Interplay of MPP5a with Rab11 synergistically builds epithelial apical polarity and zonula adherens.

Adherens junction remodeling regulated by apical polarity proteins constitutes a major driving force for tissue morphogenesis, although the precise mechanism remains inconclusive. Here, we report that, in zebrafish, the Crumbs complex component MPP5a interacts with small GTPase Rab11 in Golgi to transport cadherin and Crumbs components synergistically to the apical domain, thus establishing apical epithelial polarity and adherens junctions. In contrast, Par complex recruited by MPP5a is incapable of interacting with Rab11 but might assemble cytoskeleton to facilitate cadherin exocytosis. In accordance, dysfunction of MPP5a induces an invasive migration of epithelial cells. This adherens junction remodeling pattern is frequently observed in zebrafish lens epithelial cells and neuroepithelial cells. The data identify an unrecognized MPP5a-Rab11 complex and describe its essential role in guiding apical polarization and zonula adherens formation in epithelial cells.

Syntheses, Crystal Structures and Antimicrobial Activity of Copper(II) Complexes with the Ligand N,N'-Bis(4-bromosalicylidene)propane-1,2-diamine.

Three new copper(II) complexes, [CuClL] (1), [CuBrL]n (2) and [CuL(NCS)]n (3), derived from the Schiff base 2,4-dichloro-6-((2-pyrrolidin-1-ylethylimino)methyl)phenol (HL) have been prepared and characterized by spectroscopy methods, as well as single crystal X-ray determination. The Cu atom in complex 1 is in square planar coordination, and those in complexes 2 and 3 are in square pyramidal coordination. The Schiff base ligand coordinates to the Cu atoms through phenolate oxygen, imino nitrogen and pyrrolidine nitrogen. The antibacterial activities of the Schiff base and the three copper complexes have been assayed on the bacteria Staphylococcus aureus and Escherichia coli, and the yeast Candida parapsilosis.

Human Placenta-Derived Mesenchymal Stem Cells Improve Neurological Function in Rats with Intrauterine Hypoxic-Ischaemic Encephalopathy by Reducing Apoptosis and Inflammatory Reactions.

BACKGROUND: Hypoxic-ischaemic encephalopathy (HIE) is a major cause of neonatal disability and mortality. Although hypothermia therapy offers some neuroprotection, the recovery of neurological function is limited. Therefore, new synergistic therapies are necessary to improve the prognosis. Mesenchymal stem cell-based therapy is emerging as a promising treatment option for HIE. In this study, we studied the therapeutic efficacy of human placenta-derived mesenchymal stem cells (PD-MSCs) in the HIE rat model and analyzed the underlying therapeutic mechanisms. METHODS: Rats were divided into 6 groups (n = 9 for each) as follows: control, HIE model, HIE + normal saline, and HIE + PD-MSC transplantation at days 7, 14 and 28 postpartum. Following PD-MSC transplantation, neurological behavior was evaluated using rotarod tests, traction tests, and the Morris water maze test. The degree of brain tissue damage was assessed by histological examination and Nissl staining. Expression levels of apoptosis-related proteins and inflammatory factors were quantified by Western blotting and enzyme-linked immunosorbent assays. Immunofluorescence was used to investigate the ability of PD-MSCs to repair the morphology and function of hippocampal neurons with hypoxic-ischaemic (HI) injury. RESULTS: PD-MSC transplantation enhanced motor coordination and muscle strength in HIE rats. This treatment also improved spatial memory ability by repairing pathological damage and preventing the loss of neurons in the cerebral cortex. The most effective treatment was observed in the HIE + PD-MSC transplantation at day 7 group. Expression levels of microtubule-associated protein-2 (MAP-2), B-cell lymphoma-2 (BCL-2), interleukin (IL)-10, and transforming growth factor (TGF -ß1) were significantly higher in the HIE + PD-MSC treatment groups compared to the HIE group, whereas the levels of BCL-2-associated X protein (BAX), BCL-2-associated agonist of cell death (BAD), IL-1ß and tumour necrosis factor α (TNF-α) were significantly lower. CONCLUSIONS: We demonstrated that intravenous injection of PD-MSC at 7, 14 and 28 days after intrauterine HI damage in a rat model could improve learning, memory, and motor function, possibly by inhibiting apoptosis and inflammatory damage. These findings indicate that autologous PD-MSC therapy could have potential application for the treatment of HIE.

Microneedle-mediated delivery of Ziconotide-loaded liposomes fused with exosomes for analgesia.

Ziconotide (ZIC) is an N-type calcium channel antagonist for treating severe chronic pain that is intolerable, or responds poorly to the administration of other drugs, such as intrathecal morphine and systemic analgesics. As it can only work in the brain and cerebrospinal fluid, intrathecal injection is the only administration route for ZIC. In this study, borneol (BOR)-modified liposomes (LIPs) were fused with exosomes from mesenchymal stem cells (MSCs) and loaded with ZIC to prepare microneedles (MNs) to improve the efficiency of ZIC across the blood-brain barrier. To evaluate local analgesic effects of MNs, the sensitivity of behavioral pain to thermal and mechanical stimuli was tested in animal models of peripheral nerve injury, diabetes-induced neuropathy pain, chemotherapy-induced pain, and ultraviolet-B (UV-B) radiation-induced neurogenic inflammatory pain. BOR-modified LIPs loaded with ZIC were spherical or nearly spherical, with a particle size of about 95 nm and a Zeta potential of -7.8 mV. After fusion with MSC exosomes, the particle sizes of LIPs increased to 175 nm, and their Zeta potential increased to -3.8 mV. The nano-MNs constructed based on BOR-modified LIPs had good mechanical properties and could effectively penetrate the skin to release drugs. The results of analgesic experiments showed that ZIC had a significant analgesic effect in different pain models. In conclusion, the BOR-modified LIP membrane-fused exosome MNs constructed in this study for delivering ZIC provide a safe and effective administration for chronic pain treatment, as well as great potential for clinical application of ZIC.

Preparation of pectin-chitosan hydrogels based on bioadhesive-design micelle to prompt bacterial infection wound healing.

The aim of this study was to design a pectin-chitosan (PEC-CS) hydrogel loaded with a bioadhesive-design micelle containing large amount of ciprofloxacin for antibacterial and healing wound applications. Pectin and chitosan are crosslinked in a safe and convenient way, and the PEC-CS hydrogel have high water content (>95 %), strong water absorption (15,000 %), good water retention (>10,000 % at 30 % RH for 12 h), and the PEC-CS hydrogels showed no cytotoxicity and hemolysis, thus providing a humid microenvironment suitable for wound. Additionally, the dopamine modified carrier can greatly improve the solubility and retention time in the wound of ciprofloxacin, effectively increase the efficiency of drug loading into the PEC-CS hydrogels and exert antibacterial activity in the wound for a long time. In vitro and in vivo pharmacodynamics experiments have shown that PEC-CS#CIP@DPDMCs hydrogels can resist bacteria and promote wound healing. Thus，The PEC-CS#CIP@DPDMCs hydrogels can be a potential anti-infective hydrogel excipient.

M6P-modified solid lipid nanoparticles loaded with matrine for the treatment of fibrotic liver.

Liver fibrosis is a key pathological process shared by the progression of various chronic liver diseases. Treatment of liver fibrosis can effectively block the occurrence and development of hepatic cirrhosis or even carcinoma. Currently, there is no effective drug delivery vehicle for curing liver fibrosis. In this study, we designed matrine (MT)-loaded mannose 6-phosphate (M6P) modified human serum albumin (HSA) conjugated solid lipid nanoparticles (SLN), named M6P-HSA-MT-SLN for treatment of hepatic fibrosis. We demonstrated that M6P-HSA-MT-SLN exhibited controlled and sustained release properties and good stability over 7 days. The drug release experiments showed that M6P-HSA-MT-SLN exhibited slow and controlled drug release characteristics. In addition, M6P-HSA-MT-SLN showed a significant targeted ability to fibrotic liver. Importantly, in vivo studies indicated that M6P-HSA-MT-SLN could significantly improve histopathological morphology and inhibit the fibrotic phenotype. In addition, in vivo experiments demonstrate that M6P-HSA-MT-SLN could reduce the expression of fibrosis markers and alleviate the damage of liver structure. Hence, the M6P-HSA-MT-SLN provide a promising strategy to deliver therapeutic agents to fibrotic liver to prevent liver fibrosis.

Reactive Oxygen Species-Responsive Polypeptide Drug Delivery System Targeted Activated Hepatic Stellate Cells to Ameliorate Liver Fibrosis.

Hepatic fibrosis is a chronic liver disease that lacks effective pharmacotherapeutic treatments. As part of the disease's mechanism, hepatic stellate cells (HSCs) are activated by damage-related stimuli to secrete excessive extracellular matrix, leading to collagen deposition. Currently, the drug delivery system that targets HSCs in the treatment of liver fibrosis remains an urgent challenge due to the poor controllability of drug release. Since the level of reactive oxygen species (ROS) increases sharply in activated HSCs (aHSCs), we designed ROS-responsive micelles for the HSC-specific delivery of a traditional Chinese medicine, resveratrol (RES), for treatment of liver fibrosis. The micelles were prepared by the ROS-responsive amphiphilic block copolymer poly(l-methionine-block-Nε-trifluoro-acetyl-l-lysine) (PMK) and a PEG shell modified with a CRGD peptide insertion. The CRGD-targeted and ROS-responsive micelles (CRGD-PMK-MCs) could target aHSCs and control the release of RES under conditions of high intracellular ROS in aHSCs. The CRGD-PMK-MCs treatment specifically enhanced the targeted delivery of RES to aHSCs both in vitro and in vivo. In vitro experiments show that CRGD-PMK-MCs could significantly promote ROS consumption, reduce collagen accumulation, and avert activation of aHSCs. In vivo results demonstrate that CRGD-PMK-MCs could alleviate inflammatory infiltration, prevent fibrosis, and protect hepatocytes from damage in fibrotic mice. In conclusion, CRGD-PMK-MCs show great potential for targeted and ROS-responsive controlled drug release in the aHSCs of liver fibrosis.

(E)-N'-[(2-Hydroxynaphthalen-1-yl)methylidene]nicotinohydrazide.

In the mol-ecule of the title compound, C(17)H(13)N(3)O(2), the naphthyl ring system and the pyridine ring form a dihedral angle of 12.2 (3)°. An intra-molecular O-H⋯N hydrogen bond generates a six-membered ring with an S(6) ring motif. This also contributes to the relative overall near planarity of the mol-ecule [r.m.s. deviation of all 22 non-H atoms = 0.107 (5) Å]. In the crystal, mol-ecules are linked through inter-molecular N-H⋯N hydrogen bonds, forming chains along the a axis.

Copper(II) and Zinc(II) Complexes Derived from N,N'-Bis(4-bromosalicylidene)propane-1,3-diamine: Syntheses, Crystal Structures and Antimicrobial Activity.

A mononuclear copper(II) complex, [CuL] (1), and a phenolato-bridged trinuclear zinc(II) complex, [Zn3Cl2L2(DMF)2] (2), where L is the deprotonated form of N,N'-bis(4-bromosalicylidene)propane-1,3-diamine (H2L), have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, and single crystal X-ray diffraction. The Cu atom in complex 1 is in square planar coordination, while the terminal and central Zn atoms in complex 2 are in square pyramidal and octahedral coordination, respectively. The antibacterial activities of the complexes have been tested on the bacteria Staphylococcus aureus and Escherichia coli, and the yeast Candida parapsilosis.

Tuning the Toxicity of Reactive Oxygen Species into Advanced Tumor Therapy.

The biological functions and toxic effects of reactive oxygen species (ROS) are generally entangled. A large amount of ROS may cause oxidative damage to cell biomolecules, leading to cell death. Tumor treatment can be carried out by using the toxicity of ROS, and various nanosystems related to ROS have been designed. In fact, the level of active oxygen in the biological microenvironment can be regulated in advanced therapeutics via designed nanoscale engineering, which can open up a new direction of treatment with specific simplicity. In this progress report, the authors first introduced how ROS causes cell death. Then, recent studies on converting the inherent toxicity from ROS into advanced treatment tools are highlighted.

Crumbs proteins stabilize the cone mosaics of photoreceptors and improve vision in zebrafish.

Although the unique organization of vertebrate cone mosaics was first described long ago, both their underlying molecular basis and physiological significance are largely unknown. Here, we demonstrate that Crumbs proteins, the key regulators of epithelial apical polarity, establish the planar cellular polarity of photoreceptors in zebrafish. Via heterophilic Crb2a-Crb2b interactions, the apicobasal polarity protein Crb2b restricts the asymmetric planar distribution of Crb2a in photoreceptors. The planar polarized Crumbs proteins thus balance intercellular adhesions and tension between photoreceptors, thereby stabilizing the geometric organization of cone mosaics. Notably, loss of Crb2b in zebrafish induces a nearsightedness-like phenotype in zebrafish accompanied by an elongated eye axis and impairs zebrafish visual perception for predation. These data reveal a detailed mechanism for cone mosaic homeostasis via previously undiscovered apical-planar polarity coordination and propose a pathogenic mechanism for nearsightedness.

N'-[(2-Hydr-oxy-1-naphth-yl)methyl-idene]-2-nitro-benzohydrazide.

In the title Schiff base compound, C(18)H(13)N(3)O(4), prepared by the reaction of 2-hydr-oxy-1-naphthaldehyde with 2-nitro-benzohydrazide, the dihedral angle between the benzene ring and naphthyl ring system is 23.0 (2)°. There is an intra-molecular O-H⋯N hydrogen bond involving the naphthalene hydr-oxy substituent and a hydrazide N atom. In the crystal structure, symmetry-related mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains propagating in [101].

2-Chloro-5-nitro-benzaldehyde thio-semicarbazone.

The title Schiff base compound, C(8)H(7)ClN(4)O(2)S, was prepared by the reaction of equimolar quanti-ties of 2-chloro-5-nitro-benzaldehyde with thio-semicarbazide in methanol. The mol-ecule adopts a trans configuration with respect to the azomethine group and the dihedral angle between the benzene ring and the thio-semicarbazide group is 6.8 (3)°. In the crystal, mol-ecules are linked through inter-molecular N-H⋯S hydrogen bonds, forming chains propagating in [010].

N'-(5-Chloro-2-hy-droxy-benzyl-idene)-2-meth-oxy-benzohydrazide.

The title Schiff base compound, C(15)H(13)ClN(2)O(3), was prepared by the reaction of equimolar quanti-ties of 5-chloro-2-hy-droxy-benzaldehyde with 2-meth-oxy-benzohydrazide in a methanol solution. The dihedral angle between the two benzene rings is 20.6 (3)°. An intra-molecular O-H⋯N hydrogen bond may influence the mol-ecular conformation. In the crystal structure, mol-ecules form chains along the b direction via inter-molecular N-H⋯O hydrogen bonds which are bifurcated involving an intra-molecular N-H⋯O hydrogen bond.

2-Hy-droxy-4-meth-oxy-benzaldehyde thio-semicarbazone.

The title Schiff base compound, C(9)H(11)N(3)O(2)S, was prepared by the reaction of equimolar quanti-ties of 2-hy-droxy-4-meth-oxy-benzaldehyde with thio-semicarbazide in methanol. The mol-ecule adopts a trans configuration with respect to the azo-methine group and an intra-molecular O-H⋯N hydrogen bond generates an S(6) ring. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O and N-H⋯S hydrogen bonds, forming a three-dimensional network.

The extracellular and intracellular regions of Crb2a play distinct roles in guiding the formation of the apical zonula adherens.

The transmembrane protein Crumbs (Crb), a key regulator of apical polarity, has a known involvement in establishment of the apical zonula adherens in epithelia, although the precise mechanism remains elusive. The zonula adherens are required to maintain the integrity and orderly arrangement of epithelia. Loss of the zonula adherens leads to morphogenetic defects in the tissues derived from epithelium. In this study, we revealed that the intracellular tail of Crb2a promoted the apical distribution of adherens junctions (AJs) in zebrafish retinal and lens epithelia, but caused assembly into unstable punctum adherens-like adhesion plaques. The extracellular region of Crb2a guided the transformation of AJs from the punctum adherens into stable zonula adherens. Accordingly, a truncated form of Crb2a lacking the extracellular region (Crb2aΔEX) could only partially rescue the retinal patterning defects in crb2a null mutant zebrafish (crb2am289). By contrast, constitutive over-expression of Crb2aΔEX disrupted the integrity of the outer limiting membrane in photoreceptors, which is derived from the zonula adherens of the retinal neuroepithelium. This study demonstrated that both the extracellular region and the intracellular tail of Crb2a are required to guide the formation of the apical zonula adherens.

N'-(2-Chloro-benzyl-idene)-4-hydroxy-benzohydrazide.

In the mol-ecule of the title compound, C(14)H(11)ClN(2)O(2), the dihedral angle between the benzene rings is 30.53 (4)°. In the crystal structure, inter-molecular O-H⋯O and N-H⋯O hydrogen bonds link the mol-ecules into a two-dimensional network. π-π contacts between benzene rings [centroid-centroid distance = 3.619 (1) Å] may further stabilize the structure. The crystal studied was found to be an inversion twin.

2-Bromo-4-chloro-6-(cyclo-pentyl-imino-meth-yl)phenol.

All atoms of the title mol-ecule, C(12)H(13)BrClNO, except the C and H atoms of the cyclo-pentane methyl-ene groups lie on a crystallographic mirror plane. The cyclo-pentane ring adopts an envelope conformation and an intra-molecular O-H⋯N hydrogen bond is observed. In the crystal, mol-ecules are stacked along the b axis by π-π inter-actions [centroid-centroid distance = 3.6424 (11) Å].

3-Hydr-oxy-N'-(2-methoxy-benzyl-idene)-2-naphthohydrazide.

In the title Schiff base compound, C(19)H(16)N(2)O(3), the dihedral angle between the mean planes of the benzene ring and the naphthyl ring system is 0.8 (2)°. The mean plane of the hydrazide group forms dihedral angles of 2.0 (2) and 2.2 (2)°, respectively, with the mean planes of the benzene ring and the naphthyl ring system. A strong intra-molecular N-H⋯O hydrogen bond is present. In the crystal, inter-molecular O-H⋯O hydrogen bonds form chains along the c axis and help to provide stability in the crystal packing.