Insulin-Like Growth Factor 2 (IGF-2) Regulates Neuronal Density and IGF-2 Distribution Following Hippocampal Intracerebral Hemorrhage

BACKGROUND

The insulin-like growth factor 2 (IGF-2) is a growth factor and anti-inflammatory cytokine that plays a crucial role in memory consolidation. However, the precise role of this factor in acute brain damage is still unclear. The present study aimed to evaluate the variations in hippocampal IGF-2 distribution on different days and investigate the effect of recombinant IGF-2 on memory cell density, and IGF-2 distribution following acute hippocampal damage resulting from intracerebral hemorrhage (ICH).

METHODS

ICH was induced by injection of 100 μL of autologous blood into the left hippocampus of 72 male Sprague-Dawley rats. Recombinant IGF-2 was injected into the damaged hippocampus 30 min post-induction of ICH in the ICH-IGF-2 group. Then, on postoperative days 1, 3, 7, and 14, samples of brain tissue were collected to perform histopathological and immunohistochemical examinations.

RESULTS

The stereological study indicated that the volume of the hippocampus and the number of neurons had a significant reduction, and the infarct volume had a significant increase following ICH. Following the injection of IGF-2, a significant improvement was observed in stereological studies. Immunohistochemical data showed that IGF-2 distribution increased in the hippocampus on different days after ICH, and IGF-2 injection led to a dramatic reduction in this distribution.

CONCLUSIONS

In summary, the gradual increase of endogenous IGF-2 as growth and anti-inflammatory factor following hemorrhagic stroke reveals a critical role of this factor in brain recovery after injury. Moreover, the injection of IGF-2 can prevent cell death and alleviate the damage caused by the hemorrhagic stroke.

Comprehensive hematological reference intervals in a healthy adult male population

Reference intervals (RIs) are important tools for improving medical decision-making. Hematology reference values can be influenced by important covariates such as genetic and environmental factors, rendering it essential to define RIs for specific populations. Therefore, we aimed to establish accurate and robust RIs for hematological markers in a healthy adult male Iranian population. This cross-sectional study was conducted in a population of 723 males aged 20-60 years old. Hematological parameters were routinely measured using a Sysmex auto analyser system (KX-21 N). The quality of assays was monitored using commercial quality control samples. The nonparametric rank method, as recommended by the Clinical and Laboratory Standards Institute (CLSI) guidelines, was used to calculate the 2.5th and 97.5th percentiles as the lower and upper reference limits, respectively. Of the 12 hematological parameters assessed, only mean platelet volume (MPV) demonstrated significant age-specific differences, requiring two partitions from 20 to 35 years (8.7-12.2 fL) and 35 to 65 years (8.5-11.5 fL). The remaining hematological parameters (e.g. leukocyte, erythrocyte, and platelet parameters) could be defined by one age range. This study established RIs for 12 routinely used hematological parameters in a healthy male population living in the northeastern region of Iran. Established RIs differed from those previously reported by other cohorts, highlighting the importance of population-specific RIs.