iMyoblasts for ex vivo and in vivo investigations of human myogenesis and disease modeling.

Skeletal muscle myoblasts (iMyoblasts) were generated from human induced pluripotent stem cells (iPSCs) using an efficient and reliable transgene-free induction and stem cell selection protocol. Immunofluorescence, flow cytometry, qPCR, digital RNA expression profiling, and scRNA-Seq studies identify iMyoblasts as a PAX3+/MYOD1+ skeletal myogenic lineage with a fetal-like transcriptome signature, distinct from adult muscle biopsy myoblasts (bMyoblasts) and iPSC-induced muscle progenitors. iMyoblasts can be stably propagated for >12 passages or 30 population doublings while retaining their dual commitment for myotube differentiation and regeneration of reserve cells. iMyoblasts also efficiently xenoengrafted into irradiated and injured mouse muscle where they undergo differentiation and fetal-adult MYH isoform switching, demonstrating their regulatory plasticity for adult muscle maturation in response to signals in the host muscle. Xenograft muscle retains PAX3+ muscle progenitors and can regenerate human muscle in response to secondary injury. As models of disease, iMyoblasts from individuals with Facioscapulohumeral Muscular Dystrophy revealed a previously unknown epigenetic regulatory mechanism controlling developmental expression of the pathological DUX4 gene. iMyoblasts from Limb-Girdle Muscular Dystrophy R7 and R9 and Walker Warburg Syndrome patients modeled their molecular disease pathologies and were responsive to small molecule and gene editing therapeutics. These findings establish the utility of iMyoblasts for ex vivo and in vivo investigations of human myogenesis and disease pathogenesis and for the development of muscle stem cell therapeutics.

Muscular dystrophies are a group of inherited genetic diseases characterised by progressive muscle weakness. They lead to disability or even death, and no cure exists against these conditions. Advances in genome sequencing have identified many mutations that underly muscular dystrophies, opening the door to new therapies that could repair incorrect genes or rebuild damaged muscles. However, testing these ideas requires better ways to recreate human muscular dystrophy in the laboratory. One strategy for modelling muscular dystrophy involves coaxing skin or other cells from an individual into becoming 'induced pluripotent stem cells'; these can then mature to form almost any adult cell in the body, including muscles. However, this approach does not usually create myoblasts, the 'precursor' cells that specifically mature into muscle during development. This limits investigations into how disease-causing mutations impact muscle formation early on. As a response, Guo et al. developed a two-step protocol of muscle maturation followed by stem cell growth selection to isolate and grow 'induced myoblasts' from induced pluripotent stem cells taken from healthy volunteers and muscular dystrophy patients. These induced myoblasts can both make more of themselves and become muscle, allowing Guo et al. to model three different types of muscular dystrophy. These myoblasts also behave as stem cells when grafted inside adult mouse muscles: some formed human muscle tissue while others remained as precursor cells, which could then respond to muscle injury and start repair. The induced myoblasts developed by Guo et al. will enable scientists to investigate the impacts of different mutations on muscle tissue and to better test treatments. They could also be used as part of regenerative medicine therapies, to restore muscle cells in patients.

Two new polycyclic polyprenylated acylphloroglucinols derivatives from Hypericum acmosepalum.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) were mainly obtained from the plants of Hypericum genus of Guttiferae family, and possessed intriguing chemical structures and appealing biological activities. Two new PPAPs derivatives, hyperacmosin C (1) and hyperacmosin D (2) were isolated from H. acmosepalum. Their structures were established by NMR, HREIMS, and experimental electronic circular dichroism spectra. Besides, compound 1 showed significant hepatoprotective activity at 10 µM against paracetamol-induced HepG2 cell damage and compound 2 could moderately increase the relative glucose consumption.

Hyperascyrins L - N, rare methylated polycyclic polyprenylated acylphloroglucinol derivatives from Hypericum ascyron.

Seven natural compounds, including new compounds hyperascyrins L-N (1-3) and four known compounds (4-7), were acquired from the aerial parts of Hypericum ascyron, that were all identified as methylated polycyclic polyprenylated acylphloroglucinol derivatives (mPPAPs). The structures of these compounds were established by NMR spectroscopy, experimental and calculated electronic circular dichroism (ECD) data. The neuroprotective activities and hepatoprotective activity of these compounds (10 µM) were evaluated. Compounds 1, 2 and 3 exhibited neuroprotection activity. Compounds 1 and 3 show hepatoprotective activity.

Methylated Polycyclic Polyprenylated Acylphloroglucinol Derivatives from Hypericum ascyron.

Hyperascyrins A-H (1-11) and four known compounds (12-15) were acquired from the air-dried aerial parts of Hypericum ascyron and were all identified as methylated polycyclic polyprenylated acylphloroglucinol derivatives. Their structures were established by NMR spectroscopy, experimental and calculated electronic circular dichroism (ECD) data, and comparison with established compounds. Compounds 8 and 9 showed protection against paracetamol-induced HepG2 cell damage at 10 µM. The neuroprotective activities of all compounds (10 µM) were evaluated, and compounds 1 and 8 exhibited mild neuroprotection against glutamate-induced toxicity in SK-N-SH cells.

[Chemical constituents of Hypericum perforatum].

A chemical investigation on the aerial parts of Hypericum perforatum resulted in the isolation of a new phloroglucinol derivatives (1), and seven known compounds (2-8). The structures of the compounds were elucidated by means of spectroscopic methods (MS, IR, 1D NMR, and 2D NMR) as 3-methyl-4,6-di (3- methyl-2-butenyl)-3-(4-methyl-3-pentenyl)-2-(2-ethyl-1-oxobutyl)-cyclohexanone (1)，hyperforin (2)，(2R,3R,4S,6R)-3-methyl-4,6-di(3-methyl-2-butenyl)-2-(2-methyl-1-oxo-propyl)-3-(4-methyl-3-pentenyl)-cyclohexanone (3)，hyperscabrin B (4)，hyperscabrin C (5)，furohyperforin isomer 1 (6)，furoadhyperforin (7)，and furohyperforin (8). Compound 1 was a new compound, and compounds 3-5 were obtained from H. perforatum for the first time.

Emodin and baicalein inhibit sodium taurocholate-induced vacuole formation in pancreatic acinar cells.

AIM: To investigate the effects of combined use of emodin and baicalein (CEB) at the cellular and organism levels in severe acute pancreatitis (SAP) and explore the underlying mechanism. METHODS: SAP was induced by retrograde infusion of 5% sodium taurocholate into the pancreatic duct in 48 male SD rats. Pancreatic histopathology score, serum amylase activity, and levels of tumour necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and IL-10 were determined to assess the effects of CEB at 12 h after the surgery. The rat pancreatic acinar cells were isolated from healthy male SD rats using collagenase. The cell viability, cell ultrastructure, intracellular free Ca2+ concentration, and inositol (1,4,5)-trisphosphate receptor (IP3R) expression were investigated to assess the mechanism of CEB. RESULTS: Pancreatic histopathology score (2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05) and serum amylase activity (2866.2 ± 617.7 vs 5241.3 ± 1410.0, P < 0.05) were significantly decreased in the CEB (three doses) treatment group compared with the SAP group (2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05). CEB dose-dependently reduced the levels of the pro-inflammatory cytokines IL-6 (466.82 ± 48.55 vs 603.50 ± 75.53, P < 0.05) and TNF-α (108.04 ± 16.10 vs 215.56 ± 74.67, P < 0.05) and increased the level of the anti-inflammatory cytokine IL-10 (200.96 ± 50.76 vs 54.18 ± 6.07, P < 0.05) compared with those in the SAP group. CEB increased cell viability, inhibited cytosolic Ca2+ concentration, and significantly ameliorated intracellular vacuoles and IP3 mRNA expression compared with those in the SAP group (P < 0.05). There was a trend towards decreased IP3R protein in the CEB treatment group; however, it did not reach statistical significance (P > 0.05). CONCLUSION: These results at the cellular and organism levels reflect a preliminary mechanism of CEB in SAP and indicate that CEB is a suitable approach for SAP treatment.

Synthesis and antitumor activities of sinomenine derivatives on rings A and C.

A series of new sinomenine derivatives were designed, synthesized, and evaluated in tumor inhibitory activity, such as human triple negative breast cancer cell line (MDA-MB-231), glioma cell line (A172), human lung cancer cell line (A549), human colon cancer cell line (HCT-8). The modifications were carried out on rings A and C of the sinomenine by esterificating on phenolic hydroxyl with good yields. The highlight of this work was that the synthetic procedures were concise and sinomenine derivatives demonstrated promising antitumor activities.

Polyisoprenylated benzoylphloroglucinol derivatives from Hypericum scabrum.

Four new polyisoprenylated benzoylphloroglucinol derivatives, hyperscabrones J-M (1-4), were isolated from the air-dried aerial parts of Hypericum scabrum. Their structures were elucidated by spectroscopic methods and were subsequently confirmed by comparing with data of known compounds. The absolute configuration of the bicyclo[3.3.1]nonane-2,4,9-trione core was defined by the experimental and calculated electronic circular dichroism (ECD) spectra. The evaluation of their hepatoprotective activities against paracetamol-induced HepG2 cell damage showed that compounds 2 and 4 exhibited significant hepatoprotection at 10µM.

Functional cloning of IGFBP-3 from human microvascular endothelial cells reveals its novel role in promoting proliferation of primitive CD34+CD38- hematopoietic cells in vitro.

Ex vivo expansion of hematopoietic stem cells (HSCs) has been investigated as a means of enhancing engraftment of transplantation therapies, but current ex vivo expansion methods typically result in a loss of functional stem cell activity. Factors that can selectively expand human HSCs remain elusive. Recently we have isolated three functionally distinct human brain microvascular endothelial cells (HBMVECs) that differ greatly in their ability to support in vitro proliferation of human umbilical cord blood (UBC) CD34+CD38-cells. Using these distinct HBMVEC populations, we have devised a cell-based functional cloning assay to identify a molecule(s) capable of facilitating expansion of HSCs in vitro. A gene encoded for IGFBP-3 (insulin-like growth factor binding protein-3) has been identified. IGFBP-3 mRNA and protein are differentially expressed in distinct HBMVEC populations. In vitro cell proliferation assay and CD34+CD38- immunophenotype analysis showed that the addition of an exogenous IGFBP-3 to cultures of purified CD34+/-CD38-Lin- cells (CD2/CD3/CD14/CD16/CD19/CD24/CD56/CD66b/GlyA depleted) enhanced proliferation of primitive hematopoietic cells with CD34+CD38- phenotype, suggesting that IGFBP-3 is capable of expanding primitive human blood cells. These expanded primitive blood cells were illustrated to maintain ability to generate functional progenitors. IGFBP-3 belongs to a family of high-affinity IGFBPs, which binds to IGFs and modulates their actions. IGFBP-3 appears to have intrinsic bioactivity that is independent of IGF binding. We are currently exploring the underlying mechanism by which IGFBP-3 modulates proliferation of primitive hematopoietic cells, and the potential of IGFBP-3 to expand pluripotent human repopulating cells capable of hematopoietic reconstitution of irradiated NOD/SCID recipients.