Improved HUMARA for the Detection of X-Linked Agammaglobulinemia Carriers.

Background: Fragment analysis of exon 1 of the human androgen receptor, known as HUMARA, is a polymerase chain reaction (PCR)-based method for detecting X-linked agammaglobulinemia (XLA) carriers. This method takes advantage of X-chromosome inactivation (XCI) in female cells. XLA is caused by mutations in the Bruton tyrosine kinase (BTK) gene, located in Xq22.1. In this study, XCI is nonrandom or skewed in B-cells. B-cells with an active X-chromosome carrying a BTK mutation do not mature. Peripheral B-cells in XLA carriers inactivate the mutated X-chromosome. Methods: HUMARA was performed using DNA from purified B-cells and total leukocytes. DNA was digested using methylation-sensitive HhaI. The PCR of the HUMARA polymorphic marker was performed with the HhaI digested samples. The lengths of the PCR products were determined. If a suspected carrier showed skewed XCI in their B-cells, the marker length that corresponded with the length determined in the index patient indicated their carrier status. Results: HUMARA was conducted on purified B-cells; this allowed easier identification of the mutated or inactive allele, as the active allele was enzymatically digested. Analysis of 30 possible carriers using modified HUMARA corroborated that the carrier status in all samples that were heterozygous for the marker using XCI calculation for leukocytes showed a Gaussian distribution, while the carrier B-cell DNA showed a skewed XCI. Conclusion: Carrier status was successfully determined for most of the analyzed samples. B-cell enrichment resulted in precise carrier determination data, reduced the sample size, and facilitated inactive and active allele identification.

Effects on cardiometabolic risk factors after reduction of artificially sweetened beverage consumption in overweight subjects. A randomised controlled trial.

BACKGROUND: The consumption of artificially sweetened beverages (ASBs) has been linked to metabolic alterations. The effect of reducing the regular consumption of these beverages on the metabolism is currently unknown. OBJECTIVE: To evaluate the effect of reducing consumption of ASBs on the metabolism in overweight young adults. DESIGN: A randomised, single-blind, controlled, 12-week, clinical trial was performed in overweight young adults who regularly consume ASBs. The 45 subjects who participated in the study were randomly divided into two groups: (1) control group (n=21) and (2) intervention group (no intake of ASBs, n=24). Body weight and composition, fasting plasma concentrations of glucose, triglycerides, insulin, cholesterol, low-density lipoproteins and high-density lipoproteins were measured at the beginning and end of the study. and the HOMA-IR was calculated. RESULTS: At the end of 12 weeks, the intervention group showed a significant decrease (as opposed to an increase in the control group) in the percentage of change in body weight (-1.22% vs 1.31%, p<0.004), body fat (-6.28% vs 6.15%, p<0.001) and insulin resistance index (-12.06 vs 38.21%, p<0.00002), as well as in levels of glucose (-4.26% vs 0.51%, p<0.05), triglycerides (-14.74% vs 19.90%, p<0.006), insulin (-8.02% vs 39.23%, p<0.00005), cholesterol (-8.71% vs 0.77%, p<0.01) and LDL (-9.46% vs 9.92%, p<0.004). CONCLUSION: A reduction in habitual consumption of ASBs in overweight young adults decreases biochemical measurements, body weight and composition, suggesting a participation in the metabolic processes.

CD38 a biomarker and therapeutic target in non-hematopoietic tumors.

The type II transmembrane glycoprotein CD38 has recently been implicated in regulating metabolism and the pathogenesis of multiple conditions, including aging, inflammation and cancer. CD38 is overexpressed in several tumor cells and microenvironment tumoral cells, associated to migration, angiogenesis, cell invasion and progression of the disease. Thus, CD38 has been used as a progression marker for different cancer types as well as in immunotherapy. This review focuses on describing the involvement of CD38 in various non-hematopoietic cancers.

CD38 Correlates with an Immunosuppressive Treg Phenotype in Lupus-Prone Mice.

CD38 is a transmembrane glycoprotein expressed by T-cells. It has been reported that patients with systemic lupus erythematosus (SLE) showed increased CD38+CD25+ T-cells correlating with immune activation and clinical signs. Contrariwise, CD38 deficiency in murine models has shown enhanced autoimmunity development. Recent studies have suggested that CD38+ regulatory T-cells are more suppressive than CD38- regulatory T-cells. Thus, we have suggested that CD38 overexpression in SLE patients could play a role in regulating immune activation cells instead of enhancing it. This study found a correlation between CD38 with FoxP3 expression and immunosuppressive molecules (CD69, IL-10, CTLA-4, and PD-1) in T-cells from lupus-prone mice (B6.MRL-Faslpr/J). Additionally, B6.MRL-Faslpr/J mice showed a decreased proportion of CD38+ Treg cells regarding wild-type mice (WT). Furthermore, Regulatory T-Cells (Treg cells) from CD38-/- mice showed impairment in expressing immunosuppressive molecules and proliferation after stimulation through the T-cell receptor (TCR). Finally, we demonstrated an increased ratio of IFN-γ/IL-10 secretion in CD38-/- splenocytes stimulated with anti-CD3 compared with the WT. Altogether, our data suggest that CD38 represents an element in maintaining activated and proliferative Treg cells. Consequently, CD38 could have a crucial role in immune tolerance, preventing SLE development through Treg cells.

Effects on cardiometabolic risk factors after reduction of artificially sweetened beverage consumption in overweight subjects. A randomised controlled trial.

BACKGROUND: The consumption of artificially sweetened beverages (ASBs) has been linked to metabolic alterations. The effect of reducing the regular consumption of these beverages on the metabolism is currently unknown. OBJECTIVE: To evaluate the effect of reducing consumption of ASBs on the metabolism in overweight young adults. DESIGN: A randomised, single-blind, controlled, 12-week, clinical trial was performed in overweight young adults who regularly consume ASBs. The 45 subjects who participated in the study were randomly divided into two groups: (1) control group (n=21) and (2) intervention group (no intake of ASBs, n=24). Body weight and composition, fasting plasma concentrations of glucose, triglycerides, insulin, cholesterol, low-density lipoproteins and high-density lipoproteins were measured at the beginning and end of the study. and the HOMA-IR was calculated. RESULTS: At the end of 12 weeks, the intervention group showed a significant decrease (as opposed to an increase in the control group) in the percentage of change in body weight (-1.22% vs 1.31%, p<0.004), body fat (-6.28% vs 6.15%, p<0.001) and insulin resistance index (-12.06 vs 38.21%, p<0.00002), as well as in levels of glucose (-4.26% vs 0.51%, p<0.05), triglycerides (-14.74% vs 19.90%, p<0.006), insulin (-8.02% vs 39.23%, p<0.00005), cholesterol (-8.71% vs 0.77%, p<0.01) and LDL (-9.46% vs 9.92%, p<0.004). CONCLUSION: A reduction in habitual consumption of ASBs in overweight young adults decreases biochemical measurements, body weight and composition, suggesting a participation in the metabolic processes.

HIV Disease Progression: Overexpression of the Ectoenzyme CD38 as a Contributory Factor?

Despite abundant evidence associating CD38 overexpression and CD4 T cell depletion in HIV infection, no causal relation has been investigated. To address this issue, a series of mechanisms are proposed, supported by evidence from different fields, by which CD38 overexpression can facilitate CD4 T cell depletion in HIV infection. According to this model, increased catalytic activity of CD38 may reduce CD4 T cells' cytoplasmic nicotin-amide adenine dinucleotide (NAD), leading to a chronic Warburg effect. This will reduce mitochondrial function. Simultaneously, CD38's catalytic products ADPR and cADPR may be transported to the cytoplasm, where they can activate calcium channels and increase cytoplasmic Ca2+ concentrations, further altering mitochondrial integrity. These mechanisms will decrease the viability and regenerative capacity of CD4 T cells. These hypotheses can be tested experimentally, and might reveal novel therapeutic targets. Also see the video abstract here https://youtu.be/k1LTyiTKPKs.

CD38 induces differentiation of immature transitional 2 B lymphocytes in the spleen.

CD38 is a surface receptor able to induce activation, proliferation, and survival of human and mouse lymphocytes; this molecule is expressed on the surface of both mature and immature B cells. In this work, the function of CD38 in the maturation of murine B lymphocytes in the spleen was analyzed. The results showed that CD38 is highly expressed on Transitional 2 (T2) B lymphocytes with an intermediate expression on Transitional 1 (T1) and mature follicular B cells (M). Correlating with a high expression of CD38, T2 cells are also larger and more granular than T1 or M B cells. T2 cells also showed high levels of other molecules, which indicate an activated phenotype. CD38 crosslinking induced proliferation and maturation of T2 B lymphocytes; in contrast, T1 subset died by apoptosis. Finally, CD38 stimulation of T2 B lymphocytes obtained from Btk-, Lyn-, or Fyn-deficient mice showed a defective differentiation; similarly, drugs interfering with PI3K or ERK decreased the proliferation or differentiation of this subset. This suggests that these molecules participate in the CD38 signaling pathway. As a whole, the results indicate that CD38 plays an important role in the regulation of B-cell maturation in the spleen.