lncRNA in cervical cancer and exerts its influence on the expression of KLF5 and the maintenance of cancer stem cell-like properties by means of downregulating miR-145.

Objective To observe the effects of Kruppel-like factor 5（KLF5）-mediated p27kip1 on the proliferation and invasion of glioma U87 cells. Methods U87 glioma cells were cultured routinely and divided into the si-NC group and si-KLF5 group. The U87 glioma cells in the si-NC group were transfected with control siRNA，and the si-KLF5 group with KLF5 siRNA. MTS experiment was used to detect the proliferation of the two groups，flow cytometry was used to detect cell cycle，Boyden experiment was used to detect cell invasion ability，and Western blotting was used to detect the expression of cell cycle-related proteins Cyclin D1，CDK4，CDK6 and epithelial-mesenchymal transition protein Snail1. Western blotting showed that the expression level of p27kip1 in the si-KLF5 group was higher than that in the si-NC group， so the si-KLF5+si-p27kip1 group，the si-NC group，and the si-KLF5 group were set，and the cells in the si-KLF5+si-p27kip1 group U87 cells were co-transfected with p27kip1 siRNA and KLF5 siRNA，the si-KLF5 group with KLF5 siRNA，and the si-NC group with control siRNA，respectively. We compared the proliferation and invasion abilities of the three groups. Results Compared with the si-NC group，the proliferation and invasion abilities of U87 cells in the si-KLF5 group were reduced（both P<0. 05），the proportion of cells in the G1 phase increased（P<0. 05），and the expression levels of Cyclin D1，CDK4，CDK6 and Snail1 proteins decreased（all P<0. 05）. The cell proliferation and invasion abilities of the si- KLF5+si-p27kip1 group were lower than those of the si-NC group（all P<0. 05），and increased as compared with that of the si-KLF5 group（P<0. 05）. Conclusion The proliferation and invasion abilities of U87 cells decrease after interference with KLF5 expression，and the mechanism is related to the up-regulation of p27kip1 expression. [ABSTRACT FROM AUTHOR]

AarF domain containing kinase 4 (ADCK4) is identified as a candidate gene associated with hereditary nephrotic syndrome (NS). Kruppel-like factor 5 (KLF5) is reported to promote podocyte survival by blocking the ERK/p38 MAPK pathways. Both ADCK4 and KLF5 are involved in the occurrence and development of podocyte disease, but their interaction remains unclear. Firstly, we found that the mRNA levels of ADCK4 and KLF5 decreased in NS patients, and both levels showed an obvious linear relationship. Secondly, we cloned the ADCK4 promoter region and examined its promoter activity in Hela, A549, and HEK 293 cell lines. Deletion analysis showed that the region − 116/− 4 relative to the transcriptional start site (TSS) was the core region of ADCK4 promoter. Thirdly, mutation analysis showed that putative binding sites for KLF5 contributed to the ADCK4 promoter activity. In HEK293 cells, we found that KLF5 upregulated the mRNA and protein levels of ADCK4. Finally, our chromatin immunoprecipitation assay found that KLF5 could bind to the specific region of ADCK4 promoter. These results showed that KLF5 can positively regulate the transcriptional activity of ADCK4. [ABSTRACT FROM AUTHOR]

Accumulating literature and evidence has highlighted the cancer stem-like cell (CSC) model as a cellular mechanism responsible for the phenotypic heterogeneity observed in various types of cancers, including cervical cancer. Long non-coding RNAs (lncRNAs) have been implicated in the retention of stem cell-like traits in cancer cells. However, the role of lncRNAs in the acquisition and maintenance of CSCs in cervical cancer remains largely unknown. Hence, the current study identified that LINC00337 knockdown diminished the CSC-like properties of CD44+/CD24low/−SFCs, evidenced by a decline in the generation of tumorospheres and colonies, a reduction in multi-drug resistance gene-1 (MDR-1), Nanog, Sox2, and Oct4 expression, along with an enhancement in cell apoptosis. RNA pull-down assays and RNA immunoprecipitation revealed the role of LINC00337 as a competing endogenous RNA (ceRNA) of microRNA-145 (miR-145). Furthermore, the miR-145 mRNA target, Kruppel-like factor 5 (KLF5), was decreased in CD44+/CD24low/−SFCs upon LINC00337 knockdown. The in vitro results were reproduced in in vivo studies, which provided verification attesting that LINC00337 knockdown attenuated the tumorigenicity of CD44+/CD24low/−SFCs in nude mice. Taken together, the key findings of the current study demonstrate that LINC00337 acts as an oncogenic lncRNA in cervical cancer and exerts its influence on the expression of KLF5 and the maintenance of cancer stem cell-like properties by means of downregulating miR-145. [ABSTRACT FROM AUTHOR]

Krüppel‐like factor 5 (KLF5) plays an oncogenic role and has diverse functions in cancer cells. However, correlation between KLF5 and clinical outcome has not been determined in patients with colorectal cancer and colorectal liver metastasis. Herein, we analyzed 65 patients with colorectal cancer who developed colorectal liver metastasis. Clinical effects were assessed through immunohistochemical analysis of primary colorectal cancer lesions and metastatic liver lesions. High expression of KLF5 in these tissues correlated with the presence of vascular invasion, elevated serum carbohydrate antigen 19‐9 levels, large diameters of metastatic liver tumors, and poor prognosis following surgery. Multivariate analyses revealed that high expression of KLF5 was an independent prognostic factor. Increased expression of KLF5 in both colorectal cancer primaries and colorectal liver metastasis was significantly associated with shorter overall survival time and time to surgical failure. Krüppel‐like factor 5 expression positively correlated with Ki‐67 and c‐Myc expression in colorectal cancer tissues. In vitro experiments with colon cancer cell lines showed that siRNA knockdown of KLF5 inhibited cell proliferation. Western blot analyses revealed that knockdown of KLF5 expression reduced cyclin D1 and c‐Myc expression. It also impaired the stem cell‐like properties of cancer cells in tumorsphere formation assays. Furthermore, anoikis assay indicated that KLF5 contributed to anoikis resistance. High KLF5 expression is associated with poor prognosis in patients with colorectal cancer and liver metastasis by promoting cell proliferation and cancer stem cell‐like properties. [ABSTRACT FROM AUTHOR]

Osteosarcoma, the most common bone malignancy, has a high morbidity rate and poor prognosis. Krüppel‐like factor 5 (KLF5) is a key transcriptional regulator of cellular proliferation whose overexpression is observed in osteosarcoma cell lines (U2OS, 143B, MG63 and SAOS2). ML264, a small‐molecule inhibitor of KLF5, exerts antiproliferative effects in colorectal cancer; however, its function in osteosarcoma remains unknown. Here, we explored the possible antitumour effects of ML264 on 143B and U2OS cell lines and murine tumour xenograft model. ML264 suppressed proliferation and clonogenic ability of osteosarcoma cells in a dose‐dependent manner. Moreover, ML264 induced G0/G1 cell cycle arrest, with no influence on apoptosis, and inhibited the migratory and invasive abilities of osteosarcoma cells, as demonstrated by wound‐healing and Transwell assays. Exposure to ML264 reduced the mRNA and protein levels of molecules associated with epithelial‐mesenchymal transition phenotype, including N‐cadherin, vimentin, Snail, matrix metalloproteinase (MMP) 9 and MMP13. Inhibition of signal transducer and activator of transcription (STAT) 3 phosphorylation and Wnt signalling was also observed. In the murine model of osteosarcoma, tumour growth was efficiently suppressed following a 10‐day treatment with ML264. Collectively, our findings demonstrate the potential value of ML264 as a novel anticancer drug for osteosarcoma. [ABSTRACT FROM AUTHOR]

Chronic inflammation plays a pivotal role in insulin resistance and type 2 diabetes, yet the mechanisms are not completely understood. Here, we demonstrated that serum LPS levels were significantly higher in newly diagnosed diabetic patients than in normal control. miR-145 level in peripheral blood mononuclear cells decreased in type 2 diabetics. LPS repressed the transcription of miR-143/145 cluster and decreased miR-145 levels. Attenuation of miR-145 activity by anti-miR-145 triggered liver inflammation and increased serum chemokines in C57BL/6 J mice. Conversely, lentivirus-mediated miR-145 overexpression inhibited macrophage infiltration, reduced body weight, and improved glucose metabolism in db/db mice. And miR-145 overexpression markedly reduced plaque size in the aorta in ApoE−/− mice. Both OPG and KLF5 were targets of miR-145. miR-145 repressed cell proliferation and induced apoptosis partially by targeting OPG and KLF5. miR-145 also suppressed NF-κB activation by targeting OPG and KLF5. Our findings provide an association of the environment with the progress of metabolic disorders. Increasing miR-145 may be a new potential therapeutic strategy in preventing and treating metabolic diseases such as type 2 diabetes and atherosclerosis. [ABSTRACT FROM AUTHOR]

Lung cancer is a harmful type of malignancy and the leading cause of cancer-associated mortality. It is therefore imperative to develop novel drugs effective for treating this cancer. The Traditional Chinese Medicine compound Britannin has been previously reported to inhibit the development of certain cancers, such as pancreatic, breast and liver cancer. Moreover, Kruppel-like factor 5 (KLF5) has been identified an on oncogene in lung cancer. In the present study, the possible regulatory effects and underlying mechanism of Britannin in lung cancer were investigated. A549 and 16HBE cells were treated with different concentrations of Britannin. Subsequently, Cell counting kit-8, EdU staining and colony formation assays were used to detect the proliferative ability of these cells. Cell migration was detected by wound healing and Transwell assays, respectively. XF96 extracellular flux analyzer was used to analyze the extent of extracellular acidification and oxygen consumption rate in cells, whereas assay kits were used to detect glucose and lactic acid levels in the cell supernatant. The targeting effect between Britannin and the KLF5 protein was investigated using molecular docking technology. The protein expression levels of KLF5 in cells challenged with Britannin was detected by western blotting. Finally, overexpression of KLF5 in A549 cells was performed before cell proliferation, migration and the glycolysis rate were measured to explore the regulatory effects of Britannin. Britannin was found to inhibit the proliferation, migration and glycolysis of lung cancer cells, during which the protein expression levels of KLF5 were decreased. This suggests that Britannin regulated the expression of KLF5 in A549 cells. Overexpression of KLF5 reversed the inhibitory effects of Britannin on the proliferation, migration and glycolysis in lung cancer cells. In conclusion, these results suggest that Britannin can inhibit cell proliferation, migration and glycolysis by downregulating KLF5 expression in lung cancer cells. [ABSTRACT FROM AUTHOR]

Early transcription factors play critical roles in the development of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Early growth response 1 (EGR1) is a transcription factor essential for various biological processes, including regulation of metabolism, differentiation, and inflammation. However, its role in ALI has been poorly reported. In this study, we aimed to determine the effect of EGR1 on ALI to gain insights into the theoretical basis for further treatment of ALI. By employing concerted molecular biology techniques, we showed that EGR1 protein was upregulated in mice. EGR1 protein was upregulated in mice and human lung epithelial cells in response to lipopolysaccharide (LPS) stimulation. EGR1 knockdown promoted autophagy and reduced LPS-induced pro-inflammatory mediator production. EGR1 was preferentially bound to the GCGTGGGCG motif region and EGR1-binding peak-related genes were mainly enriched in autophagy and injury stress-related pathways. Additionally, EGR1 promoted Krüppel-like factor 5 (KLF5) transcription by binding to the KLF5 promoter region, and KLF5 knockdown significantly decreased inflammatory damage, suggesting that EGR1 promotes ALI progression by regulating KLF5 expression. Furthermore, ML264, an inhibitor of the EGR1/KLF5 pathway axis, displayed a protective role in ALI to reduce inflammation. In conclusion, our findings demonstrate the potential of EGR1 knockdown to inhibit KLF5 and promote autophagy, further reducing the inflammatory response to mitigate ALI/ARDS. The EGR1/KLF5 pathway axis may be a valuable therapeutic target for the treatment of ALI/ARDS. [ABSTRACT FROM AUTHOR]

The discovery of hypoxia-inducible factor (HIF)-prolyl hydroxylase inhibitor (PHI) has revolutionized the treatment strategy for renal anemia. However, the presence of multiple transcription targets of HIF raises safety concerns regarding HIF-PHI. Here, we explored the dose-dependent effect of MK-8617 (MK), a kind of HIF-PHI, on renal fibrosis. MK was administered by oral gavage to mice for 12 wk at doses of 1.5, 5, and 12.5 mg/kg. In vitro, the human proximal tubule epithelial cell line HK-2 was treated with increasing doses of MK administration. Transcriptome profiling was performed, and fibrogenesis was evaluated. The dose-dependent biphasic effects of MK on tubulointerstitial fibrosis (TIF) were observed in chronic kidney disease mice. Accordingly, high-dose MK treatment could significantly enhance TIF. Using RNA-sequencing, combined with in vivo and in vitro experiments, we found that Krüppel-like factor 5 (KLF5) expression level was significantly increased in the proximal tubular cells, which could be transcriptionally regulated by HIF-1α with high-dose MK treatment but not low-dose MK. Furthermore, our study clarified that HIF-1α-KLF5-TGF-β1 signaling activation is the potential mechanism of high-dose MK-induced TIF, as knockdown of KLF5 reduced TIF in vivo. Collectively, our study demonstrates that high-dose MK treatment initiates TIF by activating HIF-1α-KLF5-TGF-β1 signaling. These findings provide novel insights into TIF induction by high-dose MK (HIF-PHI), suggesting that the safety dosage window needs to be emphasized in future clinical applications. [ABSTRACT FROM AUTHOR]

Abnormal expression of microRNA (miR)-21 has been reported in various types of cancers. However, the role and mechanism of miR-21 remain to be elucidated in acute myeloid leukemia (AML). In the present study, it was observed that miR-21 was upregulated and Krüppel-like factor 5 (KLF5) was downregulated in AML cells compared with normal bone marrow cells. Dual luciferase reporter assays revealed that KLF5 was a direct target of miR-21. Indeed, miR-21 overexpression resulted in a downregulation of KLF5 expression, while miR-21 inhibition had the opposite effect in AML cells. In addition, miR-21 overexpression promoted the proliferation of AML cells in vitro. Notably, using a mouse xenograft model, miR-21 overexpression was demonstrated to result in enhanced tumor growth and suppressed KLF5 expression in the xenograft tumors in vivo. In conclusion, the present results indicated that miR-21 promoted proliferation through directly regulating KLF5 expression in AML cells. miR-21 may thus serve as an oncogene in AML, providing a potential target for AML therapy. [ABSTRACT FROM AUTHOR]

Background: Previous research has revealed that Krüppel‐like factor 5 (KLF5) may affect DNA damage repair pathways; however, the associated molecular mechanisms are unclear. Methods: The expression of KLF5 was studied by immunohistochemical staining in paired tumour and normal tissues from 90 patients with ESCC. We studied the effects of KLF5 knockdown on cell proliferation and apoptosis with or without cisplatin treatment in A549 and H1299 cell lines. Moreover, we examined the effect of KLF5 on the DNA damage response. Results: KLF5 was significantly overexpressed in non‐small cell lung cancer (NSCLC) tissues, and high KLF5 expression predicted poor prognosis for NSCLC patients. The inhibition of KLF5 markedly augmented cisplatin‐induced cell apoptosis. In addition, we observed that KLF5 knockdown could decrease DNA repair potential by inhibiting H2AX S139 phosphorylation in response to cisplatin. Moreover, silencing of KLF5 in NSCLC cell lines inhibited the phosphorylation of checkpoint kinases Chk1 S345 and Chk2 T68. KLF5 knockdown permits cells with broken or damaged DNA strands to enter mitosis by inhibiting the activation of H2AX, Chk1 and Chk2, resulting in mitotic catastrophe. Conclusion: KLF5 plays a significant role in the DNA damage response by regulating DNA damage checkpoint proteins. Inhibition of KLF5 may be a potential therapeutic target for NSCLC patients with cisplatin resistance. [ABSTRACT FROM AUTHOR]

Krüppel‐like factor 5 (KLF5) both suppresses and promotes tumor growth depending on cellular context. The mechanisms underlying tumor promotion could be targetable for therapy. Although a number of transcriptional targets of KLF5 have been identified and implicated in KLF5‐mediated tumor growth, how KLF5 regulates these genes remains to be addressed. Here we performed coimmunoprecipitation (co‐IP) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) in the TSU‐Pr1 bladder cancer cell line, in which KLF5 is shown to promote tumor growth, to identify KLF5‐interacting nuclear proteins that are necessary for KLF5's tumor promoting function. LC–MS/MS revealed 122 potential KLF5 binding proteins in the nuclear proteins precipitated by the KLF5 antibody, and the top nine candidates included AHNAK, TFAM, HSDL2, HNRNPC, CINP, IST1, FBL, PABPC1 and SNRNP40. SRB assays of these nine proteins indicated that silencing CINP had the most potent inhibitory effect on cell growth in KLF5‐expressing cells but did not affect parental TSU‐Pr1 cells. Further analyses not only confirmed the physical interaction between KLF5 and CINP, also demonstrated that knockdown of CINP attenuated the effects of KLF5 on cell cycle progression, apoptosis and tumorigenesis. Silencing CINP also attenuated the effect of KLF5 on the expression of a number of genes and signaling pathways, including cell cycle regulator Cyclin D1 and apoptosis‐related Caspase 7. These results suggest that CINP is a cofactor of KLF5 that is crucial for the promotion of tumor growth, and that the KLF5‐CINP interaction could be a novel therapeutic target for inhibiting KLF5‐promoted tumor growth. What's new? The role of Krüppel‐like factor 5 (KLF5) in promoting cell proliferation and tumorigenesis is well‐established, but although several KLF5 transcriptional targets have been identified, how KLF5 regulates these genes remains elusive. Here, using immunoprecipitation combined with mass spectrometry, the authors identified a number of KLF5‐interacting nuclear proteins. Functional screening revealed that the Cdk2‐interacting protein CINP is required for KLF5's tumor promoting function and a KLF5 cofactor. CINP knockdown attenuated the effects of KLF5 on cell and tumor growth by decelerating cell cycle progression and inducing apoptosis in KLF5‐expressing cells. The KLF5‐CINP interaction provides a therapeutic opportunity for targeting KLF5‐mediated tumorigenesis. [ABSTRACT FROM AUTHOR]

Abstract The transcription factor Krüppel-like factor 5 (KLF5) is highly expressed in many cancers and serves as a prognostic factor. However, the function of KLF5 in hepatocellular carcinoma (HCC) is unclear. In this study, we found that KLF5 was significantly overexpressed in HCC cell lines and specimens, and high KLF5 expression predicted a poor prognosis for HCC patients. Then, we studied the effects of KLF5 on the proliferation, apoptosis, migration and invasion of HCC cells in vitro and vivo. The inhibition of KLF5 markedly inhibited HCC growth and metastasis, while KLF5 overexpression promoted these processes. In addition, we observed that KLF5 could promote the epithelial-mesenchymal transition (EMT) in HCC via the PI3K/AKT/Snail signaling pathway. The silencing of KLF5 in HCC cell lines downregulated the expression of N-cadherin, Vimentin and Snail and increased the expression of the epithelial marker E-cadherin. The expression of MMP2 and MMP9 was also decreased in KLF5-silenced HCC cells. However, opposite results were observed in the KLF5-overexpressing group. These results indicate that KLF5 plays a significant role in HCC progression and metastasis and induces EMT via activating PI3K/AKT/Snail signaling, and the inhibition of KLF5 may be a potential treatment modality for patients with HCC. Highlights • Krüppel-like factor 5 (KLF5) is serves as a prognostic factor in many cancers. • The role of KLF5 in hepatocellular carcinoma (HCC) is unclear. • This study indicate that KLF5 promotes tumorigenesis and progression in HCC. • This study indicate that KLF5 induces EMT via activating PI3K/AKT/Snail signaling. • Inhibition of KLF5 may be a potential treatment modality for patients with HCC. [ABSTRACT FROM AUTHOR]

Diabetic nephropathy (DN) is one of the most common microvascular complications associated with diabetes mellitus (DM); the incidence has been predicted to reach 7.7% by 2030 on a global scale. Krüppel-like factor 5 (KLF5) is involved in numerous important biological processes; however, the potential effects of KLF5 on podocytes in patients with diabetic nephrotic (DN) have not yet been investigated. In the present study, synaptopodin expression in podocytes was investigated using an immunofluorescence assay. Following this, the proliferation of podocytes was investigated using an MTT assay. In addition, KLF5 was overexpressed in podocytes, and cell cycle arrest and apoptosis was subsequently investigated using flow cytometry. Western blotting and reverse transcription-quantitative polymerase chain reaction assays were performed to detect the expression levels of genes involved in the cell cycle and apoptosis, and the extracellular signal-regulated protein kinase (ERK)/p38 mitogen-activated protein (MAP) kinase pathway. The results demonstrated that treatment with puromycin aminonucleoside (PAN) suppressed the proliferation of podocytes in a dose- and time-dependent manner, and overexpression of KLF5 induced cell cycle arrest of podocytes regulated by PAN. Furthermore, overexpression of KLF5 was revealed to have inhibited PAN-induced apoptosis of podocytes, and that overexpression of KLF5 suppressed the ERK/p38 MAP kinase pathway in podocytes induced by PAN. Therefore, the results of the present study suggested that KLF5 may represent a potential therapeutic target for treatment of patients with DN. [ABSTRACT FROM AUTHOR]

Recently, microRNA (miR)‑590‑5p has been shown to inhibit tumorigenesis in colorectal and breast cancer; however, its function in osteosarcoma (OS) requires further investigation. In the present study miR‑590‑5p expression was poorly expressed in OS samples and cell lines when compared with that observed in normal cells. In addition, overexpression of miR‑590‑5p significantly reduced the proliferation, migration and invasion of SAOS2 and U2OS cells in vitro, as well as inhibiting tumor sizes in vivo. The results revealed that miR‑590‑5p directly targeted Kruppel‑like factor 5 (KLF5) in SAOS2 and U2OS cells. Their expression was inversely correlated with OS tissues. Finally, it was demonstrated that overexpression of KLF5 rescued the inhibitory effects of miR‑590‑5p on cell proliferation, migration and invasion. Overall, the results of the present study suggested that the miR‑590‑5p/KLF5 axis may regulate OS progression and thus, may be a novel therapeutic target for the treatment of patients with OS. [ABSTRACT FROM AUTHOR]

Various microRNAs (miRs) have been demonstrated to serve important roles in gastric cancer (GC). miR-153 in particular has been reported to serve a suppressive role in GC; however, the underlying mechanism remains unclear. In the present study Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to examine the mRNA and protein expression of Kruppel-like factor 5. An MTT, wound healing and transwell assay were used to study cell proliferation, migration and invasion, respectively. In the present study, quantitative polymerase chain reaction data indicated that miR-153 was significantly downregulated in GC tissues compared with the adjacent non-tumor tissues. In addition, the reduced expression of miR-153 was significantly associated with GC aggressiveness and poor prognosis of patients. The expression of miR-153 was also reduced in GC cell lines, including KATO III, NCI-N87, SNU-16 and SNU-5, when compared with normal gastric epithelial GES-1 cells. Overexpression of miR-153 in the GC SNU-5 cells by miR-153 mimic transfection significantly inhibited the cell proliferation, migration and invasion. Furthermore, KLF5 was identified as a target gene of miR-153 in SNU-5 cells by bioinformatics prediction. It was observed that KLF5 was significantly upregulated in GC tissues and cell lines, and its expression was negatively regulated by miR-153 in SNU-5 cells. Overexpression of KLF5 impaired the suppressive effects of miR-153 on the proliferation, migration and invasion of SNU-5 cells. In conclusion, the present study demonstrated that miR-153 serves a tumor suppressive role in GC, at least partly, through directly targeting KLF5, thus highlighting the clinical significance of miR-153 in GC. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRs) are important in hepatocellular carcinoma (HCC) progression. miR‑145‑5p acts as a tumor suppressor in certain malignancies, however, its role in HCC remains unclear. The present study aimed to perform a functional analysis of miR‑145‑5p in HCC in order to elucidate its role in the pathogenesis of HCC. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to analyze tissue and cellular expression of miR‑145‑5p in HCC. Following miRNA mimics transfection, cell viability, apoptosis and cells migration were determined by Cell Counting kit‑8, Annexin V‑FITC/propidium iodide staining and Transwell analyses. The target of miR‑145‑5p was analyzed by luciferase reporter assay and western blot analysis. It was observed that miR‑145‑5p was significantly decreased in HCC tissues and cell lines. Overexpression of miR‑145‑5p significantly increased apoptosis, reduced cell proliferation and suppressed HCC cell migration. Kruppel‑like factor 5 (KLF5) is regarded as a target of miR‑145‑5p in HCC cells. In addition, KLF5 overexpression partially attenuated the tumor suppressive effects of miR‑145‑5p. KLF5 expression was negatively associated with levels of miR‑145‑5p in HCC tissues. The present study demonstrated that miRNA‑145‑5p may, by targeting KLF5, partially suppress HCC cell growth and motility. The results of the present study suggested that miRNA‑145‑5p alteration in HCC may serve a role in the progression of HCC. [ABSTRACT FROM AUTHOR]

Intervertebral disc degeneration causes low back pain.Interleukin-1β (IL-1β) is a well-known inflammatory mediator that is involved in disc degeneration but its molecular mechanisms on catabolic and anabolic events in nucleus pulposus (NP) cells remain unclear. Krüppel-like factor 5 (KLF5) is associated with inflammation and was previously shown to cause cartilage degradation. In this study, we revealed that KLF5 is involved in IL-1β activated NF-kB cascade by enhancing both p65 phosphorylation and p65 acetylation. Moreover, the catabolic effect of KLF5 can be abolished by transforming growth factor-β (TGF-β) via promoting the proteasomal degradation of KLF5. Therefore, a KLF5 inhibitor ML264 was further proved to synergize with TGF-β to attenuate IL-1β-induced intervertebral disc degeneration. These results indicate the critical role of KLF5 in regulating intervertebral disc metabolism and suggest KLF5 inhibitor such as ML264 as potential compound for treatment of degenerative disc disease. [ABSTRACT FROM AUTHOR]

Caspase recruitment domain-containing protein 11 (CARD11) has been reported as functioning in multiple types of cancers. In the present study, the role and mechanism of CARD11 in gastric cancer was investigated. First, CARD11 expression in gastric cancer tissues and the association of CARD11 with overall survival were analyzed by the encyclopedia of RNA interactomes database. CARD11 expression in gastric cancer cells was detected by western blotting and reverse transcription-quantitative PCR analyses. After CARD11 silencing, cell proliferation was evaluated by Cell Counting Kit-8 assay, 5-ethynyl-2'-deoxyuridine staining and flow cytometry analysis. Wound healing and Transwell assays were used to measure the capacities of cell migration and invasion. Additionally, the expression levels of epithelial-mesenchymal transition (EMT)-related proteins and mTOR-related proteins were detected by western blot analysis. HumanTFDB predicted the binding of the transcription factor Krüppel-like factor 5 (KLF5) to the CARD11 promoter, which was confirmed by dual luciferase reporter and chromatin immunoprecipitation assays. To explore the regulatory effects between KLF5 and CARD11, KLF5 was overexpressed to perform the rescue experiments in gastric cancer cells with CARD11 silencing. Results revealed that CARD11 was highly expressed in gastric cancer and was associated with poor prognosis. CARD11 interference inhibited the proliferation of gastric cancer cells and induced cell cycle arrest. Additionally, CARD11 silencing suppressed the migration, invasion and EMT of gastric cancer cells, accompanied by upregulated E-cadherin expression and downregulated N-cadherin and vimentin expression. Moreover, the transcription factor KLF5 positively regulated the transcription of CARD11 in gastric cancer. KLF5 overexpression reversed the effects of interference of CARD11 expression in gastric cancer cells to promote their proliferation, migration, invasion and EMT. KLF5 overexpression also led to a reduction in cell cycle arrest. Finally, interference of CARD11 expression suppressed the mTOR pathway, which was activated by KLF5. In conclusion, KLF5-mediated CARD11 promoted the proliferation, migration and invasion of gastric cancer cells. [ABSTRACT FROM AUTHOR]

Cell division cycle associated 5 (CDCA5) is correlated with the development and progression of many malignant tumors. However, little is known about its role in epithelial ovarian cancer (EOC) progression. In this study, the clinical value, biological function and underlying mechanisms of CDCA5 in EOC were evaluated. CDCA5 mRNA and protein levels were substantially upregulated in EOC and had a significant positive correlation with adverse clinicopathological characteristics and a poor prognosis. CDCA5 facilitated proliferation, invasion, and metastasis and disrupted mitochondrial-mediated endogenous apoptosis by activating the cell cycle pathway and inhibiting the P53 pathway in EOC cells. Conversely, knockdown of CDCA5 expression blocked the malignant activities of EOC cells and suppressed the growth of xenograft tumors in vivo. Mechanistically, the transcription factor KLF5 bound to a specific site in the CDCA5 promoter and promoted CDCA5 expression. Moreover, KLF5 overexpression rescued the negative regulation of inhibited CDCA5 expression on EOC cell proliferation. In conclusion, our findings revealed that CDCA5 promoted tumor progression of EOC via the KLF5/CDCA5/cell cycle and P53 axes, which might provide new insights into the roles of CDCA5 in EOC. [Display omitted] • CDCA5 is highly expressed in epithelial ovarian cancer and is associated with poor prognosis. • Interfering with the expression of CDCA5 makes cells stagnate in G2/M phase and promotes cell apoptosis. • Overexpression of CDCA5 promotes tumor progression by activating cell cycle and inhibiting P54 pathway. • KLF5 mediated CDCA5 expression promotes malignant activity of tumor cells. [ABSTRACT FROM AUTHOR]

LSECs (Liver sinusoidal endothelial cells) are the portal of liver, their pathological angiogenesis plays a constructive role in etiopathogenesis of liver fibrosis by affecting liver tissue repair and inflammatory drive. Although intervention in angiogenesis can effectively inhibit abnormal activation of LSEC, no effective drugs have been found to treat liver fibrosis. We investigated the effect of the natural compound Curcumol on LSEC angiogenesis and elucidated the novel underlying mechanism, expecting to provide a scientific basis for exploring potential therapeutic drugs for liver fibrosis. Various cellular and molecular assays, as well as genetic assays, were used to detect pathological angiogenesis and changes in glycolysis levels in cultured rat LSECs and mouse liver fibrosis models. Transcription factor KLF5 is able to influence the angiogenic properties of LSEC by regulating the glycolytic process, and affect the expression of LDH-A by transcriptionally binding to its promoter. In our study, we were surprised to find that LDH-A (the final step of glycolysis) has a strong regulatory effect on the glycolytic process of LSEC. Through in-depth study, we found that LDH-A could affect the transcriptional activity of KLF5, thus forming a positive feedback loop. Curcumol could break this positive feedback loop and inhibit the glycolysis-dependent angiogenic nature of LSEC, thus alleviating liver fibrosis. Curcumol reduced extracellular matrix (ECM) deposition, attenuated pathological angiogenesis in LSEC, and decreased the level of CCl 4 -induced liver fibrosis in mice. Our results demonstrated the great utilization potentiality of KLF5 in liver fibrosis, and the innovative discovery that LDH-A regulates the glycolytic process and forms a malignant feedback loop by exerting non-enzymatic effects. It also reveals the prospect of Curcumol-regulated KLF5/LDH-A feedback loop in the treatment of liver fibrosis, providing a new option for the future medicine of liver fibrosis. [Display omitted] [ABSTRACT FROM AUTHOR]

Background Hydrogen sulfide (H2S) is a gasotransmitter that regulates multiple cardiovascular functions. Krüppel‐like factor 5 (KLF5) exerts diverse functions in the cardiovascular system. Whether and how H2S regulates KLF5 in myocardial hypertrophy is unknown. Methods and Results In our study, hypertrophic myocardial samples in the clinic were collected and underwent histological and molecular biological analysis. Spontaneously hypertensive rats and neonatal rat cardiomyocytes were studied for functional and signaling responses to GYY4137, an H2S‐releasing compound. Expression of cystathionine γ‐lyase, a principal enzyme for H2S generation in heart, decreased in human hypertrophic myocardium, whereas KLF5 expression increased. After GYY4137 administration for 4 weeks, myocardial hypertrophy was inhibited in spontaneously hypertensive rats, as demonstrated by improvement in cardiac structural parameters, heart mass, size of cardiac myocytes, and expression of atrial natriuretic peptide. H2S diminished expression of KLF5 in myocardium of spontaneously hypertensive rats and in hypertrophic cardiomyocytes. H2S also inhibits platelet‐derived growth factor A promoter activity, decreased recruitment of KLF5 to the platelet‐derived growth factor A promoter, and reduced atrial natriuretic peptide expression in angiotensin II–stimulated cardiomyocytes, and these effects are suppressed by KLF5 knockdown. KLF5 promoter activity and KLF5 expression was also reversed by H2S. H2S increased the S‐sulfhydration on specificity protein 1 in cardiomyocytes. Moreover, H2S decreased KLF5 promoter activity; reduced KLF5 mRNA expression; attenuated specificity protein 1 binding activity with KLF5 promoter; and inhibited hypertrophy after specificity protein 1 mutated at Cys659, Cys689, and Cys692 but not Cys664 overexpression. Conclusions These findings suggest that H2S regulates KLF5 transcription activity via specificity protein 1 S‐sulfhydration at Cys664 to prevent myocardial hypertrophy.