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Sreekumar S, Kiran MS. Localized trans-browning and pro-angiogenesis inductive self-assembled collagen resveratrol bio-matrix for tissue repair and regeneration in obese conditions. Int J Biol Macromol 2024; 263:130322. [PMID: 38408584 DOI: 10.1016/j.ijbiomac.2024.130322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/18/2024] [Indexed: 02/28/2024]
Abstract
The present study probes into the complexities of wound management in obesity by proposing a novel biomaterial designed to reprogram the altered skin physiology prevalent in obese conditions. The strategy involves the development of a multifunctional biomaterial addressing issues such as excessive exudate, pressure ulcers, and reduced vascularity. The bio-matrix demonstrates the localized transformation of white adipocytes through trans-browning, coupled with the simultaneous induction of angiogenesis at obese wound sites, resulting in expedited wound closure. The collagen bio-matrices, stabilized with Resveratrol (Rsv), exhibit remarkable thermal, mechanical, and biological stability. The porous 3D microstructure of the Rsv-stabilized collagen bio-matrix closely resembled the natural extracellular matrix, facilitating effective cell adhesion. The bio-matrix exhibited the unique capability to induce localized thermogenesis in the subcutaneous fat layer while concurrently activating angiogenesis. In vivo wound healing studies conducted on DIO-C57BL6 mice demonstrated complete healing within 10 days, showcasing accelerated tissue regeneration, blood vessel formation, robust collagen deposition, and significant activation of browning in the subcutaneous adipose layer. This study introduces the concept of tailored regenerative biomaterials with the ability to reprogram the challenging wound environment associated with obesity. This innovative approach opens up new avenues for enhanced wound care strategies, particularly for bariatric patients.
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Affiliation(s)
- Sreelekshmi Sreekumar
- Biological Materials Laboratory, Council of Scientific and Industrial Research-Central Leather Research Institute, Chennai, Tamil Nadu 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Manikantan Syamala Kiran
- Biological Materials Laboratory, Council of Scientific and Industrial Research-Central Leather Research Institute, Chennai, Tamil Nadu 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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Xiang L, Liu M, Xiang G, Yue L, Zhang J, Xu X, Dong J. Dapagliflozin promotes white adipose tissue browning though regulating angiogenesis in high fat induced obese mice. BMC Pharmacol Toxicol 2024; 25:26. [PMID: 38504370 PMCID: PMC10949628 DOI: 10.1186/s40360-024-00747-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 03/13/2024] [Indexed: 03/21/2024] Open
Abstract
Browning of white adipose tissue (WAT) is become an appealing target for therapeutics in the treatment of obesity and related metabolic diseases. Dapagliflozin is widely used in the treatment of type 2 diabetes, and it is also found that the drug exhibits regulate systemic metabolism such as obesity, insulin resistance and hepatic steatosis. However, the precise role of dapagliflozin on WAT remodeling remains to be elucidated. The current study aimed to explore the role of dapagliflozin on WAT browning in high-fat diet (HFD)-induced obese mice. Male C57BL/6J mice (n = 6 per group) were used to establish obesity model by following feeding with HFD for 6 weeks. The mice were randomly treated with or without dapagliflozin for the experimental observation. The volume and fat fraction of WAT were quantified, H&E, UCP-1 staining and immunohistochemistry were conducted to investigate the white-to-brown fat conversion and angiogenesis in WAT respectively. Quantitative real-time polymerase chain reaction (qPCR) was employed to explore the mRNA expression levels of genes related to fat browning and angiogenesis in WAT. Subsequently, 3T3-L1 cells were used to explore the effect of dapagliflozin on preadipocytes differentiation in vitro. Our results demonstrated that dapagliflozin could reduce body weight gain and promote WAT browning in HFD induced obese mice via regulating lipogenesis and angiogenesis in WAT. Furthermore, dapagliflozin reduce cells differentiation, up-regulate the expression of WAT browning and angiogenesis genes in 3T3-L1 adipocytes in vitro. In conclusion, dapagliflozin can potentially promote WAT browning in HFD induced obese mice via improving lipogenesis and angiogenesis in WAT.
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Affiliation(s)
- Lin Xiang
- Department of Endocrinology, General Hospital of Central Theater Command, Wuluo Road 627, Wuhan, Hubei Province, 430070, China
| | - Min Liu
- Department of Endocrinology, General Hospital of Central Theater Command, Wuluo Road 627, Wuhan, Hubei Province, 430070, China
| | - Guangda Xiang
- Department of Endocrinology, General Hospital of Central Theater Command, Wuluo Road 627, Wuhan, Hubei Province, 430070, China
| | - Ling Yue
- Department of Endocrinology, General Hospital of Central Theater Command, Wuluo Road 627, Wuhan, Hubei Province, 430070, China
| | - Junxia Zhang
- Department of Endocrinology, General Hospital of Central Theater Command, Wuluo Road 627, Wuhan, Hubei Province, 430070, China
| | - Xiaoli Xu
- Department of Endocrinology, General Hospital of Central Theater Command, Wuluo Road 627, Wuhan, Hubei Province, 430070, China.
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Rujin 2nd Road, Shanghai, China.
| | - Jing Dong
- Department of Endocrinology, General Hospital of Central Theater Command, Wuluo Road 627, Wuhan, Hubei Province, 430070, China.
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Sreekumar S, Vijayan V, Gangaraj KP, Kiran MS. Apigenin Self-Assembled Collagen Biomatrix for Reprogramming the Obese Wound Microenvironment for Its Management and Repair. ACS APPLIED BIO MATERIALS 2024; 7:1317-1335. [PMID: 38357783 DOI: 10.1021/acsabm.3c00609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
Wound management in obesity is complicated by excessive exudates from wounded areas, pressure ulcerations due to stacking of the fat layer, and vascular rarefaction. The current study explored the development of biomaterials for reprogramming the altered wound microenvironment under obese conditions. Self-assembled collagen biomatrix with trans and de novo browning activator, apigenin, was fabricated as a soft tissue regenerative wound dressing material. The as-synthesized self-assembled collagen biomatrix exhibited excellent thermal, mechanical, and biological stability with a superior wound exudate absorption capacity. The apigenin self-assembled collagen biomatrix exhibited porous 3-D microstructure that mimicked the extracellular matrix that promoted cell adhesion and proliferation. The apigenin self-assembled collagen multifunctional biomatrix triggered adaptive localized thermogenesis in the subcutaneous fat layer, resulting in the activation of angiogenesis and fibroblast spreading and migration. The in vivo wound healing assay performed in DIO-C57BL6 mice showed faster tissue regeneration within 9 days, with well-defined neo-epidermis, blood vessel formation, thick collagen deposition, minimal inflammation, and significant activation of browning in the subcutaneous adipose layer. This study paves the way forward for the development of specialized regenerative biomatrices that reprogram the obese wound bed for faster tissue regeneration.
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Affiliation(s)
- Sreelekshmi Sreekumar
- Biological Materials Laboratory, Council of Scientific and Industrial Research- Central Leather Research Institute, Chennai, Tamil Nadu India, 600020
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Vinu Vijayan
- Biological Materials Laboratory, Council of Scientific and Industrial Research- Central Leather Research Institute, Chennai, Tamil Nadu India, 600020
| | | | - Manikantan Syamala Kiran
- Biological Materials Laboratory, Council of Scientific and Industrial Research- Central Leather Research Institute, Chennai, Tamil Nadu India, 600020
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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Sreekumar S, Vijayan V, Gangaraj KP, Thangasornaraja M, Kiran MS. Caffeine-reinforced Collagen as Localized Microenvironmental Trans-Browning Bio-Matrix for Soft Tissue Repair and Regeneration in Bariatric Condition. Adv Biol (Weinh) 2024; 8:e2300544. [PMID: 38155149 DOI: 10.1002/adbi.202300544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/11/2023] [Indexed: 12/30/2023]
Abstract
The wound exudates, hypoperfusion of the subcutaneous fat layer, and poor vasculature worsen wound management in obese subjects. In the current study, a multifunctional Caffeine-reinforced collagen biomaterial is developed that can simultaneously modulate lipid metabolism and angiogenesis in obese wound microenvironments for faster tissue regeneration. The biomaterial is fabricated specialized for obese conditions to initiate simultaneous lipolysis and angiogenesis locally in the hypoxic subcutaneous fat in wound margins of obese subjects. Caffeine-reinforced collagen biomatrix shows better structural integrity, thermal stability, bio-compatibility, and lesser proteolytic susceptibility. Caffeine-collagen biomaterial promote angiogenesis, fibroblast migration, and localized browning of white adipocytes to activate thermogenesis in the subcutaneous fat layer at the wound site. Full-thickness excision wound healing studies performed in obese C57BL6 mice shows faster wound closure within day 9 when compare to control mice. The Caffeine-reinforced collagen biomaterial remodeled the wound site locally by activating fibroblast to secrete collagen, activate endothelial cells to promote angiogenesis, and induce browning in white adipocytes in subcutaneous fat. The study opens a new direction in bariatric tissue regenerative medicine by locally modulating lipid metabolism, angiogenesis, and trans-browning at the injured site for faster complete restoration of the damaged tissue.
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Affiliation(s)
- Sreelekshmi Sreekumar
- Biological Materials Laboratory, Council of Scientific and Industrial Research- Central Leather Research Institute, Chennai, TN, 600020, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Vinu Vijayan
- Biological Materials Laboratory, Council of Scientific and Industrial Research- Central Leather Research Institute, Chennai, TN, 600020, India
| | | | - Menakha Thangasornaraja
- Biological Materials Laboratory, Council of Scientific and Industrial Research- Central Leather Research Institute, Chennai, TN, 600020, India
| | - Manikantan Syamala Kiran
- Biological Materials Laboratory, Council of Scientific and Industrial Research- Central Leather Research Institute, Chennai, TN, 600020, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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Ravishankar K, Km S, Sreekumar S, Sivan S, Kiran MS, Lobo NP, Jaisankar SN, Raghavachari D. Microwave-assisted synthesis of crosslinked ureido chitosan for hemostatic applications. Int J Biol Macromol 2024; 260:129648. [PMID: 38246465 DOI: 10.1016/j.ijbiomac.2024.129648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 01/23/2024]
Abstract
In this study, we present a facile method for introducing hydrophilic ureido groups (NH2-CO-NH-) into chitosan using a microwave-assisted reaction with molten urea, with the aim of enhancing chitosan's interaction with blood components for improved hemostasis. The formation of the ureido groups through nucleophilic addition reaction between the amine groups in chitosan and in situ generated isocyanic acid was confirmed by FTIR, CP/TOSS 13C NMR, and CP/MAS 15N NMR spectroscopic techniques. However, in stark contrast to the glucans, the said modification introduced extensive crosslinking in chitosan. Spectroscopic studies identified these crosslinks as carbamate bridges (-NH-COO-), which were likely formed by the reaction between the ureido groups and hydroxyl groups of adjacent chains through an isocyanate intermediate. These carbamate bridges improved ureido chitosan's environmental stability, making it particularly resistant to changes in pH and temperature. In comparison to chitosan, the crosslinked ureido chitosan synthesized here exhibited good biocompatibility and cell adhesion, rapidly arrested the bleeding in a punctured artery with minimal hemolysis, and induced early activation and aggregation of platelets. These properties render it an invaluable material for applications in hemostasis, particularly in scenarios that necessitate stability against pH variations and degradation.
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Affiliation(s)
- Kartik Ravishankar
- Polymer Science and Technology Division, CSIR-Central Leather Research Institute (CSIR-CLRI), Adyar, Chennai 600 020, Tamil Nadu, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, Uttar Pradesh, India.
| | - Shelly Km
- Department of Chemistry, Indian Institute of Technology Madras (IIT Madras), Chennai 600 036, Tamil Nadu, India
| | - Sreelekshmi Sreekumar
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, Uttar Pradesh, India; Biological Materials Laboratory, CSIR-Central Leather Research Institute (CSIR-CLRI), Adyar, Chennai 600 020, Tamil Nadu, India
| | - Sisira Sivan
- Polymer Science and Technology Division, CSIR-Central Leather Research Institute (CSIR-CLRI), Adyar, Chennai 600 020, Tamil Nadu, India
| | - Manikantan Syamala Kiran
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, Uttar Pradesh, India; Biological Materials Laboratory, CSIR-Central Leather Research Institute (CSIR-CLRI), Adyar, Chennai 600 020, Tamil Nadu, India
| | - Nitin Prakash Lobo
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, Uttar Pradesh, India; Centre for Analysis, Testing, Evaluation& Reporting Services (CATERS), CSIR-Central Leather Research Institute (CSIR-CLRI), Adyar, Chennai 600 020, Tamil Nadu, India
| | - Sellamuthu N Jaisankar
- Polymer Science and Technology Division, CSIR-Central Leather Research Institute (CSIR-CLRI), Adyar, Chennai 600 020, Tamil Nadu, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, Uttar Pradesh, India.
| | - Dhamodharan Raghavachari
- Department of Chemistry, Indian Institute of Technology Madras (IIT Madras), Chennai 600 036, Tamil Nadu, India
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Sreekumar S, Gangaraj KP, Kiran MS. Modulation of angiogenic switch in reprogramming browning and lipid metabolism in white adipocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159423. [PMID: 37956709 DOI: 10.1016/j.bbalip.2023.159423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 11/15/2023]
Abstract
Thermogenic activation via trans-and de novo browning of white adipocytes is a promising strategy to accelerate lipid metabolism for regulating obesity-related disorders. In this study, we investigated the intricate interplay between angiogenic regulation and browning in white adipocytes using the bioactive compound, resveratrol (Rsv). Rsv has previously been documented for its regulatory influence on the trans and de novo browning of white adipocytes. Our findings revealed that concurrent activation of angiogenesis is prerequisite for inducing browning within the microenvironment of white adipocytes when exposed to browning activators. Additionally, we observed a significant browning effect on white adipocytes when the local adipose tissue environment was prompted to undergo angiogenesis, notably facilitated by a proangiogenic molecule known as Vascular endothelial growth factor (VEGF). Intriguingly, this effect was reversed when angiogenesis was inhibited by treatment with the antiangiogenic agent thalidomide. Furthermore, the study revealed the role of VEGF in paracrine activation of white adipocytes resulting in the induction of browning in both 3T3-L1 cell lines and primary mouse white adipocytes. The cross-talk between angiogenesis and browning was found to be initiated via the transcriptional activation of Estrogen receptor α (ERα) triggering the VEGF/VEGFR2 signaling pathway leading to browning and a reconfiguration of lipid metabolism within adipocytes. In conclusion, this study sheds light on the intricate cross-talk between angiogenesis and browning of white adipocytes. Notably, the findings underscore the reciprocal relationship between these processes, wherein inhibition of one process exerts discernible effects on the other.
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Affiliation(s)
- Sreelekshmi Sreekumar
- Biological Materials Laboratory, Council of Scientific and Industrial Research - Central Leather Research Institute, Chennai, Tamil Nadu 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | | | - Manikantan Syamala Kiran
- Biological Materials Laboratory, Council of Scientific and Industrial Research - Central Leather Research Institute, Chennai, Tamil Nadu 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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Aslan MN, Sukan-Karaçağıl B, Acar-Tek N. Roles of citrus fruits on energy expenditure, body weight management, and metabolic biomarkers: a comprehensive review. Nutr Rev 2023:nuad116. [PMID: 37702528 DOI: 10.1093/nutrit/nuad116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023] Open
Abstract
Citrus fruits are widely consumed for their nutritional and health benefits. They belong to the Rutaceae and have many varieties, such as sweet orange (Citrus sinensis), which is the most popular. Citrus fruits are rich in water (>80%), dietary fiber, and vitamins. They also contain bioactive components, which may modulate energy metabolism and lipid oxidation through various mechanisms. These mechanisms include stimulating β3-adrenergic receptors, increasing mitochondrial biogenesis and thermogenesis, activating AMP kinase and peroxisome proliferator-activated receptor-gamma coactivator-1α pathways, inhibiting lipogenesis and lipid accumulation, and inducing browning of white adipose tissue. This review summarizes the mechanisms and outcomes of citrus fruits and their metabolites on energy metabolism and body weight in different experimental models. The literature was searched for in vitro and in vivo animal and human studies that investigated the effects of citrus consumption on energy expenditure, thermogenesis, adipogenesis, and lipid accumulation. Citrus fruits and their metabolites have shown promising effects on energy metabolism and lipid oxidation in in vitro and in vivo animal studies. However, the evidence from human studies is limited and inconsistent. Possible reasons for the discrepancy are briefly discussed, and knowledge gaps and research needs are identified for future studies. Citrus fruits may have beneficial effects on energy metabolism and body weight, but more rigorous and well-designed human trials are needed to confirm their efficacy and safety.
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Affiliation(s)
- Merve Nur Aslan
- Faculty of Health Sciences, Department of Nutrition and Dietetics, Bolu Abant Izzet Baysal University, Bolu, Turkey
- Department of Nutrition and Dietetics, Institute of Health Sciences, Gazi University, Ankara, Turkey
| | - Betül Sukan-Karaçağıl
- Department of Nutrition and Dietetics, Institute of Health Sciences, Gazi University, Ankara, Turkey
| | - Nilüfer Acar-Tek
- Faculty of Health Sciences, Department of Nutrition and Dietetics, Gazi University, Ankara, Turkey
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Vijayan V, Sreekumar S, Ahina KM, Lakra R, Kiran MS. Lanthanum Oxide Nanoparticles Reinforced Collagen ƙ-Carrageenan Hydroxyapatite Biocomposite as Angio-Osteogenic Biomaterial for In Vivo Osseointegration and Bone Repair. Adv Biol (Weinh) 2023; 7:e2300039. [PMID: 37080950 DOI: 10.1002/adbi.202300039] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/22/2023] [Indexed: 04/22/2023]
Abstract
A composite biomatrix fabricated with collagen, ƙ-carrageenan, hydroxyapatite reinforced with lanthanum oxide nanoparticles is explored as proangiogenic and osteogenic bone tissue repair biomaterial. The biomatrix shows increased physical and biological stability as observed from proteolytic degradation and thermal stability studies. The addition of lanthanum oxide nanoparticles facilitates good osseointegration coupled with simultaneous activation of proangiogenic properties to act as a bone mimicking material. The minimal level of reactive oxygen species and superior cytocompatibility help the as-synthesized biomatrix in achieving capillary migration into the bone micro environment. The composite biomatrix upregulates the expression of VEGF, VEGF-R2 genes in endothelial cells and osteopontin, osteocalcin in osteoblasts cells, respectively. The in vivo hard tissue repair experiment conducted in a rat model shows complete healing of the bone defect by eight weeks with the application of collagen-ƙ-carrageenan-hydroxyapatite-lanthanum oxide nanoparticle biomaterial when compared to the biomaterial made out of individual constituents alone. The biomaterial matrix gets biointegrated into the bone tissue and exerts its therapeutic value in bringing a faster osseo repair process. The study shows the feasibility of using rare-earth metal nanoparticles in combination with protein-polysaccharide biopolymers for bone regeneration.
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Affiliation(s)
- Vinu Vijayan
- Biological Materials Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai, Tamil Nadu, 600020, India
- University of Madras, Chennai, Tamil Nadu, 600005, India
| | - Sreelekshmi Sreekumar
- Biological Materials Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai, Tamil Nadu, 600020, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Kannoth Madappurakkal Ahina
- Biological Materials Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai, Tamil Nadu, 600020, India
| | - Rachita Lakra
- Biological Materials Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai, Tamil Nadu, 600020, India
| | - Manikantan Syamala Kiran
- Biological Materials Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai, Tamil Nadu, 600020, India
- University of Madras, Chennai, Tamil Nadu, 600005, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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Angiogenesis-Browning Interplay Mediated by Asprosin-Knockout Contributes to Weight Loss in Mice with Obesity. Int J Mol Sci 2022; 23:ijms232416166. [PMID: 36555807 PMCID: PMC9783228 DOI: 10.3390/ijms232416166] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/09/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Asprosin (ASP) is a recently identified adipokine secreted by white adipose tissue (WAT). It plays important roles in the maintenance of glucose homeostasis in the fasting state and in the occurrence and development of obesity. However, there is no report on whether and how ASP would inhibit angiogenesis and fat browning in the mouse adipose microenvironment. Therefore, the study sought to investigate the effects of ASP-knockout on angiogenesis and fat browning, and to identify the interaction between them in the ASP-knockout mouse adipose microenvironment. In the experiments in vivo, the ASP-knockout alleviated the obesity induced by a high fat diet (HFD) and increased the expressions of the browning-related proteins including uncoupling protein 1 (UCP1), PRD1-BF-1-RIZ1 homologus domain-containing protein-16 (PRDM16) and PPAR gamma coactivator 1 (PGC1-α) and the endothelial cell marker (CD31). In the experiments in vitro, treatment with the conditional medium (CM) from ASP-knockout adipocytes (ASP-/--CM) significantly promoted the proliferation, migration and angiogenesis of vascular endothelial cells, and increased the expressions of vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor 2 (VEGFR2) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/endothelial nitric oxide synthase (eNOS) pathway proteins. In addition, the treatment with CM from endothelial cells (EC-CM) markedly reduced the accumulation of lipid droplets and increased the expressions of the browning-related proteins and the mitochondrial contents. Moreover, the treatment with EC-CM significantly improved the energy metabolism in 3T3-L1 adipocytes. These results highlight that ASP-knockout can promote the browning and angiogenesis of WAT, and the fat browning and angiogenesis can interact in the mouse adipose microenvironment, which contributes to weight loss in the mice with obesity.
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