The production of reactive oxygen species in TLR-stimulated granulocytes is not enhanced by hyperglycemia in diabetes

Cadmium induced immunosuppression through TLR-IκBα-NFκB signaling by promoting autophagic degradation

Environmental and occupational exposure to cadmium (Cd) poses a serious threat to human health. Recent studies indicate that Cd perturbs the immune system and increases the risk of pathogenicity and mortality of bacterial or virus infection. However, the underlying mechanism of Cd-modulated immune responses remains unclear. In this study, we aim to investigate the role of Cd in the immune function of mouse spleen tissues and its primary T cells with Concanavalin A (ConA, a well-known T cell mitogen) activation condition, and elucidate the molecular mechanism. The results showed that Cd exposure inhibited ConA-induced the expressions of tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) in mouse spleen tissues. Furthermore, the transcriptomic profile by RNA-sequence reveals that: (1) Cd exposure can alter immune system process; (2) Cd may affect the NFκB signaling pathway. Both in vitro and in vivo results showed that Cd exposure reduced ConA-activated toll-like receptor 9 (TLR9)-IκBα-NFκB signaling, and the expressions of TLR9, TNF-α and IFN-γ, which were effectively reversed by autophagy-lysosomal inhibitors. All these results confirmedly demonstrated that, by promoting the autophagy-lysosomal degradation of TLR9, Cd suppressed immune response under ConA activation condition. This study provides insight on the mechanism of Cd immunnotoxicity, which might contribute to the prevention of Cd toxicity in the future.

New Advances on Pathophysiology of Diabetes Neuropathy and Pain Management: Potential Role of Melatonin and DPP-4 Inhibitors

Pre-diabetes and diabetes are growing threats to the modern world. Diabetes mellitus (DM) is associated with comorbidities such as hypertension (83.40%), obesity (90.49%), and dyslipidemia (93.43%), creating a substantial burden on patients and society. Reductive and oxidative (Redox) stress level imbalance and inflammation play an important role in DM progression. Various therapeutics have been investigated to treat these neuronal complications. Melatonin and dipeptidyl peptidase IV inhibitors (DPP-4i) are known to possess powerful antioxidant and anti-inflammatory properties and have garnered significant attention in the recent years. In this present review article, we have reviewed the recently published reports on the therapeutic efficiency of melatonin and DPP-4i in the treatment of DM. We summarized the efficacy of melatonin and DPP-4i in DM and associated complications of diabetic neuropathy (DNP) and neuropathic pain. Furthermore, we discussed the mechanisms of action and their efficacy in the alleviation of oxidative stress in DM.

TLR2 Agonistic Small Molecules: Detailed Structure-Activity Relationship, Applications, and Future Prospects

Toll-like receptors (TLRs) are the pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) in microbial species. Among the various TLRs, TLR2 has a special place due to its ability to sense the widest repertoire of PAMPs owing to its heterodimerization with either TLR1 or TLR6, broadening its ligand diversity against pathogens. Various scaffolds are reported to activate TLR2, which include naturally occurring lipoproteins, synthetic lipopeptides, and small heterocyclic molecules. We described a detailed SAR in TLR2 agonistic scaffolds and also covered the design and chemistry for the conjugation of TLR2 agonists to antigens, carbohydrates, polymers, and fluorophores. The approaches involved in delivery of TLR2 agonists such as lipidation of antigen, conjugation to polymers, phosphonic acids, and other linkers to achieve surface adsorption, liposomal formulation, and encapsulating nanoparticles are elaborated. The crystal structure analysis and computational modeling are also included with the structural features that facilitate TLR2 activation.

Prominent and emerging anti-diabetic molecular targets

Diabetes is on the rise across the globe affecting more than 463 million people and crucially increasing morbidities of diabetes-associated diseases. Urgent and immense actions are needed to improve diabetes prevention and treatment. Regarding the correlation of diabetes with many associated diseases, inhibition of the disease progression is more crucial than controlling symptoms. Currently, anti-diabetic drugs are accompanied by undesirable side-effects and target confined types of biomolecules. Thus, extensive research is demanding to identify novel disease mechanisms and molecular targets as probable candidates for effective treatment of diabetes. This review discusses the conventional molecule targets that have been applied for their therapeutic rationale in treatment of diabetes. Further, the emerging and prospective molecular targets for the future focus of library screenings are presented.

ROS systems are a new integrated network for sensing homeostasis and alarming stresses in organelle metabolic processes

Reactive oxygen species (ROS) are critical for the progression of cardiovascular diseases, inflammations and tumors. However, the mechanisms of how ROS sense metabolic stress, regulate metabolic pathways and initiate proliferation, inflammation and cell death responses remain poorly characterized. In this analytic review, we concluded that: 1) Based on different features and functions, eleven types of ROS can be classified into seven functional groups: metabolic stress-sensing, chemical connecting, organelle communication, stress branch-out, inflammasome-activating, dual functions and triple functions ROS. 2) Among the ROS generation systems, mitochondria consume the most amount of oxygen; and nine types of ROS are generated; thus, mitochondrial ROS systems serve as the central hub for connecting ROS with inflammasome activation, trained immunity and immunometabolic pathways. 3) Increased nuclear ROS production significantly promotes cell death in comparison to that in other organelles. Nuclear ROS systems serve as a convergent hub and decision-makers to connect unbearable and alarming metabolic stresses to inflammation and cell death. 4) Balanced ROS levels indicate physiological homeostasis of various metabolic processes in subcellular organelles and cytosol, while imbalanced ROS levels present alarms for pathological organelle stresses in metabolic processes. Based on these analyses, we propose a working model that ROS systems are a new integrated network for sensing homeostasis and alarming stress in metabolic processes in various subcellular organelles. Our model provides novel insights on the roles of the ROS systems in bridging metabolic stress to inflammation, cell death and tumorigenesis; and provide novel therapeutic targets for treating those diseases. (Word count: 246).

Atorvastatin Inhibited ROS Generation and Increased IL-1β And IL-6 Release by Mononuclear Cells from Diabetic Patients

BACKGROUND

Atorvastatin (ATV) inhibits the conversion of 3-Hydroxy-3-Methylglutaryl Coenzyme A (HMG-CoA) to mevalonate formation and promotes lowering of the LDL cholesterol fraction. However, ATV exhibits pleiotropic metabolic actions beyond cholesterol-lowering properties.

OBJECTIVE

We aimed to evaluate the effect of ATV on oxidizing species generation and cytokine secretion in Peripheral Blood Mononuclear Cells (PBMNC) of Type 2 Diabetes Mellitus (T2DM) patients in comparison to healthy control.

METHODS

Both NADPH-oxidase-dependent and mitochondrial ROS generation were assessed by chemoluminescence luminol-dependent assay and fluorometric experiment, using Dichlorofluorescein Assay (DCFH-DA), respectively. IL-1β and IL-6 were quantified by classical ELISA.

RESULTS

ATV inhibited NADPH-oxidase dependent ROS generation, but showed no effect on mitochondrial ROS generation and activated IL-1β and IL-6 secretions in PBMNC from control and T2DM patients. ROS generation and cytokine secretion in the presence of an inhibitor of Protein Kinase Cβ (iPKCβ) and ATV led to similar results. The secretion of IL-1β, PDB-induced in the presence of iPKCβ, but not ATV, was increased. ATV and iPKCβ exacerbated PDB-induced IL-6 secretion. LPS activated the secretion of IL-1β and IL-6 which was potentiated by ATV.

CONCLUSION

ATV inhibited ROS generation and activated IL-1 β/IL-6 secretion in PBMNC of diabetes patients. Its effect was not affected by the hyperglycemia.

C60 fullerene and its nanocomplexes with anticancer drugs modulate circulating phagocyte functions and dramatically increase ROS generation in transformed monocytes

Background

C₆₀ fullerene-based nanoformulations are proposed to have a direct toxic effect on tumor cells. Previous investigations demonstrated that C₆₀ fullerene used alone or being conjugated with chemotherapeutic agents possesses a potent anticancer activity. The main aim of this study was to investigate the effect of C₆₀ fullerene and its nanocomplexes with anticancer drugs on human phagocyte metabolic profile in vitro.

Methods

Analysis of the metabolic profile of phagocytes exposed to C₆₀ fullerene in vitro revealed augmented phagocytic activity and down-regulated reactive nitrogen species generation in these cells. Additionally, cytofluorimetric analysis showed that C₆₀ fullerene can exert direct cytotoxic effect on normal and transformed phagocytes through the vigorous induction of intracellular reactive oxygen species generation.

Results

Cytotoxic action as well as the pro-oxidant effect of C₆₀ fullerene was more pronounced toward malignant phagocytes. At the same time, C₆₀ fullerenes have the ability to down-regulate the pro-oxidant effect of cisplatin on normal cells. These results indicate that C₆₀ fullerenes may influence phagocyte metabolism and have both pro-oxidant and antioxidant properties.

Conclusions

The antineoplastic effect of C₆₀ fullerene has been observed by direct toxic effect on tumor cells, as well as through the modulation of the functions of effector cells of antitumor immunity.

Toll-like receptor 2 and type 2 diabetes

Innate immunity plays a crucial role in the pathogenesis of type 2 diabetes and related complications. Since the toll-like receptors (TLRs) are central to innate immunity, it appears that they are important participants in the development and pathogenesis of the disease. Previous investigations demonstrated that TLR2 homodimers and TLR2 heterodimers with TLR1 or TLR6 activate innate immunity upon recognition of damage-associated molecular patterns (DAMPs). Several DAMPs are released during type 2 diabetes, so it may be hypothesized that TLR2 is significantly involved in its progression. Here, we review recent data on the important roles and status of TLR2 in type 2 diabetes and related complications.