Improvement of immune dysregulation in individuals with long COVID at 24-months following SARS-CoV-2 infection.

This study investigates the humoral and cellular immune responses and health-related quality of life measures in individuals with mild to moderate long COVID (LC) compared to age and gender matched recovered COVID-19 controls (MC) over 24 months. LC participants show elevated nucleocapsid IgG levels at 3 months, and higher neutralizing capacity up to 8 months post-infection. Increased spike-specific and nucleocapsid-specific CD4+ T cells, PD-1, and TIM-3 expression on CD4+ and CD8+ T cells were observed at 3 and 8 months, but these differences do not persist at 24 months. Some LC participants had detectable IFN-γ and IFN-ß, that was attributed to reinfection and antigen re-exposure. Single-cell RNA sequencing at the 24 month timepoint shows similar immune cell proportions and reconstitution of naïve T and B cell subsets in LC and MC. No significant differences in exhaustion scores or antigen-specific T cell clones are observed. These findings suggest resolution of immune activation in LC and return to comparable immune responses between LC and MC over time. Improvement in self-reported health-related quality of life at 24 months was also evident in the majority of LC (62%). PTX3, CRP levels and platelet count are associated with improvements in health-related quality of life.

ApoA-I Protects Pancreatic ß-Cells From Cholesterol-Induced Mitochondrial Damage and Restores Their Ability to Secrete Insulin.

BACKGROUND: High cholesterol levels in pancreatic ß-cells cause oxidative stress and decrease insulin secretion. ß-cells can internalize apo (apolipoprotein) A-I, which increases insulin secretion. This study asks whether internalization of apoA-I improves ß-cell insulin secretion by reducing oxidative stress. METHODS: Ins-1E cells were cholesterol-loaded by incubation with cholesterol-methyl-ß-cyclodextrin. Insulin secretion in the presence of 2.8 or 25 mmol/L glucose was quantified by radioimmunoassay. Internalization of fluorescently labeled apoA-I by ß-cells was monitored by flow cytometry. The effects of apoA-I internalization on ß-cell gene expression were evaluated by RNA sequencing. ApoA-I-binding partners on the ß-cell surface were identified by mass spectrometry. Mitochondrial oxidative stress was quantified in ß-cells and isolated islets with MitoSOX and confocal microscopy. RESULTS: An F1-ATPase ß-subunit on the ß-cell surface was identified as the main apoA-I-binding partner. ß-cell internalization of apoA-I was time-, concentration-, temperature-, cholesterol-, and F1-ATPase ß-subunit-dependent. ß-cells with internalized apoA-I (apoA-I+ cells) had higher cholesterol and cell surface F1-ATPase ß-subunit levels than ß-cells without internalized apoA-I (apoA-I- cells). The internalized apoA-I colocalized with mitochondria and was associated with reduced oxidative stress and increased insulin secretion. The IF1 (ATPase inhibitory factor 1) attenuated apoA-I internalization and increased oxidative stress in Ins-1E ß-cells and isolated mouse islets. Differentially expressed genes in apoA-I+ and apoA-I- Ins-1E cells were related to protein synthesis, the unfolded protein response, insulin secretion, and mitochondrial function. CONCLUSIONS: These results establish that ß-cells are functionally heterogeneous, and apoA-I restores insulin secretion in ß-cells with elevated cholesterol levels by improving mitochondrial redox balance.

Zerumbone liquid crystalline nanoparticles protect against oxidative stress, inflammation and senescence induced by cigarette smoke extract in vitro.

The purpose of this study was to evaluate the potential of zerumbone-loaded liquid crystalline nanoparticles (ZER-LCNs) in the protection of broncho-epithelial cells and alveolar macrophages against oxidative stress, inflammation and senescence induced by cigarette smoke extract in vitro. The effect of the treatment of ZER-LCNs on in vitro cell models of cigarette smoke extract (CSE)-treated mouse RAW264.7 and human BCi-NS1.1 basal epithelial cell lines was evaluated for their anti-inflammatory, antioxidant and anti-senescence activities using colorimetric and fluorescence-based assays, fluorescence imaging, RT-qPCR and proteome profiler kit. The ZER-LCNs successfully reduced the expression of pro-inflammatory markers including Il-6, Il-1ß and Tnf-α, as well as the production of nitric oxide in RAW 264.7 cells. Additionally, ZER-LCNs successfully inhibited oxidative stress through reduction of reactive oxygen species (ROS) levels and regulation of genes, namely GPX2 and GCLC in BCi-NS1.1 cells. Anti-senescence activity of ZER-LCNs was also observed in BCi-NS1.1 cells, with significant reductions in the expression of SIRT1, CDKN1A and CDKN2A. This study demonstrates strong in vitro anti-inflammatory, antioxidative and anti-senescence activities of ZER-LCNs paving the path for this formulation to be translated into a promising therapeutic agent for chronic respiratory inflammatory conditions including COPD and asthma.

Zerumbone-incorporated liquid crystalline nanoparticles inhibit proliferation and migration of non-small-cell lung cancer in vitro.

Lung cancer is the second most prevalent type of cancer and is responsible for the highest number of cancer-related deaths worldwide. Non-small-cell lung cancer (NSCLC) makes up the majority of lung cancer cases. Zerumbone (ZER) is natural compound commonly found in the roots of Zingiber zerumbet which has recently demonstrated anti-cancer activity in both in vitro and in vivo studies. Despite their medical benefits, ZER has low aqueous solubility, poor GI absorption and oral bioavailability that hinders its effectiveness. Liquid crystalline nanoparticles (LCNs) are novel drug delivery carrier that have tuneable characteristics to enhance and ease the delivery of bioactive compounds. This study aimed to formulate ZER-loaded LCNs and investigate their effectiveness against NSCLC in vitro using A549 lung cancer cells. ZER-LCNs, prepared in the study, inhibited the proliferation and migration of A549 cells. These inhibitory effects were superior to the effects of ZER alone at a concentration 10 times lower than that of free ZER, demonstrating a potent anti-cancer activity of ZER-LCNs. The underlying mechanisms of the anti-cancer effects by ZER-LCNs were associated with the transcriptional regulation of tumor suppressor genes P53 and PTEN, and metastasis-associated gene KRT18. The protein array data showed downregulation of several proliferation associated proteins such as AXL, HER1, PGRN, and BIRC5 and metastasis-associated proteins such as DKK1, CAPG, CTSS, CTSB, CTSD, and PLAU. This study provides evidence of potential for increasing the potency and effectiveness of ZER with LCN formulation and developing ZER-LCNs as a treatment strategy for mitigation and treatment of NSCLC.

Effect of insulin insufficiency on ultrastructure and function in skeletal muscle.

BACKGROUND: Decreased insulin availability and high blood glucose levels, the hallmark features of poorly controlled diabetes, drive disease progression and are associated with decreased skeletal muscle mass. We have shown that mice with ß-cell dysfunction and normal insulin sensitivity have decreased skeletal muscle mass. This project asks how insulin deficiency impacts on the structure and function of the remaining skeletal muscle in these animals. METHODS: Skeletal muscle function was determined by measuring exercise capacity and specific muscle strength prior to and after insulin supplementation for 28 days in 12-week-old mice with conditional ß-cell deletion of the ATP binding cassette transporters ABCA1 and ABCG1 (ß-DKO mice). Abca1 and Abcg1 floxed (fl/fl) mice were used as controls. RNAseq was used to quantify changes in transcripts in soleus and extensor digitorum longus muscles. Skeletal muscle and mitochondrial morphology were assessed by transmission electron microscopy. Myofibrillar Ca2+ sensitivity and maximum isometric single muscle fibre force were assessed using MyoRobot biomechatronics technology. RESULTS: RNA transcripts were significantly altered in ß-DKO mice compared with fl/fl controls (32 in extensor digitorum longus and 412 in soleus). Exercise capacity and muscle strength were significantly decreased in ß-DKO mice compared with fl/fl controls (P = 0.012), and a loss of structural integrity was also observed in skeletal muscle from the ß-DKO mice. Supplementation of ß-DKO mice with insulin restored muscle integrity, strength and expression of 13 and 16 of the dysregulated transcripts in and extensor digitorum longus and soleus muscles, respectively. CONCLUSIONS: Insulin insufficiency due to ß-cell dysfunction perturbs the structure and function of skeletal muscle. These adverse effects are rectified by insulin supplementation.

Applications and advancements of nanoparticle-based drug delivery in alleviating lung cancer and chronic obstructive pulmonary disease.

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are among the leading causes of mortality worldwide. Cigarette smoking is among the main aetiologic factors for both ailments. These diseases share common pathogenetic mechanisms including inflammation, oxidative stress, and tissue remodelling. Current therapeutic approaches are limited by low efficacy and adverse effects. Consequentially, LC has a 5-year survival of < 20%, while COPD is incurable, underlining the necessity for innovative treatment strategies. Two promising emerging classes of therapy against these diseases include plant-derived molecules (phytoceuticals) and nucleic acid-based therapies. The clinical application of both is limited by issues including poor solubility, poor permeability, and, in the case of nucleic acids, susceptibility to enzymatic degradation, large size, and electrostatic charge density. Nanoparticle-based advanced drug delivery systems are currently being explored as flexible systems allowing to overcome these limitations. In this review, an updated summary of the most recent studies using nanoparticle-based advanced drug delivery systems to improve the delivery of nucleic acids and phytoceuticals for the treatment of LC and COPD is provided. This review highlights the enormous relevance of these delivery systems as tools that are set to facilitate the clinical application of novel categories of therapeutics with poor pharmacokinetic properties. This picture was generated with BioRender.

Agarwood oil nanoemulsion counteracts LPS-induced inflammation and oxidative stress in RAW264.7 mouse macrophages.

PURPOSE: Oxidative stress and inflammation are key pathophysiological features of chronic respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD). Agarwood oil obtained from Aquilaria trees has promising antioxidant and anti-inflammatory activities. However, its clinical application is hampered by poor solubility. A viable approach to overcome this involves formulation of oily constituents into emulsions. Here, we have investigated the antioxidant and anti-inflammatory potential of an agarwood oil-based nanoemulsion (DE'RAAQSIN) against lipopolysaccharide (LPS)-induced RAW264.7 mouse macrophages in vitro. METHODS: The antioxidant and anti-inflammatory activity of DE'RAAQSIN was assessed by measuring the levels of ROS and nitric oxide (NO) produced, using the DCF-DA assay and the Griess reagent assay, respectively. The molecular pathways activated by DE'RAAQSIN were investigated via qPCR. RESULTS: LPS stimulation of RAW264.7 cells increased the production of nitric oxide (NO) and ROS and resulted in the overexpression of the inducible nitric oxide synthase (iNOS) gene. Furthermore, LPS induced the upregulation of the expression of key proinflammatory genes (IL-6, TNF-α, IL-1ß, and CXCL1) and of the antioxidant gene heme oxygenase-1 (HO-1). DE'RAAQSIN demonstrated potent antioxidant and anti-inflammatory activity by significantly reducing the levels of ROS and of secreted NO, simultaneously counteracting the LPS-induced overexpression of iNOS, IL-6, TNF-α, IL-1ß, and HO-1. These findings were corroborated by in silico activity prediction and physicochemical analysis of the main agarwood oil components. CONCLUSIONS: We propose DE'RAAQSIN as a promising alternative managing inflammatory disorders, opening the platform for further studies aimed at understanding the effectiveness of DE'RAAQSIN.

Agarwood Oil Nanoemulsion Attenuates Cigarette Smoke-Induced Inflammation and Oxidative Stress Markers in BCi-NS1.1 Airway Epithelial Cells.

Chronic obstructive pulmonary disease (COPD) is an irreversible inflammatory respiratory disease characterized by frequent exacerbations and symptoms such as cough and wheezing that lead to irreversible airway damage and hyperresponsiveness. The primary risk factor for COPD is chronic cigarette smoke exposure, which promotes oxidative stress and a general pro-inflammatory condition by stimulating pro-oxidant and pro-inflammatory pathways and, simultaneously, inactivating anti-inflammatory and antioxidant detoxification pathways. These events cause progressive damage resulting in impaired cell function and disease progression. Treatments available for COPD are generally aimed at reducing the symptoms of exacerbation. Failure to regulate oxidative stress and inflammation results in lung damage. In the quest for innovative treatment strategies, phytochemicals, and complex plant extracts such as agarwood essential oil are promising sources of molecules with antioxidant and anti-inflammatory activity. However, their clinical use is limited by issues such as low solubility and poor pharmacokinetic properties. These can be overcome by encapsulating the therapeutic molecules using advanced drug delivery systems such as polymeric nanosystems and nanoemulsions. In this study, agarwood oil nanoemulsion (agarwood-NE) was formulated and tested for its antioxidant and anti-inflammatory potential in cigarette smoke extract (CSE)-treated BCi-NS1.1 airway basal epithelial cells. The findings suggest successful counteractivity of agarwood-NE against CSE-mediated pro-inflammatory effects by reducing the expression of the pro-inflammatory cytokines IL-1α, IL-1ß, IL-8, and GDF-15. In addition, agarwood-NE induced the expression of the anti-inflammatory mediators IL-10, IL-18BP, TFF3, GH, VDBP, relaxin-2, IFN-γ, and PDGF. Furthermore, agarwood-NE also induced the expression of antioxidant genes such as GCLC and GSTP1, simultaneously activating the PI3K pro-survival signalling pathway. This study provides proof of the dual anti-inflammatory and antioxidant activity of agarwood-NE, highlighting its enormous potential for COPD treatment.

Phytantriol-Based Berberine-Loaded Liquid Crystalline Nanoparticles Attenuate Inflammation and Oxidative Stress in Lipopolysaccharide-Induced RAW264.7 Macrophages.

Inflammation and oxidative stress are interrelated processes that represent the underlying causes of several chronic inflammatory diseases that include asthma, cystic fibrosis, chronic obstructive pulmonary disease (COPD), allergies, diabetes, and cardiovascular diseases. Macrophages are key initiators of inflammatory processes in the body. When triggered by a stimulus such as bacterial lipopolysaccharides (LPS), these cells secrete inflammatory cytokines namely TNF-α that orchestrate the cellular inflammatory process. Simultaneously, pro-inflammatory stimuli induce the upregulation of inducible nitric oxide synthase (iNOS) which catalyzes the generation of high levels of nitric oxide (NO). This, together with high concentrations of reactive oxygen species (ROS) produced by macrophages, mediate oxidative stress which, in turn, exacerbates inflammation in a feedback loop, resulting in the pathogenesis of several chronic inflammatory diseases. Berberine is a phytochemical embedded with potent in vitro anti-inflammatory and antioxidant properties, whose therapeutic application is hindered by poor solubility and bioavailability. For this reason, large doses of berberine need to be administered to achieve the desired pharmacological effect, which may result in toxicity. Encapsulation of such a drug in liquid crystalline nanoparticles (LCNs) represents a viable strategy to overcome these limitations. We encapsulated berberine in phytantriol-based LCNs (BP-LCNs) and tested the antioxidant and anti-inflammatory activities of BP-LCNs in vitro on LPS-induced mouse RAW264.7 macrophages. BP-LCNs showed potent anti-inflammatory and antioxidant activities, with significant reduction in the gene expressions of TNF-α and iNOS, followed by concomitant reduction of ROS and NO production at a concentration of 2.5 µM, which is lower than the concentration of free berberine concentration required to achieve similar effects as reported elsewhere. Furthermore, we provide evidence for the suitability for BP-LCNs both as an antioxidant and as an anti-inflammatory agent with potential application in the therapy of chronic inflammatory diseases.

Short Chain Fatty Acids: Fundamental mediators of the gut-lung axis and their involvement in pulmonary diseases.

The human microbiota is fundamental to correct immune system development and balance. Dysbiosis, or microbial content alteration in the gut and respiratory tract, is associated with immune system dysfunction and lung disease development. The microbiota's influence on human health and disease is exerted through the abundance of metabolites produced by resident microorganisms, where short-chain fatty acids (SCFAs) represent the fundamental class. SCFAs are mainly produced by the gut microbiota through anaerobic fermentation of dietary fibers, and are known to influence the homeostasis, susceptibility to and outcome of many lung diseases. This article explores the microbial species found in healthy human gastrointestinal and respiratory tracts. We investigate factors contributing to dysbiosis in lung illness, and the gut-lung axis and its association with lung diseases, with a particular focus on the functions and mechanistic roles of SCFAs in these processes. The key focus of this review is a discussion of the main metabolites of the intestinal microbiota that contribute to host-pathogen interactions: SCFAs, which are formed by anaerobic fermentation. These metabolites include propionate, acetate, and butyrate, and are crucial for the preservation of immune homeostasis. Evidence suggests that SCFAs prevent infections by directly affecting host immune signaling. This review covers the various and intricate ways through which SCFAs affect the immune system's response to infections, with a focus on pulmonary diseases including chronic obstructive pulmonary diseases, asthma, lung cystic fibrosis, and tuberculosis. The findings reviewed suggest that the immunological state of the lung may be indirectly influenced by elements produced by the gut microbiota. SCFAs represent valuable potential therapeutic candidates in this context.

Unravelling the Therapeutic Potential of Nano-Delivered Functional Foods in Chronic Respiratory Diseases.

Chronic inflammation of the respiratory tract is one of the most concerning public health issues, as it can lead to chronic respiratory diseases (CRDs), some of which are more detrimental than others. Chronic respiratory diseases include chronic obstructive pulmonary disease (COPD), asthma, lung cancer, and pulmonary fibrosis. The conventional drug therapies for the management and treatment of CRDs only address the symptoms and fail to reverse or recover the chronic-inflammation-mediated structural and functional damage of the respiratory tract. In addition, the low efficacy and adverse effects of these drugs have directed the attention of researchers towards nutraceuticals in search of potential treatment strategies that can not only ameliorate CRD symptoms but also can repair and reverse inflammatory damage. Hence, there is a growing interest toward investigating the medicinal benefits of nutraceuticals, such as rutin, curcumin, zerumbone, and others. Nutraceuticals carry many nutritional and therapeutic properties, including anti-inflammatory, antioxidant, anticancer, antidiabetic, and anti-obesity properties, and usually do not have as many adverse effects, as they are naturally sourced. Recently, the use of nanoparticles has also been increasingly studied for the nano drug delivery of these nutraceuticals. The discrete size of nanoparticles holds great potential for the level of permeability that can be achieved when transporting these nutraceutical compounds. This review is aimed to provide an understanding of the use of nutraceuticals in combination with nanoparticles against CRDs and their mechanisms involved in slowing down or reversing the progression of CRDs by inhibiting pro-inflammatory signaling pathways.

Evaluation of the Cytotoxic Activity and Anti-Migratory Effect of Berberine-Phytantriol Liquid Crystalline Nanoparticle Formulation on Non-Small-Cell Lung Cancer In Vitro.

Non-small-cell lung cancer (NSCLC) is the most common form of lung cancer, which is a leading cause of cancer-related deaths worldwide. Berberine is an isoquinoline alkaloid that is commercially available for use as a supplement for the treatment of diabetes and cardiovascular diseases. However, the therapeutic benefits of berberine are limited by its extremely low bioavailability and toxicity at higher doses. Increasing evidence suggests that the incorporation of drug compounds in liquid crystal nanoparticles provides a new platform for the safe, effective, stable, and controlled delivery of the drug molecules. This study aimed to formulate an optimized formulation of berberine-phytantriol-loaded liquid crystalline nanoparticles (BP-LCNs) and to investigate the in vitro anti-cancer activity in a human lung adenocarcinoma A549 cell line. The BP-LCN formulation possessing optimal characteristics that was used in this study had a favorable particle size and entrapment efficiency rate (75.31%) and a superior drug release profile. The potential mechanism of action of the formulation was determined by measuring the mRNA levels of the tumor-associated genes PTEN, P53, and KRT18 and the protein expression levels with a human oncology protein array. BP-LCNs decreased the proliferation, migration, and colony-forming activity of A549 cells in a dose-dependent manner by upregulating the mRNA expression of PTEN and P53 and downregulating the mRNA expression of KRT18. Similarly, BP-LCNs also decreased the expression of proteins related to cancer cell proliferation and migration. This study highlights the utility of phytantriol-based LCNs in incorporating drug molecules with low GI absorption and bioavailability to increase their pharmacological effectiveness and potency in NSCLC.

Attenuation of Cigarette-Smoke-Induced Oxidative Stress, Senescence, and Inflammation by Berberine-Loaded Liquid Crystalline Nanoparticles: In Vitro Study in 16HBE and RAW264.7 Cells.

Cigarette smoke is considered a primary risk factor for chronic obstructive pulmonary disease. Numerous toxicants present in cigarette smoke are known to induce oxidative stress and airway inflammation that further exacerbate disease progression. Generally, the broncho-epithelial cells and alveolar macrophages exposed to cigarette smoke release massive amounts of oxidative stress and inflammation mediators. Chronic exposure of cigarette smoke leads to premature senescence of airway epithelial cells. This impairs cellular function and ultimately leads to the progression of chronic lung diseases. Therefore, an ideal therapeutic candidate should prevent disease progression by controlling oxidative stress, inflammation, and senescence during the initial stage of damage. In our study, we explored if berberine (an alkaloid)-loaded liquid crystalline nanoparticles (berberine-LCNs)-based treatment to human broncho-epithelial cells and macrophage inhibits oxidative stress, inflammation, and senescence induced by cigarette-smoke extract. The developed berberine-LCNs were found to have favourable physiochemical parameters, such as high entrapment efficiency and sustained in vitro release. The cellular-assay observations revealed that berberine-LCNs showed potent antioxidant activity by suppressing the generation of reactive oxygen species in both broncho-epithelial cells (16HBE) and macrophages (RAW264.7), and modulating the genes involved in inflammation and oxidative stress. Similarly, in 16HBE cells, berberine-LCNs inhibited the cigarette smoke-induced senescence as revealed by X-gal staining, gene expression of CDKN1A (p21), and immunofluorescent staining of p21. Further in-depth mechanistic investigations into antioxidative, anti-inflammatory, and antisenescence research will diversify the current findings of berberine as a promising therapeutic approach for inflammatory lung diseases caused by cigarette smoking.

HDL and Diabetes.

Diabetes is a worldwide public health issue, with the number of cases expected to reach 642 million by 2040. Patients with diabetes are at a two- to four-fold increased risk of developing cardiovascular disease. This chapter focuses on the anti-diabetic and cardioprotective functions of plasma high-density lipoproteins (HDLs). HDLs and the main HDL apolipoprotein, apoA-I, improves pancreatic beta cell function. ApoA-I also improves insulin sensitivity. The development of novel, bifunctional HDL-based interventions are a promising therapeutic option for the treatment of cardiometabolic diseases.

The Australian dingo is an early offshoot of modern breed dogs.

Dogs are uniquely associated with human dispersal and bring transformational insight into the domestication process. Dingoes represent an intriguing case within canine evolution being geographically isolated for thousands of years. Here, we present a high-quality de novo assembly of a pure dingo (CanFam_DDS). We identified large chromosomal differences relative to the current dog reference (CanFam3.1) and confirmed no expanded pancreatic amylase gene as found in breed dogs. Phylogenetic analyses using variant pairwise matrices show that the dingo is distinct from five breed dogs with 100% bootstrap support when using Greenland wolf as the outgroup. Functionally, we observe differences in methylation patterns between the dingo and German shepherd dog genomes and differences in serum biochemistry and microbiome makeup. Our results suggest that distinct demographic and environmental conditions have shaped the dingo genome. In contrast, artificial human selection has likely shaped the genomes of domestic breed dogs after divergence from the dingo.

HDL maturation and remodelling.

Cholesterol in the circulation is mostly transported in an esterified form as a component of lipoproteins. The majority of these cholesteryl esters are produced in nascent, discoidal high density lipoproteins (HDLs) by the enzyme, lecithin:cholesterol acyltransferase (LCAT). Discoidal HDLs are discrete populations of particles that consist of a phospholipid bilayer, the hydrophobic acyl chains of which are shielded from the aqueous environment by apolipoproteins that also confer water solubility on the particles. The progressive LCAT-mediated accumulation of cholesteryl esters in discoidal HDLs generates the spherical HDLs that predominate in normal human plasma. Spherical HDLs contain a core of water insoluble, neutral lipids (cholesteryl esters and triglycerides) that is surrounded by a surface monolayer of phospholipids with which apolipoproteins associate. Although spherical HDLs all have the same basic structure, they are extremely diverse in size, composition, and function. This review is concerned with how the biogenesis of discoidal and spherical HDLs is regulated and the mechanistic basis of their size and compositional heterogeneity. Current understanding of the impact of this heterogeneity on the therapeutic potential of HDLs of varying size and composition is also addressed in the context of several disease states.

High Density Lipoproteins and Diabetes.

Epidemiological studies have established that a high plasma high density lipoprotein cholesterol (HDL-C) level is associated with reduced cardiovascular risk. However, recent randomised clinical trials of interventions that increase HDL-C levels have failed to establish a causal basis for this relationship. This has led to a shift in HDL research efforts towards developing strategies that improve the cardioprotective functions of HDLs, rather than simply increasing HDL-C levels. These efforts are also leading to the discovery of novel HDL functions that are unrelated to cardiovascular disease. One of the most recently identified functions of HDLs is their potent antidiabetic properties. The antidiabetic functions of HDLs, and recent key advances in this area are the subject of this review. Given that all forms of diabetes are increasing at an alarming rate globally, there is a clear unmet need to identify and develop new approaches that will complement existing therapies and reduce disease progression as well as reverse established disease. Exploration of a potential role for HDLs and their constituent lipids and apolipoproteins in this area is clearly warranted. This review highlights focus areas that have yet to be investigated and potential strategies for exploiting the antidiabetic functions of HDLs.