Biochemical and clinical relevance of alpha lipoic acid: antioxidant and anti-inflammatory activity, molecular pathways and therapeutic potential

The molecular nature of lipoic acid (LA) clarifies its capability of taking part to a variety of biochemical reactions where redox state is meaningful. The pivotal action of LA is the antioxidant activity due to its ability to scavenge and inactivate free radicals. Furthermore, LA has been shown to chelate toxic metals both directly and indirectly by its capability to enhance intracellular glutathione (GSH) levels. This last property is due to its ability to interact with GSH and recycle endogenous GSH. LA exhibits significant antioxidant activity protecting against oxidative damage in several diseases, including neurodegenerative disorders. Interestingly, LA is unique among natural antioxidants for its capability to satisfy a lot of requirements, making it a potentially highly effective therapeutic agent for many conditions related with oxidative damage. In particular, there are evidences showing that LA has therapeutic activity in lowering glucose levels in diabetic conditions. Similarly, LA supplementation has multiple beneficial effects on the regression of the mitochondrial function and on oxidative stress associated with several diseases and aging

SPARC expression in CML is associated to imatinib treatment and to inhibition of leukemia cell proliferation

BACKGROUND: SPARC is a matricellular glycoprotein with growth-inhibitory and antiangiogenic activity in some cell types. The study of this protein in hematopoietic malignancies led to conflicting reports about its role as a tumor suppressor or promoter, depending on its different functions in the tumor microenvironment. In this study we investigated the variations in SPARC production by peripheral blood cells from chronic myeloid leukemia (CML) patients at diagnosis and after treatment and we identified the subpopulation of cells that are the prevalent source of SPARC. METHODS: We evaluated SPARC expression using real-time PCR and western blotting. SPARC serum levels were detected by ELISA assay. Finally we analyzed the interaction between exogenous SPARC and imatinib (IM), in vitro, using ATP-lite and cell cycle analysis. RESULTS: Our study shows that the CML cells of patients at diagnosis have a low mRNA and protein expression of SPARC. Low serum levels of this protein are also recorded in CML patients at diagnosis. However, after IM treatment we observed an increase of SPARC mRNA, protein, and serum level in the peripheral blood of these patients that had already started at 3 months and was maintained for at least the 18 months of observation. This SPARC increase was predominantly due to monocyte production. In addition, exogenous SPARC protein reduced the growth of K562 cell line and synergized in vitro with IM by inhibiting cell cycle progression from G1 to S phase. CONCLUSION: Our results suggest that low endogenous SPARC expression is a constant feature of BCR/ABL positive cells and that IM treatment induces SPARC overproduction by normal cells. This exogenous SPARC may inhibit CML cell proliferation and may synergize with IM activity against CML

Targeted Metabolomics Highlights Dramatic Antioxidant Depletion, Increased Oxidative/Nitrosative Stress and Altered Purine and Pyrimidine Concentrations in Serum of Primary Myelofibrosis Patients

To date, little is known concerning the circulating levels of biochemically relevant metabolites (antioxidants, oxidative/nitrosative stress biomarkers, purines, and pyrimidines) in patients with primary myelofibrosis (PMF), a rare form of myeloproliferative tumor causing a dramatic decrease in erythropoiesis and angiogenesis. In this study, using a targeted metabolomic approach, serum samples of 22 PMF patients and of 22 control healthy donors were analyzed to quantify the circulating concentrations of hypoxanthine, xanthine, uric acid (as representative purines), uracil, β-pseudouridine, uridine (as representative pyrimidines), reduced glutathione (GSH), ascorbic acid (as two of the main water-soluble antioxidants), malondialdehyde, nitrite, nitrate (as oxidative/nitrosative stress biomarkers) and creatinine, using well-established HPLC method for their determination. Results showed that PMF patients have dramatic depletions of both ascorbic acid and GSH (37.3- and 3.81-times lower circulating concentrations, respectively, than those recorded in healthy controls, p < 0.0001), accompanied by significant increases in malondialdehyde (MDA) and nitrite + nitrate (4.73- and 1.66-times higher circulating concentrations, respectively, than those recorded in healthy controls, p < 0.0001). Additionally, PMF patients have remarkable alterations of circulating purines, pyrimidines, and creatinine, suggesting potential mitochondrial dysfunctions causing energy metabolism imbalance and consequent increases in these cell energy-related compounds. Overall, these results, besides evidencing previously unknown serum metabolic alterations in PMF patients, suggest that the determination of serum levels of the aforementioned compounds may be useful to evaluate PMF patients on hospital admission for adjunctive therapies aimed at recovering their correct antioxidant status, as well as to monitor patients’ status and potential pharmacological treatments

Bortezomib modulates CHIT1 and YKL40 in monocyte-derived osteoclast and in myeloma cells

Osteolytic bone disease is a common manifestation of multiple myeloma (MM) that leads to progressive skeleton destruction and is the most severe cause of morbidity in MM patients.It results from increased osteolytic activity and decrease osteoblastic function. Activation of mammalian chitinases CHIT1 and YKL40 is associated with osteoclast (OCs) differentiation and bone digestion. In the current study, we investigated the effect of two Bortezomib’s concentration (BO) (2.5 nM and 5nM) on osteoclastogenesis by analyzing regulation of chitinase expression. OCs exposition to BO was able to inhibit the expression of different OCs markers such as RANK, CTSK, TRAP and MMP9. In addition BO-treatment reduced CHIT1 enzymatic activity and both CHIT1 and YKL40 mRNA expression levels and cytoplasmatic and secreted protein. Moreover, immunofluorescence evaluation of mature OCs showed that BO was able to translocate YKL40 into the nucleus, while CHIT1 remained into the cytoplasm. Since MM cell lines such as U266, SKM-M1 and MM1 showed high levels of CHIT1 activity, we analyzed bone resorption ability of U266 using dentin disc assay resorption pits. Silencing chitinase proteins in U266 cell line with specific siRNAs, resulted in pits number reduction on dentine discs. In conclusion, we showed that BO decreases osteoclastogenesis and reduces bone resorption in OCs and U266 cell line by modulating the chitinases CHIT1 and YKL40. These results indicate that chitinases may be a therapeutic target for bone disease in MM patients

Effect of Lipoic Acid on the Biochemical Mechanisms of Resistance to Bortezomib in SH-SY5Y Neuroblastoma Cells

Neuroblastoma (NB) is an extracranial solid cancer and the most common cancer in infancy. Despite the standard treatment for NB is based on the combination of chemotherapeutic drugs such as doxorubicin, vincristine, cyclophosphamide, and cisplatin, chemoresistance occurs over the time. The aim of the present research was to evaluate the effect of bortezomib (BTZ) (50 nM) on NB cell viability and how lipoic acid (ALA) (100 μM) modifies pharmacological response to this chemotherapeutic agent. Cell viability was assessed by ATP luminescence assay whereas expression of oxidative stress marker (i.e., heme oxygenase-1) and endoplasmic reticulum stress proteins was performed by real-time PCR, western blot, and immunofluorescence. Our data showed that BTZ treatment significantly reduced cell viability when compared to untreated cultures (about 40%). Interestingly, ALA significantly reduced the efficacy of BTZ (about 30%). Furthermore, BTZ significantly induced heme oxygenase-1 as a result of increased oxidative stress and such overexpression was prevented by concomitant treatment with ALA. Similarly, ALA significantly reduced BTZ-mediated endoplasmic reticulum stress as measured by reduction in BiP1 and IRE1α, ERO1α, and PDI expression. In conclusion, our data suggest that BTZ efficacy is dependent on cellular redox status and such mechanisms may be responsible of chemoresistance to this chemotherapeutic agent

Effectiveness, safety, and tolerability of delayed dexamethasone, rituximab, and cyclophosphamide as first-line treatment in patients with Waldenström macroglobulinemia: data from the Sicilian Myeloma Network

BackgroundWaldenström macroglobulinemia (WM) is a rare and indolent B-cell lymphoproliferative disorder with greater incidence in elderly patients where a precise algorithm of initial therapy is still not clear. Immunochemotherapy regimen consisting of dexamethasone, rituximab, and oral cyclophosphamide (DRC) is considered a suitable first-line treatment because of its safety, efficacy, and manageability.Patients and methodsWe retrospectively describe the results of 36 consecutive treatment-naïve patients with WM who were treated from June 2013 until June 2021 with the DRC regimen every 4 weeks instead of 3 weeks, for six cycles. The median age was 69 years (range, 42–85 years), with one-third being older than 75 years. Most patients had features of advanced disease, with nearly 60% being high risk. Median IgM level prior to treatment initiation was 2.9 g/dL.ResultsOverall response rate was 80% after a median time of two cycles, with 67% of patients achieving at least partial response. After a median follow-up of 59 months, the median overall survival (OS) was not reached and the median time to next treatment (TTNT) was 48 months (95% CI 25–87 months). Approximately 70% of the evaluable study population had a 3-year survival without additional treatment, while 75% had a 3-year OS rate. The treatment was well-tolerated with only two patients (6%) recorded to have grade 3 pneumonia and no grade 3 hematological toxicity maybe due to the regular use of growth factors for red and white blood cells. Baseline albumin level and achievement of at least minimal or partial response had a significant impact on TTNT, while baseline hemoglobin and IgA level affected outcome in terms of OS (p < 0.05).ConclusionThis is the first real-life experience describing the use of the DRC regimen in treatment-naive patients with WM with administration of therapy every 4 weeks instead of 3 weeks showing apparent comparable efficacy, along with good tolerability and safety, especially in terms of hematological toxicity, independently from comorbidity burden

In-vitro NET-osis induced by COVID-19 sera is associated to severe clinical course in not vaccinated patients and immune-dysregulation in breakthrough infection

: Since neutrophil extracellular traps formation (NET-osis) can be assessed indirectly by treating healthy neutrophils with blood-derived fluids from patients and then measuring the NETs response, we designed a pilot study to convey high-dimensional cytometry of peripheral blood immune cells and cytokines, combined with clinical features, to understand if NET-osis assessment could be included in the immune risk profiling to early prediction of clinical patterns, disease severity, and viral clearance at 28 days in COVID-19 patients. Immune cells composition of peripheral blood, cytokines concentration and in-vitro NETosis were detected in peripheral blood of 41 consecutive COVID-19 inpatients, including 21 mild breakthrough infections compared to 20 healthy donors, matched for sex and age. Major immune dysregulation in peripheral blood in not-vaccinated COVID-19 patients compared to healthy subjects included: a significant reduction of percentage of unswitched memory B-cells and transitional B-cells; loss of naïve CD3+CD4+CD45RA+ and CD3+CD8+CD45RA+ cells, increase of IL-1β, IL-17A and IFN-γ. Myeloid compartment was affected as well, due to the increase of classical (CD14++CD16-) and intermediate (CD14++CD16+) monocytes, overexpressing the activation marker CD64, negatively associated to the absolute counts of CD8+ CD45R0+ cells, IFN-γ and IL-6, and expansion of monocytic-like myeloid derived suppressor cells. In not-vaccinated patients who achieved viral clearance by 28 days we found at hospital admission lower absolute counts of effector cells, namely CD8+T cells, CD4+ T-cells and CD4+CD45RO+ T cells. Percentage of in-vitro NET-osis induced by patients' sera and NET-osis density were progressively higher in moderate and severe COVID-19 patients than in mild disease and controls. The percentage of in-vitro induced NET-osis was positively associated to circulating cytokines IL-1β, IFN-γ and IL-6. In breakthrough COVID-19 infections, characterized by mild clinical course, we observed increased percentage of in-vitro NET-osis, higher CD4+ CD45RO+ and CD8+ CD45RO+ T cells healthy or mild-COVID-19 not-vaccinated patients, reduced by 24 h of treatment with ACE inhibitor ramipril. Taken together our data highlight the role of NETs in orchestrating the complex immune response to SARS-COV-2, that should be considered in a multi-target approach for COVID-19 treatment

IMMUNE ESCAPE MECHANISMS IN HEMATOLOGICAL DISEASES

The interactions between the immune system and the tumor cells occur through complex events that lead to tumor eradication or immune evasion by cancer. Recently, the prognostic role of Myeloid derived suppressor cells (MDSC) accumulation has been documented for some hematological malignancies where they correlates with disease progression and persistence of minimal residual disease. We first evaluated the change of MDSC frequency in hematological patients during therapy founding a significant correlation between the number of persistent monocytic-MDSC and major molecular response (MMR) value in chronic myeloid leukemia patients treated with dasatinib. Moreover, our data demonstrated that tumor cells, through the release of soluble factors and exosomes, are able to expand monocytic-MDSC, creating an immunotolerant environment that results in T cell anergy and facilitates tumor growth. In addition, cancer cells are also able to promote immune dysfunction in MSC with their consequent commitment, via TLR4 signaling, toward an activated status promoting immune escape through the polarization of neutrophils in immunosuppressive cells

IGFBP-6: At the Crossroads of Immunity, Tissue Repair and Fibrosis

Insulin-like growth factors binding protein-6 (IGFBP-6) is involved in a relevant number of cellular activities and represents an important factor in the immune response, particularly in human dendritic cells (DCs). Over the past several years, significant insights into the IGF-independent effects of IGFBP-6 were discovered, such as the induction of chemotaxis, capacity to increase oxidative burst and neutrophils degranulation, ability to induce metabolic changes in DCs, and, more recently, the regulation of the Sonic Hedgehog (SHH) signaling pathway during fibrosis. IGFBP-6 has been implicated in different human diseases, and it plays a rather controversial role in the biology of tumors. Notably, well established relationships between immunity, stroma activity, and fibrosis are prognostic and predictive of response to cancer immunotherapy. This review aims at describing the current understanding of mechanisms that link IGFBP-6 and fibrosis development and at highlighting the multiple roles of IGFBP-6 to provide an insight into evolutionarily conserved mechanisms that can be relevant for inflammation, tumor immunity, and immunological diseases