Insulin-like growth factor-1 short-period therapy stimulates bone marrow cells in obese swiss mice.

Bone marrow cells (BMCs) from obese Swiss mice fed with Western diet show mitochondrial dysfunction. Obesity interferes with BMCs disrupting energetic metabolism, stimulating apoptosis, and reducing cell proliferation since adipose tissue releases inflammatory adipokines into the medullar microenvironment. These changes lead to reduction of BMC differentiation capacity and hematopoiesis impairment, a process responsible for blood cell continuous production through hematopoietic stem cells (HSCs). This work aimed to analyze the effects of IGF-1 therapy on BMC viability in Western diet-induced obesity, in vivo. We observed that after only 1 week of treatment, obese Swiss mice presented reduced body weight and visceral fat and increased mitochondrial oxidative capacity and coupling, indicating mitochondrial function improvement. In addition, IGF-1 was able to reduce apoptosis of total BMCs, stem cell subpopulations (hematopoietic and mesenchymal), and leukocytes, restoring all progenitor hematopoietic lineages. The treatment also contributed to increase proliferative capacity of hematopoietic stem cells and leukocytes, keeping the hematopoietic and immune systems balanced. Therefore, we conclude that IGF-1 short period therapy improved BMC survival, proliferation, and differentiation capacity in obese Swiss mice.

Bone marrow mononuclear cell transplantation improves mitochondrial bioenergetics in the liver of cholestatic rats.

Mitochondrial dysfunction has been associated with liver cholestatis. Toxic bile salt accumulation leads to chronic injury with mitochondrial damage, ROS increase and apoptosis, resulting in liver dysfunction. This study aimed to analyze mitochondrial bioenergetics in rats with hepatic fibrosis induced by bile duct ligation (BDL) after BMMNC transplantation. Livers were collected from normal rats, fibrotic rats after 14 and 21 days of BDL (F14d and F21d) and rats that received BMMNC at 14 days of BDL, analyzed after 7 days. F21d demonstrated increased collagen I content and consequently decrease after BMMNC transplantation. Both F14d and F21d had significantly reduced mitochondrial oxidation capacity and increased mitochondrial uncoupling, which were restored to levels similar to those of normal group after BMMNC transplantation. In addition, F21d had a significantly increase of UCP2, and reduced PGC-1α content. However, after BMMNC transplantation both proteins returned to levels similar to normal group. Moreover, F14d had a significantly increase in 4-HNE content compared to normal group, but after BMMNC transplantation 4-HNE content significantly reduced, suggesting oxidative stress reduction. Therefore, BMMNC transplantation has a positive effect on hepatic mitochondrial bioenergetics of cholestatic rats, increasing oxidative capacity and reducing oxidative stress, which, in turn, contribute to liver function recover.

Bone marrow mononuclear cell transplantation increases metalloproteinase-9 and 13 and decreases tissue inhibitors of metalloproteinase-1 and 2 expression in the liver of cholestatic rats.

Liver fibrosis results from chronic injury followed by activation of macrophages and fibrogenic cells like myofibroblasts and activated hepatic stellate cells. These fibrogenic cells express α-smooth muscle actin (α-SMA) and produce excessive extracellular matrix (ECM), with disorganization and loss of function of hepatic parenchyma. It is known that increased levels of metalloproteinases (MMPs) in liver fibrosis are associated with reduction of the pathologic ECM and fibrosis resolution. Recently, it has been shown that bone marrow mononuclear cells (BMMNCs) may reduce collagen and α-SMA expression, and ameliorate liver function in cholestatic rats. Therefore, this study aimed to analyze MMP-2, MMP-9 and MMP-13, and tissue inhibitors of MMPs (TIMPs)-1 and TIMP-2 in the liver of cholestatic rats transplanted with BMMNC. Animals were divided into normal rats, cholestatic rats obtained after 14 and 21 days of bile duct ligation (BDL), and rats obtained after 14 days of BDL that received BMMNCs and were killed after 7 days. MMP and TIMP expression was assessed by Western blotting, along with α-SMA, CD68 and CD11b expression by confocal microscopy. Western blotting analysis showed that 14-day BDL animals had significantly reduced amounts of MMP-2 and MMP-13, but increased amounts of MMP-9 compared to normal rats. After 21 days of BDL, overall MMP amounts were decreased and TIMPs were increased. BMMNC transplantation significantly increased MMP-9 and MMP-13, and decreased TIMP expression. Increased MMP activity was confirmed by zymography. MMP-9 and MMP-13 were expressed by macrophages near fibrotic septa, suggesting BMMNC may stimulate MMP production in fibrotic livers, contributing to ECM degradation and hepatic regeneration.

Bone marrow cell transplantation is associated with fibrogenic cells apoptosis during hepatic regeneration in cholestatic rats.

Liver fibrosis is accompanied by hepatocyte death and proliferation of α-SMA(+) fibrogenic cells (activated hepatic stellate cells and myofibroblasts), which synthesize extracellular matrix components that contribute to disorganization of the hepatic parenchyma and loss of liver function. Therefore, apoptosis of these fibrogenic cells is important to hepatic regeneration. This study aimed to analyze the effect of cell therapy using bone marrow mononuclear cell (BMMNC) transplantation on α-SMA expression and on apoptosis of hepatic cells during liver fibrosis induced by bile duct ligation (BDL). Livers were collected from normal rats, fibrotic rats after 14 and 21 days of BDL, and rats that received BMMNC at 14 days of BDL and were analyzed after 7 days. Apoptosis in fibrogenic cells was analyzed by immunoperoxidase, confocal microscopy, and Western blotting, and liver regeneration was assessed by proliferating cell nuclear antigen staining. Results showed that caspase-3 and proliferating cell nuclear antigen expression were significantly increased in the BMMNC-treated group. Additionally, confocal microscopy analysis showed cells coexpressing α-SMA and caspase-3 in these animals, suggesting fibrogenic cell death. These results suggest a novel role for BMMNC in liver regeneration during fibrotic disease by stimulating fibrogenic cells apoptosis and hepatocyte proliferation, probably through secretion of specific cytokines that modulate the hepatic microenvironment toward an antifibrogenic balance.