[1] Subjournal of Science: Using CRISPR/Cas9 to Repair Genetic Defects in Hematopoietic Stem Cells Derived from Patients with a Rare Immunodeficiency Disorder

　　doi: 10.1126/scitranslmed.aah3480

　　In a new study, researchers from the National Institute of Allergy and Infectious Diseases (NIAID) at the U.S. National Institutes of Health (NIH), MaxCyte, and Leidos Biomedical Research have developed a novel approach to correct a defective gene in hematopoietic stem cells derived from patients with X-linked chronic granulomatous disease (X-CGD). When transplanted into mice, these repaired hematopoietic stem cells generated functionally normal white blood cells, suggesting that this strategy could potentially be used to treat patients with X-CGD. The findings were published on January 11, 2017, in the journal Science Translational Medicine, under the title “CRISPR-Cas9 gene repair of hematopoietic stem cells from patients with X-linked chronic granulomatous disease.”

　　X‑CGD is a rare inherited immunodeficiency disorder caused by mutations in the CYBB gene. The CYBB gene provides the genetic instructions for producing the NOX2 protein. Defects in NOX2 impair the ability of white blood cells to fight infections, leaving X‑CGD patients highly susceptible to life‑threatening infections. In this new study, researchers focused on a specific CYBB mutation: a single‑base change that results in the production of a nonfunctional NOX2 protein.

　　[2] Nat Bio Eng: Breakthrough! Scientists have successfully regenerated the outer layer of the heart using stem cells.

　　News Reading: Researchers use stem cells to regenerate the external layer of a human heart

　　Recently, a research report published in the international journal Nature Biomedical Engineering described how researchers at Pennsylvania State University successfully regenerated human cardiac epicardial cells using stem cells. The researchers noted that as early as 2012, they discovered that treating human stem cells with specific chemical agents—simultaneously activating them and inhibiting the Wnt signaling pathway—could promote their differentiation into cardiomyocytes. Cardiomyocytes, the middle layer of the heart’s three‑layered structure, are highly contractile and play a crucial role in pumping blood throughout the body.

　　The Wnt signaling pathway is a specialized signal-transduction cascade composed of proteins that uses cell-surface receptors to transmit signals into the cell. Professor Xiaojun Lance Lian stated, “We need to provide cardiac progenitor cells with additional cues to induce their differentiation into epicardial cells; however, prior to this study, the nature of these specific cues remained unclear. Our findings now demonstrate that by reactivating the Wnt signaling pathway within these cells, we can redirect cardiac progenitor cells toward an epicardial lineage rather than a cardiomyogenic one.”

　　[3] Nature: Landmark! For the first time, human gastric fundus tissue has been generated using pluripotent stem cells.

　　doi: 10.1038/nature21021

　　In a new study, Dr. Jim Wells, Director of the Pluripotent Stem Cell Division at Cincinnati Children’s Hospital Medical Center, and his team used pluripotent stem cells to generate human stomach fundus tissue—capable of producing gastric acid and digestive enzymes—in vitro. The findings were published online on January 4, 2017, in the journal Nature, under the title “Wnt/β-catenin promotes gastric fundus specification in mice and humans.” This research was conducted two years after Wells’ team had successfully cultured the hormone‑producing region of the stomach—the antrum.

　　This discovery means that scientists can now cultivate specific regions of the human stomach, enabling them to study diseases in unprecedented ways, develop models for new therapies, and gain insights into human gastric development and health.

　　Wells said, “Given that we can culture human gastric antrum and fundus organoids, we can investigate how these gastric tissues interact physiologically, mount distinct responses to infection and injury, and respond to pharmacological treatments. Gastric diseases affect millions of people in the United States, and gastric cancer is the third leading cause of cancer‑related mortality worldwide.”

　　[4] Adv Healthc Mater: Magnetic-Controlled Stem Cells Developed for Targeted Drug Delivery to Tumors

　　DOI: 10.1002/adhm.201600843

　　Scientists from Tomsk Polytechnic University (TPU) have developed a new technique for controlling mesenchymal stem cells (MSCs), which could enable more effective cancer treatment. To target tumor cells, the researchers are harnessing magnetic fields to guide patients’ own cells, which, being autologous, are not rejected by the immune system and can deliver therapeutic agents directly to the tumor site. This innovative approach was jointly developed by researchers from TPU, Pavlov First Saint Petersburg State Medical University, and Queen’s College, University of London.

　　They combined approximately 10-micrometer‑sized MSCs with magnetic microparticles loaded with the drug, then used an external magnetic field to guide the cells toward the tumor tissue. Once at the tumor site, the microparticles release their encapsulated drug, enabling precise delivery to the tumor while sparing healthy tissues.

　　“MSCs themselves exhibit tumor tropism, and they can also differentiate into bone, fat, muscle, or connective tissue both in vivo and in vitro. Consequently, MSCs are highly attractive for use in regenerative therapies, as well as in gene and cell engineering,” said Alexander Timin, one of the co-authors and a researcher at TPU.

　　[5] Nat Commun: Breakthrough! Scientists have successfully developed a new version of stem cells that may hold significant therapeutic potential.

　　doi: 10.1038/NCOMMS13724

　　Recently, a research report published in the international journal Nature Communications described how researchers from North Carolina State University, the First Affiliated Hospital of Zhengzhou University in China, and other institutions have developed a synthetic version of a novel cardiac stem cell (CSC). Compared with natural stem cells, these synthetic cells exhibit therapeutic potential while reducing the risk of disease associated with stem cell therapies. Moreover, the newly engineered stem cells demonstrate notable stability, and this technology holds promise for advancing the development of other types of stem cells.

　　Stem cell therapy exerts its effects by promoting endogenous repair within the body; that is, it can facilitate the repair of damaged tissues by secreting various paracrine factors, which include proteins and genetic material. However, when stem cell therapy successfully treats a disease, it may also trigger tumor growth and elicit immune rejection responses. Moreover, these stem cells are inherently fragile and must undergo a series of critical procedures—such as cryopreservation—before they can be administered.

　　[6] Nature Subjournal: Major Breakthrough! Scientists Have Developed Artificially Synthesized Stem Cells for Treating Heart Disease

　　DOI: 10.1038/NCOMMS13724

　　Multiple studies have shown that stem cell therapy primarily repairs damaged tissues through paracrine mechanisms—by secreting proteins, nucleic acids, and other bioactive molecules. Although the efficacy of stem cell therapy has been widely demonstrated, the treatment still carries certain potential risks, such as inducing tumor formation in the host and triggering immune rejection responses. Furthermore, stem cells themselves are inherently fragile, difficult to preserve, and challenging to handle, presenting additional limitations.

　　Professor Ke Cheng, the corresponding author of this paper and affiliated with North Carolina State University and the University of North Carolina at Chapel Hill, has long been dedicated to research on cardiac stem cells. This time, Professor Cheng’s laboratory in North Carolina collaborated with Professor Jinying Zhang at the First Affiliated Hospital of Zhengzhou University to develop an artificially synthesized stem cell that carries both secreted factors and a cell membrane derived from cardiac stem cells, which they have named cell-mimicking microparticles (CMMP).

　　Cheng said, “Our design approach involves isolating secretory factors from native cardiac stem cells, fusing them with biodegradable microparticles to form microspheres, and then coating these spheres with the cell membrane of cardiac stem cells. We refer to these microspheres, which can mimic the functional properties of cell therapy, as cell-mimicking microparticles (CMMP).”

　　[7] Cell Reports: A New Method for Converting Stem Cells into Neurons

　　DOI: 10.1016/j.celrep.2016.07.035

　　Because it is extremely difficult to obtain fully functional human neurons, studying neurological disorders in the laboratory poses significant challenges. However, a recently developed technology by researchers at Duke–NUS Medical School can rapidly and efficiently generate neurons relevant to neurological disorders in the lab, offering new hope for research into these conditions.

　　Based on the type of neurotransmitter they release, neurons can be classified as excitatory or inhibitory. For example, neurons that secrete glutamate are excitatory, while those that release γ‑aminobutyric acid (GABA) are inhibitory. Inhibitory neurons are implicated in disorders such as epilepsy, yet researchers currently understand very little about them. “The main reason,” says Dr. Alfted Sun, a postdoctoral fellow at the Genome Institute of Singapore under A*STAR, “is the lack of a rapid and efficient method for generating these neurons in vitro.” Indeed, existing protocols for differentiating stem cells into GABA‑secreting neurons are time‑consuming, often taking more than six months to complete, which severely constrains progress in this area of research.