Interleukin-1 beta targeted therapy for type 2 diabetes

Metabolic regulation of the immune system in health and diseases: mechanisms and interventions

Metabolism, including glycolysis, oxidative phosphorylation, fatty acid oxidation, and other metabolic pathways, impacts the phenotypes and functions of immune cells. The metabolic regulation of the immune system is important in the pathogenesis and progression of numerous diseases, such as cancers, autoimmune diseases and metabolic diseases. The concept of immunometabolism was introduced over a decade ago to elucidate the intricate interplay between metabolism and immunity. The definition of immunometabolism has expanded from chronic low-grade inflammation in metabolic diseases to metabolic reprogramming of immune cells in various diseases. With immunometabolism being proposed and developed, the metabolic regulation of the immune system can be gradually summarized and becomes more and more clearer. In the context of many diseases including cancer, autoimmune diseases, metabolic diseases, and many other disease, metabolic reprogramming occurs in immune cells inducing proinflammatory or anti-inflammatory effects. The phenotypic and functional changes of immune cells caused by metabolic regulation further affect and development of diseases. Based on experimental results, targeting cellular metabolism of immune cells becomes a promising therapy. In this review, we focus on immune cells to introduce their metabolic pathways and metabolic reprogramming, and summarize how these metabolic pathways affect immune effects in the context of diseases. We thoroughly explore targets and treatments based on immunometabolism in existing studies. The challenges of translating experimental results into clinical applications in the field of immunometabolism are also summarized. We believe that a better understanding of immune regulation in health and diseases will improve the management of most diseases.

The downregulation of SCGN induced by lipotoxicity promotes NLRP3-mediated β-cell pyroptosis

Lipotoxicity is a well-established phenomenon that could exacerbate damage to islet β-cells and play a significant role in the development of type 2 diabetes, the underlying mechanisms of which, however, remain unclear. In lipotoxic conditions, secretagogin (SCGN), an EF-hand calcium-binding protein abundantly expressed in islets, is found to undergo downregulation. In light of this, we aim to explore the role of SCGN in lipotoxicity-induced β-cell injury. Our findings show that exposure to ox-LDL in vitro or long-term high-fat diets (HFD) in vivo decreases SCGN expression and induces pyroptosis in β-cells. Moreover, restoring SCGN partially reverses the pyroptotic cell death under ox-LDL or HFD treatments. We have observed that the downregulation of SCGN facilitates the translocation of ChREBP from the cytosol to the nucleus, thereby promoting TXNIP transcription. The upregulation of TXNIP activates the NLRP3/Caspase-1 pathway, leading to pyroptotic cell death. In summary, our study demonstrates that lipotoxicity leads to the downregulation of SCGN expression in islet β-cells, resulting in ChREBP accumulation in the nucleus and subsequent activation of the NLRP3/Caspase-1 pyroptotic pathway. Thus, administering SCGN could be a potential therapeutic strategy to alleviate β-cell damage induced by lipotoxicity in type 2 diabetes.

Review of the direct and indirect effects of hyperglycemia on the HPA axis in T2DM and the co-occurrence of depression

Type 2 diabetes mellitus (T2DM) is characterized by persistent hyperglycemia which is further associated with hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. Several studies have shown that HPA axis hyperactivity is heightened in the chronic hyperglycemic state with severe hyperglycemic events more likely to result in a depressive disorder. The HPA axis is also regulated by the immune system. Upon stress, under homeostatic conditions, the immune system is activated via the sympatho-adrenal-medullary axis resulting in an immune response which secretes proinflammatory cytokines. These cytokines aid in the activation of the HPA axis during stress. However, in T2DM, where there is persistent hyperglycemia, the immune system is dysregulated resulting in the elevated concentrations of these cytokines. The HPA axis, already activated by the hyperglycemia, is further activated by the cytokines which all contribute to a diagnosis of depression in patients with T2DM. However, the onset of T2DM is often preceded by pre-diabetes, a reversible state of moderate hyperglycemia and insulin resistance. Complications often seen in T2DM have been reported to begin in the pre-diabetic state. While the current management strategies have been shown to ameliorate the moderate hyperglycemic state and decrease the risk of developing T2DM, research is necessary for clinical studies to profile these direct effects of moderate hyperglycemia in pre-diabetes on the HPA axis and the indirect effects moderate hyperglycemia may have on the HPA axis by investigating the components of the immune system that play a role in regulating this pathway.

Characteristics of elderly diabetes patients: focus on clinical manifestation, pathogenic mechanism, and the role of traditional Chinese medicine

Diabetes mellitus has become a major public health issue globally, putting an enormous burden on global health systems and people. Among all diseased groups, a considerable part of patients are elderly, while their clinical features, pathogenic processes, and medication regimens are different from patients of other ages. Despite the availability of multiple therapies and techniques, there are still numerous elderly diabetes patients suffering from poor blood glucose control, severe complications, and drug adverse effects, which negatively affect the quality of life in their golden years. Traditional Chinese Medicine (TCM) has been widely used in the treatment of diabetes for several decades, and its relevant clinical practice has confirmed that it has a satisfactory effect on alleviating clinical symptoms and mitigating the progression of complications. Chinese herbal medicine and its active components were used widely with obvious clinical advantages by multiple targets and signaling pathways. However, due to the particular features of elderly diabetes, few studies were conducted to explore Traditional Chinese Medicine intervention on elderly diabetic patients. This study reviews the research on clinical features, pathogenic processes, treatment principles, and TCM treatments, hoping to provide fresh perspectives on the prevention and management strategies for elderly diabetes.

Angiotensin I-converting enzyme type 2 expression is increased in pancreatic islets of type 2 diabetic donors

AIMS

Angiotensin I-converting enzyme type 2 (ACE2), a pivotal SARS-CoV-2 receptor, has been shown to be expressed in multiple cells, including human pancreatic beta-cells. A putative bidirectional relationship between SARS-CoV-2 infection and diabetes has been suggested, confirming the hypothesis that viral infection in beta-cells may lead to new-onset diabetes or worse glycometabolic control in diabetic patients. However, whether ACE2 expression levels are altered in beta-cells of diabetic patients has not yet been investigated. Here, we aimed to elucidate the in situ expression pattern of ACE2 in Type 2 diabetes (T2D) with respect to non-diabetic donors which may account for a higher susceptibility to SARS-CoV-2 infection in beta-cells.

MATERIAL AND METHODS

Angiotensin I-converting enzyme type 2 immunofluorescence analysis using two antibodies alongside insulin staining was performed on formalin-fixed paraffin embedded pancreatic sections obtained from n = 20 T2D and n = 20 non-diabetic (ND) multiorgan donors. Intensity and colocalisation analyses were performed on a total of 1082 pancreatic islets. Macrophage detection was performed using anti-CD68 immunohistochemistry on serial sections from the same donors.

RESULTS

Using two different antibodies, ACE2 expression was confirmed in beta-cells and in pancreas microvasculature. Angiotensin I-converting enzyme type 2 expression was increased in pancreatic islets of T2D donors in comparison to ND controls alongside with a higher colocalisation rate between ACE2 and insulin using both anti-ACE2 antibodies. CD68+ cells tended to be increased in T2D pancreata, in line with higher ACE2 expression observed in serial sections.

CONCLUSIONS

Higher ACE2 expression in T2D islets might increase their susceptibility to SARS-CoV-2 infection during COVID-19 in T2D patients, thus worsening glycometabolic outcomes and disease severity.

Prolonged Inhibition of the MEK1/2-ERK Signaling Axis Primes Interleukin-1 Beta Expression through Histone 3 Lysine 9 Demethylation in Murine Macrophages

Macrophages undergo different cellular states upon activation that can be hyporesponsive (tolerated) or hyperresponsive (primed or trained) to subsequent stimuli. Epigenetic modifications are known to play key roles in determining these cellular states. However, little is known about the role of signaling pathways that lead to these epigenetic modifications. Here, we examined the effects of various inhibitors targeting key signaling pathways induced by lipopolysaccharide (LPS) on tolerance and priming in murine macrophages. We found that a prolonged inhibition (>18 h) of the mitogen-activated protein kinase (MEK)1/2-extracellular signal-regulated kinase (ERK)1/2 signaling axis reversed tolerance and primed cells in expressing interleukin (IL)-1β and other inflammatory cytokines such as IL-6, tumor necrosis factor (TNF)α, and CXCL10. The ectopic expression of catalytically active and inactive MEK1 mutants suppressed and enhanced IL-1β expression, respectively. A transcriptomic analysis showed that cells primed by the MEK1/2 inhibitor U0126 expressed higher levels of gene sets associated with immune responses and cytokine/chemokine production, but expressed lower levels of genes with cell cycle progression, chromosome organization, and heterochromatin formation than non-primed cells. Of interest, the mRNA expressions of the histone 3 lysine 9 (H3K9) methyltransferase Suv39h1 and the H3K9 methylation reader Cbx5 were substantially suppressed, whereas the H3K9 demethylase Kdm7a was enhanced, suggesting a role of the MEK1/2-ERK signaling axis in H3K9 demethylation. The H3K9 trimethylation levels in the genomic regions of IL-1β, TNFα, and CXCL10 were decreased by U0126. Also, the H3K9 methyltransferase inhibitor BIX01294 mimicked the U0126 training effects and the overexpression of chromobox homolog (CBX)5 prevented the U0126 training effects in both RAW264.7 cells and bone-marrow-derived macrophages. Collectively, these data suggest that the prolonged inhibition of the MEK1/2-ERK signaling axis reverses tolerance and primed macrophages likely through decreasing the H3K9 methylation levels.

Oral non-viral gene delivery platforms for therapeutic applications

Since gene therapy can regulate gene and protein expression directly, it has a great potential to prevent or treat a variety of genetic or acquired diseases through vaccines such as viral infections, cystic fibrosis, and cancer. Owing to their high efficacy, in vivo gene therapy trials are usually conducted intravenously, which is usually costly and invasive. There are several advantages to oral drug administration over intravenous injections, such as better patient compliance, ease of use, and lower cost. However, gene therapy is successful if the oligonucleotides can cross the cell membrane easily and reach the nucleus after the endosomal escape. In order to accomplish this task and deliver the cargo to the intended location, appropriate delivery systems should be introduced. This review summarizes oral delivery systems developed for effective gene delivery, vaccination, and treatment of various diseases. Studies have also shown that oral delivery approaches are potentially applicable to treat various diseases, especially inflammatory bowel disease, stomach, and colorectal cancers. Also, the current review provides an update overview on the development of non-viral and oral gene delivery techniques for gene therapy and vaccination purposes.

Gestational low dietary protein induces intrauterine inflammation and alters the programming of adiposity & insulin sensitivity in the adult offspring

Malnutrition associated with low dietary protein can induce gestational inflammation and sets a long-lasting metabolic impact on the offspring even after replenishment. The work investigated whether a low-protein diet (LPD) during pregnancy and lactation induces intrauterine inflammation and predisposes offspring to adiposity and insulin resistance in their adult life. Female Golden Syrian hamsters were fed LPD (10.0% energy from protein) or a control diet (CD, 20.0 % energy from protein) from preconception until lactation. All pups were switched to CD after lactation and continued until the end. Maternal LPD increased intrauterine inflammation by enhancing neutrophil infiltration, amniotic hsCRP, oxidative stress, and mRNA expression of NFκβ, IL8, COX2, and TGFβ in the chorioamniotic membrane (P<.05). The prepregnancy body weight, placental, and fetal weights, serum AST and ALT were decreased, while blood platelets, lymphocytes, insulin, and HDL were significantly increased in LPD-fed dams (P<.05). A postnatal switch to an adequate protein could not prevent hyperlipidemia in the 6-months LPD/CD offspring. The lipid profile and liver functions were restored over 10 months of protein feeding but failed to normalize fasting glucose and body fat accumulation compared to CD/CD. LPD/CD showed elevated GLUT4 expression & activated pIRS1 in the skeletal muscle and increased expression of IL6, IL1β, and p65-NFκB proteins in the liver (P<.05). In conclusion, present data suggest that maternal protein restriction may induce intrauterine inflammation and affect liver inflammation in the adult offspring by an influx of fats from adipose that may alter lipid metabolism and reduce insulin sensitivity in skeletal muscle.

The Associations between Cytokine Levels, Kidney and Heart Function Biomarkers, and Expression Levels of Angiotensin-Converting Enzyme-2 and Neuropilin-1 in COVID-19 Patients

Background: Higher expression of angiotensin-converting enzyme-2 (ACE-2) in addition to neuropilin-1 (NRP-1) can lead to a cytokine storm which is correlated to higher mortality rate and contributes to the progression of renal diseases and the pathogenesis of coronary heart disease (CHD) in COVID-19 patients. Aim: We herein sought to examine correlations between cytokine levels, ACE-2 and NRP-1 expression, renal function biomarkers, and cardiac enzymes in COVID-19 patients. Patients and Methods: For the study, 50 healthy subjects and 100 COVID-19 patients were enrolled. Then, confirmed cases of COVID-19 were divided into two groups—those with moderate infection and those with severe infection—and compared to healthy controls. Serum creatinine, urea, CK-MB, LDH, troponin I, IL-1β, IL-4, IL-10, IL-17, and INF-γ levels were estimated. We also studied the gene expression for ACE-2 and NRP-1 in blood samples utilizing quantitative real-time polymerase chain reaction (qRT-PCR). Results: All COVID-19 patients demonstrated a significant increase in the levels of serum creatinine, urea, CK-MB, LDH, and troponin I, as well as examined cytokines compared to the healthy controls. Furthermore, ACE-2 mRNA and NRP-1 mRNA expression levels demonstrated a significant increase in both severe and moderate COVID-19 patient groups. In the severe group, serum creatinine and urea levels were positively correlated with IL-10, INF-γ, NRP-1, and ACE-2 expression levels. Moreover, LDH was positively correlated with all the examined cytokine, NRP-1, and ACE-2 expression levels. Conclusion: Deficits in renal and cardiac functions might be attributable to cytokine storm resulting from the higher expression of ACE-2 and NRP-1 in cases of COVID-19.

Bioavailability of Hesperidin and Its Aglycone Hesperetin—Compounds Found in Citrus Fruits as a Parameter Conditioning the Pro-Health Potential (Neuroprotective and Antidiabetic Activity)—Mini-Review

Hesperidin and hesperetin are polyphenols that can be found predominantly in citrus fruits. They possess a variety of pharmacological properties such as neuroprotective and antidiabetic activity. However, the bioavailability of these compounds is limited due to low solubility and restricts their use as pro-healthy agents. This paper described the limitations resulting from the low bioavailability of the presented compounds and gathered the methods aiming at its improvement. Moreover, this work reviewed studies providing pieces of evidence for neuroprotective and antidiabetic properties of hesperidin and hesperetin as well as providing a detailed look into the significance of reported modes of action in chronic diseases. On account of a well-documented pro-healthy activity, it is important to look for ways to overcome the problem of poor bioavailability.

Fructose-mediated NLRP3 activation induces inflammation and lipogenesis in adipose tissue

Adipose tissue plays a crucial role in energy intake and regulation of metabolic homeostasis. Fructose consumption implicates in development and progression of metabolic dysfunctions. Fructose is a lipogenic sugar known to induce inflammatory response. However, the role of specific inflammatory signal such as nucleotide-binding and oligomerization domain-like receptor, leucine-rich repeat and pyrin domain containing protein 3 (NLRP3) in fructose-induced inflammatory response and its relevance to lipogenesis in adipose tissue are elusive. We assessed NLRP3 activation and its significance in inflammatory response and lipogenesis in epididymal adipose tissue of 60% fructose diet (HFrD)-fed rats. The long term consumption of HFrD led to impairment of glucose metabolism, development of visceral adiposity, insulin resistance, and elevation of serum triglycerides level, accompanied by activation of NLRP3 in adipose tissue. NLRP3 inflammasome activation in adipose tissue was associated with up-regulated expression of Nlrp3, Asc, and Caspase-1, and raised caspase-1 activity, which resulted in increased expression of IL-1β and IL-18 and secretion of IL-1β. Moreover, lipid accumulation and expression of transcription factors exacerbating accumulation of lipids were augmented in adipose tissue of HFrD-fed rats. Treatment with glyburide, quercetin or allopurinol corrected HFrD-induced dyslipidemia or hyperuricemia, and blocked NLRP3 activation, leading to mitigated inflammatory signalling and lipid accumulation in adipose tissue, improved glucose tolerance and insulin sensitivity in HFrD-fed rats. These data suggest the role of NLRP3 inflammasome to establish linkage among inflammation, lipid accumulation and insulin resistance in adipose tissue, and targeting NLRP3 inflammasome may be a plausible approach for prevention and management for fructose-induced metabolic impairments.

The Promising Role of Microbiome Therapy on Biomarkers of Inflammation and Oxidative Stress in Type 2 Diabetes: A Systematic and Narrative Review

Background

One in 10 adults suffer from type 2 diabetes (T2D). The role of the gut microbiome, its homeostasis, and dysbiosis has been investigated with success in the pathogenesis as well as treatment of T2D. There is an increasing volume of literature reporting interventions of pro-, pre-, and synbiotics on T2D patients.

Methods

Studies investigating the effect of pro-, pre-, and synbiotics on biomarkers of inflammation and oxidative stress in T2D populations were extracted from databases such as PubMed, Scopus, Web of Science, Embase, and Cochrane from inception to January 2022.

Results

From an initial screening of 5,984 hits, 47 clinical studies were included. Both statistically significant and non-significant results have been compiled, analyzed, and discussed. We have found various promising pro-, pre-, and synbiotic formulations. Of these, multistrain/multispecies probiotics are found to be more effective than monostrain interventions. Additionally, our findings show resistant dextrin to be the most promising prebiotic, followed closely by inulin and oligosaccharides. Finally, we report that synbiotics have shown excellent effect on markers of oxidative stress and antioxidant enzymes. We further discuss the role of metabolites in the resulting effects in biomarkers and ultimately pathogenesis of T2D, bring attention toward the ability of such nutraceuticals to have significant role in COVID-19 therapy, and finally discuss few ongoing clinical trials and prospects.

Conclusion

Current literature of pro-, pre- and synbiotic administration for T2D therapy is promising and shows many significant results with respect to most markers of inflammation and oxidative stress.

Hyperglycemia Induces Inflammatory Response of Human Macrophages to CD163-Mediated Scavenging of Hemoglobin-Haptoglobin Complexes

Hyperglycemia, a hallmark of diabetes, can induce inflammatory programming of macrophages. The macrophage scavenger receptor CD163 internalizes and degrades hemoglobin-haptoglobin (Hb-Hp) complexes built due to intravascular hemolysis. Clinical studies have demonstrated a correlation between impaired scavenging of Hb-Hp complexes via CD163 and diabetic vascular complications. Our aim was to identify whether hyperglycemia is able to amplify inflammation via Hb-Hp complex interactions with the immune system. M(IFNγ), M(IL-4), and control M0 macrophages were differentiated out of primary human monocytes in normo- (5 mM) and hyperglycemic (25 mM) conditions. CD163 gene expression was decreased 5.53 times in M(IFNγ) with a further decrease of 1.99 times in hyperglycemia. Hyperglycemia suppressed CD163 surface expression in M(IFNγ) (1.43 times). Flow cytometry demonstrated no impairment of Hb-Hp uptake in hyperglycemia. However, hyperglycemia induced an inflammatory response of M(IFNγ) to Hb-Hp1-1 and Hb-Hp2-2 uptake with different dynamics. Hb-Hp1-1 uptake stimulated IL-6 release (3.03 times) after 6 h but suppressed secretion (5.78 times) after 24 h. Contrarily, Hb-Hp2-2 uptake did not affect IL-6 release after 6h but increased secretion after 24 h (3.06 times). Our data show that hyperglycemia induces an inflammatory response of innate immune cells to Hb-Hp1-1 and Hb-Hp2-2 uptake, converting the silent Hb-Hp complex clearance that prevents vascular damage into an inflammatory process, hereby increasing the susceptibility of diabetic patients to vascular complications.

The effect of etanercept and anakinra on experimental type 2 diabetes pathology in rats

In this study, the effects of etanercept, anakinra, and their combination on streptozotocin-induced type 2 diabetes in rats were pathologically evaluated. A total of 30 rats were separated into 5 groups as control (C), diabetes (D), diabetes + anakinra (DA), diabetes + etanercept (DE), and diabetes + anakinra + etanercept (DAE). Anakinra (10 mg/kg/day, s.c.) and etanercept (10 mg/kg, twice weekly, s.c.) were administered to the DA and DE groups, respectively, and the DAE group received both anakinra and etanercept for 21 days. Histopathologically, pathological changes related to diabetes in internal organs occurred in the diabetes group, and there was a significant decrease (improvement) in these changes in the treatment groups (P < 0.05). There was no significant difference (P > 0.05) between the treatment groups, but some changes in the liver and kidneys were higher in the combined group which should be taken into account for longer use. Although there was no significant difference, etanercept was more effective on pancreatic lesion scores and anakinra was more effective on testicular changes. As a result, the single or combined use of IL-1 and TNF-α antagonists anakinra and etanercept were effective in the treatment of type 2 diabetes in rats without any toxic-pathological effect.

Oral Gene Therapy of HFD-Obesity via Nonpathogenic Yeast Microcapsules Mediated shRNA Delivery

Obesity is a chronic systemic inflammatory disease, which occurs when energy intake exceeds the energy consumption. Therefore, controlling energy intake or increasing physical consumption can effectively control obesity. However, in reality, it is very difficult for the majority of obese patients to lose weight by autonomously controlling diet. In this study, oral shRNA/yeast microcapsules were constructed with non-virus-mediated IL-1β shRNA interference vectors and non-pathogenic Saccharomyces cerevisiae. Moreover, high-fat diet induced obese mice were established to assess the weight loss effect of IL-1β shRNA/yeast microcapsules via the oral route. After IL-1β shRNA/yeast treatment, body weight and fat weight was reduced. Compared with the control group, higher average food intake but lower energy conversion rate was observed in IL-1β shRNA/yeast group. In addition, lipid metabolism related cytokines and blood glucose concentration in the circulating blood was improved after IL-1β shRNA/yeast treatment. Yeast microcapsules mediated IL-1β shRNA delivery can effectively improve obesity. Noteworthy, this kind of non-diet-controlled weight loss strategy does not need diet control, and shows good biocompatibility. It is good news to obese patients who need to lose weight but cannot control their diet.

The Role of Interleukin-1β in Destruction of Transplanted Islets

Islet transplantation is a promising β-cell replacement therapy for type 1 diabetes, which can reduce glucose lability and hypoglycemic episodes compared with standard insulin therapy. Despite the tremendous progress made in this field, challenges remain in terms of long-term successful transplant outcomes. The insulin independence rate remains low after islet transplantation from one donor pancreas. It has been reported that the islet-related inflammatory response is the main cause of early islet damage and graft loss after transplantation. The production of interleukin-1β (IL-1β) has considered to be one of the primary harmful inflammatory events during pancreatic procurement, islet isolation, and islet transplantation. Evidence suggests that the innate immune response is upregulated through the activity of Toll-like receptors and The NACHT Domain-Leucine-Rich Repeat and PYD-containing Protein 3 inflammasome, which are the starting points for a series of signaling events that drive excessive IL-1β production in islet transplantation. In this review, we show recent contributions to the advancement of knowledge of IL-1β in islet transplantation and discuss several strategies targeting IL-1β for improving islet engraftment.

The Road Less Traveled? Unconventional Protein Secretion at Parasite-Host Interfaces

Protein secretion in eukaryotic cells is a well-studied process, which has been known for decades and is dealt with by any standard cell biology textbook. However, over the past 20 years, several studies led to the realization that protein secretion as a process might not be as uniform among different cargos as once thought. While in classic canonical secretion proteins carry a signal sequence, the secretory or surface proteome of several organisms demonstrated a lack of such signals in several secreted proteins. Other proteins were found to indeed carry a leader sequence, but simply circumvent the Golgi apparatus, which in canonical secretion is generally responsible for the modification and sorting of secretory proteins after their passage through the endoplasmic reticulum (ER). These alternative mechanisms of protein translocation to, or across, the plasma membrane were collectively termed “unconventional protein secretion” (UPS). To date, many research groups have studied UPS in their respective model organism of choice, with surprising reports on the proportion of unconventionally secreted proteins and their crucial roles for the cell and survival of the organism. Involved in processes such as immune responses and cell proliferation, and including far more different cargo proteins in different organisms than anyone had expected, unconventional secretion does not seem so unconventional after all. Alongside mammalian cells, much work on this topic has been done on protist parasites, including genera Leishmania, Trypanosoma, Plasmodium, Trichomonas, Giardia, and Entamoeba. Studies on protein secretion have mainly focused on parasite-derived virulence factors as a main source of pathogenicity for hosts. Given their need to secrete a variety of substrates, which may not be compatible with canonical secretion pathways, the study of mechanisms for alternative secretion pathways is particularly interesting in protist parasites. In this review, we provide an overview on the current status of knowledge on UPS in parasitic protists preceded by a brief overview of UPS in the mammalian cell model with a focus on IL-1β and FGF-2 as paradigmatic UPS substrates.

Alpha-lipoic acid alleviates NAFLD and triglyceride accumulation in liver via modulating hepatic NLRP3 inflammasome activation pathway in type 2 diabetic rats

The occurrence of nonalcoholic fatty liver disease (NAFLD) is associated with type 2 diabetes mellitus (T2DM). The activation of nucleotide-binding domain and leucine-rich-containing family, pyrin domain-containing 3 (NLRP3) inflammasome in the liver may lead to hepatic fat accumulation. Alpha-lipoic acid (ALA) has been reported to improve IR in a T2DM rodent model. We investigated the effects of ALA on NLRP3 inflammasome activation and fat accumulation in the liver of a high-fat diet (HFD) plus streptozotocin (STZ)-induced T2DM rats. The HFD/STZ-induced T2DM rats were orally administered ALA (50, 100, or 200 mg/kg BW) once a day for 13 weeks. The results showed that the liver triglyceride contents of T2DM rats were 11.35 ± 1.84%, whereas the administration of 50, 100, and 200 mg/kg BW ALA significantly reduced the liver triglyceride contents of T2DM rats to 4.14 ± 0.59%, 4.02 ± 0.41%, and 3.01 ± 1.07%, respectively. Moreover, 200 mg/kg BW ALA significantly decreased the hepatic levels of NLRP3 inflammasome activation-related proteins NLRP3, caspase-1, and interleukin-1β expression by 40.0%, 60.1%, and 24.5%, respectively, in T2DM rats. Furthermore, the expression levels of hepatic fat synthesis-related proteins decreased, namely a 45.4% decrease in sterol regulatory element-binding protein-1c, whereas the expression of hepatic lipid oxidation-related proteins increased, including a 27.5% increase in carnitine palmitoyltransferase, in T2DM rats after 200 mg/kg BW ALA treatment. We concluded that ALA treatment may suppress hepatic NLRP3 inflammasome activation, consequently alleviating NAFLD and excess hepatic lipid accumulation in HFD/STZ-induced T2DM rats.

Paving the Road Toward Exploiting the Therapeutic Effects of Ginsenosides: An Emphasis on Autophagy and Endoplasmic Reticulum Stress

Programmed cell death processes such as apoptosis and autophagy strongly contribute to the onset and progression of cancer. Along with these lines, modulation of cell death mechanisms to combat cancer cells and elimination of resistance to apoptosis is of great interest. It appears that modulation of autophagy and endoplasmic reticulum (ER) stress with specific agents would be beneficial in the treatment of several disorders. Interestingly, it has been suggested that herbal natural products may be suitable candidates for the modulation of these processes due to few side effects and significant therapeutic potential. Ginsenosides are derivatives of ginseng and exert modulatory effects on the molecular mechanisms associated with autophagy and ER stress. Ginsenosides act as smart phytochemicals that confer their effects by up-regulating ATG proteins and converting LC3-I to -II, which results in maturation of autophagosomes. Not only do ginsenosides promote autophagy but they also possess protective and therapeutic properties due to their capacity to modulate ER stress and up- and down-regulate and/or dephosphorylate UPR transducers such as IRE1, PERK, and ATF6. Thus, it would appear that ginsenosides are promising agents to potentially restore tissue malfunction and possibly eliminate cancer.

Methanol leaf extract of Momordica charantia protects alloxan-induced hepatopathy through modulation of caspase-9 and interleukin-1β signaling pathways in rats

Background and Aim:

Momordica charantia is a highly valued plant, widely distributed in the tropical and subtropical regions. The plant is reported to have a wide range of medicinal uses. This study was designed to explore the ameliorative potential of M. charantia methanol leaf extract in alloxan-induced diabetic animal model with a particular focus on the liver.

Materials and Methods:

Hepatoprotective effect of methanol leaf extract of M. charantia was assessed in alloxan-induced toxicity in 50 rats divided into five groups (A-E) (n=10). Group A normal control, Group B was toxicant group, and Group C animals received glibenclamide treatment while Groups D and E received extracts at 200 and 400 mg/kg doses, respectively. The experiment lasted for 28 days. Histopathological changes, blood glucose level, and serum enzymes such as aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase, oxidative status and caspase-9, and interleukin-1β (IL-1β) were evaluated.

Results:

Extract-treatment caused a decreased blood glucose level, markers of oxidative stress such as malondialdehyde and hydrogen peroxide (H₂O₂). Treatment of rats with leaf extract of M. charantia resulted in increased levels and activities of protein thiols, non-protein thiols, glutathione (GSH), glutathione peroxidase, glutathione S-transferase, and superoxide dismutase indicating its antioxidant potential. The liver section revealed mild distortion of the hepatic architecture compared to the toxicant group, while decreased expressions of caspase-9 and IL-1β in extract-treated groups was observed.

Conclusion:

The plant extract exhibited antioxidant, anti-apoptotic, and anti-inflammatory effects, thus showing its hepatoprotective property.

The Influence of IL-1B Gene Polymorphisms on H. pylori Infection and Triple Treatment Response Among Jordanian Population

Background

Helicobacter pylori (H. pylori) is considered the main cause of gastritis, peptic ulcer and gastric carcinoma in the human populations. H. pylori infection influences the secretion level of several proinflammatory cytokines including IL-1β, which encoded by the IL-1B gene.

Objective

The current study aimed to investigate whether IL-1B gene polymorphisms are associated with H. pylori infection among the Jordanian population and responses to triple therapy.

Subjects and Methods

The gastroscopic examination was performed on 412 subjects for H. pylori infection diagnosis, 257 subjects were found to be infected by H. Pylori (positive cases), whereas 155 subjects were uninfected (negative controls). The IL-1B gene T-31C and C3954T polymorphisms were genotyped by PCR-RFLP.

Results

It was found that the T-31C polymorphism has a significant association with H. pylori infection (P<0.05), and the TT genotype frequency was significantly higher in infected subjects (50.2%) compared to controls (38.7%). On the other hand, no significant association was detected between C3954T SNPs and H. pylori infection among the Jordanian population. In addition, none of the examined polymorphisms were found to influence the responses to triple therapy.

Conclusion

The IL-1B gene T-31C SNP might be associated with an enhanced risk of H. pylori infection among the Jordanian population.

Disrupting phosphatase SHP2 in macrophages protects mice from high-fat diet-induced hepatic steatosis and insulin resistance by elevating IL-18 levels

Chronic low-grade inflammation plays an important role in the pathogenesis of type 2 diabetes. Src homology 2 domain-containing tyrosine phosphatase-2 (SHP2) has been reported to play diverse roles in different tissues during the development of metabolic disorders. We previously reported that SHP2 inhibition in macrophages results in increased cytokine production. Here, we investigated the association between SHP2 inhibition in macrophages and the development of metabolic diseases. Unexpectedly, we found that mice with a conditional SHP2 knockout in macrophages (cSHP2-KO) have ameliorated metabolic disorders. cSHP2-KO mice fed a high-fat diet (HFD) gained less body weight and exhibited decreased hepatic steatosis, as well as improved glucose intolerance and insulin sensitivity, compared with HFD-fed WT littermates. Further experiments revealed that SHP2 deficiency leads to hyperactivation of caspase-1 and subsequent elevation of interleukin 18 (IL-18) levels, both in vivo and in vitro Of note, IL-18 neutralization and caspase-1 knockout reversed the amelioration of hepatic steatosis and insulin resistance observed in the cSHP2-KO mice. Administration of two specific SHP2 inhibitors, SHP099 and Phps1, improved HFD-induced hepatic steatosis and insulin resistance. Our findings provide detailed insights into the role of macrophagic SHP2 in metabolic disorders. We conclude that pharmacological inhibition of SHP2 may represent a therapeutic strategy for the management of type 2 diabetes.

Hydrogen sulfide modulates high glucose-induced NLRP3 inflammasome activation in 3T3-L1 adipocytes

Activation of the NACHT leucine rich repeat and pyd domains-containing 3 (NLRP3) inflammasome plays an important role in the initiation of inflammation in adipose tissue in diabetic patients. However, the mechanisms underlying this are not fully understood. Hydrogen sulfide (H₂S) has been shown to have anti-inflammatory properties in various cell types. The present study aimed to investigate the effect of H₂S on high glucose (HG)-induced NLRP3 inflammasome activation in adipocytes. Adipocytes were differentiated from 3T3-L1 cells and treated with low glucose (LG), HG, H₂S donor sodium hydrosulfide (NaHS) or N-acetyl-tyrosyl-valyl- alanyl-aspartyl chloromethyl ketone, an inhibitor of the cysteine protease caspase-1. The expression levels of NLRP3, apoptosis-associated speck-like protein containing A CARD (ASC) and caspase-1, and the release of interleukin (IL)-1β and IL-18 were measured. The results of the present study indicated that HG increased the expression levels of NLRP3, ASC and cleaved caspase-1, and the release of IL-1β and IL-18 in adipocytes. Caspase-1 inhibition abolished HG-induced production of IL-1β and IL-18 in adipocytes. Furthermore, NaHS inhibited the expression of NLRP3, ASC and cleaved caspase-1, and the production of IL-1β and IL-18 in adipocytes treated with HG. In conclusion, HG may increase and exogenous H₂S may inhibit HG-induced NLRP3 inflammasome activation in adipocytes.

Effect of Robinia pseudoacacia Leaf Extract on Interleukin-1β-mediated Tumor Angiogenesis

BACKGROUND/AIM

Interleukin (IL)-1β is a pro-inflammatory cytokine that has recently been established as a stimulator of angiogenesis via regulation of proangiogenic factor expression in the tumor microenvironment. This study aimed to demonstrate the inhibitory effects of Robinia pseudoacacia leaf extract (RP) on IL-1β-mediated tumor angiogenesis.

MATERIALS AND METHODS

Secreted embryonic alkaline phosphatase (SEAP) reporter gene assay, ex vivo and in vitro tube formation assay, western blot, and quantitative PCR were used to analyze the inhibitory effect of RP on IL-1β-mediated angiogenesis.

RESULTS

RP inhibited secretion of SEAP, blocked IL-1β signaling, and inhibited IL-1β-mediated angiogenesis in ex vivo and in vitro assays. RP inhibited nuclear translocation of NF-ĸB by suppressing phosphorylation of IL-1β signaling protein kinases and inhibited mRNA expression of IL-1β-induced pro-angiogenic factors including VEGFA, FGF2, ICAM1, CXCL8, and IL6.

CONCLUSION

RP suppressed IL-1β-mediated angiogenesis and, thus, could be a promising agent in anticancer therapy.

Characteristics of diabetic macular edema patients refractory to anti-VEGF treatments and a dexamethasone implant

Purpose

To determine the characteristics of diabetic macular edema (DME) patients refractory to intravitreal bevacizumab (IVB) treatments and an additional dexamethasone implant.

Methods

We classified 119 DME patients according to whether or not they are responsive to 3 consecutive monthly anti-VEGF treatments and/or an additional dexamethasone implant. We compared their concentrations of IL (interleukin)-1β, IL-8, IL-10, IL-17, placental growth factor (PlGF), and vascular endothelial growth factor (VEGF) in the aqueous humor as well as their optical coherence tomography (OCT) findings, and baseline characteristics. We used logistic regression analyses to identify preoperative factors related to refractoriness to treatments.

Results

Of 119 treatment-naïve DME patients, 50 (42.02%) patients showed responsiveness [central subfield thickness (CST) < 300μm] after 3 IVBs, and 59 (49.58%) patients showed responsiveness after an additional dexamethasone implant, but 10 (8.40%) patients showed CST 300 ≥ μm even after both treatments. Refractory DME patients showed significantly higher number of hyperreflective foci (HF) in the OCT and higher average level of aqueous IL-1β at baseline (p<0.001 and p = 0.042, respectively). In the logistic regression analysis, higher number of HF in the OCT was associated with the refractoriness to both treatments (odds ratio [OR]: 7.03, p = 0.007)

Conclusions

Higher number of HF in the OCT at the initial visit was associated with poor responses to IVBs and an additional dexamethasone implant.

Polymer brush based fluorescent immunosensor for direct monitoring of interleukin-1β in rat blood

A sandwich immunosensor was successfully developed for monitoring of interleukin-1β (IL-1β) in rat whole blood. The substrate stainless steel (SS) was first coated with a polydopamine layer and subsequently grafted with poly(ethylene glycol) methacrylate brushes, onto which a sandwich immunosensor was modified for detection of IL-1β. The device has been successfully applied for monitoring of IL-1β with a limit of detection of 4.7 pg mL^-1, and a linear detection range of 12.5-200 pg mL^-1. Good specificity and selectivity for monitoring of IL-1β in rat macrophage secretion were achieved. Furthermore, this device was validated by detection of IL-1β in rat whole blood samples with greater concentrations observed in obese rats compared to control, and strong positive correlation between concentrations of IL-1β and blood glucose. These results suggest this device is feasible for direct detection of target analytes in biological samples.

Inflammatory Consequences of Maternal Diabetes on the Offspring Brain: a Hippocampal Organotypic Culture Study

Gestational diabetes is a disorder associated with abnormal chronic inflammation that poses a risk to the developing fetus. We investigated the effects of experimentally induced diabetes (streptozotocin model) in Wistar female rats on the inflammatory status of the hippocampi of their offspring. Additionally, the impact of antidiabetic drugs (metformin and glyburide) on inflammatory processes was evaluated. Organotypic hippocampal cultures (OHCs) were prepared from the brains of the 7-day-old rat offspring of control and diabetic mother rats. On the 7th day in vitro, the cultures were pretreated with metformin (3 μM) or glyburide (1 μM) and then stimulated for 24 h with lipopolysaccharide (LPS, 1 μg/ml). The OHCs obtained from the offspring of diabetic mothers were characterized by the increased mortality of cells and an enhanced susceptibility to damage caused by LPS. Although we showed that LPS stimulated the secretion of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) in the control and diabetic cultures, the levels of IL-1β and IL-6 in the OHC medium obtained from the offspring of diabetic mothers were more pronounced. In the diabetic cultures, enhanced levels of TLR-4 and the overactivation of the NLRP3 inflammasome were demonstrated. Metformin and glyburide pretreatment normalized the LPS-induced IL-1β secretion in the control and diabetic cultures. Furthermore, glyburide diminished both: LPS-induced IL-6 and TNF-α secretion in the control and diabetic cultures and increased NF-κB p65 subunit phosphorylation. Glyburide also diminished the levels of the NLRP3 subunit and caspase-1, but only in the diabetic cultures. The results showed that maternal diabetes affected inflammatory processes in the offspring brain and increased hippocampal sensitivity to the LPS-induced inflammatory response. The use of antidiabetic agents, especially glyburide, had a beneficial impact on the changes caused by maternal diabetes.

Oral contraceptive use increases risk of inflammatory and coagulatory disorders in women with Polycystic Ovarian Syndrome: An observational study

Polycystic ovarian syndrome (PCOS) is a multispectral disorder requiring lifelong management. Its pathophysiology is still being explored which makes its treatment options restrained. Present study explores impact of oral contraceptive mode of treatment on metabolic, hormonal, inflammation and coagulation profile of PCOS women. 50 subjects diagnosed with Rotterdam criteria receiving no drug treatment served as controls whereas 50 subjects receiving only OCPs (Ethinyl estradiol 0.03 mg, Levonorgestrel 0.15 mg) as a mode of treatment at least for six-months served as cases. Ferriman-Gallwey score and hormonal profile improved on OCP treatment. However, parameters like weight, Body mass index, waist-hip ratio, Oral glucose tolerance test, lipid profile, insulin, HOMA-IR, adiponectin, interleukin1β, visfatin, resistin, tissue factor, PT and APTT showed considerable derangements in OCP group. All above parameters are associated with the risk of diabetes mellitus, dyslipidemia, coronary vascular disease, cancers, hypercoagulable state, venous thromboembolism and thrombotic events. Long-term use of OCPs needs to be considered carefully for PCOS patients who are already burdened with associated risk factors. This study was conducted in a region where women do not have much access to high-end screening and diagnostic facilities that further exacerbates their clinical outcomes. Large scale, long-term studies need to be designed to further evaluate safety use of OCPs in PCOS women.

Serum protein signature of coronary artery disease in type 2 diabetes mellitus

Background

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM). The purpose of the present study was to discriminate the Indian CAD patients with or without T2DM by using multiple pathophysiological biomarkers.

Methods

Using sensitive multiplex protein assays, we assessed 46 protein markers including cytokines/chemokines, metabolic hormones, adipokines and apolipoproteins for evaluating different pathophysiological conditions of control, T2DM, CAD and T2DM with CAD patients (T2DM_CAD). Network analysis was performed to create protein-protein interaction networks by using significantly (p < 0.05) altered protein markers in each disease using STRING 10.5 database. We used two supervised analysis methods i.e., between class analysis (BCA) and principal component analysis (PCA) to reveals distinct biomarkers profiles. Further, random forest classification (RF) was used to classify the diseases by the panel of markers.

Results

Our two supervised analysis methods BCA and PCA revealed a distinct biomarker profiles and high degree of variability in the marker profiles for T2DM_CAD and CAD. Thereafter, the present study identified multiple potential biomarkers to differentiate T2DM, CAD, and T2DM_CAD patients based on their relative abundance in serum. RF classified T2DM based on the abundance patterns of nine markers i.e., IL-1β, GM-CSF, glucagon, PAI-I, rantes, IP-10, resistin, GIP and Apo-B; CAD by 14 markers i.e., resistin, PDGF-BB, PAI-1, lipocalin-2, leptin, IL-13, eotaxin, GM-CSF, Apo-E, ghrelin, adipsin, GIP, Apo-CII and IP-10; and T2DM _CAD by 12 markers i.e., insulin, resistin, PAI-1, adiponectin, lipocalin-2, GM-CSF, adipsin, leptin, Apo-AII, rantes, IL-6 and ghrelin with respect to the control subjects. Using network analysis, we have identified several cellular network proteins like PTPN1, AKT1, INSR, LEPR, IRS1, IRS2, IL1R2, IL6R, PCSK9 and MYD88, which are responsible for regulating inflammation, insulin resistance, and atherosclerosis.

Conclusion

We have identified three distinct sets of serum markers for diabetes, CAD and diabetes associated with CAD in Indian patients using nonparametric-based machine learning approach. These multiple marker classifiers may be useful for monitoring progression from a healthy person to T2DM and T2DM to T2DM_CAD. However, these findings need to be further confirmed in the future studies with large number of samples.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1755-5) contains supplementary material, which is available to authorized users.

Luteolin-Enriched Artichoke Leaf Extract Alleviates the Metabolic Syndrome in Mice with High-Fat Diet-Induced Obesity

This current study aimed to elucidate the effects and possible underlying mechanisms of long-term supplementation with dietary luteolin (LU)-enriched artichoke leaf (AR) in high-fat diet (HFD)-induced obesity and its complications (e.g., dyslipidemia, insulin resistance, and non-alcoholic fatty liver disease) in C57BL/6N mice. The mice were fed a normal diet, an HFD, or an HFD plus AR or LU for 16 weeks. In the HFD-fed mice, AR decreased the adiposity and dyslipidemia by decreasing lipogenesis while increasing fatty acid oxidation, which contributed to better hepatic steatosis. LU also prevented adiposity and hepatic steatosis by suppressing lipogenesis while increasing biliary sterol excretion. Moreover, AR and LU prevented insulin sensitivity by decreasing the level of plasma gastric inhibitory polypeptide and activity of hepatic glucogenic enzymes, which may be linked to the lowering of inflammation as evidenced by the reduced plasma interleukin (IL)-6, IL-1β, and plasminogen activator inhibitor-1 levels. Although the anti-metabolic syndrome effects of AR and LU were similar, the anti-adiposity and anti-dyslipidemic effects of AR were more pronounced. These results in mice with diet-induced obesity suggest that long-term supplementation with AR can prevent adiposity and related metabolic disorders such as dyslipidemia, hepatic steatosis, insulin resistance, and inflammation.

Immunostimulatory effect of pepsin enzymatic extract from Porphyra yezoensis on murine splenocytes

BACKGROUND

Porphyra yezoensis is a red alga consumed mainly in Korea, Japan, and China for food. This study researches the immunological effect of pepsin extract of P. yezoensis (PPEE) on murine splenocytes.

RESULTS

PPEE was not toxic on murine splenocytes and dramatically increased the proliferation of splenocytes compared with untreated control. Flow cytometry assay performed to sum up the effect of PPEE (31.3 and 62.5 µg mL^-1 ) on major immune cells revealed that PPEE had no effect on the function of CD3e⁺ CD4⁺ T-helper cells, CD3e⁺ CD8⁺ T-cytotoxic cells, or CD44⁺ CD62L^- effector T cells in splenocytes compared with untreated control. More importantly, CD45⁺ CD11b⁺ macrophage and dendritic cell populations and Ly-6C⁺ Ly-6G⁺ macrophages/monocytes in splenocytes were activated by PPEE treatment compared with untreated control. Further experiments showed that PPEE treatment increased the secretion of macrophage-derived cytokines such as interleukin-1β, tumor necrosis factor-α, and interleukin-12, and macrophage-activating cytokines interferon-γ and interleukin-10 compared with untreated control.

CONCLUSION

Taken together, these results suggest that PPEE has an immune stimulatory effect on macrophages, dendritic cells, and memory T cells. This property signifies the potential medicinal value of PPEE in clinical implications for immune-compromised diseases. © 2017 Society of Chemical Industry.

Potential Probiotic Microorganisms in Kefir

Probiotic microorganisms are defined as living microorganisms that provide health benefits on the host when administered in adequate amounts. The benefits include improvement of microbial balance immune system and oral health, provision of cholesterol-lowering effect, and antimicrobial activity against a wide variety of bacteria and some fungi. Kefir microbiota contains active living microorganisms. Many researches were carried out that potential probiotic bacteria such as Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus kefir, Lactobacillus kefiranofaciens, Leuconostoc mesenteroides, or yeasts like microorganisms such as Saccharomyces cerevisiae, Kluyveromyces lactis, and Kluyveromyces marxianus were isolated from kefir grains. This chapter presents the data both on the probiotic bacteria isolated from kefir grains or kefir and the probiotic properties of kefir produced with these microorganisms.

Role of NLRP3 inflammasome in the pathogenesis of cardiovascular diseases

NLRP3 inflammasome is a key multiprotein signaling platform that tightly controls inflammatory responses and coordinates antimicrobial host defenses by activating caspase-1 for the subsequent maturation of pro-inflammatory cytokines, IL-1β and IL-18, and induces pyroptosis. The assembly and activation of NLRP3 inflammasome are linked to the pathogenesis of several cardiovascular disease risk factors, such as hypertension and diabetes, and their major consequences-myocardial remodeling. The study of the NLRP3 inflammasome in these cardiovascular disease states may uncover important triggers and endogenous modulators of the disease, and lead to new treatment strategies. This review outlines current insights into NLRP3 inflammasome research associated with cardiovascular diseases and discusses the questions that remain in this field.

Study of the NLRP3 inflammasome component genes and downstream cytokines in patients with type 2 diabetes mellitus with carotid atherosclerosis

BACKGROUND

A role for the NLRP3 inflammasome has been reported in various diseases, such as diabetes mellitus, atherosclerosis (AS), nephropathy, rheumatism, and others, although limited information is available concerning the role of the NLRP3 inflammasome, interleukin-1β (IL-1β) and interleukin-18 (IL-18) in patients with type 2 diabetes mellitus (T2DM) and carotid atherosclerosis (CAS). Therefore, this cross-sectional study investigated these inflammatory components in patients with T2DM complicated with carotid atherosclerosis (T2DM + CAS).

METHODS

A total of 107 inpatients or outpatients were included,including 81 T2DM + CAS patients and 26 T2DM patients. Patients with T2DM or T2DM + CAS were recruited to compare the expression levels of NLRP3 pathway genes (NLRP3, ASC and caspase-1 mRNA) and the serum IL-1β and IL-18 concentrations. In the T2DM + CAS group, patients with thickened intima media thickness (IMT) and those with plaques were compared, and the correlation of the 5 variables with Crouse scores were analyzed.

RESULTS

The expression of NLRP3 pathway genes except caspase-1 was significantly higher in patients with T2DM and CAS compared to T2DM patients. Serum IL-1β and IL-18 concentrations shows no difference between the T2DM + CAS and T2DM group. In the T2DM + CAS group, the expression levels of the three inflammasome genes and IL-18 were increased in patients with thickened IMT compared to those with the plaque. All of the above factors negatively correlated with Crouse scores.

CONCLUSION

NLRP3 inflammasome pathway activity is significantly increased in patients with AS and T2DM at the early stage of plaque formation.

Human umbilical cord-derived mesenchymal stem cells ameliorate insulin resistance by suppressing NLRP3 inflammasome-mediated inflammation in type 2 diabetes rats

BACKGROUND

Insulin resistance is one of the most common and important pathological features of type 2 diabetes (T2D). Recently, insulin resistance is increasingly considered to be associated with systemic chronic inflammation. Elevated levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in blood are predictive indicators of the development of T2D. Mesenchymal stem cell (MSC)-based therapies have been proven to have potential immunomodulation and anti-inflammatory properties through their paracrine effects; however, the mechanism for the anti-inflammatory effect of MSCs in enhancing insulin sensitivity is still uncertain.

METHODS

In the present experiment, we used HepG2 cells, a human hepatoma cell line, and a MSC-HepG2 transwell culturing system to investigate the anti-inflammatory mechanism of human umbilical cord-derived MSCs (UC-MSCs) under palmitic acid (PA) and lipopolysaccharide (LPS)-induced insulin resistance in vitro. Insulin resistance was confirmed by glycogen assay kit and glucose assay kit. Inflammatory factor release was detected by ELISA, gene expression was tested by quantitative real-time PCR, and insulin signaling activation was determined by western blotting analysis. The changes of inflammatory factors and insulin signaling protein were also tested in T2D rats injected with UC-MSCs.

RESULTS

Treating HepG2 cells with PA-LPS caused NLRP3 inflammation activation, including overexpression of NLRP3 and caspase-1, and overproduction of IL-1β and IL-18 as well as TNF-α from HepG2 cells. The elevated levels of these inflammatory cytokines impaired insulin receptor action and thereby prevented downstream signaling pathways, exacerbating insulin resistance in HepG2 cells. Importantly, UC-MSCs cocultured with HepG2 could effectively alleviate PA and LPS-induced insulin resistance by blocking the NLRP3 inflammasome activation and inflammatory agents. Furthermore, knockdown of NLRP3 or IL-1β partially improved PA and LPS-induced insulin signaling impairments in the presence of UC-MSCs. Similarly, UC-MSC infusion significantly ameliorated hyperglycemia in T2D rats and decreased inflammatory activity, which resulted in improved insulin sensitivity in insulin target tissues.

CONCLUSIONS

Our results indicated that UC-MSCs could attenuate insulin resistance and this regulation was correlated with their anti-inflammatory activity. Thus, MSCs might become a novel therapeutic strategy for insulin resistance and T2D in the near future.

Hyperglycemia induces mixed M1/M2 cytokine profile in primary human monocyte-derived macrophages

Hyperglycaemia is a key factor in diabetic pathology. Macrophages are essential regulators of inflammation which can be classified into two major vectors of polarisation: classically activated macrophages (M1) and alternatively activated macrophages (M2). Both types of macrophages play a role in diabetes, where M1 and M2-produced cytokines can have detrimental effects in development of diabetes-associated inflammation and diabetic vascular complications. However, the effect of hyperglycaemia on differentiation and programming of primary human macrophages was not systematically studied. We established a unique model to assess the influence of hyperglycaemia on M1 and M2 differentiation based on primary human monocyte-derived macrophages. The effects of hyperglycaemia on the gene expression and secretion of prototype M1 cytokines TNF-alpha and IL-1beta, and prototype M2 cytokines IL-1Ra and CCL18 were quantified by RT-PCR and ELISA. Hyperglycaemia stimulated production of TNF-alpha, IL-1beta and IL-1Ra during macrophage differentiation. The effect of hyperglycaemia on TNF-alpha was acute, while the stimulating effect on IL-1beta and IL-1Ra was constitutive. Expression of CCL18 was supressed in M2 macrophages by hyperglycaemia. However the secreted levels remained to be biologically significant. Our data indicate that hyperglycaemia itself, without additional metabolic factors induces mixed M1/M2 cytokine profile that can support of diabetes-associated inflammation and development of vascular complications.

Type 3 Diabetes: Cross Talk between Differentially Regulated Proteins of Type 2 Diabetes Mellitus and Alzheimer's Disease

Type 3 Diabetes (T3D) is a neuroendocrine disorder that represents the progression of Type 2 Diabetes Mellitus (T2DM) to Alzheimer’s disease (AD). T3D contributes in the increase of the total load of Alzheimer’s patients worldwide. The protein network based strategies were used for the analysis of protein interactions and hypothesis was derived describing the possible routes of communications among proteins. The hypothesis provides the insight on the probable mechanism of the disease progression for T3D. The current study also suggests that insulin degrading enzyme (IDE) could be the major player which holds the capacity to shift T2DM to T3D by altering metabolic pathways like regulation of beta-cell development, negative regulation of PI3K/AKT pathways and amyloid beta degradation.

Crosstalk between the heart and peripheral organs in heart failure

Mediators from peripheral tissues can influence the development and progression of heart failure (HF). For example, in obesity, an altered profile of adipokines secreted from adipose tissue increases the incidence of myocardial infarction (MI). Less appreciated is that heart remodeling releases cardiokines, which can strongly impact various peripheral tissues. Inflammation, and, in particular, activation of the nucleotide-binding oligomerization domain-like receptors with pyrin domain (NLRP3) inflammasome are likely to have a central role in cardiac remodeling and mediating crosstalk with other organs. Activation of the NLRP3 inflammasome in response to cardiac injury induces the production and secretion of the inflammatory cytokines interleukin (IL)-1β and IL-18. In addition to having local effects in the myocardium, these pro-inflammatory cytokines are released into circulation and cause remodeling in the spleen, kidney, skeletal muscle and adipose tissue. The collective effects of various cardiokines on peripheral organs depend on the degree and duration of myocardial injury, with systematic inflammation and peripheral tissue damage observed as HF progresses. In this article, we review mechanisms regulating myocardial inflammation in HF and the role of factors secreted by the heart in communication with peripheral tissues.

Interrelationship Between Periapical Lesion and Systemic Metabolic Disorders

BACKGROUND

Periapical periodontitis, also known as periapical lesion, is a common dental disease, along with periodontitis (gum disease). Periapical periodontitis is a chronic inflammatory disease, caused by endodontic infection, and its development is regulated by the host immune/inflammatory response. Metabolic disorders, which are largely dependent on life style such as eating habits, have been interpreted as a "metabolically-triggered" low-grade systemic inflammation and may interact with periapical periodontitis by triggering immune modulation. The host immune system is therefore considered the common fundamental mechanism of both disease conditions.

METHOD

We have reviewed >200 articles to discuss the interrelationship between periapical lesions and metabolic disorders including type 2 diabetes mellitus, hypertension, and non-alcoholic fatty liver diseases (NAFLD), and their common pathological background in immunology/osteoimmunology and cytokine biology.

RESULTS

An elevated inflammatory state caused by metabolic disorders can impact the clinical outcome of periapical lesions and interfere with wound healing after endodontic treatment. Although additional well-designed clinical studies are needed, periapical lesions appear to affect insulin sensitivity and exacerbate non-alcoholic steatohepatitis.

CONCLUSION

Immune regulatory cytokines produced by various cell types, including immune cells and adipose tissue, play an important role in this interrelationship.

Ginsenoside Rb1 and compound K improve insulin signaling and inhibit ER stress-associated NLRP3 inflammasome activation in adipose tissue

Background

This study was designed to investigate whether ginsenoside Rb1 (Rb1) and compound K (CK) ameliorated insulin resistance by suppressing endoplasmic reticulum (ER) stress-induced inflammation in adipose tissue.

Methods

To induce ER stress, epididymal adipose tissue from mice or differentiated 3T3 adipocytes were exposed to high glucose. The effects of Rb1 and CK on reactive oxygen species production, ER stress, TXNIP/NLRP3 inflammasome activation, inflammation, insulin signaling activation, and glucose uptake were detected by western blot, emzyme-linked immunosorbent assay, or fluorometry.

Results

Rb1 and CK suppressed ER stress by dephosphorylation of IRE1α and PERK, thereby reducing TXNIP-associated NLRP3 inflammasome activation in adipose tissue. As a result, Rb1 and CK inhibited IL-1β maturation and downstream inflammatory factor IL-6 secretion. Inflammatory molecules induced insulin resistance by upregulating phosphorylation of insulin receptor substrate-1 at serine residues and impairing insulin PI3K/Akt signaling, leading to decreased glucose uptake by adipocytes. Rb1 and CK reversed these changes by inhibiting ER stress-induced inflammation and ameliorating insulin resistance, thereby improving the insulin IRS-1/PI3K/Akt-signaling pathway in adipose tissue.

Conclusion

Rb1 and CK inhibited inflammation and improved insulin signaling in adipose tissue by suppressing ER stress-associated NLRP3 inflammation activation. These findings offered novel insight into the mechanism by which Rb1 and CK ameliorate insulin resistance in adipose tissue.

Damage-associated molecular patterns and their pathological relevance in diabetes mellitus

Diabetes, a group of metabolic and age-related diseases, is a major global health problem, the incidence of which has increased dramatically in recent decades. Type 1 diabetes mellitus (T1DM) is a complex, T cell-mediated autoimmune disease characterized by immune cell infiltration and chronic inflammation in the islets of Langerhans. Type 2 diabetes mellitus (T2DM) is a complex metabolic disease characterized by hyperglycemia (high blood sugar) resulting from insulin resistance and β-cell dysfunction. The involvement of inflammatory processes, such as immune cell infiltration, and chronic inflammation in the pathogenesis of diabetes is less well understood in T2DM than in T1DM. However, studies conducted in the past decade have shown a strong link between inflammation and metabolic dysfunction. They have also shown that chronic inflammation plays a key role in the pathogenesis of both T1DM and T2DM. Two immunological factors commonly contribute to the pathogenesis of diabetes: the activation of inflammasomes and the release of proinflammatory cytokines in response to damage-associated molecular patterns (DAMPs). Inflammasomes are intracellular multiprotein molecular platforms. DAMPs act as endogenous danger signals. Here, we review current research on the function(s) of inflammasomes and DAMPs and discuss their pathological relevance and therapeutic implications in diabetes.

Plasma IL-1Ra: linking hyperapoB to risk factors for type 2 diabetes independent of obesity in humans

Background/Objective:

Plasma apoB predicts the incidence of type 2 diabetes (T2D); however, the link between apoB-linpoproteins and risks for T2D remain unclear. Insulin resistance (IR) and compensatory hyperinsulinemia characterize prediabetes, and the involvement of an activated interleukin-1 (IL-1) family, mainly IL-1β and its receptor antagonist (IL-Ra), is well documented. ApoB-lipoproteins were reported to promote IL-1β secretion in immune cells; however, in vivo evidence is lacking. We hypothesized that obese subjects with hyperapoB have an activated IL-1 system that explains hyperinsulinemia and IR in these subjects.

Subjects/Methods:

We examined 81 well-characterized normoglycemic men and postmenopausal women (⩾27 kg m⁻², 45–74 years, non-smokers, sedentary, free of chronic disease). Insulin secretion and sensitivity were measured by the gold-standard Botnia clamp, which is a combination of a 1-h intravenous glucose tolerance test (IVGTT) followed by 3-h hyperinsulinemic euglycemic clamp.

Results:

Plasma IL-1β was near detection limit (0.071–0.216 pg ml⁻¹), while IL-1Ra accumulated at 1000-folds higher (77–1068 pg ml⁻¹). Plasma apoB (0.34–1.80 g l⁻¹) associated significantly with hypersinsulinemia (total_IVGTT: C-peptide r=0.27, insulin r=0.22), IR (M/I=−0.29) and plasma IL-1Ra (r=0.26) but not with IL-1β. Plasma IL-1Ra associated with plasma IL-1β (r=0.40), and more strongly with hyperinsulinemia and IR than apoB, while the association of plasma IL-1β was limited to second phase and total insulin secretion (r=0.23). Adjusting the association of plasma apoB to hyperinsulinemia and IR for IL-1Ra eliminated these associations. Furthermore, despite equivalent body composition, subjects with hyperapoB (⩾80th percentile, 1.14 g l⁻¹) had higher C-peptide secretion and lower insulin sensitivity than those with low plasma apoB (⩽20th percentile, 0.78 g l⁻¹). Adjustment for plasma IL-1 Ra eliminated all group differences.

Conclusion:

Plasma apoB is associated with hyperinsulinemia and IR in normoglycemic obese subjects, which is eliminated upon adjustment for plasma IL-1Ra. This may implicate the IL-1 family in elevated risks for T2D in obese subjects with hyperapoB.

Interleukin 1β-Responsive MicroRNA-146a Is Critical for the Cytokine-Induced Tolerance and Cross-Tolerance to Toll-Like Receptor Ligands

Unwarranted overproduction of cytokines, such as interleukin (IL)-1β, can cause moderate to severe pathological complications, and thus elaborate mechanisms are needed to regulate its onset and termination. One such, well-known, mechanism is endotoxin tolerance, generally described as controlling lipopolysaccharide Toll-like receptor 4 (LPS-TLR4) signaling. Similarly, cytokine-induced tolerance plays an important role in regulating an overactive cytokine response. In this report, the capability of IL-1β to induce tolerance and cross-tolerance to various inflammatory ligands was investigated. IL-1β-stimulated THP-1 monocytes showed a gradual increase of microRNA (miR)-146a, reaching 15-fold expression by 24 h. miR-146a upregulation induced tolerance toward subsequent challenges of IL-1β, LPS, peptidoglycan, Pam and flagellin in THP-1 cells. The induction of tolerance was dependent on the IL-1β priming dose and associated increase of miR-146a expression. Moreover, IL-1β-treated THP-1 cells showed sustained miR-146a upregulation that repressed IRAK1 and TRAF6 adaptor molecules. Transfection of miR-146a alone mimicked IL-1β-induced tolerance in monocytes, while cells transfected with miR-146a inhibitor increased chemokine production. A comparable cytokine response regulated by miR-146a was also detected in lung epithelial A549 cells, purified human monocytes and mouse peritoneal macrophages. Thus, our studies showed that miR-146a was crucial for monocytic cell-based IL-1β tolerance and cross-tolerance, and thus opens the way for future research in the development of therapeutics for inflammatory diseases.

Positive association of free triiodothyronine with pancreatic β-cell function in people with prediabetes

AIM

To analyse the effects of thyroid hormones on β-cell function and glucose metabolism in people with prediabetes who are euthyroid.

METHODS

A total of 111 people who were euthyroid underwent 75-g oral glucose tolerance tests, of whom 52 were assigned to the normal glucose tolerance and 59 to the prediabetes groups. Homeostatic model assessment of β-cell function, insulinogenic index and areas under the curve for insulin and glucose were evaluated as indices of pancreatic β-cell function.

RESULTS

In both groups, BMI, fasting insulin, homeostasis model assessment ratio and HDL cholesterol correlated significantly with all indices of pancreatic β-cell function. Free triiodothyronine correlated positively with all insulin secretion indices in the prediabetes group. Multiple linear regression analysis showed that free triiodothyronine was an independent variable that had a positive correlation with all indices of β-cell function in the prediabetes group. By contrast, no such correlation was found in the normal glucose tolerance group.

CONCLUSIONS

Free triiodothyronine is associated with both basal and glucose-stimulated insulin secretion in people with prediabetes who are euthyroid; therefore, the regulation of insulin secretion by thyroid hormones is a potentially novel therapeutic target for the treatment of diabetes.

The interleukin-1 receptor antagonist anakinra improves endothelial dysfunction in streptozotocin-induced diabetic rats

Background

Endothelial dysfunction is a crucial early phenomenon in vascular diseases linked to diabetes mellitus and associated to enhanced oxidative stress. There is increasing evidence about the role for pro-inflammatory cytokines, like interleukin-1β (IL-1β), in developing diabetic vasculopathy. We aimed to determine the possible involvement of this cytokine in the development of diabetic endothelial dysfunction, analysing whether anakinra, an antagonist of IL-1 receptors, could reduce this endothelial alteration by interfering with pro-oxidant and pro-inflammatory pathways into the vascular wall.

Results

In control and two weeks evolution streptozotocin-induced diabetic rats, either untreated or receiving anakinra, vascular reactivity and NADPH oxidase activity were measured, respectively, in isolated rings and homogenates from mesenteric microvessels, while nuclear factor (NF)-κB activation was determined in aortas. Plasma levels of IL-1β and tumor necrosis factor (TNF)-α were measured by ELISA. In isolated mesenteric microvessels from control rats, two hours incubation with IL-1β (1 to 10 ng/mL) produced a concentration-dependent impairment of endothelium-dependent relaxations, which were mediated by enhanced NADPH oxidase activity via IL-1 receptors. In diabetic rats treated with anakinra (100 or 160 mg/Kg/day for 3 or 7 days before sacrifice) a partial improvement of diabetic endothelial dysfunction occurred, together with a reduction of vascular NADPH oxidase and NF-κB activation. Endothelial dysfunction in diabetic animals was also associated to higher activities of the pro-inflammatory enzymes cyclooxygenase (COX) and the inducible isoform of nitric oxide synthase (iNOS), which were markedly reduced after anakinra treatment. Circulating IL-1β and TNF-α levels did not change in diabetic rats, but they were lowered by anakinra treatment.

Conclusions

In this short-term model of type 1 diabetes, endothelial dysfunction is associated to an IL-1 receptor-mediated activation of vascular NADPH oxidase and NF-κB, as well as to vascular inflammation. Moreover, endothelial dysfunction, vascular oxidative stress and inflammation were reduced after anakinra treatment. Whether this mechanism can be extrapolated to a chronic situation or whether it may apply to diabetic patients remain to be established. However, it may provide new insights to further investigate the therapeutic use of IL-1 receptor antagonists to obtain vascular benefits in patients with diabetes mellitus and/or atherosclerosis.

Adipose tissue inflammation in glucose metabolism

Obesity is now recognised as a low grade, chronic inflammatory disease that is linked to a myriad of disorders including cancer, cardiovascular disease and type 2 diabetes (T2D). With respect to T2D, work in the last decade has revealed that cells of the immune system are recruited to white adipose tissue beds (WAT), where they can secrete cytokines to modulate metabolism within WAT. As many of these cytokines are known to impair insulin action, blocking the recruitment of immune cells has been purported to have therapeutic utility for the treatment of obesity-induced T2D. As inflammation is critical for host defence, and energy consuming in nature, the blockade of inflammatory processes may, however, result in unwanted complications. In this review, we outline the immunological changes that occur within the WAT with respect to systemic glucose homeostasis. In particular, we focus on the role of major immune cell types in regulating nutrient homeostasis and potential initiating stimuli for WAT inflammation.