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Beatty CJ, Ruiz-Lozano RE, Quiroga-Garza ME, Perez VL, Jester JV, Saban DR. The Yin and Yang of non-immune and immune responses in meibomian gland dysfunction. Ocul Surf 2024; 32:81-90. [PMID: 38224775 DOI: 10.1016/j.jtos.2024.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 01/04/2024] [Accepted: 01/12/2024] [Indexed: 01/17/2024]
Abstract
Meibomian gland dysfunction (MGD) is a leading cause of dry eye disease and one of the most common ophthalmic conditions encountered in eye clinics worldwide. These holocrine glands are situated in the eyelid, where they produce specialized lipids, or meibum, needed to lubricate the eye surface and slow tear film evaporation - functions which are critical to preserving high-resolution vision. MGD results in tear instability, rapid tear evaporation, changes in local microflora, and dry eye disease, amongst other pathological entities. While studies identifying the mechanisms of MGD have generally focused on gland obstruction, we now know that age is a major risk factor for MGD that is associated with abnormal cell differentiation and renewal. It is also now appreciated that immune-inflammatory disorders, such as certain autoimmune diseases and atopy, may trigger MGD, as demonstrated through a T cell-driven neutrophil response. Here, we independently discuss the underlying roles of gland and immune related factors in MGD, as well as the integration of these two distinct mechanisms into a unified perspective that may aid future studies. From this unique standpoint, we propose a revised model in which glandular dysfunction and immunopathogenic pathways are not primary versus secondary contributors in MGD, but are fluid, interactive, and dynamic, which we likened to the Yin and Yang of MGD.
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Affiliation(s)
- Cole J Beatty
- Department of Integrative Immunobiology, Duke University School of Medicine, Durham, NC, USA; Duke Eye Center, Duke University School of Medicine, Foster Center for Ocular Immunology at Duke Eye Center, Durham, NC, USA
| | - Raul E Ruiz-Lozano
- Duke Eye Center, Duke University School of Medicine, Foster Center for Ocular Immunology at Duke Eye Center, Durham, NC, USA
| | - Manuel E Quiroga-Garza
- Duke Eye Center, Duke University School of Medicine, Foster Center for Ocular Immunology at Duke Eye Center, Durham, NC, USA
| | - Victor L Perez
- Duke Eye Center, Duke University School of Medicine, Foster Center for Ocular Immunology at Duke Eye Center, Durham, NC, USA.
| | - James V Jester
- Department of Ophthalmology and Biomedical Engineering, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA.
| | - Daniel R Saban
- Department of Integrative Immunobiology, Duke University School of Medicine, Durham, NC, USA; Duke Eye Center, Duke University School of Medicine, Foster Center for Ocular Immunology at Duke Eye Center, Durham, NC, USA.
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2
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Tang Y, Zhang W, Wang Y, Li H, Zhang C, Wang Y, Lin Y, Shi H, Xiang H, Huang L, Zhu J. Expression Variation of CPT1A Induces Lipid Reconstruction in Goat Intramuscular Precursor Adipocytes. Int J Mol Sci 2023; 24:13415. [PMID: 37686221 PMCID: PMC10488119 DOI: 10.3390/ijms241713415] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
Intramuscular fat (IMF) deposition is one of the most important factors affecting meat quality and is closely associated with the expression of carnitine palmitoyl transferase 1A (CPT1A) which facilitates the transfer of long-chain fatty acids (LCFAs) into the mitochondria. However, the role of how CPT1A regulates the IMF formation remains unclear. Herein, we established the temporal expression profile of CPT1A during the differentiation of goat intramuscular precursor adipocytes. Functionally, the knockdown of CPT1A by siRNA treatment significantly increased the mRNA expression of adipogenic genes and promoted lipid deposition in goat intramuscular precursor adipocytes. Meanwhile, a CPT1A deficiency inhibited cell proliferation and promoted cell apoptosis significantly. CPT1A was then supported by the overexpression of CPT1A which significantly suppressed the cellular triglyceride deposition and promoted cell proliferation although the cell apoptosis also was increased. For RNA sequencing, a total of 167 differential expression genes (DEGs), including 125 upregulated DEGs and 42 downregulated DEGs, were observed after the RNA silencing of CPT1A compared to the control, and were predicted to enrich in the focal adhesion pathway, cell cycle, apoptosis and the MAPK signaling pathway by KEGG analysis. Specifically, blocking the MAPK signaling pathway by a specific inhibitor (PD169316) rescued the promotion of cell proliferation in CPT1A overexpression adipocytes. In conclusion, the expression variation of CPT1A may reconstruct the lipid distribution between cellular triglyceride deposition and cell proliferation in goat intramuscular precursor adipocyte. Furthermore, we demonstrate that CPT1A promotes the proliferation of goat adipocytes through the MAPK signaling pathway. This work widened the genetic regulator networks of IMF formation and delivered theoretical support for improving meat quality from the aspect of IMF deposition.
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Affiliation(s)
- Yinmei Tang
- Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Key Laboratory of Sichuan Province, Southwest Minzu University, Chengdu 610225, China; (Y.T.); (Y.W.); (H.L.); (C.Z.); (Y.W.); (Y.L.); (H.X.); (L.H.)
| | - Wenyang Zhang
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Southwest Minzu University, Ministry of Education, Chengdu 610041, China;
| | - Yinggui Wang
- Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Key Laboratory of Sichuan Province, Southwest Minzu University, Chengdu 610225, China; (Y.T.); (Y.W.); (H.L.); (C.Z.); (Y.W.); (Y.L.); (H.X.); (L.H.)
| | - Haiyang Li
- Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Key Laboratory of Sichuan Province, Southwest Minzu University, Chengdu 610225, China; (Y.T.); (Y.W.); (H.L.); (C.Z.); (Y.W.); (Y.L.); (H.X.); (L.H.)
| | - Changhui Zhang
- Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Key Laboratory of Sichuan Province, Southwest Minzu University, Chengdu 610225, China; (Y.T.); (Y.W.); (H.L.); (C.Z.); (Y.W.); (Y.L.); (H.X.); (L.H.)
| | - Yong Wang
- Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Key Laboratory of Sichuan Province, Southwest Minzu University, Chengdu 610225, China; (Y.T.); (Y.W.); (H.L.); (C.Z.); (Y.W.); (Y.L.); (H.X.); (L.H.)
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Southwest Minzu University, Ministry of Education, Chengdu 610041, China;
| | - Yaqiu Lin
- Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Key Laboratory of Sichuan Province, Southwest Minzu University, Chengdu 610225, China; (Y.T.); (Y.W.); (H.L.); (C.Z.); (Y.W.); (Y.L.); (H.X.); (L.H.)
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Southwest Minzu University, Ministry of Education, Chengdu 610041, China;
| | - Hengbo Shi
- College of Animal Science, Zhejiang University, Hangzhou 310058, China;
| | - Hua Xiang
- Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Key Laboratory of Sichuan Province, Southwest Minzu University, Chengdu 610225, China; (Y.T.); (Y.W.); (H.L.); (C.Z.); (Y.W.); (Y.L.); (H.X.); (L.H.)
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Southwest Minzu University, Ministry of Education, Chengdu 610041, China;
| | - Lian Huang
- Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Key Laboratory of Sichuan Province, Southwest Minzu University, Chengdu 610225, China; (Y.T.); (Y.W.); (H.L.); (C.Z.); (Y.W.); (Y.L.); (H.X.); (L.H.)
| | - Jiangjiang Zhu
- Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Key Laboratory of Sichuan Province, Southwest Minzu University, Chengdu 610225, China; (Y.T.); (Y.W.); (H.L.); (C.Z.); (Y.W.); (Y.L.); (H.X.); (L.H.)
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Southwest Minzu University, Ministry of Education, Chengdu 610041, China;
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Li J, Huang Q, Yang C, Yu C, Zhang Z, Chen M, Ren P, Qiu M. Molecular Regulation of Differential Lipid Molecule Accumulation in the Intramuscular Fat and Abdominal Fat of Chickens. Genes (Basel) 2023; 14:1457. [PMID: 37510361 PMCID: PMC10379444 DOI: 10.3390/genes14071457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/12/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Reducing abdominal fat (AF) accumulation and increasing the level of intramuscular fat (IMF) simultaneously is a major breeding goal in the poultry industry. To explore the different molecular mechanisms underlying AF and IMF, gene expression profiles in the breast muscle (BM) and AF from three chicken breeds were analyzed. A total of 4737 shared DEGs were identified between BM and AF, of which 2602 DEGs were upregulated and 2135 DEGs were downregulated in the BM groups compared with the AF groups. DEGs involved in glycerophospholipid metabolism and glycerolipid metabolism were potential regulators, resulting in the difference in lipid metabolite accumulation between IMF and AF. The PPAR signaling pathway was the most important pathway involved in tissue-specific lipid deposition. Correlation analysis showed that most representative DEGs enriched in the PPAR signaling pathway, such as FABP5, PPARG, ACOX1, and GK2, were negatively correlated with PUFA-enriched glycerophospholipid molecules. Most DEGs related to glycerophospholipid metabolism, such as GPD2, GPD1, PEMT, CRLS1, and GBGT1, were positively correlated with glycerophospholipid molecules, especially DHA- and arachidonic acid (ARA)-containing glycerophospholipid molecules. This study elucidated the molecular mechanism underlying tissue-specific lipid deposition and poultry meat quality.
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Affiliation(s)
- Jingjing Li
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Qinke Huang
- Guangyuan City Animal Husbandry Seed Management Station, Guangyuan 628107, China
| | - Chaowu Yang
- Sichuan Animal Science Academy, Chengdu 610066, China
| | - Chunlin Yu
- Sichuan Animal Science Academy, Chengdu 610066, China
| | | | - Meiying Chen
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Peng Ren
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Mohan Qiu
- Sichuan Animal Science Academy, Chengdu 610066, China
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Yang X, Reneker LW, Zhong X, Huang AJW, Jester JV. Meibomian gland stem/progenitor cells: The hunt for gland renewal. Ocul Surf 2023; 29:497-507. [PMID: 37422152 PMCID: PMC10528929 DOI: 10.1016/j.jtos.2023.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/29/2023] [Accepted: 07/05/2023] [Indexed: 07/10/2023]
Abstract
Meibomian glands (MGs) secrete lipid (meibum) onto the ocular surface to form the outermost layer of the tear film. Proper meibum secretion is essential for stabilizing the tear film, reducing aqueous tear evaporation, and maintaining the homeostasis of the ocular surface. Atrophy of MG as occurs with aging, leads to reduction of meibum secretion, loss of ocular surface homeostasis and evaporative dry eye disease (EDED). Since MGs are holocrine glands, secretion of meibum requires continuous self-renewal of lipid-secreting acinar meibocytes by stem/progenitor cells, whose proliferative potential is dramatically reduced with age leading to MG atrophy and an age-related meibomian gland dysfunction (ARMGD). Understanding the cellular and molecular mechanisms regulating meibocyte stem/progenitor cell maintenance and renewal may provide novel approaches to regenerating MG and treating EDED. Towards that end, recent label retaining cell and lineage-tracing experiments as well as knock-out transgenic mouse studies have begun to identify the location and identities of meibocyte progenitor cells and potential growth and transcription factors that may regulate meibocyte renewal. In addition, recent reports have shown that ARMGD may be reversed by novel therapeutics in mice. Herein, we discuss our current understanding of meibocyte stem/progenitor cells and the hunt for gland renewal.
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Affiliation(s)
- Xiaowei Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Lixing W Reneker
- Department of Ophthalmology, University of Missouri, Columbia, MO, USA
| | - Xingwu Zhong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China; Hainan Eye Hospital and Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Haikou, Hainan, China
| | - Andrew J W Huang
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, Missouri, USA
| | - James V Jester
- Department of Ophthalmology and Biomedical Engineering, University of California Irvine, Irvine, CA, USA.
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Butovich IA, Wilkerson A, Goggans KR, Belyaeva OV, Kedishvili NY, Yuksel S. Sdr16c5 and Sdr16c6 control a dormant pathway at a bifurcation point between meibogenesis and sebogenesis. J Biol Chem 2023; 299:104725. [PMID: 37075844 PMCID: PMC10206187 DOI: 10.1016/j.jbc.2023.104725] [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: 02/21/2023] [Revised: 03/23/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023] Open
Abstract
Genes Sdr16c5 and Sdr16c6 encode proteins that belong to a superfamily of short-chain dehydrogenases/reductases (SDR16C5 and SDR16C6). Simultaneous inactivation of these genes in double-KO (DKO) mice was previously shown to result in a marked enlargement of the mouse Meibomian glands (MGs) and sebaceous glands, respectively. However, the exact roles of SDRs in physiology and biochemistry of MGs and sebaceous glands have not been established yet. Therefore, we characterized, for the first time, meibum and sebum of Sdr16c5/Sdr16c6-null (DKO) mice using high-resolution MS and LC. In this study, we demonstrated that the mutation upregulated the overall production of MG secretions (also known as meibogenesis) and noticeably altered their lipidomic profile, but had a more subtle effect on sebogenesis. The major changes in meibum of DKO mice included abnormal accumulation of shorter chain, sebaceous-type cholesteryl esters and wax esters (WEs), and a marked increase in the biosynthesis of monounsaturated and diunsaturated Meibomian-type WEs. Importantly, the MGs of DKO mice maintained their ability to produce typical extremely long chain Meibomian-type lipids at seemingly normal levels. These observations indicated preferential activation of a previously dormant biosynthetic pathway that produce shorter chain, and more unsaturated, sebaceous-type WEs in the MGs of DKO mice, without altering the elongation patterns of their extremely long chain Meibomian-type counterparts. We conclude that the Sdr16c5/Sdr16c6 pair may control a point of bifurcation in one of the meibogenesis subpathways at which biosynthesis of lipids can be redirected toward either abnormal sebaceous-type lipidome or normal Meibomian-type lipidome in WT mice.
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Affiliation(s)
- Igor A Butovich
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Graduate School of Biomedical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
| | - Amber Wilkerson
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kelli R Goggans
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Olga V Belyaeva
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Natalia Y Kedishvili
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Seher Yuksel
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Li J, Yan P, Li Y, Han M, Zeng Q, Li J, Yu Z, Zhang D, Chen X. Harnessing the power of Raman spectroscopic imaging for ophthalmology. Front Chem 2023; 11:1211121. [PMID: 37252371 PMCID: PMC10213270 DOI: 10.3389/fchem.2023.1211121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 05/04/2023] [Indexed: 05/31/2023] Open
Abstract
Eye diseases can cause great inconvenience to people's daily life; therefore, it is necessary to study the causes of ocular diseases and related physiological processes. Raman spectroscopic imaging (RSI) is a non-destructive, non-contact detection technique with the advantages of label-free, non-invasive and highly specific. Compared with other mature imaging technologies, RSI can provide real-time molecular information and high-resolution imaging at relatively low cost, making it very suitable for quantitative detection of biological molecules. RSI can reflect the overall situation of the sample, revealing the content distribution of the same substance in different areas of the sample. This review focuses on the recent advances in ophthalmology, with particular emphasis on the powerful use of RSI techniques, as well as its combination with other imaging techniques. Finally, we prospect the wider application and future potential of RSI approaches in ophthalmology.
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Affiliation(s)
- Jing Li
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated People’s Hospital of Northwest University, Xi’an, Shaanxi, China
| | - Peirao Yan
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Yong Li
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated People’s Hospital of Northwest University, Xi’an, Shaanxi, China
| | - Ming Han
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Qi Zeng
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Juan Li
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated People’s Hospital of Northwest University, Xi’an, Shaanxi, China
| | - Zhe Yu
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated People’s Hospital of Northwest University, Xi’an, Shaanxi, China
| | - Dongjie Zhang
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Xueli Chen
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
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7
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Portal C, Lin Y, Rastogi V, Peterson C, Yiu SCH, Foster JW, Wilkerson A, Butovich IA, Iomini C. Primary cilia control cellular patterning of Meibomian glands during morphogenesis but not lipid composition. Commun Biol 2023; 6:282. [PMID: 36932132 PMCID: PMC10023665 DOI: 10.1038/s42003-023-04632-5] [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: 08/04/2022] [Accepted: 02/27/2023] [Indexed: 03/19/2023] Open
Abstract
Meibomian glands (MGs) are modified sebaceous glands producing the tear film's lipids. Despite their critical role in maintaining clear vision, the mechanisms underlying MG morphogenesis in development and disease remain obscure. Cilia-mediate signals are critical for the development of skin adnexa, including sebaceous glands. Thus, we investigated the role of cilia in MG morphogenesis during development. Most cells were ciliated during early MG development, followed by cilia disassembly during differentiation. In mature glands, ciliated cells were primarily restricted to the basal layer of the proximal gland central duct. Cilia ablation in keratine14-expressing tissue disrupted the accumulation of proliferative cells at the distal tip but did not affect the overall rate of proliferation or apoptosis. Moreover, impaired cellular patterning during elongation resulted in hypertrophy of mature MGs with increased meibum volume without altering its lipid composition. Thus, cilia signaling networks provide a new platform to design therapeutic treatments for MG dysfunction.
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Affiliation(s)
- Céline Portal
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Yvonne Lin
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Varuni Rastogi
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Cornelia Peterson
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Samuel Chi-Hung Yiu
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - James W Foster
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Amber Wilkerson
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Igor A Butovich
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Graduate School of Biomedical Sciences, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Carlo Iomini
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA.
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA.
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Ishtiaq SM, Arshad MI, Khan JA. PPARγ signaling in hepatocarcinogenesis: Mechanistic insights for cellular reprogramming and therapeutic implications. Pharmacol Ther 2022; 240:108298. [PMID: 36243148 DOI: 10.1016/j.pharmthera.2022.108298] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/26/2022] [Accepted: 10/04/2022] [Indexed: 11/30/2022]
Abstract
Liver cancer or hepatocellular carcinoma (HCC) is leading cause of cancer-related mortalities globally. The therapeutic approaches for chronic liver diseases-associated liver cancers aimed at modulating immune check-points and peroxisome proliferator-activated receptor gamma (PPARγ) signaling pathway during multistep process of hepatocarcinogenesis that played a dispensable role in immunopathogenesis and outcomes of disease. Herein, the review highlights PPARγ-induced effects in balancing inflammatory (tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1) and anti-inflammatory cytokines (IL-10, transforming growth factor beta (TGF-β), and interplay of PPARγ, hepatic stellate cells and fibrogenic niche in cell-intrinsic and -extrinsic crosstalk of hepatocarcinogenesis. PPARγ-mediated effects in pre-malignant microenvironment promote growth arrest, cell senescence and cell clearance in liver cancer pathophysiology. Furthermore, PPARγ-immune cell axis of liver microenvironment exhibits an immunomodulation strategy of resident immune cells of the liver (macrophages, natural killer cells, and dendritic cells) in concomitance with current clinical guidelines of the European Association for Study of Liver Diseases (EASL) for several liver diseases. Thus, mechanistic insights of PPARγ-associated high value targets and canonical signaling suggest PPARγ as a possible therapeutic target in reprogramming of hepatocarcinogenesis to decrease burden of liver cancers, worldwide.
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Affiliation(s)
- Syeda Momna Ishtiaq
- Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad 38040, Pakistan
| | | | - Junaid Ali Khan
- Department of Pharmacology and Physiology, MNS University of Agriculture, Multan 60000, Pakistan.
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Paranjpe V, Galor A, Grambergs R, Mandal N. The role of sphingolipids in meibomian gland dysfunction and ocular surface inflammation. Ocul Surf 2022; 26:100-110. [PMID: 35973562 PMCID: PMC10259413 DOI: 10.1016/j.jtos.2022.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 07/17/2022] [Accepted: 07/22/2022] [Indexed: 11/26/2022]
Abstract
Inflammation occurs in response to tissue injury and invasion of microorganisms and is carried out by the innate and adaptive immune systems, which are regulated by numerous chemokines, cytokines, and lipid mediators. There are four major families of bioactive lipid mediators that play an integral role in inflammation - eicosanoids, sphingolipids (SPL), specialized pro-resolving mediators (SPM), and endocannabinoids. SPL have been historically recognized as important structural components of cellular membranes; their roles as bioactive lipids and inflammatory mediators are recent additions. Major SPL metabolites, including sphingomyelin, ceramide, ceramide 1-phosphate (C1P), sphingosine, sphingosine 1-phosphate (S1P), and their respective enzymes have been studied extensively, primarily in cell-culture and animal models, for their roles in cellular signaling and regulating inflammation and apoptosis. Less focus has been given to the involvement of SPL in eye diseases. As such, the aim of this review was to examine relationships between the SPL family and ocular surface diseases, focusing on their role in disease pathophysiology and discussing the potential of therapeutics that disrupt SPL pathways.
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Affiliation(s)
- Vikram Paranjpe
- Department of Ophthalmology, New York University School of Medicine, 550 First Avenue, New York, NY, 10016, USA
| | - Anat Galor
- Miami Veterans Administration Medical Center, 1201 NW 16th St, Miami, FL, 33125, USA; Bascom Palmer Eye Institute, University of Miami, 900 NW 17th Street, Miami, FL, 33136, USA.
| | - Richard Grambergs
- Departments of Ophthalmology, Anatomy and Neurobiology, University of Tennessee Health Sciences Center, Hamilton Eye Institute, 930 Madison Avenue, Memphis, TN, 38163, USA
| | - Nawajes Mandal
- Departments of Ophthalmology, Anatomy and Neurobiology, University of Tennessee Health Sciences Center, Hamilton Eye Institute, 930 Madison Avenue, Memphis, TN, 38163, USA; Memphis VA Medical Center, Memphis, TN, 38104, USA.
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Nuwormegbe S, Park NY, Park HJ, Jin Y, Kim SW, Jester JV. Induction of meibocyte differentiation by three-dimensional, matrigel culture of immortalized human meibomian gland epithelial cells to form acinar organoids. Ocul Surf 2022; 26:271-282. [PMID: 36341959 PMCID: PMC10364613 DOI: 10.1016/j.jtos.2022.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 09/20/2022] [Accepted: 10/19/2022] [Indexed: 11/05/2022]
Abstract
PURPOSE Recent studies have shown that two-dimensional (2D) culture of primary rabbit and immortalized human meibomian gland epithelial cells (iHMGEC) do not recapitulate normal meibocyte differentiation and fail to express critical enzymes necessary for synthesis of meibum lipids. The purpose of this study was to test the hypothesis that 3D-spheroid culture of iHMGEC can facilitate meibocyte differentiation and induce the expression of acyl-CoA wax-alcohol acyltransferase 2 (AWAT2), shown to be required for synthesis of meibum wax esters. METHODS iHMGEC were suspended in matrigel/basement membrane matrix and grown in proliferation media to form distinct cell clusters or spheroids. Cells were then treated with serum-free, differentiation media (advanced DMEM/F12) with and without FGF10 and synthetic agonists for the nuclear lipid receptor, peroxisome proliferator activator receptor gamma (PPARγ). Cells were then evaluated for differentiation markers using western blotting, immunocytochemistry (ICC) and real-time PCR. Control cells were grown in standard 2D culture systems. RESULTS Under proliferative conditions, 3D culture induced the formation of KRT5+ spheroids that contained a Ki67+/P63+ undifferentiated, basal cell population. When spheroids were switched to differentiation media containing PPARγ agonists, two different organoid populations were detected, a KRT6low population that was AWAT2+/PPARγ+ and a KRT6high population that was AWAT2-/PPARγ-, suggesting that iHMGEC exhibit a dual differentiation potential toward either a ductal or meibocyte organoid phenotype. CONCLUSION The 3D culturing of iHMGEC can induce the formation of both meibocyte and ductal organoids and may thus serve as a better in vitro model system for studying the regulatory mechanisms controlling meibomian gland function.
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Affiliation(s)
- Selikem Nuwormegbe
- Research Institute of Metabolism and Inflammation, Yonsei University, Wonju College of Medicine, Wonju, Ilsan-ro, Gangwon-do, 26426, Republic of Korea
| | - Na-Young Park
- Research Institute of Metabolism and Inflammation, Yonsei University, Wonju College of Medicine, Wonju, Ilsan-ro, Gangwon-do, 26426, Republic of Korea
| | - Hee Joo Park
- Research Institute of Metabolism and Inflammation, Yonsei University, Wonju College of Medicine, Wonju, Ilsan-ro, Gangwon-do, 26426, Republic of Korea
| | - Yeonwoo Jin
- Department of Ophthalmology, Yonsei University, Wonju College of Medicine, Wonju, Ilsan-ro, Gangwon-do, 26426, Republic of Korea
| | - Sun Woong Kim
- Department of Ophthalmology, Yonsei University, Wonju College of Medicine, Wonju, Ilsan-ro, Gangwon-do, 26426, Republic of Korea; Research Institute of Metabolism and Inflammation, Yonsei University, Wonju College of Medicine, Wonju, Ilsan-ro, Gangwon-do, 26426, Republic of Korea.
| | - James V Jester
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, USA.
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11
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Su AC, Zhang LY, Zhang JG, Hu YY, Liu XY, Li SC, Xian XH, Li WB, Zhang M. The Regulation of Autophagy by p38 MAPK-PPARγ Signaling During the Brain Ischemic Tolerance Induced by Cerebral Ischemic Preconditioning. DNA Cell Biol 2022; 41:838-849. [PMID: 35944278 DOI: 10.1089/dna.2022.0087] [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: 11/13/2022] Open
Abstract
Several studies indicated that autophagy activation participates in brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIP). However, the mechanism of autophagy activation during the process still remains unclear. The present study aimed to evaluate the role of p38 MAPK-peroxisome proliferator-activated receptor γ (PPARγ) signaling cascade in autophagy during the CIP-induced BIT. The results shown that, initially, autophagy activation was observed after CIP in the model of global cerebral ischemia in rats, as was indicated by the upregulation of Beclin 1 expression, an increase in LC3-II/LC3-I ratio, the enhanced LC3 immunofluorescence, and a rise in the number of autophagosomes in the neurons of the hippocampal CA1 area. Besides, the inhibitor of autophagy 3-methyladenine obliterated the neuroprotection induced by CIP. Furthermore, the upregulation of p-p38 MAPK and PPARγ expressions was earlier than autophagy activation after CIP. In addition, pretreatment with SB203580 (the inhibitor of p38 MAPK) reversed CIP-induced PPARγ upregulation, autophagy activation, and neuroprotection. Pretreatment with GW9662 (the inhibitor of PPARγ) reversed autophagy activation and neuroprotection, while it had no effect on p-p38 MAPK upregulation induced by CIP. These data suggested that the p38 MAPK-PPARγ signaling pathway participates in autophagy activation during the induction of BIT by CIP.
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Affiliation(s)
- A-Chou Su
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang, People's Republic of China.,Hebei Key Laboratory of Critical Disease Mechanism and Intervention, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Ling-Yan Zhang
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang, People's Republic of China.,Hebei Key Laboratory of Critical Disease Mechanism and Intervention, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Jing-Ge Zhang
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang, People's Republic of China.,Hebei Key Laboratory of Critical Disease Mechanism and Intervention, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Yu-Yan Hu
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang, People's Republic of China.,Hebei Key Laboratory of Critical Disease Mechanism and Intervention, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Xi-Yun Liu
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang, People's Republic of China.,Hebei Key Laboratory of Critical Disease Mechanism and Intervention, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Shi-Chao Li
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang, People's Republic of China.,Hebei Key Laboratory of Critical Disease Mechanism and Intervention, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Xiao-Hui Xian
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang, People's Republic of China.,Hebei Key Laboratory of Critical Disease Mechanism and Intervention, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Wen-Bin Li
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang, People's Republic of China.,Hebei Key Laboratory of Critical Disease Mechanism and Intervention, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Min Zhang
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang, People's Republic of China.,Hebei Key Laboratory of Critical Disease Mechanism and Intervention, Hebei Medical University, Shijiazhuang, People's Republic of China
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12
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Association of Serum Lipid Level with Meibum Biosynthesis and Meibomian Gland Dysfunction: A Review. J Clin Med 2022; 11:jcm11144010. [PMID: 35887773 PMCID: PMC9323051 DOI: 10.3390/jcm11144010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/27/2022] [Accepted: 07/05/2022] [Indexed: 11/16/2022] Open
Abstract
The primary role of meibomian glands (MGs) is to actively synthesize and secret lipids and proteins spread onto the tear film, and the glandular lipids promote tear stability, prevent evaporation, and reduce friction. Meibomian gland dysfunction (MGD) is the leading cause of dry eye disease and one of the most common ophthalmic problems worldwide. MGs are densely innervated and regulated by hormones and growth factors. However, since the polar and nonpolar lipids are produced through processes in MGs that are not completely understood, a relevant question has been raised: Would the altered systemic lipids metabolism affect the physiology and structure of MGs? This review introduces the recent update regarding the relationships between serum lipid and MGD in clinical and basic research while providing answers to this question. A causal relationship remains to be established; however, serum lipid level or dyslipidemia may be related to MGD directly or indirectly, or both. Further studies are warranted to establish the role of serum lipid level and meibocyte differentiation/maturation and lipid synthesis.
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13
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Zou L, Liao M, Zhen Y, Zhu S, Chen X, Zhang J, Hao Y, Liu B. Autophagy and beyond: Unraveling the complexity of UNC-51-like kinase 1 (ULK1) from biological functions to therapeutic implications. Acta Pharm Sin B 2022; 12:3743-3782. [PMID: 36213540 PMCID: PMC9532564 DOI: 10.1016/j.apsb.2022.06.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/27/2022] [Accepted: 06/02/2022] [Indexed: 12/13/2022] Open
Abstract
UNC-51-like kinase 1 (ULK1), as a serine/threonine kinase, is an autophagic initiator in mammals and a homologous protein of autophagy related protein (Atg) 1 in yeast and of UNC-51 in Caenorhabditis elegans. ULK1 is well-known for autophagy activation, which is evolutionarily conserved in protein transport and indispensable to maintain cell homeostasis. As the direct target of energy and nutrition-sensing kinase, ULK1 may contribute to the distribution and utilization of cellular resources in response to metabolism and is closely associated with multiple pathophysiological processes. Moreover, ULK1 has been widely reported to play a crucial role in human diseases, including cancer, neurodegenerative diseases, cardiovascular disease, and infections, and subsequently targeted small-molecule inhibitors or activators are also demonstrated. Interestingly, the non-autophagy function of ULK1 has been emerging, indicating that non-autophagy-relevant ULK1 signaling network is also linked with diseases under some specific contexts. Therefore, in this review, we summarized the structure and functions of ULK1 as an autophagic initiator, with a focus on some new approaches, and further elucidated the key roles of ULK1 in autophagy and non-autophagy. Additionally, we also discussed the relationships between ULK1 and human diseases, as well as illustrated a rapid progress for better understanding of the discovery of more candidate small-molecule drugs targeting ULK1, which will provide a clue on novel ULK1-targeted therapeutics in the future.
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Affiliation(s)
- Ling Zou
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen 518060, China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Minru Liao
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yongqi Zhen
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shiou Zhu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xiya Chen
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen 518060, China
| | - Jin Zhang
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen 518060, China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
- Corresponding authors. Tel./fax: +86 28 85503817.
| | - Yue Hao
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen 518060, China
- Corresponding authors. Tel./fax: +86 28 85503817.
| | - Bo Liu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
- Corresponding authors. Tel./fax: +86 28 85503817.
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14
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Liu R, Li J, Xu Y, Chen Z, Ye H, Tang J, Wei L, Liang L. Melatonin Attenuates LPS-Induced Proinflammatory Cytokine Response and Lipogenesis in Human Meibomian Gland Epithelial Cells via MAPK/NF-κB Pathway. Invest Ophthalmol Vis Sci 2022; 63:6. [PMID: 35506935 PMCID: PMC9078073 DOI: 10.1167/iovs.63.5.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Inflammation contributes to the development of meibomian gland dysfunction (MGD) under specific disease conditions, but the underlying mechanisms remain elusive. We examined whether lipopolysaccharide (LPS) induced a proinflammatory cytokine response and lipogenesis in human meibomian gland epithelial cells (HMGECs) and whether melatonin (MLT), a powerful anti-inflammatory regent in the eyes, could protect against LPS-induced disorders. Methods Human meibomian gland (MG) tissues and immortalized HMGECs were stained to identify Toll-like receptor (TLR) 4 and MLT receptors (MT1 and MT2). HMGECs were pretreated with or without MLT and then stimulated with LPS. Then, TLR4 activation, cytokine levels, lipid synthesis, apoptosis, autophagy, and MAPK/NF-κB factor phosphorylation in HMGECs were analyzed. Results TLR4, MT1, and MT2 were expressed in human MG acini and HMGECs. Pretreatment with MLT inhibited the TLR4/MyD88 signaling and attenuated proinflammatory cytokine response and lipogenesis in LPS-stimulated HMGECs, which manifested as decreased production of cytokines (IL-1β, IL-6, IL-8, and TNF-α), reduced lipid droplet formation, and downregulated expression of meibum lipogenic proteins (ADFP, ELOVL4, and SREBP-1). Phospho-histone H2A.X foci, lysosome accumulation, and cytoplasmic cleaved caspase 3/LC3B-II staining were increased in LPS-stimulated HMGECs, indicating enhanced cell death mediated by apoptosis and autophagy during LPS-induced lipogenesis. MLT downregulated cleaved caspase 3 levels and the Bax/Bcl-2 ratio to alleviate apoptosis and ameliorated the expression of Beclin 1 and LC3B-II to inhibit autophagy. The protective mechanisms of MLT include the inhibition of MAPK and NF-κB phosphorylation. Conclusions MLT attenuated lipogenesis, apoptosis, and autophagy in HMGECs induced by proinflammatory stimuli, indicating the protective potential of MLT in MGD.
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Affiliation(s)
- Ren Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Jing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Yue Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Ziyan Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Huijing Ye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Jinhui Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Lai Wei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Lingyi Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
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15
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Huang L, Luo J, Song N, Gao W, Zhu L, Yao W. CRISPR/Cas9-Mediated Knockout of miR-130b Affects Mono- and Polyunsaturated Fatty Acid Content via PPARG-PGC1α Axis in Goat Mammary Epithelial Cells. Int J Mol Sci 2022; 23:3640. [PMID: 35409000 PMCID: PMC8998713 DOI: 10.3390/ijms23073640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/09/2022] [Accepted: 03/24/2022] [Indexed: 02/01/2023] Open
Abstract
MicroRNA (miRNA)-130b, as a regulator of lipid metabolism in adipose and mammary gland tissues, is actively involved in lipogenesis, but its endogenous role in fatty acid synthesis remains unclear. Here, we aimed to explore the function and underlying mechanism of miR-130b in fatty acid synthesis using the CRISPR/Cas9 system in primary goat mammary epithelial cells (GMEC). A single clone with deletion of 43 nucleotides showed a significant decrease in miR-130b-5p and miR-130b-3p abundances and an increase of target genes PGC1α and PPARG. In addition, knockout of miR-130b promoted triacylglycerol (TAG) and cholesterol accumulation, and decreased the proportion of monounsaturated fatty acids (MUFA) C16:1, C18:1 and polyunsaturated fatty acids (PUFA) C18:2, C20:3, C20:4, C20:5, C22:6. Similarly, the abundance of fatty acid synthesis genes ACACA and FASN and transcription regulators SREBP1c and SREBP2 was elevated. Subsequently, interference with PPARG instead of PGC1α in knockout cells restored the effect of miR-130b knockout, suggesting that PPARG is responsible for miR-130b regulating fatty acid synthesis. Moreover, disrupting PPARG inhibits PGC1α transcription and translation. These results reveal that miR-130b directly targets the PPARG-PGC1α axis, to inhibit fatty acid synthesis in GMEC. In conclusion, miR-130b could be a potential molecular regulator for improving the beneficial fatty acids content in goat milk.
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Affiliation(s)
| | - Jun Luo
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang 712100, China; (L.H.); (N.S.); (W.G.); (L.Z.); (W.Y.)
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16
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Chen X, Wu T, Gong Z, Guo J, Liu X, Zhang Y, Li Y, Ferraro P, Li B. Lipid droplets as endogenous intracellular microlenses. LIGHT, SCIENCE & APPLICATIONS 2021; 10:242. [PMID: 34873142 PMCID: PMC8648767 DOI: 10.1038/s41377-021-00687-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 10/31/2021] [Accepted: 11/23/2021] [Indexed: 05/24/2023]
Abstract
Using a single biological element as a photonic component with well-defined features has become a new intriguing paradigm in biophotonics. Here we show that endogenous lipid droplets in the mature adipose cells can behave as fully biocompatible microlenses to strengthen the ability of microscopic imaging as well as detecting intra- and extracellular signals. By the assistance of biolenses made of the lipid droplets, enhanced fluorescence imaging of cytoskeleton, lysosomes, and adenoviruses has been achieved. At the same time, we demonstrated that the required excitation power can be reduced by up to 73%. The lipidic microlenses are finely manipulated by optical tweezers in order to address targets and perform their real-time imaging inside the cells. An efficient detecting of fluorescence signal of cancer cells in extracellular fluid was accomplished due to the focusing effect of incident light by the lipid droplets. The lipid droplets acting as endogenous intracellular microlenses open the intriguing route for a multifunctional biocompatible optics tool for biosensing, endoscopic imaging, and single-cell diagnosis.
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Affiliation(s)
- Xixi Chen
- Institute of Nanophotonics, Jinan University, 511443, Guangzhou, China
| | - Tianli Wu
- Institute of Nanophotonics, Jinan University, 511443, Guangzhou, China
| | - Zhiyong Gong
- Institute of Nanophotonics, Jinan University, 511443, Guangzhou, China
| | - Jinghui Guo
- Department of Physiology, School of Medicine, Jinan University, 510632, Guangzhou, China
| | - Xiaoshuai Liu
- Institute of Nanophotonics, Jinan University, 511443, Guangzhou, China
| | - Yao Zhang
- Institute of Nanophotonics, Jinan University, 511443, Guangzhou, China.
| | - Yuchao Li
- Institute of Nanophotonics, Jinan University, 511443, Guangzhou, China.
| | - Pietro Ferraro
- CNR-ISASI, Institute of Applied Sciences and Intelligent Systems «E. Caianiello», Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy.
| | - Baojun Li
- Institute of Nanophotonics, Jinan University, 511443, Guangzhou, China.
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17
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Phan MAT, Madigan MC, Stapleton F, Willcox M, Golebiowski B. Human meibomian gland epithelial cell culture models: Current progress, challenges, and future directions. Ocul Surf 2021; 23:96-113. [PMID: 34843998 DOI: 10.1016/j.jtos.2021.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/04/2021] [Accepted: 11/23/2021] [Indexed: 12/13/2022]
Abstract
The widely used immortalised human meibomian gland epithelia cell (iHMGEC) line has made possible extensive studies of the biology and pathophysiology of meibomian glands (MG). Tissue culture protocols for iHMGEC have been revised and modified to optimise the growth conditions for cell differentiation and lipid accumulation. iHMGEC proliferate in serum-free medium but require serum or other appropriate exogenous factors to differentiate. Several supplements can enhance differentiation and neutral lipid accumulation in iHMGEC grown in serum-containing medium. In serum-free medium, rosiglitazone, a peroxisome proliferator activator receptor-γ (PPARγ) agonist, is reported to induce iHMGEC differentiation, neutral lipid accumulation and expression of key biomarkers of differentiation. iHMGEC cultured in serum-containing medium under hypoxia or with azithromycin increases DNAse 2 activity, a biomarker of terminal differentiation in sebocytes. The production of lipids with composition similar to meibum has not been observed in vitro and this remains a major challenge for iHMGEC culture. Innovative methodologies such as 3D ex vivo culture of MG and generation of MG organoids from stem cells are important for further developing a model that more closely mimics the in vivo biology of human MG and to facilitate the next generation of studies of MG disease and dry eye.
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Affiliation(s)
- Minh Anh Thu Phan
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia.
| | - Michele C Madigan
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia
| | - Fiona Stapleton
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia
| | - Blanka Golebiowski
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia
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18
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Expression of Acyl-CoA wax-alcohol acyltransferase 2 (AWAT2) by human and rabbit meibomian glands and meibocytes. Ocul Surf 2021; 23:60-70. [PMID: 34838721 PMCID: PMC10393063 DOI: 10.1016/j.jtos.2021.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 11/18/2021] [Accepted: 11/20/2021] [Indexed: 11/22/2022]
Abstract
PURPOSE Previously, we showed that Acyl-CoA wax-alcohol acyltransferase 2 (AWAT2), an essential enzyme required for meibum wax ester synthesis, was not expressed by immortalized human meibomian gland epithelial cells (hMGEC) in culture. To begin to understand the mechanisms controlling AWAT2 expression, we have analyzed its expression in human and rabbit meibomian glands and cultured meibocytes. METHODS Rabbit meibocyte progenitor cells (rMPC) were first grown in Cnt-BM.1 basal medium (Cellntec) supplemented with rhEGF, FGF10, and ROCK inhibitor (Y-27632 dihydrochloride), and then passed at 70-80% confluency with Accutase. Differentiation of rMPC to meibocytes (rMC) was induced by removal of Y-27632 and addition of 1 mM calcium with and without PPARγ agonists. RNA from the tissue, primary, passaged rMPC and differentiated rMC were obtained for AWAT2 qPCR analysis. Proteins and cells were evaluated for western blotting and neutral lipid synthesis, respectively. For comparison, human meibomian glands were separated for RNA and protein analysis. hMGEC was cultured to collect RNA and protein. RESULTS Rabbit rMPCs were successfully grown, passaged, and differentiated, showing a significant increase in lipid droplet accumulation. AWAT2 RNA was highly expressed in tissue but showed a -16.9 log2 fold decrease in primary and passaged rMPCs and was not induced by differentiation to rMC. By comparison, human meibomian glands showed high expression of AWAT2, and hMGEC expressed non-detectable levels of AWAT2 transcripts or protein. CONCLUSIONS AWAT2 expression is lost in cultured rMPC and rMC suggesting that cells in culture do not undergo complete meibocyte differentiation and require yet to be identified culture conditions.
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19
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Lin Z, Ni L, Teng C, Zhang Z, Wu L, Jin Y, Lu X, Lin Z. Eicosapentaenoic Acid-Induced Autophagy Attenuates Intervertebral Disc Degeneration by Suppressing Endoplasmic Reticulum Stress, Extracellular Matrix Degradation, and Apoptosis. Front Cell Dev Biol 2021; 9:745621. [PMID: 34805156 PMCID: PMC8599281 DOI: 10.3389/fcell.2021.745621] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/19/2021] [Indexed: 12/19/2022] Open
Abstract
Intervertebral disc degeneration (IDD) is a major cause of low back pain (LBP), but there is still a lack of effective therapy. Multiple studies have reported that endoplasmic reticulum (ER) stress and extracellular matrix (ECM) degradation exert an enormous function on the occurrence and development of IDD. Autophagy can effectively repair ER stress and maintain ECM homeostasis. Eicosapentaenoic acid (EPA) can specifically induce autophagy. The purpose of this study is to demonstrate that EPA can promote autophagy, reduce ECM degradation and ER stress in vitro, thereby reducing cell apoptosis, and the protective effects of EPA in an IDD-rat model in vivo. Western blot and immunofluorescence were used to detect the autophagic flux, ER stress, ECM degradation, and apoptosis in nucleus pulposus cells (NPCs) treated by EPA. We also used puncture-induced IDD rats as experimental subjects to observe the therapeutic effect of EPA on IDD. Our findings indicated that EPA can effectively improve the autophagy activity in NPCs, inhibit the endoplasmic reticulum stress process, reduce the degree of cell apoptosis, and exert protective effects on the anabolism and catabolism of ECM. In addition, in vivo investigations demonstrated that EPA ameliorated the progression of puncture-induced IDD in rats. In conclusion, this study revealed the intrinsic mechanisms of EPA's protective role in NPCs and its potential therapeutic significance for the treatment of IDD.
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Affiliation(s)
- Zhen Lin
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Libin Ni
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Cheng Teng
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Zhao Zhang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Long Wu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Yu Jin
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China.,Department of Orthopedics, Shaoxing People's Hospital (Shaoxing Hospital, Zhejiang University School of Medicine), Shaoxing, China
| | - Xinlei Lu
- The School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Zhongke Lin
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
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20
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Development of mode of action networks related to the potential role of PPARγ in respiratory diseases. Pharmacol Res 2021; 172:105821. [PMID: 34403731 DOI: 10.1016/j.phrs.2021.105821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 11/30/2022]
Abstract
The peroxisome proliferator-activated receptor γ (PPARγ) is a key transcription factor, operating at the intercept of metabolic control and immunomodulation. It is ubiquitously expressed in multiple tissues and organs, including lungs. There is a growing body of information supporting the role of PPARγ signalling in respiratory diseases. The aim of the present study was to develop mode of action (MoA) networks reflecting the relationships between PPARγ signalling and the progression/alleviation of a spectrum of lung pathologies. Data mining was performed using the resources of the NIH PubMed and PubChem information systems. By linking available data on pathological/therapeutic effects of PPARγ modulation, knowledge-based MoA networking at different levels of biological organization (molecular, cellular, tissue, organ, and system) was performed. Multiple MoA networks were developed to relate PPARγ modulation to the progress or the alleviation of pulmonary disorders, triggered by diverse pathogenic, genetic, chemical, or mechanical factors. Pharmacological targeting of PPARγ signalling was discussed with regard to ligand- and cell type-specific effects in the context of distinct disease inductor- and disease stage-dependent patterns. The proposed MoA networking analysis allows for a better understanding of the potential role of PPARγ modulation in lung pathologies. It presents a mechanistically justified basis for further computational, experimental, and clinical monitoring studies on the dynamic control of PPARγ signalling in respiratory diseases.
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21
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Abstract
Purpose: The meibomian glands are located in the tarsal plate of the upper and lower eyelid and are responsible for the production of a lipid-rich secretion, the meibum, which forms the outer component of the tear film. Meibomian gland dysfunction results in excessive evaporation of the tear film and is the leading cause of dry eye disease (DED). Despite the high prevalence of DED, the etiology of meibomian gland dysfunction is only basically understood. In addition, the molecular mechanisms of meibomian gland maturation and physiological function are currently the focus of research.Methods: A systematic literature search was performed using the main scientific databases, including all relevant published articles up to September 2020.Results: This article provides an overview of the current state of knowledge about meibomian gland stem cells, cell surface marker expression and PPARγ signaling, as well as the pathological causes of meibomian gland dysfunction.Conclusion: Androgen deficiency, hyperkeratinization, PPARγ signaling and inflammatory reactions including neutrophil extracellular traps (NETs) seem to be key factors within the pathological processes of the meibomian gland.
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Affiliation(s)
- Jana Dietrich
- Institute of Anatomy, Department of Functional and Clinical Anatomy, Friedrich Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Fabian Garreis
- Institute of Anatomy, Department of Functional and Clinical Anatomy, Friedrich Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Friedrich Paulsen
- Institute of Anatomy, Department of Functional and Clinical Anatomy, Friedrich Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Department of Topographic Anatomy and Operative Surgery, Sechenov University, Moscow, Russia
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22
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Tang M, Liu T, Jiang P, Dang R. The interaction between autophagy and neuroinflammation in major depressive disorder: From pathophysiology to therapeutic implications. Pharmacol Res 2021; 168:105586. [PMID: 33812005 DOI: 10.1016/j.phrs.2021.105586] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/19/2021] [Accepted: 03/25/2021] [Indexed: 12/14/2022]
Abstract
The past decade has revealed neuroinflammation as an important mechanism of major depressive disorder (MDD). Nod-like receptors family pyrin domain containing 3 (NLRP3) inflammasome is the key regulator interleukin-1β (IL-1β) maturation, whose activation has been reported in MDD patients and various animal models. Function as a dominant driver of neuroinflammation, NLRP3 bridges the gap between immune activation with stress exposure, and further leads to subsequent occurrence of neuropsychiatric disorders such as MDD. Of note, autophagy is a tightly regulated cellular degradation pathway that removes damaged organelles and intracellular pathogens, and maintains cellular homeostasis from varying insults. Serving as a critical cellular monitoring system, normal functioned autophagy signaling prevents excessive NLRP3 inflammasome activation and subsequent release of IL-1 family cytokines. This review will describe the current understanding of how autophagy regulates NLRP3 inflammasome activity and discuss the implications of this regulation on the pathogenesis of MDD. The extensive crosstalk between autophagy pathway and NLRP3 inflammasome is further discussed, as it is critical for developing new therapeutic strategies for MDD aimed at modulating the neuroinflammatory responses.
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Affiliation(s)
- Mimi Tang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Ting Liu
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Pei Jiang
- Institute of Clinical Pharmacy, Jining First People's Hospital, Jining Medical University, Jining 272000, China.
| | - Ruili Dang
- Institute of Clinical Pharmacy, Jining First People's Hospital, Jining Medical University, Jining 272000, China.
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23
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Meibomian Gland Dysfunction: What Have Animal Models Taught Us? Int J Mol Sci 2020; 21:ijms21228822. [PMID: 33233466 PMCID: PMC7700490 DOI: 10.3390/ijms21228822] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/17/2020] [Accepted: 11/19/2020] [Indexed: 12/16/2022] Open
Abstract
Studies have estimated that currently 344 million people worldwide and 16.4 million adults in the US have some form of dry eye disease (DED). It is believed that approximately 70% of DED cases are due to some form of evaporative dry eye, for which Meibomian gland dysfunction (MGD) is the major cause. Unfortunately, currently there is no effective treatment for MGD, and solely palliative care is available. Given the importance of MGD in DED, there has been a growing interest in studying Meibomian gland development, homeostasis and pathology, and, also, in developing therapies for treating and/or preventing MGD. For such, animal models have shown to be a vital tool. Much of what is known today about the Meibomian gland and MGD was learnt from these important animal models. In particular, canine and rabbit models have been essential for studying the physiopathology and progression of DED, and the mouse model, which includes different knockout strains, has enabled the identification of specific pathways potentially involved in MGD. Herein, we provide a bibliographic review on the various animal models that have been used to study Meibomian gland development, Meibomian gland homeostasis and MGD, primarily focusing on publications between 2000 and 2020.
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