Short-Chain Acyl-CoA Dehydrogenase as a Therapeutic Target for Cardiac Fibrosis.

ABSTRACT: Cardiac fibrosis is considered as unbalanced extracellular matrix production and degradation, contributing to heart failure. Short-chain acyl-CoA dehydrogenase (SCAD) negatively regulates pathological cardiac hypertrophy. The purpose of this study was to investigate the possible role of SCAD in cardiac fibrosis. In vivo experiments were performed on spontaneously hypertensive rats (SHR) and SCAD-knockout mice. The cardiac tissues of hypertensive patients with cardiac fibrosis were used for the measurement of SCAD expression. In vitro experiments, with angiotensin II (Ang II), SCAD siRNA and adenovirus-SCAD were performed using cardiac fibroblasts (CFs). SCAD expression was significantly decreased in the left ventricles of SHR. Notably, swim training ameliorated cardiac fibrosis in SHR in association with the elevation of SCAD. The decrease in SCAD protein and mRNA expression levels in SHR CFs were in accordance with those in the left ventricular myocardium of SHR. In addition, SCAD expression was downregulated in CFs treated with Ang II in vitro, and SCAD siRNA interference induced the same changes in cardiac fibrosis as Ang II-treated CFs, while adenovirus-SCAD treatment significantly reduced the Ang II-induced CFs proliferation, alpha smooth muscle actin (α-SMA), and collagen expression. In SHR infected with adenovirus-SCAD, the cardiac fibrosis of the left ventricle was significantly decreased. However, cardiac fibrosis occurred in conventional SCAD-knockout mice. SCAD immunofluorescence intensity of cardiac tissue in hypertensive patients with cardiac fibrosis was lower than that of healthy subjects. Altogether, the current experimental outcomes indicate that SCAD has a negative regulatory effect on cardiac fibrosis and support its potential therapeutic target for suppressing cardiac fibrosis.

Neuroinflammation of Microglial Regulation in Alzheimer's Disease: Therapeutic Approaches.

Alzheimer's disease (AD) is a complex degenerative disease of the central nervous system that is clinically characterized by a progressive decline in memory and cognitive function. The pathogenesis of AD is intricate and not yet fully understood. Neuroinflammation, particularly microglial activation-mediated neuroinflammation, is believed to play a crucial role in increasing the risk, triggering the onset, and hastening the progression of AD. Modulating microglial activation and regulating microglial energy metabolic disorder are seen as promising strategies to intervene in AD. The application of anti-inflammatory drugs and the targeting of microglia for the prevention and treatment of AD has emerged as a new area of research interest. This article provides a comprehensive review of the role of neuroinflammation of microglial regulation in the development of AD, exploring the connection between microglial energy metabolic disorder, neuroinflammation, and AD development. Additionally, the advancements in anti-inflammatory and microglia-regulating therapies for AD are discussed.

A novel multifunctional anti-CEA-IL15 molecule displays potent antitumor activities.

INTRODUCTION: Interleukin-15 (IL-15) is an immunomodulatory cytokine. It can activate and expand cytotoxic CD8 T lymphocytes and natural killer cells, leading to potent antitumor effects. Various forms of IL-15 are now in different stages of development for cancer immunotherapy. One of the major issues with IL-15 or IL15-IL15Rα fusion is high toxicity due to systemic activation of immune cells. MATERIALS AND METHODS: In this study, we engineered a nanobody-cytokine fusion molecule, anti-CEA-IL15, in which an anti-CEA nanobody was linked to an IL15Rα-IL15 fusion. The nanobody-cytokine fusion exhibited multiple mechanisms to kill tumor cells, including promoting immune cell proliferation and directing antibody-dependent cytotoxicity against CEA-positive tumor cells. RESULTS: In xenograft models, anti-CEA-IL15 was localized in the tumor microenvironment and exhibited more potent antitumor activities than non-targeting IL-15, supporting potential application of this multifunctional fusion molecule in tumor immunotherapy. CONCLUSION: We generated and validated a tumortargeting fusion protein, anti-CEA-IL15, which has potent cytokine activity to activate and mobilize the immune system to fight cancer cells. Such strategies may also be applied to other cytokines and tumor-targeting molecules to increase antitumor efficacy.

Site-specific PEGylation of an anti-CEA/CD3 bispecific antibody improves its antitumor efficacy.

INTRODUCTION: Bispecific antibodies that engage immune cells to kill cancer cells are actively pursued in cancer immunotherapy. Different types of bispecific antibodies, including single-chain fragments, Fab fragments, nanobodies, and immunoglobulin Gs (IgGs), have been studied. However, the low molecular weight of bispecific antibodies with single-chain or Fab fragments generally leads to their rapid clearance in vivo, which limits the therapeutic potential of these bispecific antibodies. MATERIALS AND METHODS: In this study, we used a site-specific PEGylation strategy to modify the bispecific single-domain antibody-linked Fab (S-Fab), which was designed by linking an anticarcinoembryonic antigen (anti-CEA) nanobody with an anti-CD3 Fab. RESULTS: The half-life (t1/2) of PEGylated S-Fab (polyethylene glycol-S-Fab) was increased 12-fold in vivo with a slightly decreased tumor cell cytotoxicity in vitro as well as more potent tumor growth inhibition in vivo compared to S-Fab. CONCLUSION: This study demonstrated that PEGylation is an effective approach to enhance the antitumor efficacy of bispecific antibodies.

A GPC3-targeting Bispecific Antibody, GPC3-S-Fab, with Potent Cytotoxicity.

This protocol describes the construction and functional studies of a bispecific antibody (bsAb), GPC3-S-Fab. bsAbs can recognize two different epitopes through their two different arms. bsAbs have been actively studied for their ability to directly recruit immune cells to kill tumor cells. Currently, the majority of bsAbs are produced in the form of recombinant proteins, either as Fc-containing bsAbs or as smaller bsAb derivatives without the Fc region. In this study, GPC3-S-Fab, an antibody fragment (Fab) based bispecific antibody, was designed by linking the Fab of anti-GPC3 antibody GC33 with an anti-CD16 single domain antibody. The GPC3-S-Fab can be expressed in Escherichia coli and purified by two affinity chromatographies. The purified GPC3-S-Fab can specifically bind to and kill GPC3 positive liver cancer cells by recruiting natural killer cells, suggesting a potential application of GPC3-S-Fab in liver cancer therapy.

BiHC, a T-Cell-Engaging Bispecific Recombinant Antibody, Has Potent Cytotoxic Activity Against Her2 Tumor Cells.

Among different cancer immunotherapy approaches, bispecific antibodies (BsAbs) are of great interest due to their ability to recruit immune cells to kill tumor cells directly. Various BsAbs against Her2 tumor cells have been proposed with potent cytotoxic activities. However, most of these formats require extensive processing to obtain heterodimeric bispecific antibodies. In this study, we describe a bispecific antibody, BiHC (bispecific Her2-CD3 antibody), constructed with a single-domain anti-Her2 and a single-chain Fv (variable fragment) of anti-CD3 in an IgG-like format. In contrast to most IgG-like BsAbs, the two arms in BiHC have different molecular weights, making it easier to separate hetero- or homodimers. BiHC can be expressed in Escherichia coli and purified via Protein A affinity chromatography. The purified BiHC can recruit T cells and induce specific cytotoxicity of Her2-expressing tumor cells in vitro. The BiHC can also efficiently inhibit the tumor growth in vivo. Thus, BiHC is a promising candidate for the treatment of Her2-positive cancers.

A single-domain antibody-linked Fab bispecific antibody Her2-S-Fab has potent cytotoxicity against Her2-expressing tumor cells.

Her2, which is frequently overexpressed in breast cancer, is one of the most studied tumor-associated antigens for cancer therapy. Anti-HER2 monoclonal antibody, trastuzumab, has achieved significant clinical benefits in metastatic breast cancer. In this study, we describe a novel bispecific antibody Her2-S-Fab targeting Her2 by linking a single domain anti-CD16 VHH to the trastuzumab Fab. The Her2-S-Fab antibody can be efficiently expressed and purified from Escherichia coli, and drive potent cancer cell killing in HER2-overexpressing cancer cells. In xenograft model, the Her2-S-Fab suppresses tumor growth in the presence of human immune cells. Our results suggest that the bispecific Her2-S-Fab may provide a valid alternative to Her2 positive cancer therapy.

A targeted IL-15 fusion protein with potent anti-tumor activity.

IL-15 has been actively investigated for its potential in tumor immunotherapy. To enhance the anti-tumor activity of IL-15, the novel PFC-1 construct was designed, which comprises the following 3 parts: (1) IL-15Rα fused with IL-15 to enhance IL-15 activity, (2) an Fc fragment to increase protein half-life, and (3) an integrin-targeting RGD peptide to enhance tumor targeting. PFC-1 showed tumor cell targeting without compromising IL-15 activity. PFC-1 also had potent anti-tumor activities in xenograft models, suggesting the potential application of this multi-functional fusion protein in tumor therapy.

Antitumor Effects and Mechanism of Novel Emodin Rhamnoside Derivatives against Human Cancer Cells In Vitro.

A series of novel anthracene L-rhamnopyranosides compounds were designed and synthesized and their anti-proliferative activities on cancer cell lines were investigated. We found that one derivative S-8 (EM-d-Rha) strongly inhibited cell proliferation of a panel of different human cancer cell lines including A549, HepG2, OVCAR-3, HeLa and K562 and SGC-790 cell lines, and displayed IC50 values in low micro-molar ranges, which are ten folds more effective than emodin. In addition, we found EM-d-Rha (3-(2",3"-Di-O-acetyl-α-L-rhamnopyranosyl-(1→4)-2',3'-di-O-acetyl-α-L-rhamnopyranosyl)-emodin) substantially induced cellular apoptosis of HepG2 and OVCAR-3 cells in the early growth stage. Furthermore, EM-d-Rha led to the decrease of mitochondrial transmembrane potential, and up-regulated the express of cells apoptosis factors in a concentration- and time-dependent manner. The results indicated the EM-d-Rha may inhibit the growth and proliferation of HepG2 cells through the pathway of apoptosis induction, and the possible molecular mechanism may due to the activation of intrinsic apoptotic signal pathway.