Kaempferol targets Krt-14 and induces cytoskeletal mineralization in osteoblasts: A mechanistic approach

A novel lncRNA ABCE1-5 regulates pulmonary fibrosis by targeting KRT14

Idiopathic pulmonary fibrosis (IPF) is a progressive and degenerative interstitial lung disease characterized by complex etiology, unclear pathogenesis, and high mortality. Long noncoding RNAs (lncRNAs) have been identified as key regulators in modulating the initiation, maintenance, and progression of pulmonary fibrosis. However, the precise pathological mechanisms through which lncRNAs are involved in IPF remain limited and require further elucidation. A novel lncABCE1-5 was identified as significantly decreased by an ncRNA microarray analysis in our eight IPF lung samples compared with three donor tissues and validated by quantitative real-time polymerase chain reaction (qRT-PCR) analysis in clinical lung samples. To investigate the biological function of ABCE1-5, we performed loss- and gain-of-function experiments in vitro and in vivo. LncABCE1-5 silencing promoted A549 cell migration and A549 and bronchial epithelial cell line (BEAS-2B) cell apoptosis while enhancing the expression of proteins associated with extracellular matrix deposition, whereas overexpression of ABCE1-5 partially attenuated transforming growth factor-beta (TGF-β)-induced fibrogenesis. Forced ABCE1-5 expression by intratracheal injection of adeno-associated virus 6 revealing the antifibrotic effect of ABCE1-5 in bleomycin (BLM)-treated mice. Mechanistically, RNA pull-down (RPD)-mass spectrometry and RNA immunoprecipitation assay demonstrated that ABCE1-5 directly binds to keratin14 (krt14) sequences, potentially impeding its expression by perturbing mRNA stability. Furthermore, decreased ABCE1-5 levels can promote krt14 expression and enhance the phosphorylation of both mTOR and Akt; overexpression of ABCE1-5 in BLM mouse lung tissue significantly attenuated the elevated levels of p-mTOR and p-AKT. Knockdown of krt14 reversed the activation of mTOR signaling mediated by ABCE1-5 silencing. Collectively, the downregulation of ABCE1-5 mediated krt14 activation, thereby activating mTOR/AKT signaling, to facilitate pulmonary fibrosis progression in IPF.NEW & NOTEWORTHY In the present study, our data first reveal that a novel lncRNA ABCE1-5 could inhibit pulmonary fibrosis through interacting with krt14 and negative regulation of its expression, and indicated ABCE1-5 also regulates the phosphorylation of mTOR and Akt, thus acting on extracellular matrix remodeling in lung fibrosis procession. These results suggest that novel molecules within the ABCE1-5-krt14-mTOR axis may serve as potential candidates for clinical application in IPF.

The SRC/NF-κB-AKT/NOS3 axis as a key mediator of Kaempferol's protective effects against oxidative stress-induced osteoclastogenesis

BACKGROUND

Osteoclasts are integral to the advancement of osteoporosis (OP), and their generation under conditions of oxidative stress (OS) involves various pathways. However, the specific mechanism through which the natural antioxidant kaempferol (KAE) mitigates the influence of OS on osteoclasts remains somewhat uncertain. This study aims to evaluate the effect of KAE on osteoclast formation under OS and explore its possible mechanism.

METHODS

Zebrafish were used to observe the effects of KAE on OP and OS. OP and OS "double disease targets" network pharmacology were used to predict the action target and mechanism of KAE on OP under OS. The effects of KAE on osteoclast differentiation induced by OS were evaluated using RWA264.7 cells induced by LPS. To elucidate the potential mechanism, we detected the expression of related factors and target genes during induction.

RESULTS

The presence of KAE exhibited potential in improving the conditions of OP and OS in zebrafish. KAE can reduce the OS of RAW 264.7 cells stimulated by LPS, inhibit the formation of osteoclasts, and change the level of related factors of OS, and reduce the increase of TRAP. The utilization of network pharmacology and target gene expression assay revealed that KAE exerted a down-regulatory effect on the expression of proto-oncogene tyrosine protein kinase (SRC), nuclear factor kappa-B (NF-κB), Serine/Threonine Kinase-1 (AKT1), Nitric Oxide Synthase 3 (NOS3) and Matrix Metallopeptidase-2 (MMP2).

CONCLUSION

Based on the results of this study, KAE may effectively mitigate OS and impede the formation of osteoclasts through the SRC/NF-κB-AKT/NOS3 axis.

YuPingFeng (YPF) upregulates caveolin-1 (CAV1) to alleviate pulmonary fibrosis through the TGF-β1/Smad2 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine (TCM) is considered a valuable asset in China's medical tradition. YPF is a classic prescription that has been derived from the "Jiu Yuan Fang" formula and consists of three herbs: Huangqi (Astragalus membranaceus Bunge), Baizhu (Atractylodes rubra Dekker), and Fangfeng (Saposhnikovia divaricata (Turcz.) Schischk). This prescription is widely acclaimed for its exceptional pharmacological properties, including potent antioxidant effects, hormone regulation, and immune modulation effects.

AIM OF THE STUDY

Previous research provides evidence suggesting that YPF may have therapeutic effects on pulmonary fibrosis. Further exploration is essential to confirm its effectiveness and elucidate the fundamental processes.

MATERIALS AND METHODS

First, the active components and target genes of YPF were extracted from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. Next, the GSE53845 dataset, which contains information on pulmonary fibrosis, was downloaded from the GEO database. Network informatics methods was then be utilized to identify target genes associated with pulmonary fibrosis. A YPF-based network of protein-protein interactions was constructed to pinpoint possible target genes for pulmonary fibrosis treatment. Additionally, an in vitro model of pulmonary fibrosis induced by bleomycin (BLM) was established to further investigate and validate the possible mechanisms underlying the effectiveness of YPF.

RESULTS

In this study, a total of 24 active ingredients of YPF, along with 178 target genes associated with the treatment, were identified. Additionally, 615 target genes related to pulmonary fibrosis were identified. Functional enrichment analysis revealed that 18 candidate genes (CGs) exhibited significant responses to tumor necrosis factor, NF-kB survival signaling, and positive regulation of apoptosis processes. Among these CGs, CAV1, VCAM1, and TP63 were identified as key target genes. Furthermore, cell experiments confirmed that the expression of CAV1 protein and RNA expression was increased in pulmonary fibrosis, but significantly decreased after treatment with YPF. Additionally, the expression of pSmad2, α-SMA, TGF-β1, and TNF-α was also decreased following YPF treatment.

CONCLUSIONS

Network pharmacology analysis revealed that YPF exhibits significant potential as a therapeutic intervention for pulmonary fibrosis by targeting various compounds and pathways. This study emphasizes that the efficacy of YPF in treating pulmonary fibrosis may be attributed to its ability to up-regulate CAV1 expression and inhibiting pulmonary fibrosis via modulation of the TGF-β1/Smad2 signaling pathway. These findings underscore the promising role of YPF and its ability to potentially alleviate pulmonary fibrosis.

Re-appraising the role of flavonols, flavones and flavonones on osteoblasts and osteoclasts- A review on its molecular mode of action

Bone disorders have become a global concern illustrated with decreased bone mineral density and disruption in microarchitecture of natural bone tissue organization. Natural compounds that promote bone health by augmenting osteoblast functions and suppressing osteoclast functions has gained much attention and offer greater therapeutic value compared to conventional therapies. Amongst several plant-based molecules, flavonoids act as a major combatant in promoting bone health through their multi-faceted biological activities such as antioxidant, anti-inflammatory, and osteogenic properties. They protect bone loss by regulating the signalling cascades involved in osteoblast and osteoclast functions. Flavonoids augment osteoblastogenesis and inhibits osteoclastogenesis through their modulation of various signalling pathways. This review discusses the role of various flavonoids and their molecular mechanisms involved in maintaining bone health by regulating osteoblast and osteoclast functions.

The cytoskeleton and connected elements in bone cell mechano-transduction

Bone is a mechano-responsive tissue that adapts to changes in its mechanical environment. Increases in strain lead to increased bone mass acquisition, whereas decreases in strain lead to a loss of bone mass. Given that mechanical stress is a regulator of bone mass and quality, it is important to understand how bone cells sense and transduce these mechanical cues into biological changes to identify druggable targets that can be exploited to restore bone cell mechano-sensitivity or to mimic mechanical load. Many studies have identified individual cytoskeletal components - microtubules, actin, and intermediate filaments - as mechano-sensors in bone. However, given the high interconnectedness and interaction between individual cytoskeletal components, and that they can assemble into multiple discreet cellular structures, it is likely that the cytoskeleton as a whole, rather than one specific component, is necessary for proper bone cell mechano-transduction. This review will examine the role of each cytoskeletal element in bone cell mechano-transduction and will present a unified view of how these elements interact and work together to create a mechano-sensor that is necessary to control bone formation following mechanical stress.

Mutation landscape of TSC1/TSC2 in Chinese patients with tuberous sclerosis complex

Genetic testing of TSC1 and TSC2 is important for the diagnosis of tuberous sclerosis complex (TSC), an autosomal dominant neurocutaneous disease. This study retrospectively reviewed 347 samples from patients with clinically suspected TSC being tested for mutations in TSC1 and TSC2 genes using next-generation sequencing and multiplex ligation-dependent probe amplification. Two hundred eighty-one patients (80.98%) were classified as definite/possible/uncertain diagnosis of TSC and the mutational spectrum of TSC1/TSC2 was described. Two hundred eighteen unique nonsynonymous SNVs/Indels (64 in TSC1, 154 in TSC2) and 13 copy number variants (CNVs) were identified in 241 samples (85.77%), including 82 novel variants. CNVs involving 12 large deletions and one duplication were detected exclusively in TSC2. Both TSC1 and TSC2 mutations were nearly uniformly distributed in their protein-coding regions. Furthermore, a string of non-TSC1/TSC2 deleterious variants in 12 genes was identified in the patients, especially overwhelmingly present in the patients with no mutation identified (NMI) in TSC1/TSC2. Our study provides a comprehensive TSC1/TSC2 mutation landscape and reveal some potential risk non-TSCs variants present in patients with NMI.

The Osteoprotective Effects Of Kaempferol: The Evidence From In Vivo And In Vitro Studies

Kaempferol is a dietary bioflavonoid ubiquitously found in various types of plant. It possesses a wide range of medicinal properties suggesting its potential clinical utility that requires further investigation. The present review intends to highlight the efficacy of kaempferol and its molecular mechanisms of action in regulating bone metabolism. Many reports have acknowledged the bone-protecting property of kaempferol and kaempferol-containing plants using in vitro and in vivo experimental models. Kaempferol supplementation showed bone-sparing effects in newborn rats, glucocorticoid-induced and ovariectomy-induced osteoporotic models as well as bone fracture models. It achieves the bone-protective effects by inhibiting adipogenesis, inflammation, oxidative stress, osteoclastic autophagy and osteoblastic apoptosis while activating osteoblastic autophagy. The anti-osteoporotic effects of kaempferol are mediated through regulation of estrogen receptor, bone morphogenetic protein-2 (BMP-2), nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling pathways. In summary, kaempferol exhibits beneficial effects on skeleton, thus is potentially effective for the prophylaxis and treatment of osteoporosis.

Kaempferol attenuates liver fibrosis by inhibiting activin receptor-like kinase 5

Liver fibrosis is a common public health problem. Patients with liver fibrosis are more likely to develop cirrhosis, or hepatocellular carcinoma (HCC) as a more serious consequence. Numerous therapeutic approaches have emerged, but the final clinical outcome remains unsatisfactory. Here, we discovered a flavonoid natural product kaempferol that could dramatically ameliorate liver fibrosis formation. Our data showed that intraperitoneal injection of kaempferol could significantly decrease the necroinflammatory scores and collagen deposition in the liver tissue. In addition, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), laminin (LN) and hyaluronic acid (HA) levels were significantly down-regulated in kaempferol treatment group compared with those in the control group. Our study also demonstrated that kaempferol markedly inhibited the synthesis of collagen and activation of hepatic stellate cells (HSCs) both in vivo and in vitro. Furthermore, the results of Western blotting revealed that kaempferol could down-regulate Smad2/3 phosphorylation dose-dependently. These bioactivities of kaempferol may result from its targeted binding to the ATP-binding pocket of activin receptor-like kinase 5 (ALK5), as suggested by the molecular docking study and LanthaScreen Eu kinase binding assay. Above all, our data indicate that kaempferol may prove to be a novel agent for the treatment of liver fibrosis or other fibroproliferative diseases.

Spinacia oleracea extract attenuates disease progression and sub-chondral bone changes in monosodium iodoacetate-induced osteoarthritis in rats

Background

Spinacia oleracea is an important dietary vegetable in India and throughout the world and has many beneficial effects. It is cultivated globally. However, its effect on osteoarthritis that mainly targets the cartilage cells remains unknown. In this study we aimed to evaluate the anti-osteoarthritic and chondro-protective effects of SOE on chemically induced osteoarthritis (OA).

Methods

OA was induced by intra-patellar injection of monosodium iodoacetate (MIA) at the knee joint in rats. SOE was then given orally at 250 and 500 mg.kg^− 1 day^− 1 doses for 28 days to these rats. Anti-osteoarthritic potential of SOE was evaluated by micro-CT, mRNA and protein expression of pro-inflammatory and chondrogenic genes, clinically relevant biomarker’s and behavioural experiments.

Results

In vitro cell free and cell based assays indicated that SOE acts as a strong anti-oxidant and an anti-inflammatory agent. Histological analysis of knee joints at the end of the experiment by safranin-o and toluidine blue staining established its protective effect. Radiological data corroborated the findings with improvement in the joint space and irregularity of the articular and atrophied femoral condyles and tibial plateau. Micro-CT analysis of sub-chondral bone indicated that SOE had the ability to mitigate OA effects by increasing bone volume to tissue volume (BV/TV) which resulted in decrease of trabecular pattern factor (Tb.Pf) by more than 200%. SOE stimulated chondrogenic marker gene expression with reduction in pro-inflammatory markers. Purified compounds isolated from SOE exhibited increased Sox-9 and Col-II protein expression in articular chondrocytes. Serum and urine analysis indicated that SOE had the potential to down-regulate glutathione S-transferase (GST) activity, clinical markers of osteoarthritis like cartilage oligometric matrix protein (COMP) and CTX-II. Overall, this led to a significant improvement in locomotion and balancing activity in rats as assessed by Open-field and Rota rod test.

Conclusion

On the basis of in vitro and in vivo experiments performed with Spinacea oleracea extract we can deduce that SOE has the ability to alleviate the MIA induced deleterious effects.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2117-9) contains supplementary material, which is available to authorized users.

Kaempferol - A dietary anticancer molecule with multiple mechanisms of action: Recent trends and advancements

The consumption of diet-based naturally bioactive metabolites is preferred to synthetic material in order to avert health-associated disorders. Among the plant-derived polyphenols, kaempferol (KMF) is considered as a valuable functional food ingredient with a broad range of therapeutic applications such as anti-cancer, antioxidant and anti-inflammatory uses. KMF acts on a range of intracellular as well as extracellular targets involved in the cell signaling pathways that in turn are known to regulate the hallmarks of cancer growth progressions like apoptosis, cell cycle, invasion or metastasis, angiogenesis and inflammation. Importantly, the understanding of mechanisms of action of KMF-mediated therapeutic effects may help the scientific community to design novel strategies for the treatment of dreadful diseases. The current review summarizes the various types of molecular targets of KMF in cancer cells as well as other health-associated disorders. In addition, this review also highlights the absorption, metabolism and epidemiological findings.

A neoflavonoid dalsissooal isolated from heartwood of Dalbergia sissoo Roxb. has bone forming effects in mice model for osteoporosis

Dalbergia sissoo Roxb. is a well known medicinal plant of India, enriched with various flavonoids used for treating multiple diseases. Earlier, we have shown that extract of Dalbergia sissoo Roxb. leaves mitigate ovariectomy induced bone loss and pure compounds (neoflavonoids) isolated from it, promote osteoblastogenesis in primary calvarial osteoblasts cells in vitro. Here, we hypothesize that dalsissooal (DSL), a novel neoflavonoid isolated from the heartwood of Dalbergia sissoo Roxb. is an important constituent of the extract that imparts bone forming effects. Treatment with DSL enhanced trabecular bone micro-architecture parameters, biomechanical strength, increased bone formation rate and mineral apposition rate in OVx mice comparable to 17β-estradiol. It increased bone formation by enhancing osteoblast gene expression and reduced bone turnover by decreasing osteoclastic gene expressions. Interestingly, we observed that DSL has no uterine estrogenic effects. At cellular levels, DSL promoted differentiation of bone marrow cells as well as calvaria osteoblast cells towards osteoblast lineage by enhancing differentiation and mineralizing ability to form mineralizing nodules via stimulating BMP-2 and RunX-2 expressions. Overall, our data suggest that oral supplementation of a novel neoflavonoid dalsissooal isolated from heartwood of Dalbergia sissoo Roxb. exhibited bone anabolic action by improving structural property of bone, promoting new bone formation and reducing bone turnover rate in post-menopausal model for osteoporosis with no uterine hyperplasia.