Publications by authors named "Hyun-Jaung Sim"

Background: The cellular prion protein (PrP), a glycoprotein encoded by the PRNP gene, is known to modulate muscle mass and exercise capacity. However, the role of PrP in the maintenance and regeneration of skeletal muscle during ageing remains unclear.

Methods: This study investigated the change in PrP expression during muscle formation using C2C12 cells and evaluated muscle function in Prnp wild-type (WT) and knock-out (KO) mice at different ages (1, 9 and 15 months).

View Article and Find Full Text PDF

The negative effects of particulate matter up to 2.5 μm in diameter (PM) and their mediating mechanisms have been studied in various tissues. However, little is known about the mechanism and long-term tracking underlying the sex-dependent effects of PM on skeletal muscle system modulation.

View Article and Find Full Text PDF

The harmful effects of fine particulate matter ≤2.5 µm in size (PM) on human health have received considerable attention. However, while the impact of PM on the respiratory and cardiovascular systems has been well studied, less is known about the effects on stem cells in the bone marrow (BM).

View Article and Find Full Text PDF

One of the most important strategies for successful aging is exercise. However, the effect of exercise can differ among individuals, even with exercise of the same type and intensity. Therefore, this study aims to confirm whether endurance training (ETR) has the same health-promoting effects on the musculoskeletal and hematopoietic systems regardless of age.

View Article and Find Full Text PDF

Ionizing irradiation (IR) causes bone marrow (BM) injury, with senescence and impaired self-renewal of hematopoietic stem cells (HSCs), and inhibiting Wnt signaling could enhance hematopoietic regeneration and survival against IR stress. However, the underlying mechanisms by which a Wnt signaling blockade modulates IR-mediated damage of BM HSCs and mesenchymal stem cells (MSCs) are not yet completely understood. We investigated the effects of osteoblastic Wntless (Wls) depletion on total body irradiation (TBI, 5 Gy)-induced impairments in hematopoietic development, MSC function, and the BM microenvironment using conditional Wls knockout mutant mice (Col-Cre;Wls) and their littermate controls (Wls).

View Article and Find Full Text PDF

Research on the negative impacts of PM have been focused on lung, brain, immune, and metabolism-related diseases. However, little is known about the mechanism underlying the effects of PM on the modulation of hematopoietic stem cell (HSC) fate. Maturation of the hematopoietic system and differentiation of hematopoietic stem progenitor cells (HSPCs) occurs soon after birth when infants are susceptible to external stresses.

View Article and Find Full Text PDF

Studies of PrP-derived prion disease generally focus on neurodegeneration. However, little is known regarding the modulation of hematopoietic stem progenitor cells (HSPCs) that express PrP in prion infection. Among bone marrow (BM) hematopoietic cells, hematopoietic stem cells (HSCs) strongly express PrP.

View Article and Find Full Text PDF

While supplemental angiopoietin-1 (Ang1) improves hematopoiesis, excessive Ang1 induces bone marrow (BM) impairment, hematopoietic stem cell (HSC) senescence, and erythropoietic defect. Here, we examined how excessive Ang1 disturbs hematopoiesis and explored whether hematopoietic defects were related to its level using K14-Cre;c-Ang1 and Col2.3-Cre;c-Ang1 transgenic mice that systemically and locally overexpress cartilage oligomeric matrix protein-Ang1, respectively.

View Article and Find Full Text PDF

Scaffolds combined with bioactive agents can enhance bone regeneration at therapeutic sites. We explore whether combined supplementation with coumaric acid and recombinant human-cartilage oligomeric matrix protein-angiopoietin 1 (rhCOMP-Ang1) is an ideal approach for bone tissue engineering. We developed coumaric acid-conjugated absorbable collagen scaffold (CA-ACS) and investigated whether implanting CA-ACS in combination with rhCOMP-Ang1 facilitates ACS- or CA-ACS-mediated bone formation using a rat model of critically sized mandible defects.

View Article and Find Full Text PDF

While total body irradiation (TBI) is an everlasting curative therapy, the irradiation can cause long-term bone marrow (BM) injuries, along with senescence of hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) via reactive oxygen species (ROS)-induced oxidative damages. Thus, ameliorating or preventing ROS accumulation and oxidative stress is necessary for TBI-requiring clinical treatments. Here, we explored whether administration of ferulic acid, a dietary antioxidant, protects against TBI-mediated systemic damages, and examined the possible mechanisms therein.

View Article and Find Full Text PDF

Numerous studies highlight the potential benefits potentials of supplemental cartilage oligomeric matrix protein-angiopoietin-1 (COMP-Ang1) through improved angiogenic effects. However, our recent findings show that excessive overexpression of COMP-Ang1 induces an impaired bone marrow (BM) microenvironment and senescence of hematopoietic stem cells (HSCs). Here, we investigated the underlying mechanisms of how excessive COMP-Ang1 affects the function of BM-conserved stem cells and hematopoiesis using mice.

View Article and Find Full Text PDF

Although functional association between Wnt signaling and bone homeostasis has been well described through genetic ablation of Wntless (Wls), the mechanisms of how osteoblastic Wls regulates the fate of bone marrow stromal cells (BMSCs) and hematopoietic stem cells (HSCs) in relation to age are not yet understood. Here, we generated Col2.3-Cre;Wls mice that were free from premature lethality and investigated age-related impacts of osteoblastic Wls deficiency on hematopoiesis, BM microenvironment, and maintenance of BMSCs (also known as BM-derived mesenchymal stem/stromal cells) and HSCs.

View Article and Find Full Text PDF

Total body irradiation (TBI) serves as an effectively curative therapy for cancer patients and adversely causes long-term residual bone marrow (BM) injury with premature senescence of hematopoietic stem cells (HSCs), which is mediated by increased production of reactive oxygen species (ROS). In the present study, we investigated how the exposure time of TBI in a mouse model affects HSCs and whether the treatment of caffeic acid (CA), a known dietary phenolic antioxidant, has a radioprotective effect. Single (S)-TBI at a sublethal dose (5 Gy) caused relatively higher induction of mitochondrial ROS and senescence-related factors in HSCs than those in hematopoietic progenitor cells (HPCs) and LineageSca-1c-Kit (LSK) cells, as well as reduced clonogenic formation and donor cell-derived reconstituting capacity.

View Article and Find Full Text PDF

Supplemental Angiopoietin 1 (Ang1) exerts its therapeutic potential on microvascular regression-associated diseases, and this potential is linked with the function of hematopoietic stem cells (HSCs). However, the underlying mechanisms of the effect of enhanced angiogenesis on the modulation of HSCs are not yet defined. Here, we generated transgenic mice expressing Cartilage Oligomeric Matrix Protein (COMP)-Ang1 in keratin 14-expressing cells.

View Article and Find Full Text PDF

Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase-1 (HO-1) signal is known to play important roles in controlling bone homeostasis. This study examined how oxidative stress affects the mineralization of embryonic stem (ES) cells by exposing them to glucose oxidase (GO), which continuously generates H2O2 at low concentrations. The roles of Nrf2/HO-1 and mitogen-activated protein kinases on osteogenesis in GO-exposed ES cells were also investigated.

View Article and Find Full Text PDF

Osteoclasts form a bone marrow (BM) cavity serving as a hematopoietic niche for the maintenance of hematopoietic stem cells (HSCs). However, the role of osteoclasts in the BM has been controversially reported and remains to be further understood. In the present study, we investigated how osteoclasts affect the modulation of hematopoietic stem/progenitor cells in the BM by administering bisphosphate alendronate (ALN) to B6 mice for 21 consecutive days to inhibit osteoclast activity.

View Article and Find Full Text PDF

Tissue engineering requires functional polymeric membrane for adequate space for cell migration and attachment within the nanostructure. Therefore, biocompatible propolis loaded polyurethane (propolis/PU) nanofibers were successfully prepared using electrospinning of propolis/PU blend solution. Here, composite nanofibers were subjected to detailed analysis using electron microscopy, FT-IR spectroscopy, thermal gravimetric analysis (TGA), and mechanical properties and water contact angle measurement.

View Article and Find Full Text PDF