Biomolecules最新文献

Transforming growth factor-beta 1 (TGF-β1)-stimulated clone 22 domain (TSC22D) family genes (including TSC22D1-TSC22D4) were identified as transcription factors. It has been demonstrated that they display multiple functions due to proteins' isoforms, redundancy, and other factors. Formerly, researchers mainly focused on its functions, like controlling cell growth and development, cell apoptosis, and balance of osmotic pressure in vivo. Nowadays, growing evidence indicates that they also play an important role in metabolic regulation and the immune system and are expected to be a new potential target for the treatment of diabetes or obesity. Despite this, it has been shown that TSC22D family genes have an inhibitory effect in multiple tumors. In this review, we significantly synthesized advances in metabolism, showing that TSC22D3 could control lipid accumulation via modulating adipogenesis and adipose differentiation, while TSC22D4 could regulate insulin sensitivity and gluconeogenesis by affecting Akt (serine/threonine kinase, also known as protein kinase B, or PKB) phosphorylation. Moreover, we provide novel insights, including the fact that TSC22D family genes function as a double-edged sword in cancer due to the type of tumor and tumor microenvironment (TME).

Dihydroartemisinin (DHA), a first-line treatment for uncomplicated malaria, has demonstrated antitumor activity against a variety of human cancers, emphasizing its potential for repurposing as an anticancer agent. However, its short half-life and poor bioavailability hinder its application in cancer therapy. We previously demonstrated that the molecular hybridization of DHA with bile acids (BAs) enhances its anticancer activity by improving stability and reducing toxicity. Based on this rationale, here, we designed and synthesized a library of DHA-based hybrids through conjugation with ursodeoxycholic and chenodeoxycholic bile acids. Different conjugation sites and both cleavable and non-cleavable linkages were explored to enable a comprehensive structure-activity relationship analysis. The resulting BA-DHA hybrids were evaluated in vitro for their anticancer activity against HCT116 and RKO colorectal cancer cell lines. As a result of the synergistic effect of the linker type and conjugation site, the BA-DHA hybrids synthesized via click chemistry emerged as the most active compounds in both cell lines, displaying 2- to 20-fold higher activity than the parent DHA. Mechanistic investigations further revealed that the click-derived BA-DHA hybrids possess enhanced anticancer activity and antimetastatic potential, achieving comparable or even superior efficacy to the parent compound at markedly lower concentrations.

New arylbenzofuran derivatives were designed, synthesized, and evaluated as potential inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Five hybrid compounds (31-35) feature a 2-phenylbenzofuran core linked via a heptyloxy spacer to an N-methylbenzylamine moiety, to enhance interactions within the active site of BChE. Biological evaluation revealed that brominated derivatives 34 and 35 showed the highest cholinesterases (ChE) inhibition compared to their chlorinated analogs, with compound 34 showing the highest activity for both AChE (IC₅₀ = 27.7 μM) and BChE (IC₅₀ = 0.7 μM). These compounds proved to be non-cytotoxic and demonstrated significant antioxidant activity in SH-SY5Y cells exposed to hydrogen peroxide (H₂O₂), highlighting their potential to mitigate oxidative stress: a key pathological factor in Alzheimer's disease. Structural activity analysis suggests that bromine substitution at position 7 and the presence of a seven-carbon linker are critical for dual ChE inhibition and selectivity towards BChE. ADMET prediction indicates favorable pharmacokinetic properties, including drug-likeness and oral bioavailability. Overall, these findings highlight the potential of the 2-arylbenzofuran as a promising scaffold for multitarget-directed ligands in Alzheimer's disease therapy.

The present study reports the design and physicochemical characterization of a hybrid nanoparticle system for the potential intranasal delivery of galantamine (GAL), aimed at improving its bioavailability. Carbon dots (CDs) were used to load GAL, enhancing its dissolution and stability, and were subsequently incorporated into a poly(lactic-co-glycolic acid)-curcumin (PLGA-Cur) conjugate matrix. The successful formation of the PLGA-Cur conjugate was verified via ¹H-NMR and FTIR spectroscopy, while the loading of GAL and its physical state in the CDs was assessed via FTIR and pXRD, respectively. The resulting GAL-CD/PLGA-Cur nanoparticles were spherical, with particle sizes varying from 153.7 nm to 256.3 nm, a uniform morphology and a narrow size distribution. In vitro release studies demonstrated a multi-phase sustained release pattern extending up to 12 days. Spectroscopic and thermal analyses confirmed successful conjugation and molecular interactions between GAL and the carrier matrix. This proof-of-concept hybrid system demonstrates promising controlled, multi-phase sustained galantamine release in vitro, highlighting the role of curcumin conjugation in modulating polymer structure and release kinetics and providing a foundation for future biological evaluation.

In this paper, we consider the inevitable large fluctuations of pressure in typical molecular dynamics (MD) simulations of ligand-protein binding problems. In simulations under the constant pressure of one bar, the pressure artifactually fluctuates over the range of ±100 bars or more. This artifact can cause gross inaccuracy in the apparent binding affinity computed as the ratio of the probability for the ligand to be bound inside the protein and the probability for the ligand to be outside the protein. Based on statistical thermodynamics, we derive a correction factor for the ligand-protein binding affinity to compensate for the artifactual pressure fluctuations. The correction factor depends on the change in the system volume between the bound and the unbound states of the ligand. We conducted four sets of MD simulations for glycerol affinities with four aquaglyceroporins: AQP10, AQP3, AQP7, and GlpF. Without the correction factor, the apparent affinity of glycerol with each of these four aquaglyceroporins is computed directly from the simulations to be very low (~1/M). With the correction factor applied, glycerol's affinity is computed to be 1/mM to 1/µM. In conclusion, glycerol has high affinity for its native facilitator aquaglyceroporins, which is in contrast to the current literature not correcting the artifactual consequences of the large pressure fluctuations in typical in silico experiments.

Free flavin adenine dinucleotide (FAD) is metabolized to flavin mononucleotide (FMN) and adenine monophosphate (AMP) by hydrolases and to 4',5'-cyclic phosphoriboflavin (cFMN) and AMP by the triose kinase FMN cyclase (TKFC). Yet, the lack of analytical standards for cFMN might have resulted in the incidence of cFMN in biological specimens being underreported. To address this shortcoming, cFMN was synthesized from either FMN or FAD. The optimization of the FAD to cFMN reaction conditions revealed that an equimolar ratio of ZnSO₄ and FAD yielded pure cFMN upon the precipitation of AMP-Zn salts. cFMN is stable to aqueous acidic and basic conditions and is readily extracted from biological samples for detection by liquid chromatography coupled with mass spectrometry. Although cFMN is hydrolyzed by liver tissue extracts to FMN and riboflavin, the mechanisms for this conversion remain elusive.

Vascular smooth muscle cells (VSMCs) in the tunica media are essential for maintaining the structure and function of the arterial wall. These cells regulate vascular tone and contribute to vasculogenesis and angiogenesis, particularly during development. Proper control of VSMC differentiation ensures the correct size and patterning of vessels. Dysregulation of VSMC behaviour in adulthood, however, is linked to serious cardiovascular diseases, including aortic aneurysm, coronary artery disease, atherosclerosis and pulmonary hypertension. VSMCs are characterised by their phenotypic plasticity, which is the capacity to transition from a contractile to a synthetic, dedifferentiated state in response to environmental cues. This phenotypic switch plays a central role in vascular remodelling, a process that drives the progression of many vascular pathologies. Epigenetic mechanisms, which are defined as heritable but reversible changes in gene expression that do not involve alterations to the DNA sequence, have emerged as key regulators of VSMC identity and behaviour. These mechanisms include DNA methylation, histone modifications, chromatin remodelling, non-coding RNA and RNA modifications. Understanding how these epigenetic processes influence VSMC plasticity is crucial to uncovering the molecular basis of vascular development and disease. This review explores the current understanding of VSMC biology, focusing on epigenetic regulation in health and pathology.

Mitochondrial Ca²⁺ signaling is increasingly recognized as a key integrator of synaptic activity, metabolism, and redox balance within the tripartite synapse. At excitatory synapses, Ca²⁺ influx through ionotropic glutamate receptors and voltage-gated channels is sensed and transduced by strategically positioned mitochondria, whose Ca²⁺ uptake and release tune tricarboxylic acid cycle activity, adenosine triphosphate synthesis, and reactive oxygen species (ROS) generation. Through these Ca²⁺-dependent processes, mitochondria are proposed to help set the threshold at which glutamatergic activity supports synaptic plasticity and homeostasis or, instead, drives hyperexcitability and excitotoxic stress. Here, we synthesize how mitochondrial Ca²⁺ dynamics in presynaptic terminals, postsynaptic spines, and perisynaptic astrocytic processes regulate glutamate uptake, recycling, and release, and how subtle impairments in these pathways may prime synapses for failure well before overt energetic collapse. We further examine the reciprocal interplay between Ca²⁺-dependent metabolic adaptations and glutamate homeostasis, the crosstalk between mitochondrial Ca²⁺ and ROS signals, and the distinct vulnerabilities of neuronal and astrocytic mitochondria. Finally, we discuss how disruption of this Ca²⁺-centered mitochondria-glutamatergic axis contributes to synaptic dysfunction and circuit vulnerability in neurodegenerative diseases, with a particular focus on Alzheimer's disease.

We aimed to highlight the roles of the pancreatic enzymes, with special reference to amylase, on glucose homeostasis in healthy pigs and in pigs with exocrine pancreatic insufficiency (EPI). Healthy pigs fed a high-fat diet (HFD) were subjected to mixed meal tolerance tests (MMTTs) and pancreatic enzyme treatments, and then blood glucose and insulin concentrations were determined. Following the development of surgically induced EPI, the same experiment was then repeated on the pigs. A significantly lower net postprandial glycemic response was observed in pigs with EPI compared to healthy pigs. Net postprandial glycemic response was not affected by enzyme supplementation during the MMTTs in healthy pigs, but it was affected by adaptation to macronutrient components of the MMTT test meal, both in healthy and EPI pigs. Net postprandial glycemic response and insulin release curves reached higher levels in Creon-treated EPI pigs compared to amylase-treated EPI pigs. In summary, glucose homeostasis mechanisms in EPI pigs were downregulated compared to healthy animals. Creon supplementation during EPI significantly increased postprandial glucose level, while amylase treatment had the opposite effect, which could be explained by its metabolic actions.

Inositol is a natural carbocyclic sugar that plays an essential role in regulating the vital cellular functions of plants and animals. Existing research has explored methyl derivatives of inositol, reporting on their various biological activities, including antitumor, anti-inflammatory, and anti-osteoporosis activities. Our previous study demonstrated that L-quebrachitol, a methyl derivative of inositol, enhances osteoblastogenesis and bone formation; however, its effect on osteoclastogenesis remains unclear. Consequently, we aimed to investigate the effect of L-quebrachitol on receptor activator of nuclear factor-κB ligand-induced osteoclastogenesis in pre-osteoclastic RAW 264.7 cells, and bone resorption in an ovariectomized rat model. The results revealed that L-quebrachitol suppressed RANK-mediated signaling, including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and Fos proto-oncogene (cFOS) pathways, at both the gene and protein levels. Moreover, the critical transcription factor for osteoclastogenesis, nuclear factor of activated T cells c1 (NFATc1), was downregulated. Inhibition of osteoclast-associated marker genes encoding proteolytic enzymes, such as tartrate-resistant acid phosphatase (TRAP), matrix metallopeptidase 9 (MMP-9), and cathepsin K, led to reduced formation of TRAP-positive multinucleated cells and resorption pits. In addition, proteasome subunit alpha type-5 (PSMA5), which is involved in the degradation of the NF-κB inhibitor, was also suppressed. In particular, the animal study clearly supported the bone homeostasis property of the agent by increasing the BV/TV (bone volume/total volume) and Tb.Th (trabecular thickness) in ovariectomized rats. These findings demonstrate the dose-dependent inhibitory effect of L-quebrachitol on osteoclastogenesis through the modulation of RANK-mediated signaling pathways and prevention of bone loss in an animal model. However, further exploration of the potential of L-quebrachitol as an effective approach for osteoporosis is required.