Is there a link between progranulin, obesity, and parameters of the metabolic syndrome in children? Findings from a longitudinal intervention study

Progranulin and Vaspin as Potential Novel Markers in the Etiology of Type 1 Diabetes in Children

Background and Objectives: Diabetes is a significant health problem, prompting the search for new therapeutic strategies. Recently, researchers have focused on identifying novel markers for the progression of this condition. It is well established that adipokines, such as progranulin and vaspin, play crucial roles in regulating lipid and carbohydrate metabolism. Materials and Methods: This single-center cross-sectional study aimed to assess serum progranulin and vaspin levels in 80 children diagnosed with type 1 diabetes (T1D) and to examine their correlation with body mass index (BMI), glycated hemoglobin, and lipid profile. The cohort included 40 children newly diagnosed with diabetes, 40 children with long-term diabetes (20 well-controlled and 20 poorly controlled), and 14 non-diabetic children as a control group. Progranulin and vaspin levels were determined using a sandwich enzyme-linked immunosorbent assay. Results: There were no significant differences in the progranulin and vaspin concentrations in the studied groups (p = 0.246 and p = 0.095, respectively). No statistically significant differences were noted in the levels of both adipokines among boys and girls within the T1D, well-controlled T1D, and poorly controlled T1D groups. We did not find any differences in the progranulin and vaspin levels among all children with T1D and healthy controls when divided based on BMI percentiles. A negative correlation was observed between progranulin concentration and the age of children in the T1D, well-controlled T1D, and healthy groups. Furthermore, progranulin correlated negatively with BMI among children with T1D. In contrast, vaspin concentration correlated positively with age among healthy children. Conclusions: Our study provides novel insights into the status of progranulin and vaspin among pediatric participants with varying levels of type 1 diabetes control. However, further research involving larger patient cohorts and different stages of sexual maturation is warranted.

Circulating progranulin in human infants: relation to prenatal growth and early postnatal nutrition

BACKGROUND

Progranulin (PGRN) displays pleiotropic biological functions and has been proposed as a biomarker for metabolic diseases. We longitudinally assessed PGRN concentrations in infants born appropriate (AGA) or small for gestational age (SGA), the latter being at risk for obesity and type 2 diabetes, especially if they experience an excessive postnatal catch-up in weight and are formula-fed (FF).

METHODS

The study population consisted of 183 infants who were exclusively breast-fed [(BF), AGA, n = 66; SGA, n = 40], or FF (AGA, n = 31; SGA, n = 46) over the first 4 months. Assessments included auxology, fasting glucose, insulin, IGF-1, high-molecular-weight adiponectin, PGRN and body composition (by DXA), at birth, and at age 4 and 12 months.

RESULTS

PGRN levels were low at birth and unaffected by prenatal growth. PGRN increased at 4 and 12 months, although to a lesser extent in SGA infants, and was unrelated to the mode of feeding. PGRN correlated with markers of adiposity, inflammation and insulin resistance in both AGA and SGA infants, especially in those FF.

CONCLUSIONS

The attenuated increase of PGRN levels in SGA infants over the first year of life, along with the association to markers of unhealthy metabolic profile, might point to a role of PGRN in future disease risks.

IMPACT

Progranulin (PGRN) displays pleiotropic biological functions and has been proposed as a biomarker for metabolic diseases. In healthy infants, PGRN concentrations are low at birth and experience a significant and progressive increase up to age 12 months, which is less marked in infants born small for gestational age (SGA) and is unrelated to the mode of feeding. Circulating PGRN is related to markers of adiposity, inflammation, and insulin sensitivity, especially in formula-fed SGA infants. PGRN may play a role in the metabolic adaptations of SGA infants during early life, potentially contributing to the risk for obesity and type 2 diabetes in this population.

Progranulin promotes bone fracture healing via TNFR pathways in mice with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) significantly increases bone fragility and fracture risk. Progranulin (PGRN) promotes bone fracture healing in both physiological and type 1 diabetic conditions. The present study aimed to investigate the role of PGRN in T2DM bone fracture healing. MKR mice (with an FVB/N genetic background) were used as the T2DM model. Drill-hole and Bonnarens and Einhorn models were used to investigate the role of PGRN in T2DM fracture healing in vivo. Primary bone marrow cells were isolated for molecular and signaling studies, and reverse transcription-polymerase chain reaction, immunohistochemical staining, and western blotting were performed to assess PGRN effects in vitro. PGRN mRNA and protein expression were upregulated in the T2DM model. Local administration of recombinant PGRN effectively promoted T2DM bone fracture healing in vivo. Additionally, PGRN could induce anabolic metabolism during endochondral ossification through the TNFR2-Akt and Erk1/2 pathways. Furthermore, PGRN showed anti-inflammatory activity in the T2DM bone regeneration process. These findings suggest that local administration of exogenous PGRN may be an alternative strategy to support bone regeneration in patients with T2DM. Additionally, PGRN might hold therapeutic potential for other TNFR-related metabolic disorders.

Inflammation Markers in Type 2 Diabetes and the Metabolic Syndrome in the Pediatric Population

PURPOSE OF REVIEW

Chronic inflammation, adipokines, and hepatokines have been identified as basis of insulin resistance and β cell failure in animal models. We present our current knowledge concerning the potential relationship between these cytokines, inflammation, metabolic syndrome (MetS), and type 2 diabetes mellitus (T2DM) in the pediatric population.

RECENT FINDINGS

Pro-inflammatory cytokines related to insulin resistance and MetS in children are tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-1β, interferon gamma, pigment epithelium-derived factor, chemerin, vaspin, and fetuin A. Anti-inflammatory cytokines associated with insulin resistance and MetS in children are leptin, adiponectin, omentin, fibroblast growth factor (FGF)-21, osteocalcin, and irisin. These anti-inflammatory cytokines are decreased (adiponectin, omentin, and osteocalcin) or increased (leptin, FGF-21, and irisin) in obesity suggesting a resistance state. TNF-α, fetuin A, and FGF-21 are altered in obese children with T2DM suggesting an involvement in β cell failure. These cytokines, adipokines, and hepatokines may be able to predict development of MetS and T2DM and have a potential therapeutic target ameliorating insulin resistance.