Adiponectin Signaling Regulates Lipid Production in Human Sebocytes

Adiponectin negatively regulates pigmentation, Wnt/β-catenin and HGF/c-Met signalling within human scalp hair follicles ex vivo

Adiponectin reportedly stimulates proliferation and elongation of human scalp hair follicles (HFs) ex vivo. In the current study, we investigated how adiponectin oligomers produced by perifollicular dermal white adipose tissue (dWAT), a potent source of adiponectin isoforms, influence human HF proliferation and pigmentation. To do so, we treated microdissected, organ-cultured HFs in the presence or absence of dWAT with a recombinant human adiponectin oligomer mix, or inhibited dWAT-derived adiponectin using a neutralizing antibody. Multiplex qPCR (Fluidigm) revealed that adiponectin oligomers downregulated pigmentation genes KITLG, PMEL and TYRP1 and Wnt genes AXIN2, LEF1 and WNT10B. In situ hybridization showed that adiponectin downregulated AXIN2 and LEF1, and up-regulated DKK1 within the dermal papilla (DP), a highly unusual transcriptional profile for a putative hair growth-promoting agent. Adiponectin oligomers also downregulated protein expression of the HGF receptor c-Met within the matrix and DP. However, adiponectin did not alter hair matrix keratinocyte proliferation within 48 h ex vivo, irrespective of the presence/absence of dWAT; HF pigmentation (Masson-Fontana histochemistry, tyrosinase activity) was also unchanged. In contrast, neutralizing adiponectin isoforms within HF + dWAT increased proliferation, melanin content and tyrosinase activity but resulted in fewer melanocytes and melanocytic dendrites, as assessed by gp100 immunostaining. These seemingly contradictory effects suggest that adiponectin exerts complex effects upon human HF biology, likely in parallel with the pro-pigmentation effects of dWAT- and DP-derived HGF. Our data suggest that dWAT-derived ratios of adiponectin isoforms and the cleaved, globular version of adiponectin may in fact determine how adiponectin impacts upon follicular pigmentation and growth.

The role of vasoactive peptides in skin homeostasis-focus on adiponectin and the kallikrein-kinin system

Vasoactive peptides often serve a multitude of functions aside from their direct effects on vasodynamics. This article will review the existing literature on two vasoactive peptides and their involvement in skin homeostasis: adiponectin and-as the main representative of the kallikrein-kinin system-bradykinin. Adiponectin is the most abundantly expressed adipokine in the human organism, where it is mainly localized in fat depots including subcutaneous adipose tissue, from where adiponectin can exert paracrine effects. The involvement of adiponectin in skin homeostasis is supported by a number of studies reporting the effects of adiponectin in isolated human keratinocytes, sebocytes, fibroblasts, melanocytes, and immune cells. Regarding skin pathology, the potential involvement of adiponectin in psoriasis, atopic dermatitis, scleroderma, keloid, and melanogenesis is discussed in this article. The kallikrein-kinin system is composed of a variety of enzymes and peptides, most of which have been identified to be expressed in the skin. This also includes the expression of bradykinin receptors on most skin cells. Bradykinin is one of the very few hormones that is targeted by treatment in routine clinical use in dermatology-in this case for the treatment of hereditary angioedema. The potential involvement of bradykinin in wound healing, psoriasis, and melanoma is further discussed in this article. This review concludes with a call for additional preclinical and clinical studies to further explore the therapeutic potential of adiponectin supplementation (for psoriasis, atopic dermatitis, wound healing, scleroderma, and keloid) or pharmacological interference with the kallikrein-kinin system (for wound healing, psoriasis, and melanoma).

Skin-associated adipocytes in skin barrier immunity: A mini-review

The skin contributes critically to health via its role as a barrier tissue against a multitude of external pathogens. The barrier function of the skin largely depends on the uppermost epidermal layer which is reinforced by skin barrier immunity. The integrity and effectiveness of skin barrier immunity strongly depends on the close interplay and communication between immune cells and the skin environment. Skin-associated adipocytes have been recognized to play a significant role in modulating skin immune responses and infection by secreting cytokines, adipokines, and antimicrobial peptides. This review summarizes the recent understanding of the interactions between skin-associated adipocytes and other skin cells in maintaining the integrity and effectiveness of skin barrier immunity.

Involvement of caveolin-1 in skin diseases

The skin is the outermost layer and largest organ in the human body. Since the skin interfaces with the environment, it has a variety of roles, including providing a protective barrier against external factors, regulating body temperature, and retaining water in the body. It is also involved in the immune system, interacting with immune cells residing in the dermis. Caveolin-1 (CAV-1) is essential for caveolae formation and has multiple functions including endocytosis, lipid homeostasis, and signal transduction. CAV-1 is known to interact with a variety of signaling molecules and receptors and may influence cell proliferation and migration. Several skin-related disorders, especially those of the inflammatory or hyperproliferative type such as skin cancers, psoriasis, fibrosis, and wound healing, are reported to be associated with aberrant CAV-1 expression. In this review, we have explored CAV-1 involvement in skin physiology and skin diseases.

Effect of Adiponectin Variant on Lipid Profile and Plasma Adiponectin Levels: A Multicenter Systematic Review and Meta-Analysis

Background. Adiponectin is a recognized antiatherogenic molecule; this study was aimed at clarifying the effects of adiponectin variants on lipid and adiponectin levels. Methods. By searching PubMed and Cochrane databases for studies published before March 31, 2022, a total of 86,610 individuals were included in the analysis. Results. Variants of rs2241766 and rs266729 were associated with decreased adiponectin and high-density lipoprotein cholesterol (HDL-C), as well as increased triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels. In contrast, the rs1501299 variant was correlated with increased adiponectin and HDL-C, as well as decreased TG, TC, and LDL-C levels. Subgroup analysis indicated that the significant effect of the rs2241766 and rs266729 variants on lipid profile was predominant in Chinese, while the significant effect of the rs1501299 variant on lipid profile was primarily in Caucasians. Moreover, a stronger effect of the rs2241766 and rs1501299 variants on LDL-C levels was observed in males, while a considerable effect of the rs266729 variant on LDL-C levels was observed in children. Conclusions. The present study indicated that Chinese with the rs2241766 and rs266729 variants were at high risk of dyslipidemia, atherosclerosis, or coronary artery disease (CAD). Males with the rs2241766 variant were at high risk of CAD. Children with the rs266729 variant had a high risk to develop dyslipidemia, atherosclerosis, and even early onset of CAD in the future. These findings are beneficial to clinical physicians to choose different management strategies for cardiovascular disease (CVD) prevention.

Endosomal Phosphatidylinositol-3-Phosphate-Associated Functions Are Dispensable for Establishment of the Cytomegalovirus Pre-Assembly Compartment but Essential for the Virus Growth

Murine cytomegalovirus (MCMV) initiates the stepwise establishment of the pre-assembly compartment (pre-AC) in the early phase of infection by the expansion of the early endosome (EE)/endosomal recycling compartment (ERC) interface and relocation of the Golgi complex. We depleted Vps34-derived phosphatidylinositol-3-phosphate (PI(3)P) at EEs by VPS34-IN1 and inhibited PI(3)P-associated functions by overexpression of 2xFYVE- and p40PX PI(3)P-binding modules to assess the role of PI(3)P-dependent EE domains in the pre-AC biogenesis. We monitored the accumulation of Rab10 and Evectin-2 in the inner pre-AC and the relocation of GM130-positive cis-Golgi organelles to the outer pre-AC by confocal microscopy. Although PI(3)P- and Vps34-positive endosomes build a substantial part of pre-AC, the PI(3)P depletion and the inhibition of PI(3)P-associated functions did not prevent the establishment of infection and progression through the early phase. The PI(3)P depletion in uninfected and MCMV-infected cells rapidly dispersed PI(3)P-bond proteins and reorganized EEs, including ablation of EE-to-ERC transport and relocation of Rab11 endosomes. The PI(3)P depletion one hour before pre-AC initiation and overexpression of 2xFYVE and p40PX domains neither prevented Rab10- and Evectin-2 accumulation, nor Golgi unlinking and relocation. These data demonstrate that PI(3)P-dependent functions, including the Rab11-dependent EE-to-ERC route, are dispensable for pre-AC initiation. Nevertheless, the virus growth was drastically reduced in PI(3)P-depleted cells, indicating that PI(3)P-associated functions are essential for the late phase of infection.

Effects of Obesity on Adiponectin System Skin Expression in Dogs: A Comparative Study

Simple Summary

Adipokines are biologically active molecules with hormonal action, produced mainly by white adipose tissue and related to the individual’s nutritional status. Adiponectin with its receptors (ADIPOR1, ADIPOR2) intervenes in the control of energy metabolism, as well as in the regulation of peripheral tissue functions. Adiponectin has a primary role in the skin in both physiological and pathological conditions, in addition, this molecule is greatly affected by nutritional status, and its serum level is lowered in the obese. In this work, the adiponectin system was evaluated in the skin of obese dogs along with adiponectin serum levels. Results were compared to normal weight dogs to evidence modifications in the obesity condition. Obesity is a widespread phenomenon in dogs, with a growing trend, as well, in humans; this condition may interfere with the local functionality of tissues, including the skin. The evaluation performed evidenced that adiponectin and ADIPOR2 skin expression is negatively correlated with the serum adiponectin level and accordingly with obesity. These findings evidence that the adiponectin system changes in the skin of obese dogs; this study also explores the role of adipokines in skin biology.

Abstract

Obesity is an important health issue in dogs since it influences a plethora of associated pathologies, including dermatological disorders. Considering the scarcity of information in pets, this work aimed to evaluate the localization and expression of adiponectin (ADIPOQ) and its two receptors (ADIPOR1 and ADIPOR2) in the skin of 10 obese dogs, compared with serum ADIPOQ level. Through immunohistochemistry, ADIPOQ and ADIPOR2 were observed in the adipose tissue, sweat and sebaceous glands, endothelium, and some connective cells. Both receptors were observed in the epidermis and the hair follicles, other than in the sweat and sebaceous glands. Real-time PCR evidenced that the ADIPOQ and ADIPOR2 transcripts were expressed 5.4-fold (p < 0.01) and 2.3-fold less (p < 0.01), respectively, in obese than in normal weight dogs, while ADIPOR1 expression did not change. Obese dogs showed lower serum ADIPOQ levels than the normal weight group. Accordingly, ADIPOQ and ADIPOR2 expression in the skin appear negatively correlated with obesity in the same way as the serum ADIPOQ level. These findings evidence that ADIPOQ system changes in the skin of obese dogs and suggest that the ADIPOQ effect on the skin is at least in part regulated by the reduced expression of ADIPOR2.

Adipokines in the Skin and in Dermatological Diseases

Adipokines are the primary mediators of adipose tissue-induced and regulated systemic inflammatory diseases; however, recent findings revealed that serum levels of various adipokines correlate also with the onset and the severity of dermatological diseases. Importantly, further data confirmed that the skin serves not only as a target for adipokine signaling, but may serve as a source too. In this review, we aim to provide a complex overview on how adipokines may integrate into the (patho) physiological conditions of the skin by introducing the cell types, such as keratinocytes, fibroblasts, and sebocytes, which are known to produce adipokines as well as the signals that target them. Moreover, we discuss data from in vivo and in vitro murine and human studies as well as genetic data on how adipokines may contribute to various aspects of the homeostasis of the skin, e.g., melanogenesis, hair growth, or wound healing, just as to the pathogenesis of dermatological diseases such as psoriasis, atopic dermatitis, acne, rosacea, and melanoma.

Adipokines as Biomarkers of Atopic Dermatitis in Adults

Atopic dermatitis (AD) is characterized by chronic, relapsing, pruritic skin inflammation and does not have a well-understood pathogenesis. In this study, we addressed the contribution of adipokines to AD eczema based on the assessment of blood levels of adiponectin, resistin, leptin, lipocalin-2, and vaspin in adult non-obese patients suffering from chronic extrinsic childhood-onset AD. We investigated 49 AD patients with a median age of 37 years. The control group consisted of 30 age-matched healthy subjects. Adipokines were assessed in the serum by ELISA assays and the severity of AD with the SCORing Atopic Dermatitis (SCORAD) index. We found that adiponectin and resistin decreased and leptin appreciably increased in AD patients when compared to those in healthy subjects. Further, the levels of adiponectin and resistin were inversely related to the intensity of eczema. In conclusion, apart from the formerly investigated role of leptin in AD, this study points to adiponectin and resistin as the potential candidate adipokine biomarkers involved in shaping eczema intensity and severity, which may help predict disease exacerbations and enable the development of effective targeted therapeutic interventions.

Effect of Weight Reduction on Treatment Outcomes for Patients with Atopic Dermatitis

BACKGROUND

Several epidemiological studies have shown that the atopic tendency increases in the obese population.

OBJECTIVE

The aim of this study was to confirm the effect of weight reduction on improvement of atopic dermatitis (AD) symptoms and to investigate the relationship between AD severity and the level of serum adipokines.

METHODS

Forty subjects who were AD outpatients were recruited for this study. Obese patients were divided into a weight maintenance group and weight reduction group. During the study period, patient information was collected that included measured body mass index (BMI), Eczema Area and Severity Index (EASI), and visual analogue scale for pruritus. Adiponectin, leptin, eosinophil count, and total immunoglobulin E were also tested.

RESULTS

In the weight reduction group, there was a significant improvement in the EASI score, however, no significant improvement was determined in the weight maintenance group. BMI and EASI showed positive correlation. The adiponectin level was lower in AD patients compared to healthy controls, and it was significantly lower in obese patients compared with normal weight patients. Serum levels of leptin were significantly different among control, obese patient group, and normal weight patient group. There was no statistically significant relationship between serum adipokine level and EASI.

CONCLUSION

In our study, weight reduction was associated with significant improvement of AD symptoms. Related adipokine levels were significantly different among the control, normal weight AD patient group, and obese AD patient group.

The Trp64Arg polymorphism in β3 adrenergic receptor (ADRB3) gene is associated with adipokines and plasma lipids: a systematic review, meta-analysis, and meta-regression

BACKGROUND

Recently, some studies claim that adipokines may modulate plasma lipids. More interestingly, the ADRB3 Trp64Arg polymorphism may regulate adipokines and play an essential role in lipids metabolism. This study aims to clarify the associations of ADRB3 Trp64Arg polymorphism with plasma adipokines and lipid levels.

METHODS

Twenty-two studies (5527 subjects) and 121 studies (54,059 subjects) were respectively identified for the association analyses of adipokines and lipids. Standardized mean difference (SMD) and 95% confidence interval (CI) were used to estimate the strength of the Trp64Arg variant in adipokines and plasma lipids. All results were recalculated after eliminating the studies with heterogeneity.

RESULTS

The carriers of the C allele (Arg at 64th position was encoded by the C allele) had higher levels of leptin and lower levels of adiponectin than the non-carriers. The carriers of the C allele had higher levels of triglycerides (TG), total cholesterol (TC), and lower levels of high-density lipoprotein cholesterol (HDL-C) than the non-carriers. Subgroup analysis certified an ethnicity (Asians), disease status (obesity), and gender (females) specific association. Sensitivity analysis indicated that the analysis results were robust and stable. Meta-regression indicated that obesity was related to adiponectin.

CONCLUSIONS

The C allele carriers of Trp64Arg polymorphism had a slight but significant influence on lipid levels, and the remarkable effects specific existed in obese Asian women. The associations of Trp64Arg polymorphism with dyslipidemia may partly be mediated by the effect of this polymorphism on adipokines. The association of Trp64Arg polymorphism with obesity may partly be mediated by the effect of this polymorphism on adipokines. The C allele carriers had abnormal levels of adipokines and lipids, and it indicated that the Trp64Arg polymorphism might represent a genetic risk factor for coronary artery disease (CAD).

Adiponectin as inducer of inflammatory and apoptosis involving in immune defense in lamprey

Adiponectin (APN) is an important cytokine secreted by fat cells that is responsible for regulating numerous biological functions. However, the APN gene in lamprey and its precise function remain unidentified. In this study, the full-length cDNA sequence of L-APN was cloned, and it encoded a protein of 267 amino acid residues with a globular domain. The results of immunohistochemistry and FACS assays showed that APN protein was distributed in multiple tissues. L-APN expression in the supraneural body (SB) and leukocytes was differentially upregulated in response to Gram-negative bacteria, Gram-positive bacteria and poly (I:C). The expression levels of inflammatory cytokines were upregulated, and a proapoptotic effect was stimulated in SB cells treated with recombinant APN. Furthermore, L-APN could inhibit cell proliferation and arrest cell growth in the G1 phase. In summary, the APN protein from the lamprey plays an important role in inhibiting cell proliferation, inducing the production of inflammatory cytokines and promoting cell apoptosis, and it is also involved in immune responses and immune defenses. Our data provide insights into the evolutionary origin of the structure and function of APN gene.

Adiponectin Attenuates the Inflammation in Atopic Dermatitis-Like Reconstructed Human Epidermis

Background

Atopic dermatitis (AD) is a chronic disorder, with a vicious cycle of repetitive inflammation and deterioration of the epidermal barrier function. Adiponectin, an adipokine, has anti-inflammatory effects on various metabolic and inflammatory disorders. Recently, its level was found to be reduced in serum and tissue samples from AD patients.

Objective

We aimed to investigate the effects of adiponectin on epidermal inflammation and barrier structures in AD skin.

Methods

A three-dimensional in vitro epidermal equivalent model mimicking AD was obtained by adding an inflammatory substance cocktail to normal human epidermal equivalents (HEEs). The expression of epidermal differentiation markers, primary inflammatory mediators, and lipid biosynthetic enzymes was compared between adiponectintreated AD-HEEs, untreated control AD-HEEs, and normal HEEs.

Results

Adiponectin co-treatment 1) inhibited the increase in mRNA expression of major inflammatory mediators (carbonic anhydrase II, neuron-specific NEL-like protein 2, thymic stromal lymphopoietin, interleukin-8, tumor necrosis factor-alpha, and human beta-defensin-2) from keratinocytes in AD-inflammatory HEEs, 2) enhanced the expression of lipid biosynthetic enzymes (fatty acid synthase, HMG CoA reductase, and serine-palmitoyl transferase), and 3) promoted the expression of differentiation factors, especially filaggrin. We also found that the expression of adiponectin receptor-1 and -2 decreased in the epidermis of chronic AD lesion.

Conclusion

Activation of the adiponectin pathway is expected to enhance epidermal differentiation and barrier function as well as attenuate inflammatory response to AD as a therapeutic approach.

Expression of Three Adipokines (Adiponectin, Leptin and Resistin) in Normal Canine Skin: a Pilot Study

Adipokines are biologically active cytokines that are mainly produced in adipose tissue. There is evidence, in man and mice, that some adipokines may be secreted in other tissues including the vascular endothelium, epithelia and sebaceous glands. Moreover, modified serum levels of adipokines have been detected in people with acne vulgaris or psoriasis; it is suspected that adipokines could contribute to local and systemic inflammatory conditions. We aimed to evaluate the expression of three adipokines (i.e. leptin, adiponectin and resistin) in normal canine skin. Formalin-fixed, paraffin wax-embedded punch biopsy samples were obtained from the sparsely-haired skin of the caudal ventral abdomen of a single clinically healthy dog with no history of skin disease. Immunohistochemistry was applied, using rabbit polyclonal primary antibodies specific for leptin, adiponectin and resistin. Adipokines were not expressed in normal canine dermis or hypodermis. In contrast, they were detected in the keratinocytes of all epidermal layers and hair follicle segments, sebocytes, apocrine gland cells and in the vascular endothelium. This is the first report on the expression of adipokines in normal canine skin, a first step in studying their role in the skin physiology and inflammatory skin diseases of dogs.

Development of new 3D human ex vivo models to study sebaceous gland lipid metabolism and modulations

OBJECTIVES

Sebaceous glands maintain skin homeostasis by producing sebum. Low production can induce hair loss and fragile skin. Overproduction provokes seborrhoea and may lead to acne and inflammatory events. To better study sebaceous gland maintenance, sebocyte maturation, lipid production and ageing or inflammatory processes, we developed innovative 3D ex vivo models for human sebaceous glands.

MATERIALS AND METHODS

Culture conditions and analytical methods optimized on sebocyte monolayers were validated on extracted sebaceous glands and allowed the development of two 3D models: (a) "air-liquid" interface and (b) human fibronectin-coated "sandwich" method. Lipid production was assessed with microscopy, fluorometry or flow cytometry analysis after Nile Red staining. Specific lipids (particularly squalene and peroxidized squalene) were measured by Gas or liquid Chromatography and Mass spectrometry.

RESULTS

This study allowed us to select appropriate conditions and design Seb4Gln culture medium inducing sebocyte proliferation and neutral lipid production. The "air-liquid" model was appropriate to induce sebocyte isolation. The "sandwich" model enabled sebaceous gland maintenance up to 42 days. A treatment with Insulin Growth Factor-1 allowed validation of the model as we succeeded in mimicking dynamic lipid overproduction.

CONCLUSION

Functional sebocyte maturation and physiological maintenance were preserved up to 6 weeks in our models. Associated with functional assays, they provide a powerful platform to mimic physiological skin lipid metabolism and to screen for active ingredients modulating sebum production.

Platycodin D May Improve Acne and Prevent Scarring by Downregulating SREBP-1 Expression Via Inhibition of IGF-1R/PI3K/Akt Pathway and Modulating Inflammation with an Increase in Collagen

Background

Although many therapeutic agents have been developed, only a few drugs are known to target multiple pathogenic factors in the treatment of acne.

Objective

The purpose of this study was to identify a new drug candidate, platycodin D, which is a substance extracted from the root of Platycodon grandiflorum.

Methods

Using western blotting and Cell Counting Kit-8 assay, we studied the effects of platycodin D on SEB-1 sebocytes, fibroblasts, and keratinocytes. We investigated its effects in view of lipogenesis, collagen production, anti-inflammatory activity, and dyskeratinization.

Results

In SEB-1 sebocytes, platycodin D showed a sebosuppressive effect by downregulating ERK and insulin- like growth factor-1R/PI3K/Akt/sterol-regulatory element binding protein-1 signaling pathways. In addition, adiponectin, one of the adipokines responsible for sebum production, was decreased in platycodin D-treated SEB-1 sebocytes. In fibroblasts, platycodin D increased collagen production and reduced inflammation by inhibiting nuclear factor kappa B and matrix metalloproteinases. Platycodin D also showed anti-inflammatory effects on keratinocytes. It also suppressed keratin 16 expression induced by lipopolysaccharide. Furthermore, platycodin D showed no cytotoxicity on both SEB-1 sebocytes and fibroblasts.

Conclusion

Our data demonstrate the clinical feasibility of platycodin D for acne treatment and the prevention of acne scarring by sebosuppressive and anti-inflammatory effects, as well as through an increase in collagen levels.

Metabolomic profiling implicates adiponectin as mediator of a favorable lipoprotein profile associated with NT-proBNP

Background

The N-terminal prohormone of brain natriuretic peptide (NT-proBNP) is an important biomarker for the diagnosis of heart failure. Apart from this and only recently recognized, NT-proBNP levels associate with higher HDL- and lower LDL-cholesterol levels comprising a favorable blood lipid profile. To further examine this observation, the lipoprotein profile in relation to NT-proBNP was examined in-depth by proton nuclear magnetic resonance spectroscopy (¹H-NMR). We complemented this investigation with a state-of-the-art untargeted metabolomics approach.

Methods

Lipoprotein particles were determined by ¹H-NMR spectroscopy in 872 subjects without self-reported diabetes from the population-based Study of Health in Pomerania (SHIP)-TREND with available NT-proBNP measurements. Comprehensive metabolomics data for plasma and urine samples were obtained. Linear regression models were performed to assess the associations between serum concentrations of NT-proBNP and the metabolites/lipoprotein particles measured in plasma or urine.

Results

An increase in serum NT-proBNP was associated with a benefical lipoprotein profile, including a decrease in VLDL, IDL and LDL-particles along with an increase in large HDL particles. These findings were replicated in a second independent cohort. Serum concentrations of NT-proBNP showed significant inverse associations with seven plasma metabolites while associations with 39 urinary metabolites, mostly comprising amino acids and related intermediates, were identified. Mediation analyses revealed adiponection as mediating factor for the associations observed with lipoproteins particles.

Conclusions

Most of the metabolic changes associated with NT-proBNP implicate significant influence on the blood lipid profile besides vasodilatory and the diuretic action of BNP signaling. Our data suggest that the more favorable lipoprotein profile as associated with elevated NT-proBNP concentrations in mainly cardiac healthy individuals might relate to adiponectin signaling indicating even indirect cardio-protective effects for NT-proBNP.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0765-1) contains supplementary material, which is available to authorized users.

The role of adiponectin and adipolin as anti-inflammatory adipokines in the formation of macrophage foam cells and their association with cardiovascular diseases

Obesity is one of the major public health concerns that is closely associated with obesity-related disorders such as type 2 diabetes mellitus (T2DM), hypertension, and atherosclerosis. Atherosclerosis is a chronic disease characterized by excess cholesterol deposition in the arterial intima and the formation of foam cells. Adipocytokines or adipokines are secreted by the adipose tissue as endocrine glands; adiponectin and adipolin are among these adipokines that are associated with obese and insulin-resistant phenotypes. Adipolin and adiponectin are cytokines that exert substantial impact on obesity, progression of atherosclerosis, insulin resistance, and glucose metabolism. In this paper, we review the formation of macrophage foam cells, which are associated with atherosclerosis, and the macrophage mechanism, which includes uptake, esterification, and release. We also summarize current information on adipose tissue-derived hormone and energy homeostasis in obesity. Finally, the role of adipokines, e.g., adipoline and adiponectin, in regulating metabolic, cardiovascular diseases is discussed.