Nanoclay gels attenuate BMP2-associated inflammation and promote chondrogenesis to enhance BMP2-spinal fusion.

Bone morphogenetic protein 2 (BMP2) is clinically applied for treating intractable fractures and promoting spinal fusion because of its osteogenic potency. However, adverse effects following the release of supraphysiological doses of BMP2 from collagen carriers are widely reported. Nanoclay gel (NC) is attracting attention as a biomaterial, given the potential for localized efficacy of administered agents.

rhBMP-2-loaded hydroxyapatite/beta-tricalcium phosphate microsphere/hydrogel composite promotes bone regeneration in a novel rat femoral nonunion model.

Background: Nonunion following fracture treatment remains a significant clinical challenge, adversely affecting the patient's quality of life and imposing a substantial economic burden. The emergence of bone morphogenetic protein 2 (BMP-2) for bone regeneration represents a promising avenue, albeit limited by side effects such as inflammatory reactions primarily due to suboptimal drug delivery systems. This study focuses on NOVOSIS putty (NP), a novel biomaterial designed for the sustained release of BMP-2, aiming to mitigate these limitations and enhance bone healing.

A synthetic retinoic acid receptor γ antagonist (7C)-loaded nanoparticle enhances bone morphogenetic protein-induced bone regeneration in a rat spinal fusion model.

Background Context: Bone morphogenetic proteins (BMPs) have potent osteoinductivity and have been applied clinically for challenging musculoskeletal conditions. However, the supraphysiological doses of BMPs used in clinical settings cause various side effects that prevent widespread use, and therefore the BMP dosage needs to be reduced.

Purpose: To address this problem, we synthesized 7C, a retinoic acid receptor γ antagonist-loaded nanoparticle (NP), and investigated its potential application in BMP-based bone regeneration therapy using a rat spinal fusion model.

Review of Basic Research about Ossification of the Spinal Ligaments Focusing on Animal Models.

Ossification of the posterior longitudinal ligament (OPLL) is a heterotopic ossification that may cause spinal cord compression. With the recent development of computed tomography (CT) imaging, it is known that patients with OPLL often have complications related to ossification of other spinal ligaments, and OPLL is now considered part of ossification of the spinal ligaments (OSL). OSL is known to be a multifactorial disease with associated genetic and environmental factors, but its pathophysiology has not been clearly elucidated.

Entanglement of Arabidopsis Seedlings to a Mesh Substrate under Microgravity Conditions in KIBO on the ISS.

The International Space Station (ISS) provides a precious opportunity to study plant growth and development under microgravity (micro-) conditions. In this study, four lines of Arabidopsis seeds (wild type, wild-type MCA1-GFP, -knockout, and -overexpressed) were cultured on a nylon lace mesh placed on Gelrite-solidified MS-medium in the Japanese experiment module KIBO on the ISS, and the entanglement of roots with the mesh was examined under micro- and 1- conditions. We found that root entanglement with the mesh was enhanced, and root coiling was induced under the micro- condition.

Gravity sensing in plant and animal cells.

Gravity determines shape of body tissue and affects the functions of life, both in plants and animals. The cellular response to gravity is an active process of mechanotransduction. Although plants and animals share some common mechanisms of gravity sensing in spite of their distant phylogenetic origin, each species has its own mechanism to sense and respond to gravity.

The gravistimulation-induced very slow Ca increase in Arabidopsis seedlings requires MCA1, a Ca-permeable mechanosensitive channel.

Gravity is a critical environmental factor affecting the morphology and function of plants on Earth. Gravistimulation triggered by changes in the gravity vector induces an increase in the cytoplasmic free calcium ion concentration ([Ca]) as an early process of gravity sensing; however, its role and molecular mechanism are still unclear. When seedlings of Arabidopsis thaliana expressing apoaequorin were rotated from the upright position to the upside-down position, a biphasic [Ca]-increase composed of a fast-transient [Ca]-increase followed by a slow [Ca]-increase was observed.

A Cyclic Nucleotide-Gated Channel, HvCNGC2-3, Is Activated by the Co-Presence of Na⁺ and K⁺ and Permeable to Na⁺ and K⁺ Non-Selectively.

Cyclic nucleotide-gated channels (CNGCs) have been postulated to contribute significantly in plant development and stress resistance. However, their electrophysiological properties remain poorly understood. Here, we characterized barley CNGC2-3 (HvCNGC2-3) by the two-electrode voltage-clamp technique in the oocyte heterologous expression system.

Exogenous application of abscisic acid (ABA) increases root and cell hydraulic conductivity and abundance of some aquaporin isoforms in the ABA-deficient barley mutant Az34.

Background and Aims Regulation of water channel aquaporins (AQPs) provides another mechanism by which abscisic acid (ABA) may influence water flow through plants. To the best of our knowledge, no studies have addressed the changes in ABA levels, the abundance of AQPs and root cell hydraulic conductivity (LpCell) in the same tissues. Thus, we followed the mechanisms by which ABA affects root hydraulics in an ABA-deficient barley mutant Az34 and its parental line 'Steptoe'.

Calcium mobilizations in response to changes in the gravity vector in Arabidopsis seedlings: possible cellular mechanisms.

Gravity influences the growth direction of higher plants. Changes in the gravity vector (gravistimulation) immediately promote the increase in the cytoplasmic free calcium ion concentration ([Ca(2+)]c) in Arabidopsis (Arabidopsis thaliana) seedlings. When the seedlings are gravistimulated by reorientation at 180°, a transient two peaked (biphasic) [Ca(2+)]c-increase arises in their hypocotyl and petioles.

A domain-based approach for analyzing the function of aluminum-activated malate transporters from wheat (Triticum aestivum) and Arabidopsis thaliana in Xenopus oocytes.

Wheat and Arabidopsis plants respond to aluminum (Al) ions by releasing malate from their root apices via Al-activated malate transporter. Malate anions bind with the toxic Al ions and contribute to the Al tolerance of these species. The genes encoding the transporters in wheat and Arabidopsis, TaALMT1 and AtALMT1, respectively, were expressed in Xenopus laevis oocytes and characterized electrophysiologically using the two-electrode voltage clamp system.

Analyses of a gravistimulation-specific Ca2+ signature in Arabidopsis using parabolic flights.

Gravity is a critical environmental factor affecting the morphology and functions of organisms on the Earth. Plants sense changes in the gravity vector (gravistimulation) and regulate their growth direction accordingly. In Arabidopsis (Arabidopsis thaliana) seedlings, gravistimulation, achieved by rotating the specimens under the ambient 1g of the Earth, is known to induce a biphasic (transient and sustained) increase in cytoplasmic calcium concentration ([Ca(2+)]c).

A microfluidic device to reduce treatment time of intracytoplasmic sperm injection.

Objective: To develop a microfluidic device that can reduce the intracytoplasmic sperm injection (ICSI) treatment time by increasing sperm concentration.

Design: We compared the ICSI treatment time required for porcine sperm using a method employing the microfluidic device and one using the conventional microdroplet method.

Settings: Academic research laboratories at Okayama University.

Expression of Arabidopsis MCA1 enhanced mechanosensitive channel activity in the Xenopus laevis oocyte plasma membrane.

Higher plants sense and respond to osmotic and mechanical stresses such as turgor, touch, flexure and gravity. Mechanosensitive (MS) channels, directly activated by tension in the cell membrane and cytoskeleton, are supposed to be involved in the cell volume regulation under hypotonic conditions and the sensing of these mechanical stresses based on electrophysiological and pharmacological studies. However, limited progress has been achieved in the molecular identification of plant MS channels.

Chloroplast-mediated activation of plant immune signalling in Arabidopsis.

Chloroplasts have a critical role in plant immunity as a site for the production for salicylic acid and jasmonic acid, important mediators of plant immunity. However, the molecular link between chloroplasts and the cytoplasmic-nuclear immune system remains largely unknown. Here we show that pathogen-associated molecular pattern (PAMP) signals are quickly relayed to chloroplasts and evoke specific Ca(2+) signatures in the stroma.

Inhibitory effects of methylglyoxal on light-induced stomatal opening and inward K+ channel activity in Arabidopsis.

Methylglyoxal (MG) is a reactive aldehyde derived by glycolysis. In Arabidopsis, MG inhibited light-induced stomatal opening in a dose-dependent manner. It significantly inhibited both inward-rectifying potassium (K(in)) channels in guard-cell protoplasts and an Arabidopsis K(in) channel, KAT1, heterologously expressed in Xenopus oocytes.

Negative feedback regulation of microbe-associated molecular pattern-induced cytosolic Ca2+ transients by protein phosphorylation.

Microbe/pathogen-associated molecular patterns (MAMPs/PAMPs) often induce rises in cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)) and protein phosphorylation. Though they are postulated to play pivotal roles in plant innate immunity, their molecular links and the regulatory mechanisms remain largely unknown. To investigate the regulatory mechanisms for MAMP-induced Ca(2+) mobilization, we have established a transgenic rice (Oryza sativa) cell line stably expressing apoaequorin, and characterized the interrelationship among MAMP-induced changes in [Ca(2+)](cyt), production of reactive oxygen species (ROS) and protein phosphorylation.

An extracellular hydrophilic carboxy-terminal domain regulates the activity of TaALMT1, the aluminum-activated malate transport protein of wheat.

Al³+ -resistant cultivars of wheat (Triticum aestivum L.) release malate through the Al³+ -activated anion transport protein Triticum aestivum aluminum-activated malate transporter 1 (TaALMT1). Expression of TaALMT1 in Xenopus oocytes and tobacco suspension cells enhances the basal transport activity (inward and outward currents present in the absence of external Al³+, and generates the same Al³+ -activated currents (reflecting the Al³+-dependent transport function) as observed in wheat cells.

Expression of epitope-tagged proteins in plants.

Although immunoelectron microscopy is a powerful tool for visualizing the subcellular localization of target proteins, it is difficult to obtain and purify the specific antibodies required for this method. Instead of raising antibodies against individual target proteins, the use of transgenic plants expressing epitope-tagged proteins and commercially available antibodies simplifies the subcellular localization of target proteins. In this chapter, an improved method for producing transgenic plants that express epitope-tagged proteins and can be used for immunoelectron microscopic analysis is described.

Aluminium reduces sugar uptake in tobacco cell cultures: a potential cause of inhibited elongation but not of toxicity.

Aluminium is well known to inhibit plant elongation, but the role in this inhibition played by water relations remains unclear. To investigate this, tobacco (Nicotiana tabacum L.) suspension-cultured cells (line SL) was used, treating them with aluminium (50 microM) in a medium containing calcium, sucrose, and MES (pH 5.

Closing plant stomata requires a homolog of an aluminum-activated malate transporter.

Plant stomata limit both carbon dioxide uptake and water loss; hence, stomatal aperture is carefully set as the environment fluctuates. Aperture area is known to be regulated in part by ion transport, but few of the transporters have been characterized. Here we report that AtALMT12 (At4g17970), a homolog of the aluminum-activated malate transporter (ALMT) of wheat, is expressed in guard cells of Arabidopsis thaliana.

Plant volatiles regulate the activities of Ca2+ -permeable channels and promote cytoplasmic calcium transients in Arabidopsis leaf cells.

A variety of plant species emit volatile compounds in response to mechanical stresses such as herbivore attack. Although these volatile compounds promote gene expression leading to anti-herbivore responses, the underlying transduction mechanisms are largely unknown. While indirect evidence suggests that the cytoplasmic free Ca(2+) concentration ([Ca(2+)](c)) plays a crucial role in the volatile-sensing mechanisms in plants, these roles have not been directly demonstrated.

Critical consideration on the relationship between auxin transport and calcium transients in gravity perception of Arabidopsis seedlings.

Plants regulate their growth and morphogenesis in response to gravity field, known as gravitropism. In the early process of gravitropism, changes in the gravity vector (gravistimulation) are transduced into certain intracellular signals, termed gravity perception. The plant hormone auxin is not only a crucial factor to represent gravitropism but also a potential signaling molecule for gravity perception.

Mechano-sensitive channels regulate the stomatal aperture in Vicia faba.

In the bright fields, stomata of the plants are fully opened to raise the transpiration rate and CO(2) uptake required for photosynthesis. Stomatal opening is driven by the activation of plasma membrane H(+)-ATPase and K(+)(in) channels, and the Ca(2+)-dependent inactivation and blockage of both components were supposed to be inevitable function to regulate the stomatal aperture. Although, it is still obscure how these activities are regulated at the open state.