Rewiring Metabolic Flux in Using a CRISPR/dCpf1-Based Bifunctional Regulation System.

, a microorganism classified as generally recognized as safe for use in the industrial production of food raw materials and additives, has encountered challenges in achieving widespread adoption and popularization as microbial cell factories. These obstacles arise from the intricate nature of manipulating metabolic flux through conventional methods, such as gene knockout and enzyme overexpression. To address this challenge, we developed a CRISPR/dCpf1-based bifunctional regulation system to bidirectionally regulate the expression of multiple genes in .

Structural derivatization strategies of natural phenols by semi-synthesis and total-synthesis.

Structural derivatization of natural products has been a continuing and irreplaceable source of novel drug leads. Natural phenols are a broad category of natural products with wide pharmacological activity and have offered plenty of clinical drugs. However, the structural complexity and wide variety of natural phenols leads to the difficulty of structural derivatization.

Constructing an Efficient Spore Display by Using Cohesin-Dockerin Interactions.

spore display has become a field of increasing interest in the past two decades. To improve the efficiency of spore display, its directed modification was performed based on the cellulosome architecture by introducing onto them divergent cohesin (Coh) modules that can specifically bind to the target enzyme bearing the matching dockerins (Doc). In this study, five different pairs of cohesins and dockerins, selected from four cellulolytic microbes, were examined for their capabilities in displaying a tetrameric enzyme β-galactosidase from IAM11001 on the surface of WB600 spores.

An appropriate ratio of unsaturated fatty acids is the constituent of hickory nut extract for neurite outgrowth in human SH-SY5Y cells.

Hickory nuts ( Sarg, CCS), a well-known Chinese medicinal nut, is thought to improve memory in Chinese folks. However, functional constituents have not been scientifically identified. In this study, human SH-SY5Y cells, combined with Q-TOF mass spectrometry (Q-TOF-MS) and standard substances, were used to evaluate the function in neuronal development and to identify constituents of CCS hydrophobic extracts (CCS-HE).

Screening of an Alkaline CMCase-Producing Strain and the Optimization of its Fermentation Condition.

Objective: Alkaline Carboxymethyl Cellulase (CMCase) is an attractive enzyme for the textile, laundry, pulp, and paper industries; however, commercial preparations with sufficient activity at alkaline conditions are scarce.

Methods: High CMCase-producing bacterial isolate, SX9-4, was screened out from soil bacteria, which was identified as Flavobacterium sp. on the basis of 16S rDNA sequencing.

Identification of angiogenesis-inhibiting peptides from Chan Su.

Chan Su is a traditional medicine prepared from toxic secretions from the auricular and skin glands of Chinese toads. Previous studies show that active components in Chan Su can inhibit the proliferation of tumor cells. To study the effect of Chan Su peptides on angiogenesis, fresh Chan Su was collected and its component peptides were isolated by an extraction and precipitation method.

Application of composite dissolving microneedles with high drug loading ratio for rapid local anesthesia.

We report a type of dissolving microneedles (DMNs) which was made of composite matrix materials of hydroxypropyl methyl cellulose (HPMC) and poly(methylvinylether‑co‑maleic anhydride) (PMVE/MA copolymer, Gantrez S-97), and was successfully loaded with lidocaine hydrochloride. The weight of lidocaine hydrochloride loaded in the microneedles tip was 70% of the weight of the whole tip. The content was 3.

Identification of anti-tumor components from toad venom.

Secretion of granular glands from the skin of amphibians is a fascinating resource of active substances, particularly for cancer therapy in clinical practice of Traditional Chinese Medicine. A variety of anti-tumor peptides have been isolated from different toads and frogs; however, no anti-tumor peptides are reported in toad venom of . Firstly, soluble fraction from fresh toad venom (FTV) was compared with that from dried toad venom (DTV), using HPLC analysis.

Expression of recombinant human acetylcholinesterase and its application in screening its inhibitors.

This study is designed to obtain recombinant human acetylcholinesterase (rhAChE) and apply it in screening acetylcholinesterase inhibitors. The rhAChE was overexpressed in HEK293 cells transfected by plasmid of pCMV-AChE with the cationic liposome and rhAChE was found to be secreted into cell culture medium. AChE activity was assayed according to modified Ellman method to obtain kinetic parameters.

HSPA5 forms specific complexes with copper.

Our previous study indicated that Hspa5 directly interacts with copper (Cu) to maintain Cu homeostasis in astrocytes. In this study, we explored the possibility that Cu forms a specific complex with Hspa5 by assaying stoichiometric binding of Cu and other metals to recombinant human HSPA5 (rh-HSPA5) in silico. Spectrophotometric analysis showed that incubation of rh-HSPA5 with Cu but not with Fe, Mn, Zn, or Pb in the presence of ascorbic acid produced an absorbance peak at 470 nm.

ER chaperone-metal interactions: links to protein folding disorders.

Chaperones in the endoplasmic reticulum play vital roles in the folding, assembly, and post-translational modification of secretory proteins and also recycle, refold, or initiate degradation of misfolded proteins. Chaperone deficiencies in either amount or function are implicated in the etiology or pathogenesis of Alzheimer's disease and other protein folding disorders of the central nervous system. In this review, we discuss evidence that chaperones become pathologic through deleterious interactions with metals and then promote protein folding disorders.

Involvement of the molecular chaperone Hspa5 in copper homeostasis in astrocytes.

Copper (Cu) ion availability in tissues and cells must be closely regulated within safe limits by Cu transporters and chaperones. Astrocytes play key roles in metal homeostasis and distribution in the brain that are only partially understood. The purpose of this study was to define the role that the protein chaperone Hspa5, also known as Grp78, plays in Cu homeostasis in astrocytes.

Copper handling by astrocytes: insights into neurodegenerative diseases.

Copper (Cu) is an essential trace element in the brain that can be toxic at elevated levels. Cu accumulation is a suspected etiology in several neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and prion-induced disorders. Astrocytes are a proposed depot in the brain for Cu and other metals, including lead (Pb).

Determination of metal interactions with the chaperone Hspa5 in human astrocytoma cells and rat astrocyte primary cultures.

Molecular chaperones assist the folding of nascent proteins during translation into their correct conformations. Neurotoxic metals such as copper (Cu) and lead (Pb) may produce a deficiency in chaperone function that compromises protein secretion and exacerbates protein aggregation, potentially promoting neurodegenerative diseases that exhibit protein aggregation. Because astrocytes function as depots in the brain for certain metals, including Cu and Pb, the interaction of metals with chaperones in these cells is of interest.

Valproate reversibly reduces neurite outgrowth by human SY5Y neuroblastoma cells.

Valproate (VPA) is a commonly prescribed mood stabilizer. However, emerging evidence indicates that VPA administration may cause reversible symptoms of Parkinsonism and cognitive decline (P/CD) in some manic patients. The mechanism of this phenomenon is unknown.

Image analysis of Ca2+ signals as a basis for neurotoxicity assays: promises and challenges.

Free intracellular calcium ([Ca(2+)](i)) controls a wide range of cellular functions such as contraction, neurotransmitter and hormone release, metabolism, cell division and differentiation. Cytosolic Ca(2+) levels are abnormal in cells exposed to toxicants and understanding how these levels become altered may improve our ability to design high-throughput methods for the sensitive detection of cellular responses to a toxic exposure. Because Ca(2+) is involved in multiple aspects of cellular function, its role in signaling is complex.

[Lead distribution and 78,000 glucose regulated protein levels in various organs of weaned rats].

Objective: To investigate lead distribution and the change of 78 000 glucose regulated protein (GRP78) in various organs of weaned rats challenged with low-level maternal origin lead.

Methods: Male littermates, bred from the female Fisher 344 rats gavaged with lead acetate or sodium acetate (1 ml of 10 mg/ml per day per animal) with male Fisher 344 rats without lead treatment, were divided into 4 groups including control (group A), gestation plus lactation (group B), gestation only (group C), and lactation only (group D). Each group had 6 litters.

Activation profiles of HSPA5 during the glomerular mesangial cell stress response to chemical injury.

Environmental injury has been associated with endoplasmic reticulum (ER) stress, a response characterized by activation of the unfolded protein response, proteasomal degradation of proteins, and induction of HSPA5, also known as GRP78 or BiP. Although HSPA5 has been implicated in the stress response to environmental injury in several cell types, its role in the glomerular ER stress response is unknown. In this study, we evaluated HSPA5 activation profiles in rat glomerular mesangial cells (rGMCs) challenged with heavy metals (HgCl2 or Pb2+ acetate) or polycyclic aromatic hydrocarbons (PAHs, ie, benzo(a)pyrene [BaP]).

A 78-kDa glucose-regulated protein is involved in the decrease of interleukin-6 secretion by lead treatment from astrocytes.

Interleukin (IL)-6 is a cytokine produced mainly by microglia and astrocytes and plays a pleiotropic role in the central nervous system. In this study, we cloned rat IL-6 cDNA into an enhanced green fluorescent protein (EGFP) or a red fluorescent protein (DsRed2) vector and rat 78-kDa glucose-regulated protein (GRP78) cDNA into an EGFP vector to construct IL-6-EGFP, IL-6-DsRed2, and GRP78-EGFP chimeras for the investigation of the mechanism of IL-6 secretion from astrocytes. The data showed that constructed IL-6-EGFP and IL-6-DsRed2 chimeras retained the secretory property, and the secretion of IL-6-EGFP from astrocytes could be attenuated by GRP78 depletion with double-stranded RNA interference.

Effects of propofol on intracellular Ca2+ homeostasis in human astrocytoma cells.

The effects of propofol, a short-acting general anesthetic, upon cell growth and Ca(2+) signaling in a human astrocytic cell line were examined. Exposure of cells to graded concentrations of propofol resulted in a dose-dependent decrease in cell number with an inhibitory concentration of cell viability (IC50) of 31.7+/-1.

Comparative non-cholinergic neurotoxic effects of paraoxon and diisopropyl fluorophosphate (DFP) on human neuroblastoma and astrocytoma cell lines.

The objective of this study was to evaluate the comparative non-cholinergic neurotoxic effects of paraoxon, which is acutely neurotoxic, and diisopropyl fluorophosphate (DFP), which induces OPIDN, in the human neuroblastoma SY5Y and the human astrocytoma cell line CCF-STTG1. SY5Y cells have been studied extensively as a model for OP-induced neurotoxicity, but CCF cells have not previously been studied. We conducted a preliminary human gene array assay of OP-treated SY5Y cells in order to assess at the gene level whether these cells can distinguish between OP compounds that do and do not cause OPIDN.

In vitro models for assessing neurotoxicity of mixtures.

Rapid and inexpensive methods are needed to investigate the interactions of complex mixtures. This commentary addresses the use of cell cultures to detect neurotoxicity of simple binary mixtures, which is a first step in the development of such methods. A small number of recent studies from our laboratory are examined.

The involvement of copper transporter in lead-induced oxidative stress in astroglia.

Lead (Pb), depositing primarily in astroglia in the brain, is a well-known neurotoxicant and a risk factor for neurologic disorders. Pb has been reported to induce oxidative stress by probably the disturbance of copper (Cu) homeostasis in astroglia. Thus, we hypothesized that Pb-induced oxidative stress is initiated by interfering with Cu transporter in astroglia.

Differential profiles of copper-induced ROS generation in human neuroblastoma and astrocytoma cells.

To determine neuronal and glial responses to copper (Cu) elevation in the CNS, human neuroblastoma and astrocytoma cells were used to compare their responses to Cu in terms of reactive oxygen species (ROS) generation and expression of enzymes responsible for anti-oxidation. Astrocytoma cells, not neuroblastoma cells, were responsive to Cu and Cu elevation was associated with ROS generation. Intracellular Cu levels as determined by inductively coupled plasma-mass spectrometry (ICP-MS), and expression levels of copper-transporting ATPase (ATP7A) and human copper transporter 1 (hCtr1) as detected by quantitative reverse transcription-polymerase chain reaction (RT-PCR), were comparable in both cell lines.