Collagen patches releasing phosphatidylserine liposomes guide M1-to-M2 macrophage polarization and accelerate simultaneous bone and muscle healing.

Bilateral communication between bones and muscles is essential for healing composite bone-muscle injuries from orthopedic surgeries and trauma. However, these injuries are often characterized by exaggerated inflammation, which can disrupt bone-muscle crosstalk, thereby seriously delaying the healing of either tissue. Existing approaches are largely effective at healing single tissues.

Bisphenol A (BPA) and Cardiovascular or Cardiometabolic Diseases.

Bisphenol A (BPA; 4,4'-isopropylidenediphenol) is a well-known endocrine disruptor. Most human exposure to BPA occurs through the consumption of BPA-contaminated foods. Cardiovascular or cardiometabolic diseases such as diabetes, obesity, hypertension, acute kidney disease, chronic kidney disease, and heart failure are the leading causes of death worldwide.

Releasable, Immune-Instructive, Bioinspired Multilayer Coating Resists Implant-Induced Fibrosis while Accelerating Tissue Repair.

Implantable biomaterials trigger foreign body reactions (FBRs), which reduces the functional life of medical devices and prevents effective tissue regeneration. Although existing therapeutic approaches can circumvent collagen-rich fibrotic encapsulation secondary to FBRs, they disrupt native tissue repair. Herein, a new surface engineering strategy in which an apoptotic-mimetic, immunomodulatory, phosphatidylserine liposome (PSL) is released from an implant coating to induce the formation of a macrophage phenotype that mitigates FBRs and improves tissue healing is described.

Vascular calcification and cellular signaling pathways as potential therapeutic targets.

Increased vascular calcification (VC) is observed in patients with cardiovascular diseases such as atherosclerosis, diabetes, and chronic kidney disease. VC is divided into three types according to its location: intimal, medial, and valvular. Various cellular signaling pathways are associated with VC, including the Wnt, mitogen-activated protein kinase, phosphatidylinositol-3 kinase/Akt, cyclic nucleotide-dependent protein kinase, protein kinase C, calcium/calmodulin-dependent kinase II, adenosine monophosphate-activated protein kinase/mammalian target of rapamycin, Ras homologous GTPase, apoptosis, Notch, and cytokine signaling pathways.

Phosphatidylserine liposome multilayers mediate the M1-to-M2 macrophage polarization to enhance bone tissue regeneration.

An appropriate immune microenvironment, governed by macrophages, is essential for rapid tissue regeneration after biomaterial implantation. The macrophage phenotypes, M1 (inflammatory) and M2 (anti-inflammatory/healing), exert opposing effects on the repair of various tissues. In this study, a new strategy to promote tissue repair and tissue-to-biomaterial integration by M1-to-M2 macrophage transition using artificial apoptotic cell mimetics (phosphatidylserine liposomes; PSLs) was developed using bone as a model tissue.

Bioinspired macrophage-targeted anti-inflammatory nanomedicine: A therapeutic option for the treatment of myocarditis.

Myocarditis is a disease characterized by inflammation of the heart muscle, which increases the risk of dilated cardiomyopathy and heart failure. Macrophage migration is a major histopathological hallmark of myocarditis, making macrophages a potential therapeutic target for the management of this disease. In the present study, we synthesized a bioinspired anti-inflammatory nanomedicine conjugated with protein G (PSL-G) that could target macrophages and induce macrophage polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype.

Protein Kinase C α-Responsive Gene Carrier for Cancer-Specific Transgene Expression and Cancer Therapy.

The presence of intracellular signal transduction and its abnormal activities in many cancers has potential for medical and pharmaceutical applications. We recently developed a protein kinase C α (PKCα)-responsive gene carrier for cancer-specific gene delivery. Here, we demonstrate an in-depth analysis of cellular signal-responsive gene carrier and the impact of its selective transgene expression in response to malfunctioning intracellular signaling in cancer cells.

Protective and healing effects of apoptotic mimic-induced M2-like macrophage polarization on pressure ulcers in young and middle-aged mice.

Pressure ulcers (PUs) have no cure and are of significant health and economic concern worldwide, owing to the increasing population of elderly individuals at high risk for PU and who have impaired tissue repair. Macrophages play a pivotal role in PU development and healing. Imbalances between M1 (inflammatory) and M2 (anti-inflammatory/reparative) macrophages result in delayed resolution of inflammation and wound healing.

Long-term profile of serological biomarkers, hepatic inflammation, and fibrosis in a mouse model of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) can be typically classified into two subgroups: non-alcoholic fatty liver and non-alcoholic steatohepatitis. Mouse models of NAFLD are useful tools for understanding the pathogenesis and progression of NAFLD and for developing drugs for its treatment. Here, we investigated the time-dependent changes in serum lipids and biochemical markers of hepatic function, hepatic inflammation, and fibrosis in mice fed a normal diet (ND) or a NAFLD diet (choline deficient, L-amino acid-defined, high-fat diet; CDAHFD) for 12 weeks.

Design of substrates and inhibitors of G protein-coupled receptor kinase 2 (GRK2) based on its phosphorylation reaction.

The G protein-coupled receptor kinase (GRK) family consists of seven cytosolic serine/threonine (Ser/Thr) protein kinases, and among them, GRK2 is involved in the regulation of an enormous range of both G protein-coupled receptors (GPCRs) and non-GPCR substrates that participate in or regulate many critical cellular processes. GRK2 dysfunction is associated with multiple diseases, including cancers, brain diseases, cardiovascular and metabolic diseases, and therefore GRK2-specific substrates/inhibitors are needed not only for studies of GRK2-mediated cellular functions but also for GRK2-targeted drug development. Here, we first review the structure, regulation and functions of GRK2, and its synthetic substrates and inhibitors.

Unique cellular interaction of macrophage-targeted liposomes potentiates anti-inflammatory activity.

Nanomedicines that suppress macrophage-mediated chronic inflammation are important therapeutics for many inflammatory diseases. The small-sized (<100 nm) apoptotic-cell-mimetic macrophage-targeted liposomes served as a long-lasting immunosuppressive agent through preferential association with CD300a receptor, unlike larger liposomes, enabling the amelioration of hepatic inflammation in mice.

Effect of Fetal Bovine Serum Concentration on Lysophosphatidylcholine-mediated Proliferation and Apoptosis of Human Aortic Smooth Muscle Cells.

Lysophosphatidylcholine (lysoPtdCho) is produced by the phospholipase A-mediated hydrolysis of phosphatidylcholine and can stimulate proliferation and apoptosis of vascular smooth muscle cells. We examined the influence of fetal bovine serum (FBS) concentration in the culture medium on lysoPtdCho-mediated apoptosis and proliferation of human aortic smooth muscle cells (HASMCs) as well as on the activation of extracellular signal-regulated kinases (ERK)1/2. In the presence of 1% FBS, HASMC viability increased after lysoPtdCho treatment at 1 and 10 μM but decreased at 25 and 50 μM.

Enhanced Osseointegration Capability of Poly(ether ether ketone) via Combined Phosphate and Calcium Surface-Functionalization.

Biomedical applications of poly(ether ether ketone) (PEEK) are hindered by its inherent bioinertness and lack of osseointegration capability. In the present study, to enhance osteogenic activity and, hence, the osseointegration capability of PEEK, we proposed a strategy of combined phosphate and calcium surface-functionalization, in which ozone-gas treatment and wet chemistry were used for introduction of hydroxyl groups and modification of phosphate and/or calcium, respectively. Surface functionalization significantly elevated the surface hydrophilicity without changing the surface roughness or topography.

Suppression of Lysophosphatidylcholine-Induced Human Aortic Smooth Muscle Cell Calcification by Protein Kinase A Inhibition.

Lysophosphatidylcholine (lysoPtdCho) is produced mainly by the phospholipase A2-dependent hydrolysis of phosphatidylcholine (PtdCho) and can induce inflammatory activation and osteogenic gene expression in vascular smooth muscle cells. However, the mechanisms mediating these processes have not been fully elucidated. In this study, we investigated whether inhibition of protein kinase A (PKA) signaling suppressed lysoPtdCho-induced calcification of human aortic smooth muscle cells (HASMC).

A high-affinity peptide substrate for G protein-coupled receptor kinase 2 (GRK2).

We synthesized a previously identified β-tubulin-derived G protein-coupled receptor kinase 2 (GKR2) peptide (GR-11-1; DEMEFTEAESNMN) and its amino-terminal extension (GR-11-1-N; GEGMDEMEFTEAESNMN) and carboxyl-terminal extension (GR-11-1-C; DEMEFTEAESNMNDLVSEYQ) peptides with the aim of finding a high-affinity peptide substrate for GRK2. GR-11-1-C showed high affinity for GRK2, but very low affinity for GKR5. Its specificity and sensitivity for GKR2 were greater than those of GR-11-1 and GR-11-1-N.

Surface plasma treatment and phosphorylation enhance the biological performance of poly(ether ether ketone).

Poly(ether ether ketone) (PEEK) has emerged as an alternative endosseous material to metal implants mainly because of its lack of allergic sensitivity and radiolucency, while maintaining similar mechanical properties with bone. However, a disadvantage of PEEK is its weak osseointegration ability compared with metal implants. To overcome this, we prepared a phosphate group-modified PEEK by plasma treatment and subsequent phosphorylation reaction.

Protein kinase A (PKA) inhibition reduces human aortic smooth muscle cell calcification stimulated by inflammatory response and inorganic phosphate.

Aims: Smooth muscle cells (SMCs) play a role in medial vascular calcification, which can be stimulated by high levels of serum phosphate and inflammatory mediators. The aim of this study was to investigate whether mitogen-activated protein kinases (MAPKs) (p38 MAPK, ERK1/2, and JNK) and protein kinase A (PKA) can participate in inorganic phosphate (Pi)- and inflammation response-stimulated SMC calcification.

Main Methods: We examined the change of Pi- and/or inflammation-stimulated human aortic smooth muscle cell (HASMC) calcification in the presence and absence of inhibitors or small interfering RNAs.

Macrophage Uptake Behavior and Anti-inflammatory Response of Bovine Brain- or Soybean-derived Phosphatidylserine Liposomes.

Phosphatidylserine (PtdSer) is mainly derived from the bovine brain cortex or soybean lecithin. We investigated macrophage uptake behavior and the anti-inflammatory response induced by liposomes containing bovine brain- (B-PSL) or soybean-derived PtdSer (S-PSL). The size of B-PSL and S-PSL was very similar.

Effect of micro-roughening of poly(ether ether ketone) on bone marrow derived stem cell and macrophage responses, and osseointegration.

Poly(ether ether ketone) (PEEK) has emerged as a candidate to replace metal implants because of its satisfactory mechanical properties, radiolucency, and lack of metal allergy. However, PEEK lacks osseointegration ability limiting its clinical applications. To overcome this problem, we prepared PEEK with a micro-rough surface using the sandblast method to modulate its osseointegration property; the sandblast method is simple, cost-effective, and is already applied to clinical metal implants.

Increased hepatic inflammation in a normal-weight mouse after long-term high-fat diet feeding.

Among five C57BL/6 mice fed a high-fat diet (HFD) for 12 weeks, one mouse showed a body weight (BW) similar to normal diet (ND)-fed mice. We compared obesity-related parameters of three groups (ND-fed mice, one HFD-fed normal-weight mouse, and HFD-fed overweight mice), including visceral fat weight, serum levels of total cholesterol (TC), glucose, and aminotransferases (AST and ALT), adipocyte size, percentage of crown-like structures, severity of hepatic steatosis, and number of inflammatory foci. Compared to ND-fed mice, the HFD-fed normal-weight mouse exhibited a similar visceral fat weight, similar serum levels of glucose and aminotransferases, and a similar percentage of crown-like structures.

Anti-obesity and anti-inflammatory effects of macrophage-targeted interleukin-10-conjugated liposomes in obese mice.

Obesity is associated with chronic inflammation and is known as a major risk factor for several diseases including chronic kidney disease, diabetes, and cardiovascular diseases. Macrophages play a critical role in the development of obesity-induced inflammation. Efficient delivery of therapeutic anti-inflammatory molecules, such as interleukin (IL)-10, to macrophages can dramatically improve therapeutic efficacy of obesity treatments.

Role of amino acid residues surrounding the phosphorylation site in peptide substrates of G protein-coupled receptor kinase 2 (GRK2).

A series of amino acid substitutions was made in a previously identified β-tubulin-derived GRK2 substrate peptide (DEMEFTEAESNMN) to examine the role of amino acid residues surrounding the phosphorylation site. Anionic amino acid residues surrounding the phosphorylation site played an important role in the affinity for GRK2. Compared to the original peptide, a modified peptide (Ac-EEMEFSEAEANMN-NH) exhibited markedly higher affinity for GRK2, but very low affinity for GRK5, suggesting that it can be a sensitive and selective peptide for GRK2.

Immobilization of calcium and phosphate ions improves the osteoconductivity of titanium implants.

In this work, to elevate weak osteoconductivity of titanium (Ti) implant, we prepared a Ti implant having both calcium and phosphate ions on its surface. To modify calcium and phosphate ions onto Ti, phosphate ions were first immobilized by treating the Ti with a NaH2PO4 solution, followed by CaCl2 treatment to immobilize calcium ions, which created the calcium and phosphate ions-modified Ti (Ca-P-Ti). X-ray photoelectron spectroscopy and thin-layer X-ray diffraction measurement confirmed that both phosphate and calcium ions were co-immobilized onto the Ti surface on the molecular level.