Long-term effects of gestational diabetes on offspring health are more pronounced in skeletal growth than body composition and glucose tolerance

Identify gestational diabetes mellitus by deep learning model from cell-free DNA at the early gestation stage

Gestational diabetes mellitus (GDM) is a common complication of pregnancy, which has significant adverse effects on both the mother and fetus. The incidence of GDM is increasing globally, and early diagnosis is critical for timely treatment and reducing the risk of poor pregnancy outcomes. GDM is usually diagnosed and detected after 24 weeks of gestation, while complications due to GDM can occur much earlier. Copy number variations (CNVs) can be a possible biomarker for GDM diagnosis and screening in the early gestation stage. In this study, we proposed a machine-learning method to screen GDM in the early stage of gestation using cell-free DNA (cfDNA) sequencing data from maternal plasma. Five thousand and eighty-five patients from north regions of Mainland China, including 1942 GDM, were recruited. A non-overlapping sliding window method was applied for CNV coverage screening on low-coverage (~0.2×) sequencing data. The CNV coverage was fed to a convolutional neural network with attention architecture for the binary classification. The model achieved a classification accuracy of 88.14%, precision of 84.07%, recall of 93.04%, F1-score of 88.33% and AUC of 96.49%. The model identified 2190 genes associated with GDM, including DEFA1, DEFA3 and DEFB1. The enriched gene ontology (GO) terms and KEGG pathways showed that many identified genes are associated with diabetes-related pathways. Our study demonstrates the feasibility of using cfDNA sequencing data and machine-learning methods for early diagnosis of GDM, which may aid in early intervention and prevention of adverse pregnancy outcomes.

Boys but Not Girls Exposed to Maternal Gestational Diabetes Mellitus Have Unfavorable Fat Distribution

BACKGROUND

Maternal gestational diabetes mellitus (GDM) and overweight are associated with an increased risk of obesity and the metabolic syndrome in the adult offspring. We studied the influence of maternal GDM on prepubertal children's body composition and bone mineral biochemistry.

METHODS

A total of 134 prepubertal Caucasian children (age range 4.4-9.7 years) were studied in a controlled cross-sectional study. Seventy-six children had been exposed to maternal GDM and 58 children born after a normal pregnancy served as controls. The outcome variables were body fat %, android fat %, gynoid fat %, android/gynoid fat ratio, bone mineral density (BMD), bone mineral content (BMC), muscle mass, lean mass (LM) and serum 25-hydroxyvitamin D, ionized calcium, phosphate, and alkaline phosphatase concentrations.

RESULTS

There were no differences in body fat %, android fat %, BMD, BMC, muscle mass, or LM between the study groups. Gynoid fat % was higher in the GDM than control children (p = 0.03). Android fat %, gynoid fat %, and android/gynoid fat ratio were higher in the GDM boys than control boys (p = 0.046, 0.037, and 0.038) respectively, but no differences were found between the GDM and control girls.

CONCLUSIONS

Boys exposed to maternal GDM presented with more unfavorable fat distribution than their controls, whereas no difference was found between the girls. Otherwise, the differences in body composition were minimal between prepubertal GDM and control children.

Nutrients, Diet, and Other Factors in Prenatal Life and Bone Health in Young Adults: A Systematic Review of Longitudinal Studies

Optimizing skeletal health in early life has potential effects on bone health later in childhood and in adulthood. We aimed to evaluate the existing evidence that maternal exposures during pregnancy have an impact on the subsequent bone health among offspring in young adults aged between 16 and 30 years. The protocol is registered in the International Prospective Register of Systematic Reviews (PROSPERO) (ID: CRD42019126890). The search was conducted up to 2 April 2019. We included seven observational prospective cohort studies that examined the association between maternal dietary factors, vitamin D concentration, age, preeclampsia, and smoking with any bone indices among offspring. The results indicated that high concentrations of maternal vitamin D; low fat intake; and high intakes of calcium, phosphorus, and magnesium may increase the bone mineral density in offspring at age 16. Evidence also suggests that the offspring of younger mothers may have a higher peak bone mass. It remains inconclusive whether there is an influence of preeclampsia or maternal smoking on bone health among young adults. Our assessment of internal validity warrants a cautious interpretation of these results, as all of the included studies were judged to have serious risks of bias. High-quality studies assessing whether prenatal prognostic factors are associated with bone health in young adults are needed.

Update on the genetic and epigenetic etiology of gestational diabetes mellitus: a review

Background

Many studies have been conducted on the genetic and epigenetic etiology of gestational diabetes mellitus (GDM) in the last two decades because of the disease’s increasing prevalence and role in global diabetes mellitus (DM) explosion. An update on the genetic and epigenetic etiology of GDM then becomes imperative to better understand and stem the rising incidence of the disease. This review, therefore, articulated GDM candidate genes and their pathophysiology for the awareness of stakeholders.

Main body (genetic and epigenetic etiology, GDM)

The search discovered 83 GDM candidate genes, of which TCF7L2, MTNR1B, CDKAL1, IRS1, and KCNQ1 are the most prevalent. Certain polymorphisms of these genes can modulate beta-cell dysfunction, adiposity, obesity, and insulin resistance through several mechanisms. Environmental triggers such as diets, pollutants, and microbes may also cause epigenetic changes in these genes, resulting in a loss of insulin-boosting and glucose metabolism functions. Early detection and adequate management may resolve the condition after delivery; otherwise, it will progress to maternal type 2 diabetes mellitus (T2DM) and fetal configuration to future obesity and DM. This shows that GDM is a strong risk factor for T2DM and, in rare cases, type 1 diabetes mellitus (T1DM) and maturity-onset diabetes of the young (MODY). This further shows that GDM significantly contributes to the rising incidence and burden of DM worldwide and its prevention may reverse the trend.

Conclusion

Mutations and epigenetic changes in certain genes are strong risk factors for GDM. For affected individuals with such etiologies, medical practitioners should formulate drugs and treatment procedures that target these genes and their pathophysiology.

Intergenerational Transmission of Diet-Induced Obesity, Metabolic Imbalance, and Osteoarthritis in Mice

OBJECTIVE

Obesity and osteoarthritis (OA) are 2 major public health issues affecting millions of people worldwide. Whereas parental obesity affects the predisposition to diseases such as cancer or diabetes in children, transgenerational influences on musculoskeletal conditions such as OA are poorly understood. This study was undertaken to assess the intergenerational effects of a parental/grandparental high-fat diet on the metabolic and skeletal phenotype, systemic inflammation, and predisposition to OA in 2 generations of offspring in mice.

METHODS

Metabolic phenotype and predisposition to OA were investigated in the first and second (F1 and F2) generations of offspring (n = 10-16 mice per sex per diet) bred from mice fed a high-fat diet (HFD) or a low-fat control diet. OA was induced by destabilizing the medial meniscus. OA, synovitis, and adipose tissue inflammation were determined histologically, while bone changes were measured using micro-computed tomography. Serum and synovial cytokines were measured by multiplex assay.

RESULTS

Parental high-fat feeding showed an intergenerational effect, with inheritance of increased weight gain (up to 19% in the F1 generation and 9% in F2), metabolic imbalance, and injury-induced OA in at least 2 generations of mice, despite the fact that the offspring were fed the low-fat diet. Strikingly, both F1 and F2 female mice showed an increased predisposition to injury-induced OA (48% higher predisposition in F1 and 19% in F2 female mice fed the HFD) and developed bone microarchitectural changes that were attributable to parental and grandparental high-fat feeding.

CONCLUSION

The results of this study reveal a detrimental effect of parental HFD and obesity on the musculoskeletal integrity of 2 generations of offspring, indicating the importance of further investigation of these effects. An improved understanding of the mechanisms involved in the transmissibility of diet-induced changes through multiple generations may help in the development of future therapies that would target the effects of obesity on OA and related conditions.

Characterization of Perinatal Risk Factors and Complications Associated With Nonsyndromic Craniosynostosis

BACKGROUND

Certain intrauterine risk factors are known to increase the risk of premature cranial suture fusion and may cause complications during birth. Some of these risk factors may be modifiable. Therefore, the authors sought to characterize the institutional patterns of prenatal risk factors and perinatal complications in nonsyndromic craniosynostosis patients compared to normal births from the surrounding area to identify areas for possible intervention or prevention.

METHODS

The medical records of all infants with nonsyndromic craniosynostosis and full birth records born at Duke University Health System from 2006 to 2017 were retrospectively reviewed. Maternal comorbidities, prenatal risk factors, and perinatal complications were collected. The North Carolina State Center for Health Statistics was queried for perinatal statistics from Durham county and the Northeastern Perinatal Care Region to represent a control cohort of normal births from the same time period and region. The primary outcome investigated was the incidence of prenatal risk factors and complications at birth associated with premature fusion of cranial sutures.

RESULTS

Eighty births with nonsyndromic craniosynostosis were included in this study. The majority of these patients were males (61.7%) and born via cesarean section (55.0%). Intrauterine growth restriction occurred in 10.0% and head trauma during delivery occurred in 2.5%. Twinning (14.8% vs 3.6%, P < 0.0001), cesarean births (55.5% vs 30.0%, P < 0.0001), and breech presentation (17.3% vs 3.2%, P < 0.0001) were significantly more common in craniosynostosis patients. Prenatally, mothers of craniosynostosis infants had higher incidence of gestational diabetes (13.5% vs 5.0%, P < 0.0001) and oligohydramnios (6.1% vs 1.3%, P < 0.0001) compared to regional controls.

CONCLUSION

This study demonstrates that premature suture fusion is associated with prenatal risk factors such as gestational diabetes and oligohydramnios. Continued research into potentially modifiable prenatal risk factors and more refined prenatal diagnostic tools has the potential to reduce both the incidence of premature suture fusion and the sequelae of birth complications in this population.

Role of omega-3 polyunsaturated fatty acids in gestational diabetes, maternal and fetal insights: current use and future directions

ω-3-Polyunsaturated fatty acids (ω-3 PUFAs) are widely used during pregnancy and gestational diabetes mellitus (GDM). ω-3 PUFAs are beneficial in the regulation of maternal and fetal metabolic function, inflammation, immunity, macrosomia (MAC), oxidative stress, preeclampsia, intrauterine growth, preterm birth, offspring metabolic function, and neurodevelopment. Dietary counseling is vital for improving therapeutic outcomes in patients with GDM. In maternal circulation, ω-3 PUFAs are transported via transporters, synthesis enzymes, and intracellular proteins, which activate nuclear receptors and play central roles in the cellular metabolic processes of placental trophoblasts. In patients with GDM, this process is compromised due to abnormal functioning of the placenta, which disrupts the normal mother to fetus transport. This results in reduced fetal levels of ω-3 PUFAs, which contributes negatively to fetal growth, metabolic function, and development. Dietary counseling and nutritional assessment remain challenging in the prevention and alleviation of GDM. Therefore, personalized approaches, including measurement of the ω-3 index, pharmacogenetic implementation strategies, and appropriate supplementation with ω-3 PUFAs are used to achieve sufficient distribution in the maternal and fetal fluids during the entire pregnancy period. Developing new dosing guidelines and personalized approaches, determining the mechanisms of ω-3 PUFAs in the placenta, and examining the pharmacodynamic and pharmacokinetics interactions involving ω-3 PUFAs will lead to better management and increase the quality of life of patients with GDM and their offspring. Moreover, different strategies for supplementing with ω-3 PUFAs, improving their placental transport, and pharmacological exploration of the maternal-fetal interactions will help to further elucidate the role of ω-3 PUFAs in women with GDM. In this review, we summarize the current information on the potential therapeutic benefits and clinical applicability of ω-3 PUFAs in patients with GDM and their offspring, highlighting recent progress and future perspectives in this field. Studies investigating the mechanisms of ω-3 PUFA transport to targeted tissues have spurred an interest in personalized treatment strategies for patients with GDM and their offspring. To implement such therapies, we need to clarify the index/ratio of ω-3 PUFAs in maternal and fetal fluids, delineate the ω-3 PUFA transport pathways, and establish the guidelines for FA profiling prepregnancy and during pregnancy-associated weight gain. Such therapies also need to take into account the gender of the fetus, and whether the patient is obese.

The C-3α Epimer of 25-Hydroxycholecalciferol from Endogenous and Exogenous Sources Supports Normal Growth and Bone Mineral Density in Weanling Rats

BACKGROUND

The C-3α epimer of 25-hydroxycholecalciferol [3-epi-25(OH)D₃] is elevated in infants.

OBJECTIVES

We tested whether increasing cholecalciferol intake results in a dose-response in plasma 3-epi-25(OH)D₃ We also examined bone and mineral metabolism in response to 3-epi-25(OH)D₃ treatment.

METHODS

Sprague Dawley rats (4 wk old) were randomly assigned (n = 6/group of each sex) to AIN-93G diets with cholecalciferol at 1 (control), 2, or 4 IU/g diet for objective 1 and to diets with 3-epi-25(OH)D₃ at 0.5 or 1 IU/g diet or 25-hydroxycholecalciferol [25(OH)D₃] at 0.5 IU/g diet for objective 2 for 8 wk. Measurements at weeks 0, 4, and 8 included body weight and length, plasma vitamin D metabolites, bone biomarkers, and bone mineral density determined by using dual-energy X-ray absorptiometry. Lumbar vertebra 3 (L3) geometry and volumetric bone mineral density (vBMD) were measured using microcomputed tomography. Differences between groups were identified for males and females separately.

RESULTS

Weight and food intake were not different between groups. Elevated plasma 3-epi-25(OH)D₃ was observed only in females in the 4 IU cholecalciferol/g diet group (mean ± SD: 24.7 ± 17.1 ng/mL), compared with the control group (5.3 ± 1.4 ng/mL; P = 0.001). By week 8, both male and female rats in the 3-epi-25(OH)D₃ groups had >87% greater plasma 3-epi-25(OH)D₃ concentrations relative to the 25(OH)D₃ reference group (P < 0.0001). At week 8 in males only, parathyroid hormone was significantly lower (P = 0.019) in both 3-epi-25(OH)D₃ groups than in the 25(OH)D₃ group, and L3 total vBMD was higher (P = 0.004) in the 0.5 IU 3-epi-25(OH)D₃ group than in the 25(OH)D₃ group.

CONCLUSIONS

Endogenously generated 3-epi-25(OH)D₃ is more prominent in female than in male rats. Exogenous 3-epi-25(OH)D₃ was as effective as 25(OH)D₃ in supporting bone mineral accretion in both sexes. It thus appears that 3-epi-25(OH)D₃ has biological activity and should be further explored.

Maternal dietary patterns during pregnancy in relation to offspring forearm fractures: prospective study from the Danish National Birth Cohort

Limited evidence exists for an association between maternal diet during pregnancy and offspring bone health. In a prospective study, we examined the association between dietary patterns in mid-pregnancy and offspring forearm fractures. In total, 101,042 pregnancies were recruited to the Danish National Birth Cohort (DNBC) during 1996–2002. Maternal diet was collected by a food frequency questionnaire. Associations were analyzed between seven dietary patterns extracted by principal component analysis and offspring first occurrence of any forearm fracture diagnosis, extracted from the Danish National Patient Register, between time of birth and end of follow-up (<16 year) (n = 53,922). In multivariable Cox regression models, offspring of mothers in the fourth vs. first quintile of the Western pattern had a significant increased risk (Hazard ratio, 95% confidence interval: 1.11, 1.01–1.23) of fractures, and there was a borderline significant positive trend (p = 0.06). The other dietary patterns showed no associations and neither did supplementary analyses of macro- and micronutrients or single food groups, except for the intake of artificially sweetened soft drinks, which was positively associated with offspring forearm fractures (p = 0.02). In the large prospective DNBC high mid-pregnancy consumption of Western diet and artificially sweetened soft drinks, respectively, indicated positive associations with offspring forearm fractures, which provides interesting hypotheses for future research.

Maternal use of flaxseed oil during pregnancy and lactation prevents morphological alterations in pancreas of female offspring from rat dams with experimental diabetes

Nutritional recommendations have promoted the increased need to consume n-3 polyunsaturated fatty acids. Flaxseed is the richest dietary source of n-3 fatty acids among plant sources and is widely used for its edible oil. This study aimed to investigate whether maternal use of flaxseed oil has effects on pancreas morphology in the female offspring of diabetic mothers. Female Wistar rats (n = 12) were induced into diabetes by a high-fat diet and low dose of streptozotocin. After confirmation of the diabetes, rats were mated, and once pregnancy was confirmed, they were allocated into three groups (n = 6): high-fat group (HG); flaxseed oil group (FOG); and control group (CG) (non-diabetic rats). At weaning, female offspring (n = 6/group) received standard chow diet. The animals were euthanized at 180 days. Pancreas was collected for histomorphometric and immunohistochemistry analysis. HG showed hypertrophy of pancreatic islets (P < 0.0001), whereas FOG offspring had islets with smaller diameters compared to HG (P < 0.0001). HG offspring showed higher percentage of larger (P = 0.0061) and lower percentage of smaller islets (P = 0.0036). HG showed lower islet insulin immunodensity at 180 days (P < 0.0001), whereas FOG was similar to CG (P < 0.0001). Flaxseed oil reduced the damage caused by maternal hyperglycaemia, promoting normal pancreas histomorphometry and β-cell mass in female offspring.

Fetal hyperglycemia and a high-fat diet contribute to aberrant glucose tolerance and hematopoiesis in adult rats

BACKGROUND

Children exposed to gestational diabetes mellitus (GDM) during pregnancy are at increased risk of obesity, diabetes, and hypertension. Our goal was to identify metabolic and hematopoietic alterations after intrauterine exposure to maternal hyperglycemia that may contribute to the pathogenesis of chronic morbidities.

METHODS

Streptozotocin treatment induced maternal hyperglycemia during the last third of gestation in rat dams. Offspring of control mothers (OCM) and diabetic mothers (ODM) were evaluated for weight, glucose tolerance, insulin tolerance, and hematopoiesis defects. The effects of aging were examined in normal and high-fat diet (HFD)-fed young (8-wk-old) and aged (11-mo-old) OCM and ODM rats.

RESULTS

Young adult ODM males on a normal diet, but not females, displayed improved glucose tolerance due to increased insulin levels. Aged ODM males and females gained more weight than OCM on a HFD and had worse glucose tolerance. Aged ODM males fed a HFD were also neutrophilic. Increases in bone marrow cellularity and myeloid progenitors preceded neutrophilia in ODM males fed a HFD.

CONCLUSION

When combined with other risk factors like HFD and aging, changes in glucose metabolism and hematopoiesis may contribute to the increased risk of obesity, type 2 diabetes, and hypertension observed in children of GDM mothers.

Effect of maternal use of flaxseed oil during pregnancy and lactation on glucose metabolism and pancreas histomorphometry of male offspring from diabetic rats

AIM

Investigate if the maternal use of flaxseed oil prevents pancreatic alterations in the offspring of diabetic mothers.

METHODS

Diabetes was induced in female wistar rats (n=12) by a high-fat diet and low-dose of streptozotocin. After the confirmation of the diabetes (glucose >300 mg/dL), rats were mated and once pregnancy was confirmed, they were allocated into three groups (n=6): high-fat group (HFG); flaxseed oil group (FOG); and control group (CG) (nondiabetic rats). At weaning, male offspring (n=12/group) received a standard chow diet. The animals were euthanized in two phases: at 100 and at 180 days, (n=6/group). The pancreas was collected for histomorphometric and immunohistochemistry analysis.

RESULTS

HFG showed hypertrophy of pancreatic islets at 100 and at 180 days (p<0.0001), while the FOG offspring had islets with smaller diameters compared to HFG at both phases of sacrifice (p<0.0001). HFG had a lower percentage of small islets when compared to CG and FOG, which had a higher percentage when compared to HFG (p=0.0053) at 100 days. At 180 days HFG showed higher percentage of larger islets (p=0.00137) and lower percentage of smaller islets (p=0.00112), when compared to FOG. HFG showed lower islet insulin immunodensity at 100 days (p<0.0001) and 180 days (p<0.0001), whereas FOG was similar to CG (p<0.0001) at 100 days and higher at 180 days (p<0.0001).

CONCLUSIONS

Flaxseed oil reduced the damage caused by maternal hyperglycemia, promoting normal pancreas histomorphometry and β cell mass.

Biochemical markers of bone resorption are present in human milk: implications for maternal and neonatal bone metabolism

AIM

This study investigated breast milk and maternal serum concentrations of biochemical markers of bone resorption, which may be implicated in both maternal and neonatal bone metabolism.

METHODS

Tests were carried out on 85 parturients 3-4 days after they gave birth. We measured their breast milk and serum concentrations for soluble receptor activator of nuclear factor kappaB ligand (sRANKL) and cross-linked N-telopeptide of type I collagen (NTx). The sRANKL and NTx concentrations were associated with several perinatal parameters.

RESULTS

Soluble receptor activator of nuclear factor kappaB ligand was detectable in breast milk at considerably lower concentrations than in maternal serum (p < 0.001), and these breast milk sRANKL concentrations were decreased in maternal diabetes (b = -0.366, 95% CI -0.622 to -0.110, p = 0.006). Breast milk NTx concentrations were higher in exclusive lactation (b = 0.269, 95% CI 0.014-0.524, p = 0.039), but lower in Caesarean sections (b = -0.224, 95% CI -0.428 to -0.019, p = 0.032).

CONCLUSION

Soluble receptor activator of nuclear factor kappaB ligand is downregulated in breast milk, particularly in the case of diabetes. Breast milk NTx upregulation characterises exclusive lactation, and its downregulation characterises Caesarean section deliveries. Nutritional interventions in foetal life and early infancy may programme adult bone health and ameliorate diseases with developmental origins, such as osteoporosis.

Effects of undenatured whey protein supplementation on CXCL12- and CCL21-mediated B and T cell chemotaxis in diabetic mice

Background

Long and persistent uncontrolled diabetes tends to degenerate the immune system and leads to an increased incidence of infection. Whey proteins (WPs) enhance immunity during early life and have a protective role in some immune disorders. In this study, the effects of camel WP on the chemotaxis of B and T cells to CXCL12 and CCL21 in diabetic mice were investigated.

Results

Flow cytometric analysis of the surface expressions of CXCR4 (CXCL12 receptor) and CCR7 (CCL21 receptor) on B and T cells revealed that the surface expressions of CXCR4 and CCR7 were not significantly altered in diabetic and WP-supplemented diabetic mice compared with control mice. Nevertheless, B and T lymphocytes from diabetic mice were found to be in a stunned state, with a marked and significant (P < 0.05) decrease in CXCL12- and CCL21-mediated actin polymerization and subsequently, a marked decrease in their chemotaxis. WP supplementation in the diabetes model was found to significantly increase CXCL12- and CCL21-mediated actin polymerization and chemotaxis in both B and T cells.

Conclusion

Our data revealed the benefits of WP supplementation in enhancing cytoskeletal rearrangement and chemotaxis in B and T cells, and subsequently improving the immune response in diabetic mice.

Maternal undernutrition during critical windows of development results in differential and sex-specific effects on postnatal adiposity and related metabolic profiles in adult rat offspring

It is well established that altered maternal nutrition may induce long-term metabolic consequences in offspring. However, the effects of maternal undernutrition during different developmental windows on sex-specific growth and metabolism in offspring are not well defined. We investigated the effect of moderate maternal undernutrition during pregnancy and/or lactation on postnatal growth and metabolic outcomes in offspring. Wistar rats were randomly assigned to one of four groups: (1) control (CONT) dams fed a standard diet throughout pregnancy and lactation; (2) dams undernourished to 50 % of CONT during pregnancy (UNP); (3) dams fed at 50 % of CONT throughout lactation (UNL); (4) dams fed at 50 % of CONT throughout pregnancy and lactation (UNPL). UNP and UNPL offspring were lighter at birth compared to CONT and UNL. UNL and UNPL offspring were growth restricted at weaning and remained smaller into adulthood. UNP males and females developed increased adiposity and hyperleptinaemia in adulthood compared to all other groups. Adiposity in UNL and UNPL males was similar to CONT offspring. In UNL and UNPL females, adiposity was lower than for CONT females. Markers of bone mass, lipid metabolism and hepatic function were altered in UNP offspring but were similar in UNL and UNPL offspring compared to CONT. Lack of catch-up growth during lactation in offspring of undernourished mothers prevented development of adiposity and related metabolic disorders in later life. These data highlight that the timing and duration of undernutrition during critical windows of development exert differential effects on postnatal outcomes in a sex-specific manner.

Vitamin C supplementation reconstitutes polyfunctional T cells in streptozotocin-induced diabetic rats

BACKGROUND

Studies have demonstrated that vitamin C supplementation enhances the immune system, prevents DNA damage, and decreases the risk of a wide range of diseases. Other study reported that leukocyte vitamin C level was low in diabetic individuals compared with nondiabetic controls.

AIM OF THE WORK

To study the effect of vitamin C on oxidative stress, blood lipid profile, and T-cell responsiveness during streptozotocin (STZ)-induced type I diabetes mellitus.

METHODS

Thirty male Sprague-Dawley rats were randomly split into three groups. The first served as a control group (n = 10) in which rats were injected with the vehicle alone. The second (n = 10) and the third groups (n = 10) were rendered diabetic by intraperitoneal (i.p.) injection of single doses of STZ (60 mg/kg body weight). The third group was supplemented with vitamin C (100 mg/kg body weight) for 2 months.

RESULTS

T lymphocytes from the diabetic rats were found to be in a stunned state, with a decreased surface expression of the CD28 costimulatory molecule, low levels of phosphorylated AKT, altered actin polymerization, diminished proliferation and cytokine production, and, eventually, a marked decrease in abundance in the periphery. Vitamin C was found to significantly decrease the elevated levels of blood hydroperoxide, glucose, cholesterol, triglycerides and low-density lipoprotein (LDL) in diabetic rats. Furthermore, it was found to restore CD28 expression, AKT phosphorylation, actin polymerization, and polyfunctional T cells (IFN-γ- and IL-2-producing cells that exhibit a high proliferation capacity).

CONCLUSION

Vitamin C treatment restores and reconstitutes polyfunctional, long-lived T cells in diabetic rats.