Long‐term repopulation of aged bone marrow stem cells using young Sca‐1 cells promotes aged heart rejuvenation

Reduced quantity and quality of stem cells in aged individuals hinders cardiac repair and regeneration after injury. We used young bone marrow (BM) stem cell antigen 1 (Sca‐1) cells to reconstitute aged BM and rejuvenate the aged heart, and examined the underlying molecular mechanisms. BM Sca‐1⁺ or Sca‐1^? cells from young (2–3 months) or aged (18–19 months) GFP transgenic mice were transplanted into lethally irradiated aged mice to generate 4 groups of chimeras: young Sca‐1⁺, young Sca‐1^?, old Sca‐1⁺, and old Sca‐1^?. Four months later, expression of rejuvenation‐related genes (Bmi1, Cbx8, PNUTS, Sirt1, Sirt2, Sirt6) and proteins (CDK2, CDK4) was increased along with telomerase activity and telomerase‐related protein (DNA‐PKcs, TRF‐2) expression, whereas expression of senescence‐related genes (p16^INK4a, P19^ARF, p27^Kip1) and proteins (p16^INK4a, p27^Kip1) was decreased in Sca‐1⁺ chimeric hearts, especially in the young group. Host cardiac endothelial cells (GFP^?CD31⁺) but not cardiomyocytes were the primary cell type rejuvenated by young Sca‐1⁺ cells as shown by improved proliferation, migration, and tubular formation abilities. C‐X‐C chemokine CXCL12 was the factor most highly expressed in homed donor BM (GFP⁺) cells isolated from young Sca‐1⁺ chimeric hearts. Protein expression of Cxcr4, phospho‐Akt, and phospho‐FoxO3a in endothelial cells derived from the aged chimeric heart was increased, especially in the young Sca‐1⁺ group. Reconstitution of aged BM with young Sca‐1⁺ cells resulted in effective homing of functional stem cells in the aged heart. These young, regenerative stem cells promoted aged heart rejuvenation through activation of the Cxcl12/Cxcr4 pathway of cardiac endothelial cells.     

ACOT12-Dependent Alteration of Acetyl-CoA Drives Hepatocellular Carcinoma Metastasis by Epigenetic Induction of Epithelial-Mesenchymal Transition

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Fundamental Understanding of Photocurrent Hysteresis in Perovskite Solar Cells

Organic–inorganic hybrid perovskite solar cells (PSCs) have become a promising candidate in the photovoltaic field due to their high power conversion efficiency and low material cost. However, the development of PSCs is limited by their poor stability under practical conditions in the presence of oxygen, moisture, sunlight, heat, and the current–voltage (I–V) hysteresis. In particular, the hysteretic I–V issue casts doubt on the validity of the photovoltaic performance results that are achieved, making it difficult to evaluate the authentic performance of PSCs. This review article focuses on understanding the I–V hysteresis behavior in PSCs and on exploring the possible reasons leading to this hysteresis phenomenon. The various strategies attempted to suppress the I–V hysteresis in PSCs are summarized, and a brief future recommendation is provided.     

Identification of steroid C27 monooxygenase isoenzymes involved in sterol catabolism and stepwise pathway engineering of Mycobacterium neoaurum for improved androst-1,4-diene-3,17-dione production

Journal of Industrial Microbiology & Biotechnology - Cholesterol oxidase, steroid C27 monooxygenase and 3-ketosteroid-Δ1-dehydrogenase are key enzymes involved in microbial catabolism of...     

Structure-activity relationships study of neolamellarin A and its analogues as hypoxia inducible factor-1 (HIF-1) inhibitors

The novel marine pyrrole alkaloid neolamellarin A derived from sponge has been shown to inhibit hypoxia-induced HIF-1 activity. In this work, we designed and synthesized neolamellarin A and its series of derivatives by a convergent synthetic strategy. The HIF-1 inhibitory activity and cytotoxicity of these compounds were evaluated in Hela cells by dual-luciferase reporter gene assay and MTT assay, respectively. The results showed that neolamellarin A 1 (IC₅₀ = 10.8 ± 1.0 μM) and derivative 2b (IC₅₀ = 11.9 ± 3.6 μM) had the best HIF-1 inhibitory activity and low cytotoxicity. Our SAR research focused on the effects of key regions aliphatic carbon chain length, aromatic ring substituents and C-7 substituent on biological activity, providing a basis for the subsequent research on the development of novel pyrrole alkaloids as HIF-1 inhibitors and design of small molecule probes for target protein identification.     

Morphogenesis and Molecular Phylogeny of the Soil Ciliate Holostichides chardezi (Ciliophora,Hypotrichia, Bakuellidae), with Redefinition of Holostichides Foissner, 1987 and Establishment of a New Genus Anteholostichides

Morphogenesis of the soil hypotrich ciliate, Holostichides chardezi Foissner, 1987, collected from southeastern China, was investigated using the protargol staining method. The main morphogenetic events follow a similar process with that of its congeners. Phylogenetic analyses based on the SSU rDNA sequence data indicate that Holostichides is nonmonophyletic; H. chardezi, the type species of Holostichides, clusters with H. heterotypicus, while H. terrae is distinctly separate from these species. H. terrae can be distinguished from H. chardezi (type species of Holostichides) and H. heterotypicus by undulating membranes relatively long and distinctly curved (vs. relatively short and straight), pharynx with (vs. without) rod‐shaped structure, and two (vs. more than two) frontoterminal cirri. Therefore, a new genus, Anteholostichides nov. gen., has been proposed for H. terrae. Further, the diagnosis of the genus Holostichides is improved.