Adiponectin Treatment Research Articles

The glycolysis-related AMPK/ULK signaling pathway mediates the inhibitory effect of adiponectin in prostate cancer cells

ObjectiveReduced adiponectin (ADPN) levels have been implicated in the pathogenesis of prostate cancer (PCa). The role of glycolysis in cancer development and treatment has attracted increasing attention. The present study aimed to elucidate its impact on PCa and to explore the mechanistic involvement of glycolysis. MethodsAn RM-1 cell xenograft model of Adpn-knockout mice was used to corroborate the effects of glycolysis, AMP-activated protein kinase (AMPK) signaling, and autophagy on tumor xenograft progression. The effect of ADPN on PCa cells was evaluated using the Cell Counting Kit-8 (CCK-8), lactate levels, and flow cytometry. The expression of glycolysis-related genes was detected using real-time RT-PCR in LNCaP and PC-3 cells after incubation with ADPN. Autophagic flux after ADPN treatment was quantified by chloroquine intervention and confocal analysis of mRFP-GFP-LC3. Alterations in the levels of adiponectin receptor 1 (AdipoR1), AMPK, Unc-51-like kinase 1 (ULK1), autophagy-related protein 7 (ATG7), p62, and microtubule-associated protein 1 light chain 3 beta (LC3B) were assessed after incubation of LNCaP cells with ADPN. ResultsProteomic analysis of xenograft tumors demonstrated significant upregulation of glycolysis in Adpn−/− mice. Lower levels of ADPN accelerated tumor xenograft growth, diminished p-AMPKα/AMPKα ratio and LC3B II/I ratio, and elevated levels of proliferating cell nuclear antigen (PCNA) within the tumor microenvironment. ADPN inhibited proliferation and glycolysis and potentiated apoptosis in both cell lines. Expression of glycolysis-related genes decreased after ADPN treatment. Autophagic flux was elevated, as evidenced by changes in autophagy-related proteins and confocal microscopy analysis of mRFP-GFP-LC3. It led to the suppression of p62 while inducing phosphorylation of AMPKα and upregulating AdipoR1, ULK1, ATG7, and LC3B II/I ratio. ConclusionADPN inhibited the proliferation and progression of PCa cell-derived tumor xenografts by inhibiting glycolysis. Specifically, ADPN effectively inhibits glycolysis and activates the downstream AMPK/ULK1 signaling pathway to suppress proliferation of PCa cells.

Regulation and molecular mechanism of adiponectin on the proliferation, apoptosis, autophagy, and chemosensitivity of LN18 Glioma cell line.

This study aimed to explore the regulatory effects and associated mechanisms of adiponectin on apoptosis and proliferation in the LN18 glioma cell line through the AMPK and Akt signaling pathways. Additionally, we sought to elucidate the impact of adiponectin on the chemosensitivity of the LN18 glioma cell line to temozolomide (TMZ). The proliferation rate of glioma cells treated with adiponectin was assessed using the cholecystokinin (CCK8) assay. The Western blot analysis was employed to assess the expression of p-Akt, p-AMPK, p-mTOR, cleaved caspase3, Bax, Cyclin D1, and Cyclin B1 following adiponectin treatment. Cell apoptosis was quantified using AnnexinV/PI flow cytometry, while changes in the cell cycle were detected using PI staining flow cytometry. The findings revealed that adiponectin upregulates p-AMPK expression and downregulates p-mTOR expression in the PTEN wild-type glioma cell line LN18, with no discernible effect on p-Akt expression. Moreover, adiponectin inhibits the proliferation rate of the PTEN wild-type glioma cell line LN18, enhances the expression of cleaved caspase3 and Bax, and significantly elevates the apoptosis rate, as evidenced by AnnexinV/PI flow cytometry. Adiponectin was observed to suppress the expression of Cyclin D1 and Cyclin B1, increase the number of cells in the G1 phase, and promote autophagy. Additionally, adiponectin augments the expression of Beclin1 and the ratio of LC3II/I in the PTEN wild-type glioma cell line LN18, while decreasing p62 expression. In conclusion, this study posits that adiponectin holds therapeutic promise for glioma treatment. Furthermore, adiponectin enhances the inhibitory effect of TMZ on the proliferation rate of LN18 cells when treated with 0.1 mM and 1 mM TMZ. These results collectively suggest that adiponectin impedes proliferation, encourages apoptosis and autophagy in the LN18 glioma cell line, and heightens its sensitivity to the chemotherapeutic drug TMZ.

Adiponectin attenuates H2O2-induced apoptosis in chicken skeletal myoblasts through the lysosomal-mitochondrial axis.

Adiponectin has previously been investigated for exerting its protective effect against myocardial injury through anti-apoptotic and anti-oxidative actions. Therefore, the present study aimed to investigate the nature and mechanism of adiponectin inhibition of H2O2-induced apoptosis in chicken skeletal myoblasts. Skeletal muscle satellite cells were differentiated and assigned into three groups. Group C was on the blank control group, group H was stimulated with the H2O2 (500μmol/L, 4h) alone group, group A + H was pre-treated with adiponectin (10μg/mL, 24h) and stimulated with the H2O2 (500μmol/L, 4h) group. Cytotoxicity inhibited by adiponectin was evaluated by the CCK-8 assay. The degree of apoptosis and oxidative damage was investigated by the TdT-mediated dUTP nick end labeling (TUNEL) and reactive oxygen species (ROS) staining assays. Oxidative stress was assessed by evaluating lipid peroxidation, superoxide dismutase, and reduced glutathione. Acridine orange (AO) staining detected lysosomal membrane permeability. The changes in mitochondrial membrane potential (MMP) were analyzed using 5,5,6,6'-tetrachloro-1,1,3,3-tetraethylimidacarbocyanine iodide (JC-1) dye under a fluorescence microscope. The lysosomal function, mitochondrial function, and apoptosis-related mRNA and protein expression levels were quantified by real-time quantitative PCR and western blot, respectively. The results suggested that adiponectin treatment attenuated H2O2-induced cytotoxicity and oxidative stress in skeletal myoblasts. Compared with H2O2 treatment, TUNEL and ROS staining demonstrated lower apoptosis upon adiponectin treatment. AO staining confirmed the amelioration of lysosomal membrane damage, and JC-1 staining revealed an increase in mitochondrial membrane potential after adiponectin treatment. At the molecular level, adiponectin treatment inhibited the expression of the lysosomal apoptotic factors cathepsin B, chymotrypsin B, and the mitochondrial apoptotic pathway cytochrome-c (cyt-c) and caspase-8; decreased the apoptotic marker gene Bax; and increased the expression of the anti-apoptotic marker gene Bcl-2. Adiponectin treatment attenuated H2O2-induced apoptosis in skeletal myoblasts, possibly by inhibiting oxidative stress and apoptosis through the lysosomal-mitochondrial axis.

Adiponectin improves endometrial receptivity in rats with polycystic ovary syndrome by upregulating the PPARα/HOXA10 pathway

To explore the role of the PPARα/HOXA10 signaling pathway in mediating the effect of adiponectin (APN) for improving endometrial receptivity in a rat model of polycystic ovary syndrome (PCOS). Forty female SD rat models with letrozole-induced PCOS were randomized, with 10 normal rats as the control, into 4 equal groups for treatment with APN alone, APN combined with GW6471 (a specific PPARα inhibitor) or the vehicle for 20 days, or no further treatment (PCOS model group). GW6471 treatment (daily dose of 1 mg/kg) and vehicle treatment were initiated on the 11th day following the start of APN treatment, all administered via intraperitoneal injection. The rats were observed for changes in estrous cycle, body weight, ovarian index and morphology, uterine index and morphology, serum hormone levels and lipid metabolism parameters. Endometrial expressions of PPARα and HOXA10 were detected with immunohistochemistry and Western blotting. The development of endometrial pinopodes was observed under electron microscope, and pregnancies of the rats were recorded. The rat models of PCOS exhibited obvious estrous cycle disorders with significantly prolonged estrous interval, increased body weight and ovarian index, decreased uterine index, disordered serum hormones and lipid metabolism (P < 0.05), and polycystic ovarian changes, and these changes were significantly improved by APN treatment. Endometrial expressions of PPARα and HOXA10 were significantly lowered in PCOS rats and effectively up-regulated after APN treatment, but GW6471 treatment obviously blocked the effect of APN (P < 0.05). APN showed strong protective effect against PCOS-induced impairment of endometrial pinopode development, and this effect was obviously attenuated by GW6471. APN also significantly increased the pregnancy rate and embryo number in PCOS rats, while GW6471 obviously reduced the embryo number and caused developmental retardation of the embryos. APN can improve endometrial receptivity in PCOS rats by upregulating the PARα/HOXA10 pathway.

Adiponectin inhibits ROS/NLRP3 inflammatory pathway through FOXO3A to ameliorate oral submucosal fibrosis.

Oral submucous fibrosis (OSF) is an oral condition characterized by chronic progression, which may lead to the development of malignancy. Currently, available treatments for OSF only provide temporary relief of symptoms, and there is a limited availability of effective interventions that can effectively cure this condition. In this study, we aimed to investigate whether adiponectin (APN) could ameliorate OSF and the mechanisms involved in it. First, human oral mucosal fibroblasts (HOMFs) were cultured, an OSF model was established using arecoline, and APN and Imiquimod treatment were administered. Then we overexpressed NLRP3 and knocked down FOXO3A. FOXO3A, fibrosis-related factors (ɑ-SMA, COL1A, CTGF), TGF-β1/Smad3 signaling-related factors (TGF-β1, p-Smad3, Smad3), NLRP3 inflammasome-related factors (NLRP3, Caspase-1, IL-1β), and ROS levels were evaluated. Finally, we explored the effect of APN on OSF in mice by in vivo experiments. We found that arecoline significantly increased ɑ-SMA, COL1A, CTGF, and TGF-β1 expressions and promoted Smad3 phosphorylation, while APN significantly inhibited the elevation of these fibrosis-related factors. ROS production was significantly elevated in HOMFs after arecoline treatment, while APN treatment inhibited ROS production. However, the addition of Imiquimod and overexpression of NLRP3 exhibited a trend of elevated ROS, resisting the inhibitory effect of APN. Furthermore, adding Imiquimod and overexpression of NLRP3 elevated ɑ-SMA, COL1A and CTGF and activated TGF-β1/Smad3 signaling pathway. Additionally, knockdown of FOXO3A enhanced APN-inhibited ɑ-SMA and COL1A. In vivo experiments further confirmed that APN ameliorated OSF in mice by inhibiting ROS/NLRP3 inflammatory pathway. In conclusion, APN ameliorated arecoline-induced OSF by promoting FOXO3A expression and downregulating the ROS/NLRP3 pathway.

Interaction between Nuclear Receptor and Alpha-Adrenergic Agonist Subtypes in Metabolism and Systemic Hemodynamics of Spontaneously Hypertensive Rats.

Partial and full PPAR-γ agonists have shown promising effects and antihypertensive and antidiabetic agents through increased plasma adiponectin concentration. This study is aimed at examining the role of PPAR-γ, alpha-adrenoceptors, and adiponectin receptors in the modulation of vasopressor responses to angiotensin II (Ang II) and adrenergic agonists, after a subset treatment of partial and full PPAR-γ agonists, each individually, and also when coupled with adiponectin in SHRs. The antioxidant potential and metabolic indices for these animals were also determined. Group I (WKY) and group II (SHR) were designated as normotensive control and hypertensive control, respectively. Groups III (SHR) and IV (SHR) received irbesartan (30 mg/kg) and pioglitazone (10 mg/kg) orally for 28 days, and groups V (SHR), VI (SHR), and VII (SHR) were treated with adiponectin (2.5 μg/kg) intraperitoneally alone, in combination with irbesartan, and in combination with pioglitazone, respectively, from days 21 to 28 only. On day 29, sodium pentobarbitone (60 mg/kg) was used to anesthetize all test animals, and systemic hemodynamic and plasma adiponectin concentrations and in vitro and in vivo antioxidant potential were measured. As compared to the WKY control, the SHR control group's noninvasive blood pressure and basal mean arterial pressure were significantly greater, along with increased arterial stiffness, lower plasma nitric oxide, adiponectin concentration, and antioxidant enzyme levels (all P < 0.05). However, they were gradually normalized by single drug treatments in all groups, and to a greater extent in the SHR + Irb + Adp group (P < 0.05). In the acute study, the dose dependant mean arterial pressure responses to intravenously administered adrenergic agonists and angiotensin-II were significantly larger in SHRs as compared to WKY by 20-25%. Adiponectin alone and in combination significantly blunted vasopressor responses to these alpha-adrenergic agonists in the SHR + Pio + Adp group by 63%, whereas attenuated responses to ANG-II administration to 70% in SHR + Irb + Adp. In conclusion, the combined treatment of adiponectin with PPAR-agonists reduced the systemic vascular responses to adrenergic agonists and improved arterial stiffness. This an evidence of the interaction of adiponectin receptors, PPAR-γ, alpha-adrenoceptors, and ANG-II in the systemic vasculature of SHRs. A significant level of synergism has also been proved among full PPAR-γ agonists and adiponectin receptors.

Adipose c-Jun NH2-terminal kinase promotes angiotensin II-induced and deoxycorticosterone acetate salt-induced hypertension and vascular dysfunction by inhibition of adiponectin production and activation of SGK1 in mice.

Adipose c-Jun NH2-terminal kinase 1/2 (JNK1/2) is a central mediator involved in the development of obesity and its complications. However, the roles of adipose JNK1/2 in hypertension remain elusive. Here we explored the role of adipose JNK1/2 in hypertension. The roles of adipose JNK1/2 in hypertension were investigated by evaluating the impact of adipose JNK1/2 inactivation in both angiotensin II (Ang II)-induced and deoxycorticosterone acetate (DOCA) salt-induced hypertensive mice. Specific inactivation of JNK1/2 in adipocytes significantly alleviates Ang II-induced and DOCA salt-induced hypertension and target organ damage in mice. Interestingly, such beneficial effects are also observed in hypertensive mice after oral administration of JNK1/2 inhibitor SP600125. Mechanistically, adipose JNK1/2 acts on adipocytes to reduce the production of adiponectin (APN), then leads to promote serum and glucocorticoid-regulated kinase 1 (SGK1) phosphorylation and increases epithelial Na + channel α-subunit (ENaCα) expression in both renal cells and adipocytes, respectively, finally exacerbates Na + retention. In addition, chronic treatment of recombinant mouse APN significantly augments the beneficial effects of adipose JNK1/2 inactivation in DOCA salt-induced hypertension. By contrast, the blood pressure-lowering effects of adipose JNK1/2 inactivation are abrogated by adenovirus-mediated SGK1 overexpression in Ang II -treated adipose JNK1/2 inactivation mice. Adipose JNK1/2 promotes hypertension and targets organ impairment via fine-tuning the multiorgan crosstalk among adipose tissue, kidney, and blood vessels.

Adiponectin and resistin modulate the progression of Alzheimer´s disease in a metabolic syndrome model.

Metabolic syndrome (MetS), a cluster of metabolic conditions that include obesity, hyperlipidemia, and insulin resistance, increases the risk of several aging-related brain diseases, including Alzheimer's disease (AD). However, the underlying mechanism explaining the link between MetS and brain function is poorly understood. Among the possible mediators are several adipose-derived secreted molecules called adipokines, including adiponectin (ApN) and resistin, which have been shown to regulate brain function by modulating several metabolic processes. To investigate the impact of adipokines on MetS, we employed a diet-induced model to induce the various complications associated with MetS. For this purpose, we administered a high-fat diet (HFD) to both WT and APP/PSN1 mice at a pre-symptomatic disease stage. Our data showed that MetS causes a fast decline in cognitive performance and stimulates Aβ42 production in the brain. Interestingly, ApN treatment restored glucose metabolism and improved cognitive functions by 50% while decreasing the Aβ42/40 ratio by approximately 65%. In contrast, resistin exacerbated Aβ pathology, increased oxidative stress, and strongly reduced glucose metabolism. Together, our data demonstrate that ApN and resistin alterations could further contribute to AD pathology.

Obesity Contributes to Transformation of Myometrial Stem-Cell Niche to Leiomyoma via Inducing Oxidative Stress, DNA Damage, Proliferation, and Extracellular Matrix Deposition.

Leiomyomas (fibroids) are monoclonal tumors in which myometrial stem cells (MSCs) turn tumorigenic after mutation, abnormal methylation, or aberrant signaling. Several factors contribute to metabolic dysfunction in obesity, including abnormal cellular proliferation, oxidative stress, and DNA damage. The present study aims to determine how adipocytes and adipocyte-secreted factors affect changes in MSCs in a manner that promotes the growth of uterine leiomyomas. Myometrial stem cells were isolated from the uteri of patients by fluorescence-activated cell sorting (FACS) using CD44/Stro1 antibodies. Enzyme-linked immunosorbent assay (ELISA), Western blot, and immunocytochemistry assays were performed on human adipocytes (SW872) co-cultured with MSCs and treated with leptin or adiponectin to examine the effects of proliferation, extracellular matrix (ECM) deposition, oxidative damage, and DNA damage. Co-culture with SW872 increased MSC proliferation compared to MSC culture alone, according to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) results. The expressions of PCNA and COL1A increased significantly with SW872 co-culture. In addition, the expression of these markers was increased after leptin treatment and decreased after adiponectin treatment in MSCs. The Wnt/β-catenin and TGF-β/SMAD signaling pathways promote proliferation and ECM deposition in uterine leiomyomas. The expression of Wnt4, β-catenin, TGFβ3, and pSMAD2/3 of MSCs was increased when co-cultured with adipocytes. We found that the co-culture of MSCs with adipocytes resulted in increased NOX4 expression, reactive oxygen species production, and γ-H2AX expression. Leptin acts by binding to its receptor (LEP-R), leading to signal transduction, resulting in the transcription of genes involved in cellular proliferation, angiogenesis, and glycolysis. In MSCs, co-culture with adipocytes increased the expression of LEP-R, pSTAT3/STAT3, and pERK1/2/ERK/12. Based on the above results, we suggest that obesity may mediate MSC initiation of tumorigenesis, resulting in leiomyomas.

Plasma adiponectin as a predictor of the effectiveness of coronary heart disease therapy in patients with metabolic syndrome

BACKGROUND: Adiponectin, an adipose tissue protein, plays a crucial role in the development of metabolic syndrome and atherosclerosis. As a potential therapeutic target, this adipokine can be considered in the context of treatment strategies.&#x0D; AIM: The aim of this study was to assess the correlation between changes in plasma adiponectin concentration during coronary heart disease therapy and the effectiveness of the treatment, as well as to examine the relationship between initial adiponectin levels and treatment outcomes in patients with metabolic syndrome.&#x0D; MATERIALS AND METHODS: The study included 31 patients with coronary heart disease and metabolic syndrome (age 59.7 5.9 years, 21 women) which underwent the reexamination after 23 years. Most patients received statins (n = 26), while some received fibrates (n = 4) and hypoglycemic drugs (n = 4). Additionally, the patients were on hypotensive and antithrombotic therapies. The effectiveness of coronary heart disease therapy was assessed by evaluating changes in the functional class of angina pectoris and exercise tolerance measured through cycle ergometry. Plasma samples were collected at the initial and reexamination periods to determine glucose, insulin, adiponectin, leptin, and lipidogram parameters.&#x0D; RESULTS: The study revealed improvements in insulin sensitivity and plasma lipid spectrum, along with reduced levels of plasma leptin and increased adiponectin levels during the course of therapy. In addition, some patients showed enhanced exercise tolerance. Among the biochemical parameters, changes in insulin resistance during therapy correlated with improvements in exercise performance indicators during cycle ergometry (r = 0.320.36, p 0.05). Moreover, multiple regression analysis indicated that the initial adiponectin concentration independently determined changes in inotropic reserve and the amount of work performed ( = 0.44, p = 0.04 and = 0.64, p = 0.008).&#x0D; CONCLUSIONS: The studys findings regarding the association of plasma adiponectin concentration with changes in exercise tolerance during coronary heart disease therapy suggest the potential for developing specific approaches to raise adiponectin levels in the future.

ERα/LKB1 complex upregulates E-cadherin expression and stimulates breast cancer growth and progression upon adiponectin exposure.

Adiponectin is the major adipocytes-secreted protein involved in obesity-related breast cancer growth and progression. We proved that adiponectin promotes proliferation in ERα-positive breast cancer cells, through ERα transactivation and the recruitment of LKB1 as ERα-coactivator. Here, we showed that adiponectin-mediated ERα transactivation enhances E-cadherin expression. Thus, we investigated the molecular mechanism through which ERα/LKB1 complex may modulate the expression of E-cadherin, influencing tumor growth, progression and distant metastasis. We demonstrated that adiponectin increases E-cadherin expression in ERα-positive 2D and higher extent in 3D cultures. This occurs through a direct activation of E-cadherin gene promoter by ERα/LKB1-complex. The impact of E-cadherin on ERα-positive breast cancer cell proliferation comes from the evidence that in the presence of E-cadherin siRNA the proliferative effects of adiponectin is no longer noticeable. Since E-cadherin connects cell polarity and growth, we investigated if the adiponectin-enhanced E-cadherin expression could influence the localization of proteins cooperating in cell polarity, such as LKB1 and Cdc42. Surprisingly, immunofluorescence showed that, in adiponectin-treated MCF-7 cells, LKB1 and Cdc42 mostly colocalize in the nucleus, impairing their cytosolic cooperation in maintaining cell polarity. The orthotopic implantation of MCF-7 cells revealed an enhanced E-cadherin-mediated breast cancer growth induced by adiponectin. Moreover, tail vein injection of MCF-7 cells showed a higher metastatic burden in the lungs of mice receiving adiponectin-treated cells compared to control. From these findings it emerges that adiponectin treatment enhances E-cadherin expression, alters cell polarity and stimulates ERα-positive breast cancer cell growth in vitro and in vivo, sustaining higher distant metastatic burden.

Abstract P2-26-18: Adiponectin regulates stem cell activity in tamoxifen-resistant breast cancer cells

Abstract Introduction: Breast cancer is the most diagnosed neoplasia and the second leading cause of malignancy death in women. Drug resistance is still the major challenge in the clinical management of breast cancer patients. Indeed, despite the improvements in the early diagnosis and in the therapeutic approaches, many breast cancer patients experience disease relapse due to de novo or acquired drug resistance. Growing evidence recognized a small population of breast cancer cells, named Breast Cancer Stem Cells (BCSCs), as the leading cause of tumor progression, metastasis formation and resistance against conventional therapy. BCSCs have some specific properties such as self-renewal, differentiation into different cell types, migration, tumorsphere formation, antioxidative activity, that make tumors more aggressive. Tumor microenvironment plays a crucial role in the regulation of stem cell proliferation and resistance to apoptosis through the secretion of cytokines and growth factors. Adipocytes represent the most abundant cellular component of mammary microenvironment. The excessive fat accumulation in obesity leads to the development of a dysfunctional adipose tissue, producing an unbalance in adipokines secretion. Among the secreted factors, adiponectin plays a crucial role in breast cancer development and progression. The aim of the present study was to investigate the effects of low adiponectin level (5 μl/ml), hallmark of obese status, on BCSCs activity in hormone-resistant cells. Methods: We tested the ability of MCF-7 wild type (WT) and tamoxifen-resistant (TR) to grow as mammospheres (Mammospheres Forming Efficiency, MFE), measuring the ability to maintain cell viability (self-renewal) upon serial non-adherent passages. mRNA levels of stemness, EMT and cell cycle markers were evaluated by qRT-PCR. CD44+/24- cell ratio, ALDH expression, ROS production, cell cycle, were analyzed by flow cytometry. Results: Adiponectin treatment significantly enhanced MFE and self-renewal capacity in TR-MCF-7 cells compared to MCF-7 WT cells. To identify the presence of BCSCs into mammospheres it has been evaluated the CD44+/CD24– biomarker signature. Flow cytometry revealed an enrichment of CD44, a trans-membrane glycoprotein which regulates growth signals in stem cells, in TR-MCF-7 mammospheres, whereas expression levels of the differentiation marker CD24 were decreased. The gene expression of these biomarkers was also analyzed by qRT-PCR. The increased BCSCs subpopulation in adiponectin-treated TR-MCF-7 mammospheres was also confirmed by the enhanced ALDH-expressing cells. qRT-PCR revealed that adiponectin increased the mRNA levels of stemness and EMT markers in TR-MCF-7 cells mammospheres. Interestingly, cell cycle analysis showed in adiponectin-treated TR-MCF-7 mammospheres a reduction of apoptosis. Moreover, flow cytometry analysis displayed a reduction of ROS levels, which generally are assumed as cues determining DNA damage-induced cell death, in adiponectin-treated TR-MCF-7 mammospheres. Conclusions: Our results demonstrated that low adiponectin level, as it occurs in obese breast cancer microenvironment, driving EMT, enhances stem-like features in TR-MCF-7 cells to sustain tumor progression. Citation Format: Giuseppina Daniela Naimo, Martina Forestiero, Alessandro Paolì, Francesca Giordano, Maria Luisa Panno, Loredana Mauro, Sebastiano Andò. Adiponectin regulates stem cell activity in tamoxifen-resistant breast cancer cells [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-26-18.

Obesity hormones and itaconate mediating inflammation in human colon cancer cells – Another lead to early-onset colon cancer?

BackgroundChronic inflammation is a key feature of obesity and a hallmark of colon cancer (CC). The obesity-related hormones leptin and adiponectin alter inflammatory gene profiles in cancer, but their specific role in CC is unclear. We have previously studied the effects of leptin and the macrophage-specific mediator itaconate on M2-like macrophages. This current study evaluates their effects on CC cells. MethodsHT-29 CC cells (derived from a young patient, stage III CC) were treated with either leptin, adiponectin, 4-octyl itaconate (OI) or dimethyl itaconate (DI). Gene expression after treatment was analyzed at four time points (3, 6, 18, and 24 h). ResultsCCL22 was upregulated after treatment with adiponectin (at 18 h [FC 16.3, p < 0.001]). IL-8 expression increased following both adiponectin (at 3 h [FC 68.1, p < 0.001]) and leptin treatments (at 6 h [FC 7.3, p < 0.001]), while OI induced downregulation of IL-8 (at 24 h [FC −5.0, p < 0.001]). CXCL10 was upregulated after adiponectin treatment (at 6 h [FC 3.0, p = 0.025]) and downregulated by both OI and DI at 24 h, respectively (OI [FC −10.0, p < 0.001]; DI [FC −10.0, p < 0.001]). IL-1β was upregulated after adiponectin treatment (at 3 h [FC 10.6, p < 0.001]) and downregulated by DI (at 24 h [FC −5.0, p < 0.001]). TNF-α expression was induced following adiponectin (at 6 h [FC 110.7, p < 0.001]), leptin (at 18 h [FC 5.8, p = 0.027]) and OI (at 3 h [FC 91.1, p = 0.001]). PPARγ was affected by both OI (at 3 h [FC 10.1, p = 0.031], at 24 h [FC −10.0, p = 0.031]) and DI (at 18 h [FC −1.7, p = 0.033]). ConclusionsObesity hormones directly affect inflammatory gene expression in HT29 CC cells, potentially enhancing cancer progression. Itaconate affects the prognostic marker PPARγ in HT29 CC cells. Leptin, adiponectin and itaconate may represent a link between obesity and CC.

Diagnostic value of multi-slice spiral computed tomography after adiponectin treatment of tracheal malignancies

Purpose: To determine the diagnostic value of multi-slice spiral computed tomography (CT) after adiponectin treatment of tracheal malignancies. &#x0D; Methods: Sixty patients with tracheal malignancies admitted to Emergency General Hospital from February 2017 to February 2021 were assigned to the study group. After physical examination, 60 healthy subjects in the same period served as the control group. All patients were treated with adiponectin. The control group was subjected to serum tumor marker testing before and after treatment, while the study group received multi-slice spiral CT before and after adiponectin treatment. &#x0D; Results: The 60 patients enrolled in the study group comprised 30 cases of squamous carcinoma, 22 cases of adenocarcinoma, and 8 cases of mucosa-associated lymphoma. Multi-slice spiral CT before treatment showed that 35 patients with tracheal malignant tumors had expansive lumen hyperplasia, while 25 patients with bulging tumors had saddle-like hyperplasia with irregular surfaces, uneven margins, and mean thickness of 5.96 ± 0.65 mm in the tracheal and bronchial walls adjacent to the luminal nodule. After treatment, the thickness of the tracheal and bronchial walls adjacent to the luminal nodule decreased to a mean value of 4.65 ± 0.48 mm. Prior to treatment, the mean enhancement value of contrast-enhanced CT was 18.98±1.23 Hu, and mean tumor diameter was 3.68 ± 0.23 cm. However, after treatment, the mean enhancement value increased to 25.98 ± 1.44 Hu, while mean tumor diameter decreased to 2.54 ± 0.20 cm in the study group. &#x0D; Conclusion: Multi-slice spiral CT has promising diagnostic value for patients with tracheal malignancies after adiponectin treatment. Therefore, it can potentially be used in the diagnosis of patients with tracheal malignancies.

Adiponectin Protects Hypoxia/Reoxygenation-Induced Cardiomyocyte Injury by Suppressing Autophagy.

Adiponectin is a cytokine produced by adipocytes and acts as a potential cardioprotective agent and plays an important role in myocardial ischemia/reperfusion injury. In a myocardial hypoxia/reoxygenation model using neonatal rat ventricular myocytes, we investigated the contribution of adiponectin-mediated autophagy to its cardioprotective effects. Cardiomyocytes were exposed to hypoxia/reoxygenation pretreated with or without adiponectin in the presence of absence of rapamycin. Cell viability was analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Western blotting assay was used to determine the expression levels of microtubule-associated proteins 1A/1B light chain 3B (LC3B), adenosine monophosphate-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), p62/sequestosome 1, unc-51 like autophagy activating kinase 1 (ULK1), and Beclin-1. Autophagosome formation was detected by monodansylcadaverine staining. We found that hypoxia induced a time dependent decline in cardiomyocyte viability, and increase in autophagy and reoxygenation further augmented hypoxia-induced autophagy induction and consequently reduced cell viability. Adiponectin treatment alleviated hypoxia/reoxygenation-induced cellular damage and autophagy in cardiomyocytes. Adiponectin treatment also attenuated hypoxia/reoxygenation-promoted cardiomyocyte autophagy even in the presence of another autophagy stimulator rapamycin in part by inhibiting vacuolar hydron-adenosine triphosphatase. Additionally, autophagy suppression by adiponectin during hypoxia/reoxygenation was associated with the attenuated phosphorylation of AMPK and ULK1, augmented phosphorylation of mTOR, and the reduced protein expression levels of Beclin-1 in cardiomyocytes. Taken together, these results suggest that adiponectin protects ischemia/reperfusion-induced cardiomyocytes by suppressing autophagy in part through AMPK/mTOR/ULK1/Beclin-1 signaling pathway.

Adiponectin reduces apoptosis of diabetic cardiomyocytes by regulating miR-711/TLR4 axis

ObjectiveTo investigate the regulation of adiponectin/miR-711 on TLR4/NF-κB-mediated inflammatory response and diabetic cardiomyocyte apoptosis.MethodsDiabetes models were established using rats and H9c2 cardiomyocytes. qRT-PCR was used to detect adiponectin, miR-711, and TLR4. MTT, β-galactosidase staining, and flow cytometry were utilized to assess cell viability, senescence, and apoptosis, respectively. The colorimetric method was used to measure caspase-3 activity, DCFH-DA probes to detect ROS, and western blotting to determine the protein levels of Bax, Bcl-2, TLR4, and p-NF-κB p65. ELISA was performed to measure the levels of adiponectin, ICAM-1, MCP-1, and IL-1β. Dual-luciferase reporter system examined the targeting relationship between miR-711 and TLR4. H&E and TUNEL staining revealed myocardial structure and apoptosis, respectively.ResultsAdiponectin and miR-711 were underexpressed and TLR4/NF-κB signaling pathway was activated in high glucose-treated H9c2 cells. High glucose treatment reduced viability, provoked inflammatory response, and accelerated senescence and apoptosis in H9c2 cells. miR-711 could bind TLR4 mRNA and inactivate TLR4/NF-κB signaling. Adiponectin treatment increased miR-711 expression and blocked TLR4/NF-κB signaling. Adiponectin/miR-711 reduced myocardial inflammation and apoptosis in diabetic rats.ConclusionAdiponectin inhibits inflammation and alleviates high glucose-induced cardiomyocyte apoptosis by blocking TLR4/NF-κB signaling pathway through miR-711.

Adiponectin and the expression of BAX and caspase 3 in high-fructose - induced testicular injury in albino mice

Introduction and Aim: The increase in the prevalence of obesity and metabolic syndrome in recent decades has been correlated with high consumption of high-fructose and high-fat diets and has been associated with increased rates of male infertility. The aim of this study was to investigate how high fructose diet exerts its effect upon testicular morphology in addition to examine the potential effects of adiponectin treatment in restoring the architecture of seminiferous tubules through the expression of immunohistochemical markers BAX and caspase-3. Materials and Methods: Twenty-five adult albino mice were divided into three groups: In Group 1, mice fed with diet contained high concentration of fructose followed by adiponectin injection, Group 2, the mice fed with high concentration of fructose diet and received a saline placebo injection, and Group 3 (control) was nourished a regular food for 8 weeks. The parameters studied included changes in animal body weight, testicular spermatogenesis index, spermatogonia count, apoptotic index, exfoliative epithelium percentage and immunohistochemical scores for testicular BAX and caspase-3 expression. Results: Animals on high fructose diet showed increase in body weight which was markedly reduced by adiponectin treatment. High fructose diet also resulted in reduced spermatogenesis index and spermatogonia count with increased apoptotic and epithelial exfoliation indices. High fructose diet was also associated with high-fructose induced obesity and significantly associated with increased BAX and caspase-3 expression alleviated by adiponectin treatment. Conclusion: High-fructose intake induces obesity and obesity-related reduction in male fertility by reducing spermatogenesis and enhancing testicular cell apoptosis via different pathophysiological mechanisms. Such effects and mechanism can be reversed and corrected with adiponectin treatment.

Adiponectin Ameliorates GMH-Induced Brain Injury by Regulating Microglia M1/M2 Polarization Via AdipoR1/APPL1/AMPK/PPARγ Signaling Pathway in Neonatal Rats.

Adiponectin (APN), a fat-derived plasma hormone, is a classic anti-inflammatory agent. Multiple studies have demonstrated the beneficial role of APN in acute brain injury, but the effect of APN in germinal matrix hemorrhage (GMH) is unclear, and the underlying molecular mechanisms remain largely undefined. In the current study, we used a GMH rat model with rh-APN treatment, and we observed that APN demonstrated a protective effect on neurological function and an inhibitory effect on neuroinflammation after GMH. To further explore the underlying mechanisms of these effects, we found that the expression of Adiponectin receptor 1 (AdipoR1) primarily colocalized with microglia and neurons in the brain. Moreover, AdiopR1, but not AdipoR2, was largely increased in GMH rats. Meanwhile, further investigation showed that APN treatment promoted AdipoR1/APPL1-mediated AMPK phosphorylation, further increased peroxisome proliferator-activated receptor gamma (PPARγ) expression, and induced microglial M2 polarization to reduce the neuroinflammation and enhance hematoma resolution in GMH rats. Importantly, either knockdown of AdipoR1, APPL1, or LKB1, or specific inhibition of AMPK/PPARγ signaling in microglia abrogated the protective effect of APN after GMH in rats. In all, we propose that APN works as a potential therapeutic agent to ameliorate the inflammatory response following GMH by enhancing the M2 polarization of microglia via AdipoR1/APPL1/AMPK/PPARγ signaling pathway, ultimately attenuating inflammatory brain injury induced by hemorrhage.

17β-estradiol rescues the damage of thiazolidinedione on chicken Sertoli cell proliferation via adiponectin

Thiazolidinedione (TZD) is an oral anti-diabetic drug that exhibits some side effects on the male reproductive system by interfering with the steroidogenesis and androgenic activity and also shows anti-proliferative effect on several cell types. This study investigated the effect of TZD on immature chicken Sertoli cell (SC) proliferation and the potential mechanism by which 17β-estradiol regulated this process. Chicken SC viability was investigated under different treatment concentration and time of TZD. 17β-estradiol (0.001 μM, 24 h) was added to analyze its effects on TZD-mediated cell viability, cell metabolic activity, cell growth, cell cycle progression, reactive oxygen species (ROS) level, antioxidant enzyme activity, mitochondria activity, oxygen consumption rate, adenosine triphosphate (ATP) level, and mitochondrial respiratory chain enzyme activity, adiponectin expression and several cell proliferation-related genes mRNA and protein levels. We performed the microRNA (miRNA) array to find TZD-induced differentially expressed miRNAs and validated whether miR-1577 can target on adiponectin via the dual luciferase reporter assay, as well as verified the effect of adiponectin addition with different concentrations on the SC viability. Further, SCs were transfected with miR-1577 agomir (a double-stranded synthetic miRNA mimic) in the presence or absence of TZD and antagomir (a single-stranded synthetic miRNA inhibitor) in the presence or absence of 17β-estradiol to analyze whether miR-1577 was involved in TZD-mediated SC proliferation and whether 17β-estradiol regulated this process. Results showed that TZD significantly inhibited SC viability, cell metabolic activity, cell growth, and cell cycle progression, while increased adiponectin level and ROS generation. TZD-treated SCs presented decreases of antioxidant enzyme activity, mitochondria activity, basal and maximal respiration, ATP production and level, mitochondrial respiratory chain enzyme activity, and mRNA and protein expressions of several cell proliferation-related genes, as well as the significant alteration of miRNA expressions (a total number of 55 miRNAs were up-regulated whereas 53 miRNAs down-regulated). Whereas, 17β-estradiol played a positive role in chicken SC proliferation and rescued the damage of TZD on SC proliferation by up-regulating miR-1577 expression whose target gene was validated to be the adiponectin. In addition, exogenous adiponectin (more than 1 μg/ml) treatment exhibited a significant inhibition on the SC viability. Transfection of miR-1577 agomir promoted the SC proliferation via down-expressed adiponectin, and increased the mitochondrial function and cell proliferation-related gene expression, while TZD weakened the positive effect of miR-1577 agomir on SCs. On the other hand, transfection of miR-1577 antagomir inhibited SC proliferation by producing the opposite effects on above parameters, while 17β-estradiol attenuated the negative effect of miR-1577 antagomir on SCs. These findings suggest down-expressed miR-1577 is involved in the regulation of TZD-inhibited SC proliferation through increasing adiponectin level, and this damage of TZD on the immature chicken SC proliferation can be ameliorated by appropriate dose of exogenous 17β-estradiol treatment. This study provides an insight into the cytoprotective effect of 17β-estradiol on TZD-damaged SC proliferation and may suggest a potential strategy for reducing the risk of SC dysfunction caused by the abuse of TZD.

Adiponectin Influences FGF2 in the Developing Porcine Corpus Luteum.

Luteal angiogenesis is regulated by pro-angiogenic hormones including fibroblast growth factor 2 (FGF2) and angiopoietin 1 (Ang1), which are regulated by the adipokine leptin during development. Another adipokine, adiponectin, exhibits an inverse relationship with leptin and has been identified in the CL. Therefore, it is hypothesized that adiponectin will influence pro-angiogenic hormones in the developing porcine CL. Crossbred sows were randomly allocated to one of two days of the estrous cycle, day 5 (D5; n = 4) or day 7 (D7; n = 5) for CL collection. Tissue was processed for immunohistochemical localization of adiponectin receptor 2 (AdipoR2), gene expression of FGF2, Ang1, leptin, AdipoR2, and cell culture for adiponectin treatment. The expression of AdipoR2 tended (p = 0.09) to be higher in D7 lutea and was more prevalently localized to the cell surface of large and small luteal cells than in D5 tissue. Adiponectin influenced (p ≤ 0.05) FGF2, leptin, and AdipoR2 gene expression relative to the dose and day (D5 or D7). Collectively, the evidence supports the supposition that adiponectin influences angiogenic factors in the developing CL.