Decrease of elevated N,N-dimethylglycine and N-methylglycine in human immunodeficiency virus infection during short-term highly active antiretroviral therapy

Dietary dimethylglycine sodium salt supplementation alleviates redox status imbalance and intestinal dysfunction in weaned piglets with intrauterine growth restriction

There are few studies on the mechanism of redox status imbalance and intestinal dysfunction in intrauterine growth restricted (IUGR) newborn piglets. Here, we investigated the mechanism of jejunum dysfunction in weaned piglets with IUGR and the mechanism through which dimethylglycine sodium salt (DMG-Na) supplementation improving the imbalance of their redox status. In this work, a total of 10 normal birth weight (NBW) newborn piglets and 20 IUGR newborn piglets were obtained. After weaning at 21 d, they were assigned to 3 groups (n = 10/group): NBW weaned piglets fed standard basal diets (NBWC); one IUGR weaned piglets fed standard basal diets (IUGRC); another IUGR weaned piglets from the same litter fed standard basal diets plus 0.1% DMG-Na (IUGRD). The piglets in these 3 groups were sacrificed at 49 d of age, and the blood and jejunum samples were collected immediately. The growth performance values in the IUGRC group were lower (P < 0.05) than those in the NBWC group. Jejunum histomorphological parameters, inflammatory cytokines, and digestive enzyme activity as well as serum immunoglobulin were lower (P < 0.05) in the IUGRC group than those in the NBWC group. Compared with these in the NBWC group, the redox status of serum, jejunum, and mitochondria and the expression levels of jejunum redox status-related, cell adhesion-related, and mitochondrial function-related genes and proteins were suppressed in the IUGRC group (P < 0.05). However, compared with those in the IUGRC group, the growth performance values, jejunum histomorphological parameters, inflammatory cytokines, digestive enzyme activity, serum immunoglobulin, redox status of serum, jejunum, and mitochondria, and the expression levels of jejunum redox status-related, cell adhesion-related, and mitochondrial function-related genes and proteins were improved (P < 0.05) in the IUGRD group. In conclusion, dietary DMG-Na supplementation alleviates redox status imbalance and intestinal dysfunction in IUGR weaned piglets mainly by activating the sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptorγcoactivator-1α (PGC1α) pathway, thereby improving their unfavorable body state.

Dietary dimethylglycine sodium salt supplementation improves growth performance, redox status, and skeletal muscle function of intrauterine growth-restricted weaned piglets

Few studies have focused on the role of dimethylglycine sodium (DMG-Na) salt in protecting the redox status of skeletal muscle, although it is reported to be beneficial in animal husbandry. This study investigated the beneficial effects of DMG-Na salt on the growth performance, longissimus dorsi muscle (LM) redox status, and mitochondrial function in weaning piglets that were intrauterine growth restricted (IUGR). Ten normal birth weight (NBW) newborn piglets (1.53 ± 0.04 kg) and 20 IUGR newborn piglets (0.76 ± 0.06 kg) from 10 sows were obtained. All piglets were weaned at 21 d of age and allocated to the three groups with 10 replicates per group: NBW weaned piglets fed a common basal diet (N); IUGR weaned piglets fed a common basal diet (I); IUGR weaned piglets fed a common basal diet supplemented with 0.1% DMG-Na (ID). They were slaughtered at 49 d of age to collect the serum and LM samples. Compared with the N group, the growth performance, LM structure, serum, and, within the LM, mitochondrial redox status, mitochondrial respiratory chain complex activity, energy metabolites, redox status-related, cell adhesion-related, and mitochondrial function-related gene expression, and protein expression deteriorated in group I (P < 0.05). The ID group showed improved growth performance, LM structure, serum, and, within the LM, mitochondrial redox status, mitochondrial respiratory chain complex activity, energy metabolites, redox status-related, cell adhesion-related, and mitochondrial function-related gene expression, and protein expression compared with those in the I group (P < 0.05). The above results indicated that the DMG-Na salt treatment could improve the LM redox status and mitochondrial function in IUGR weaned piglets via the nuclear factor erythroid 2-related factor 2/sirtuin 1/peroxisome proliferator-activated receptorγcoactivator-1α network, thus improving their growth performance.

Micronutrients, Metabolic Complications, and Inflammation in Ugandan Children With HIV

BACKGROUND

Selenium, zinc, and chromium are essential micronutrients. Their alterations have been associated with HIV disease progression, metabolic complications, and mortality.

METHODS

This is a cross-sectional study in children with perinatally acquired HIV (PHIV, n = 57), HIV-exposed uninfected (HEU, n = 59), and HIV-unexposed uninfected (HIV-, n = 56) children aged 2 to 10 years old, age- and sex-matched, enrolled in Uganda. PHIV were on stable antiretroviral therapy (ART) with undetectable viral load. We measured plasma concentrations of selenium, zinc, and chromium as well as markers of systemic inflammation, monocyte activation, and gut integrity.

RESULTS

Among PHIV children, 93% had viral load ≤20 copies/mL, median CD4 was 37%, and 77% were receiving a nonnucleotide reserve transcriptase regimen. Median age of all participants was 8 years and 55% were girls. Median selenium concentrations were higher in PHIV compared with the HEU and HIV groups (P < 0.001), 46% of children overall had low zinc status (P = 0.18 between groups). Higher selenium, but not chromium or zinc, was associated with lower IL6, sTNFRI and II, and higher beta d glucan, a marker of fungal translocation, zonulin, a marker of gut permeability, oxidized LDL and insulin resistance (P ≤ 0.01).

CONCLUSION

In this cohort of PHIV on ART in Uganda, there is a high prevalence of low zinc status overall. Higher plasma selenium concentrations were associated with lower systemic inflammation and higher gut integrity markers. Although our findings do not support the use of micronutrient supplementation broadly for PHIV in Uganda, further studies are warranted to assess the role of selenium supplements in attenuating heightened inflammation.

Dimethylglycine sodium salt protects against oxidative damage and mitochondrial dysfunction in the small intestines of mice

Few studies have investigated the use of dimethylglycine sodium salt (DMG‑Na) to protect against small intestinal damage, despite its prevalence in the treatment of human diseases. The present study aimed to evaluate the protective effects of DMG‑Na against oxidative damage and mitochondrial dysfunction in the small intestines of mice. A total of 100 male Kunming mice were randomly assigned to five groups (n=20 per group): i) Mice gastric intubation with 0.3 ml sterile saline solution (once), then subcutaneously injected with sterile saline solution (0.5 ml) after 1 h (CON); ii) mice gastric intubation with 12 mg DMG‑Na/0.3 ml of sterile saline solution once, then subcutaneously injected with sterile saline solution (0.5 ml) 1 h later (D); iii) mice gastric intubation with 0.3 ml sterile saline solution once, then subcutaneously injected with indomethacin (10 mg/kg BW) 1 h later (IN); iv) mice gastric intubation with 12 mg DMG‑Na/0.3 ml sterile saline solution once, then subcutaneously injected with indomethacin (10 mg/kg BW) 1 h later (DIN); and v) mice subcutaneously injected with indomethacin (10 mg/kg BW), then gastrically intubated with 12 mg DMG‑Na/0.3 ml sterile saline solution once after 1 h (IND). The present study was evaluated the effects of DMG‑Na on mice intestinal damage induced by indomethacin injection. The histological morphology of the small intestine improved (P<0.05) in the DIN and IND groups, compared with the IN group. The antioxidant system was enhanced, oxidative damage was reduced, and the expression of antioxidant‑associated genes was increased in the small intestine and its mitochondria in the DIN and IND groups, compared with the IN group. The above results suggested that pretreatment and treatment with DMG‑Na reduced oxidative damage by enhancing antioxidant capacity, increasing the expression of antioxidant‑associated genes, ameliorating mitochondrial dysfunction and suppressing apoptosis. Further study is required to determine the specific mechanism by which pretreatment and treatment with DMG‑Na reduced small intestinal damage.

Association between Plasma Homocysteine Levels and Neuronal Injury in HIV Infection

Objective

To investigate the role of homocysteine in neuronal injury in HIV infection.

Methods

Using a cross-sectional design and archived samples, we compared concentrations of plasma homocysteine and cerebrospinal fluid (CSF) neurofilament light protein (NFL), a sensitive marker of neuronal injury, in 83 HIV-1-infected subjects without antiretroviral treatment. We also analyzed plasma vitamin B₁₂, serum folate, CSF, and plasma HIV RNA, the immune activation marker neopterin in CSF and serum, and albumin ratio as a marker of blood-brain barrier integrity. Twenty-two subjects provided a second sample median of 12.5 months after antiretroviral treatment initiation.

Results

A significant correlation was found between plasma homocysteine and CSF NFL concentrations in untreated individuals (r = 0.52, p < 0.0001). As expected, there was a significant inverse correlation between homocysteine and B₁₂ (r = –0.41, p < 0.001) and folate (r = –0.40, p = < 0.001) levels. In a multiple linear regression analysis homocysteine stood out as an independent predictor of CSF NFL in HIV-1-infected individuals. The correlation of plasma homocysteine and CSF NFL was also present in the group receiving antiretroviral therapy (r = 0.51, p = 0.016).

Conclusion

A correlation between plasma homocysteine and axonal injury, as measured by CSF NFL, was found in both untreated and treated HIV. While this study is not able to prove a causal link, homocysteine and functional B₁₂/folate deficiency appear to play a role in neural injury in HIV-infected individuals.

N, N-Dimethylglycine decreases oxidative stress and improves in vitro development of bovine embryos

The antioxidant effect of N, N-dimethylglycine (DMG) on in vitro-produced (IVP) bovine embryos was examined. After in vitro fertilization, presumptive zygotes were cultured with or without 0.1 μM DMG under different oxygen tensions. The percentage of embryos developing to the blastocyst stage was lowest under a 20% oxygen concentration without DMG, and it was significantly increased (P < 0.05) by applying a 5% oxygen concentration. Under the 20% oxygen concentration, supplementation of the medium with DMG significantly improved blastocyst development, which was nearly equal to that achieved under 5% oxygen without DMG. Furthermore, a tendentious increase (P = 0.06) in blastocyst cell numbers was observed when DMG was applied. In the second experiment, addition of H₂O₂ (0.5 mM) to the culture medium significantly (P < 0.01) reduced the percentage of embryos developing to the blastocyst stage. However, DMG supplementation prevented this reduction. In conclusion, DMG enhanced the in vitro development of IVP bovine embryos by acting as an antioxidant.

Elevated homocysteine levels in human immunodeficiency virus-infected patients under antiretroviral therapy: A meta-analysis

AIM: To evaluate the association between the levels of homocysteine (Hcy), folate, vitamin B12 in human immunodeficiency virus (HIV)-infected patients who were treated with antiretroviral therapy (ART) or not treated with ART.

METHODS: The PubMed and Scielo databases were searched. Eligible studies regarding plasma Hcy level in HIV-infected patients were firstly identified. After careful analysis by two independent researches, the identified articles were included in the review according to two outcomes (1) Hcy, folate and vitamin B12 blood concentration in HIV-infected subjects vs health controls and; (2) Hcy blood concentration in HIV-infected subjects under ART vs not treated with ART. RevMan (version 5.2) was employed for data synthesis.

RESULTS: A total of 12 studies were included in outcome 1 (1649 participants, 932 cases and 717 controls). Outcome 1 meta-analysis demonstrated higher plasma Hcy (2.05 µmol/L; 95%CI: 0.10 to 4.00, P < 0.01) and decreased plasma folate concentrations (-2.74 ng/mL; 95%CI: -5.18 to -0.29, P < 0.01) in HIV-infected patients compared to healthy controls. No changes in vitamin B12 plasma concentration were observed between groups. All studies included in the outcome 2 meta-analysis (1167 participants; 404 HIV-infected exposed to ART and 757 HIV-infected non-ART patients) demonstrated higher mean Hcy concentration in subjects HIV-infected under ART compared to non-ART HIV subjects (4.13 µmol/L; 95%CI: 1.34 to 6.92, P < 0.01).

CONCLUSION: This meta-analysis demonstrated that the levels of Hcy and folate, but not vitamin B12, were associated with HIV infection. In addition, Hcy levels were higher in HIV-infected patients who were under ART compared to HIV-infected patients who were not exposed to ART. Our results suggest that hyperhomocysteinemia should be included among the several important metabolic disturbances that are associated with ART in patients with HIV infection.

A novel amino acid analysis method using derivatization of multiple functional groups followed by liquid chromatography/tandem mass spectrometry

We have developed a novel amino acid analysis method using derivatization of multiple functional groups (amino, carboxyl, and phenolic hydroxyl groups).

Effects of N, N-dimethylglycine on the development of in vitro produced bovine embryos

This study investigated the effects of N, N-Dimethylglycine (DMG) on the development of in vitro produced (IVP) bovine embryos. IVP embryos were obtained by in vitro fertilization of in vitro matured oocytes for 6 h. In Experiment 1, IVP embryos were cultured in mSOFaa supplemented with bovine serum albumin but without glucose (SOF1) for 4 days, transferred to mSOFaa (with 5% fetal bovine serum and 1.5 mM glucose; SOF2) supplemented with 0 (control), 0.1,1 or 10 microM DMG and cultured for an additional 7 days (11 days in total) to assess their development in vitro. When cultured in the medium with 0.1 microM DMG, a significantly higher number of IVP embryos developed to the blastocyst and hatched blastocyst stages (40.3 and 40.8%, respectively) compared with the other groups (18.7-31.0% and 15.0-28.7%, respectively; P<0.05, analysis of variance). In Experiment 2, IVP embryos were cultured in SOF1 with or without 0.1 microM DMG for 4 days, transferred to SOF2 with or without 0.1 microM DMG and further cultured as in Experiment 1; DMG was added to either SOF1 or SOF2 and to both of them to assess its exposure effects on embryo development. When cultured continuously with DMG for 11 days, significantly higher rates of IVP embryos developed into blastocyst and hatched blastocyst stages (39.0 and 47.7%, respectively) compared with the other groups (31.0-32.2% and 29.5-31.0%, respectively; P<0.05). In Experiment 3, we examined developmental speed of IVP embryos cultured with or without addition of 0.1 microM DMG to IVC medium after 7 days of IVC. When DMG was added to IVC medium, the ratio of embryos developed to advanced developmental stages (No. of embryos developed to the blastocyst and expanded blastocyst stages/No. of embryos developed to the morula stage) was 28.7% (86/3) and 7 times higher than that of those cultured without DMG, 4.0% (52/13). These results suggest that addition of 0.1 microM DMG to mSOFaa during IVC of IVP bovine embryos has a promoting effect on their development.

Micronutrients in HIV-positive persons receiving highly active antiretroviral therapy

In HIV-infected persons, low serum concentrations of vitamins and minerals, termed micronutrients, are associated with an increased risk of HIV disease progression and mortality. Micronutrient supplements can delay HIV disease progression and reduce mortality in HIV-positive persons not receiving highly active antiretroviral therapy (HAART). With the transition to more universal access to HAART, a better understanding of micronutrient deficiencies and the role of micronutrient supplements in HIV-positive persons receiving HAART has become a priority. The provision of simple, inexpensive micronutrient supplements as an adjunct to HAART may have several cellular and clinical benefits, such as a reduction in mitochondrial toxicity and oxidative stress and an improvement in immune reconstitution. We reviewed observational and trial evidence on micronutrients in HIV-positive persons receiving HAART to summarize the current literature and suggest future research priorities. A small number of observational studies have suggested that some, but not all, micronutrients may become replete after HAART initiation, and few intervention studies have found that certain micronutrients may be a beneficial adjunct to HAART. However, most of these studies had some major limitations, including a small sample size, a short duration of follow-up, a lack of adjustment for inflammatory markers, and an inadequate assessment of HIV-related outcomes. Therefore, few data are available to determine whether HAART ameliorates micronutrient deficiencies or to recommend or refute the benefit of providing micronutrient supplements to HIV-positive persons receiving HAART. Because micronutrient supplementation may cause harm, randomized placebo-controlled trials are needed. Future research should determine whether HAART initiation restores micronutrient concentrations, independent of inflammatory markers, and whether micronutrient supplements affect HIV-related outcomes in HIV-positive persons receiving HAART.

Influence of folate serum concentration on plasma homocysteine levels in HIV-positive patients exposed to protease inhibitors undergoing HAART

BACKGROUND

Homocysteinemia (Hcy) increase and risk factors in HIV-positive patients are not clear yet.

METHODS

HIV-positive patients on stable highly active antiretroviral therapy (HAART) regimens for at least 6 months were enrolled in this cross-sectional study. Among other factors, vitamin B12, folate and length of exposure to protease inhibitors (PIs) were evaluated for their possible correlation with hyper-Hcy (>13 micromol/l in females; >15 micromol/l in males) by logistic regression analysis.

RESULTS

Ninety-eight HIV-positive patients were recruited. Twenty-eight (28.6%) had hyper-Hcy. Length of exposure to antiretroviral therapy and PIs did not result to be significantly associated with hyper-Hcy risk. Normal folate level was the only factor associated with the outcome, resulting protective from hyper-Hcy, either at univariate (OR = 0.22; CI 95% = 0.06-0.86; p = 0.029) and multivariable (OR = 0.24; CI 95% = 0.06-0.94; p = 0.04) logistic regression analysis. Folate predictive value of hyper-Hcy risk was driven by levels in the lowest quartiles of the study population (i.e. <10.9 nmol/l).

CONCLUSIONS

No significant correlations were observed between hyper-Hcy and length of exposure to antiretroviral therapy or PIs. Folate could be a confounding factor in the association between hyper-Hcy and PI exposure found by others. The potential value of folate supplementation, in those who are deficient and in those with hyper-Hcy, merits study.

Determination of choline, betaine, and dimethylglycine in plasma by a high-throughput method based on normal-phase chromatography-tandem mass spectrometry

BACKGROUND

The quaternary ammonium compounds, choline and betaine, and dimethylglycine (DMG) reside along a metabolic pathway linked to the synthesis of neurotransmitters and membrane phospholipids and to homocysteine remethylation and, therefore, folate status. Lack of a convenient, high-throughput method for the determination of these compounds has prevented population-based studies of their possible associations with lifestyle, nutrition, and chronic diseases.

METHODS

Serum or plasma samples were deproteinized by mixing with three volumes of acetonitrile that contained d(9)-choline and d(9)-betaine as internal standards. We used a normal-phase silica column for the separation of choline (retention time, 2.8 min), betaine (1.3 min), DMG (1.15 min), and internal standards, which were detected as positive ions by tandem mass spectroscopy in the multiple-reaction monitoring mode, using the molecular transitions m/z 104-->60 (choline), m/z 113-->69 (d(9)-choline), m/z 118-->59 (betaine), m/z 127-->68 (d(9)-betaine), and m/z 104-->58 (DMG).

RESULTS

For all three metabolites, the assay was linear in the range 0.4-400 micromol/L, and the lower limit of the detection (signal-to-noise ratio = 5) was < or =0.3 micromol/L. The within- and between-day imprecision (CVs) was 2.1-7.2% and 3.5-8.8%, respectively. The analytical recovery was 87-105%. The fasting plasma concentrations (median, 25th-75th percentiles) were 8.0 (7.0-9.3) micromol/L for choline, 31.7 (27.0-41.1) micromol/L for betaine, and 1.66 (1.30-2.02) micromol/L for DMG in 60 healthy blood donors. In individuals who had eaten a light breakfast, plasma concentrations of all three metabolites were significantly (25-30%) higher than in fasting individuals.

CONCLUSION

This is the first method for the combined measurement of choline, betaine, and DMG in human plasma or serum. The assay is characterized by simple sample preparation, no derivatization, high throughput, imprecision (CV) <10%, detection limits below the values seen in volunteers, and the high specificity provided by tandem mass spectroscopy.