Neuronal diversity of neuropeptide signaling, including galanin, in the mouse locus coeruleus.

The locus coeruleus (LC) is a small nucleus in the pons from which ascending and descending projections innervate major parts of the central nervous system. Its major transmitter is norepinephrine (NE). This system is evolutionarily conserved, including in humans, and its functions are associated with wakefulness and related to disorders, such as depression. Here, we performed single-cell ribonucleic acid-sequencing (RNA-seq) to subdivide neurons in the LC (24 clusters in total) into 3 NE, 17 glutamate, and 5 γ-aminobutyric acid (GABA) subtypes, and to chart their neuropeptide, cotransmitter, and receptor profiles. We found that NE neurons expressed at least 19 neuropeptide transcripts, notably galanin (Gal) but not Npy, and >30 neuropeptide receptors. Among the galanin receptors, Galr1 was expressed in ~19% of NE neurons, as was also confirmed by in situ hybridization. Unexpectedly, Galr1 was highly expressed in GABA neurons surrounding the NE ensemble. Patch-clamp electrophysiology and cell-type-specific Ca2+-imaging using GCaMP6s revealed that a GalR1 agonist inhibits up to ~35% of NE neurons. This effect is direct and does not rely on feed-forward GABA inhibition. Our results define a role for the galanin system in NE functions, and a conceptual framework for the action of many other peptides and their receptors.

Human induced pluripotent stem cell/embryonic stem cell-derived pyramidal neuronal precursors show safety and efficacy in a rat spinal cord injury model.

Nerve regeneration and circuit reconstruction remain a challenge following spinal cord injury (SCI). Corticospinal pyramidal neurons possess strong axon projection ability. In this study, human induced pluripotent stem cells (iPSCs) were differentiated into pyramidal neuronal precursors (PNPs) by addition of small molecule dorsomorphin into the culture. iPSC-derived PNPs were transplanted acutely into a rat contusion SCI model on the same day of injury. Following engraftment, the SCI rats showed significantly improved motor functions compared with vehicle control group as revealed by behavioral tests. Eight weeks following engraftment, the PNPs matured into corticospinal pyramidal neurons and extended axons into distant host spinal cord tissues, mostly in a caudal direction. Host neurons rostral to the lesion site also grew axons into the graft. Possible synaptic connections as a bridging relay may have been formed between host and graft-derived neurons, as indicated by pre- and post-synaptic marker staining and the regulation of chemogenetic regulatory systems. PNP graft showed an anti-inflammatory effect at the injury site and could bias microglia/macrophages towards a M2 phenotype. In addition, PNP graft was safe and no tumor formation was detected after transplantation into immunodeficient mice and SCI rats. The potential to reconstruct a neuronal relay circuitry across the lesion site and to modulate the microenvironment in SCI makes PNPs a promising cellular candidate for treatment of SCI.

Involvement of Scratch2 in GalR1-mediated depression-like behaviors in the rat ventral periaqueductal gray.

Galanin receptor1 (GalR1) transcript levels are elevated in the rat ventral periaqueductal gray (vPAG) after chronic mild stress (CMS) and are related to depression-like behavior. To explore the mechanisms underlying the elevated GalR1 expression, we carried out molecular biological experiments in vitro and in animal behavioral experiments in vivo. It was found that a restricted upstream region of the GalR1 gene, from -250 to -220, harbors an E-box and plays a negative role in the GalR1 promoter activity. The transcription factor Scratch2 bound to the E-box to down-regulate GalR1 promoter activity and lower expression levels of the GalR1 gene. The expression of Scratch2 was significantly decreased in the vPAG of CMS rats. Importantly, local knockdown of Scratch2 in the vPAG caused elevated expression of GalR1 in the same region, as well as depression-like behaviors. RNAscope analysis revealed that GalR1 mRNA is expressed together with Scratch2 in both GABA and glutamate neurons. Taking these data together, our study further supports the involvement of GalR1 in mood control and suggests a role for Scratch2 as a regulator of depression-like behavior by repressing the GalR1 gene in the vPAG.

Update on GPCR-based targets for the development of novel antidepressants.

Traditional antidepressants largely interfere with monoaminergic transport or degradation systems, taking several weeks to have their therapeutic actions. Moreover, a large proportion of depressed patients are resistant to these therapies. Several atypical antidepressants have been developed which interact with G protein coupled receptors (GPCRs) instead, as direct targeting of receptors may achieve more efficacious and faster antidepressant actions. The focus of this review is to provide an update on how distinct GPCRs mediate antidepressant actions and discuss recent insights into how GPCRs regulate the pathophysiology of Major Depressive Disorder (MDD). We also discuss the therapeutic potential of novel GPCR targets, which are appealing due to their ligand selectivity, expression pattern, or pharmacological profiles. Finally, we highlight recent advances in understanding GPCR pharmacology and structure, and how they may provide new avenues for drug development.

[Effect of berberine hydrochloride on cell wall integrity of Candida albicans hypha].

The aim of this paper was to investigate the effect of berberine hydrochloride on the cell wall integrity of Candida albicans hypha. The minimal inhibitory concentration(MIC) of berberine hydrochloride against clinical and standard C. albicans strains was detected by micro liquid-based dilution method; the effect of berberine hydrochloride on the colony formation of C. albicans SC5314 was investigated by spot assay; the effect of berberine hydrochloride on the metabolism of C. albicans SC5314 hypha was checked by XTT reduction assay, and the viability of C. albicans SC5314 hypha was tested by fluorescent staining assay. The effect of berberine hydrochloride on the morphology of C. albicans SC5314 hypha was examined by scanning electron microscope. The changes in the cell wall of C. albicans SC5314 hypha after berberine hydrochloride treatment were detected by transmission electron microscopy. The effect of berberine hydrochloride on ß-glucan from C. albicans SC5314 was detected by flow cytometry. The effect of berberine hydrochloride on hypha-specific gene ECE1 and ß-glucan synthase genes FKS1 and FKS2 in C. albicans was examined by qRT-PCR. The results showed that berberine hydrochloride showed a strong inhibitory effect on both clinical and standard strains of C. albicans, and the MIC was 64-128 µg·mL~(-1). Spot assay, XTT redunction assay and fluorescent staining assay showed that with the increase of berberine hydrochloride concentration, the viability of C. albicans SC5314 gradually decreased. The transmission electron microscopy scanning assay showed that this compound could cause cell wall damage of C. albicans. The flow cytometry analysis showed the exposure degree of C. albicans ß-glucan. The qRT-PCR further showed that berberine hydrochloride could significantly down-regulate hypha-specific gene ECE1 and ß-glucan synthase-related gene FKS1 and FKS2. In conclusion, this compound can down-regulate C. albicans and ß-glucan synthase-related gene expressions, so as to destroy the cell wall structure of C. albicans, expose ß-glucan and damage the integrity of the wall.

[Main components in butyl alcohol extract of Baitouweng Decoction inhibited neutrophil chemotaxis].

The present study aims to investigate the effects of the main components(aesculin, berberine hydrochloride, and anemoside B4) in the butyl alcohol extract of Baitouweng Decoction(BAEB) on the chemotaxis of neutrophils induced by dimethyl sulfoxide(DMSO). HL60 cells were cultivated in RPMI-1640 complete medium, and transferred into a 6-well plate(2 × 10~5 per mL) with 4 mL in each well, followed by incubation with DMSO at 1.3% for five days. The morphologic changes of cells were observed under an inverted microscope. The CD11 b expression after DMSO induction was analyzed by flow cytometry. The effects of aesculin, berberine hydrochloride, and anemoside B4 on the cell proliferation and migration were detected by CCK8 assay and Transwell assay, respectively. The effects of the main components on the production and polarization of F-actin protein were also examined by flow cytometry and laser confocal microscopy. PI3 K/Akt signaling pathway was checked by Western blot. As revealed by the results, neutrophil-like HL60 cells were observed after DMSO induction. The CD11 b expression in these cells increased significantly as indicated by the flow cytometry. Additionally, 100 µg·mL~(-1) aesculin, 8 µg·mL~(-1) berberine hydrochloride, and 80 µg·mL~(-1) anemoside B4 were potent in inhibiting the migration of neutrophils and reducing F-actin expression. Berberine hydrochloride was verified to be capable of diminishing phosphorylated PI3 K/Akt protein expression. The findings indicate that aesculin, anemoside B4, and especially berberine hydrochloride in the BAEB can inhibit the chemotaxis of neutrophils, which is possibly achieved by the inhibition of F-actin and PI3 K/Akt signaling pathway.

Galanin Protects Rat Cortical Astrocyte from Oxidative Stress: Involvement of GalR2 and pERK1/2 Signal Pathway.

The neuropeptide galanin and its receptors have been found to have protective effects on neurons. However, the role of galanin on astrocytes is still unclear. The present study is aimed at investigating the effects of galanin on the viability of cultured rat cortical astrocytes after oxidative stress induced by H2O2 and possible receptor and signaling mechanisms involved. Treatment of galanin had significant protective effects against H2O2-induced toxicity in the cultured cortical astrocytes. H2O2 induced an upregulation of phosphorylated extracellular signal-related kinase1/2 (pERK1/2) in astrocytes, which was suppressed by coapplication of galanin, suggesting an involvement of the pERK1/2 signal pathway in the protective effects of galanin. GalR2 has higher expression levels than GalR1 and GalR3 in the cultured cortical astrocytes, and GalR2 agonist AR-M1896 mimicked galanin effects on the astrocytes, implying that galanin protective effects mainly mediated by GalR2. Meanwhile, galanin had no effect on the A1-type transformation of rat cortical astrocytes. All those results suggest that galanin protects rat cortical astrocytes from oxidative stress by suppressing H2O2-induced upregulation of pERK1/2, mainly through GalR2.

NPY Receptor 2 Mediates NPY Antidepressant Effect in the mPFC of LPS Rat by Suppressing NLRP3 Signaling Pathway.

Accumulated evidences show that neuroinflammation play a pivotal role in the pathogenesis of depression. Neuropeptide Y (NPY) and its receptors have been demonstrated to have anti-inflammative as well as antidepressant effects. In the present study, the ability of NPY to modulate depressive-like behaviors induced by lipopolysaccharides (LPS) in rats and the receptors and signaling mechanisms involved were investigated. Continuous injection LPS (i.p) for 4 days led to development of depressive-like behaviors in rats, accompanied with M1-type microglia activation and increased levels of IL-1ß as well as decreased levels of NPY and Y2R expression in the mPFC selectively. Local injection of NPY into the medial prefrontal cortex (mPFC) ameliorated the depression-like behaviors and suppressed the NLRP3 inflammasome signaling pathway. Y2R agonist PYY (3-36) mimicked and Y2R antagonist BIIE0246 abolished the NPY effects in the mPFC. All these results suggest that NPY and Y2R in the mPFC are involved in the pathophysiology of depression and NPY plays an antidepressant role in the mPFC mainly via Y2R, which suppresses the NLRP3 signaling pathway, in LPS-induced depression model rats.

Depression-like behavior in rat: Involvement of galanin receptor subtype 1 in the ventral periaqueductal gray.

The neuropeptide galanin coexists in rat brain with serotonin in the dorsal raphe nucleus and with noradrenaline in the locus coeruleus (LC), and it has been suggested to be involved in depression. We studied rats exposed to chronic mild stress (CMS), a rodent model of depression. As expected, these rats showed several endophenotypes relevant to depression-like behavior compared with controls. All these endophenotypes were normalized after administration of a selective serotonin reuptake inhibitor. The transcripts for galanin and two of its receptors, galanin receptor 1 (GALR1) and GALR2, were analyzed with quantitative real-time PCR using laser capture microdissection in the following brain regions: the hippocampal formation, LC, and ventral periaqueductal gray (vPAG). Only Galr1 mRNA levels were significantly increased, and only in the latter region. After knocking down Galr1 in the vPAG with an siRNA technique, all parameters of the depressive behavioral phenotype were similar to controls. Thus, the depression-like behavior in rats exposed to CMS is likely related to an elevated expression of Galr1 in the vPAG, suggesting that a GALR1 antagonist could have antidepressant effects.

Activation of galanin receptor 1 inhibits locus coeruleus neurons via GIRK channels.

The noradrenergic neurons of the locus coeruleus (LC) are associated with various brain functions and psychiatric disorders, such as addiction and depression. It has been shown that neuropeptide galanin (GAL) inhibits neuronal excitability in LC, but the mechanisms remain unclear. In the present study, we investigated the ionic and signal transduction mechanisms underlying inhibitory effect of GAL on LC neurons using whole-cell patch clamp recording in rat brain slices. Bath application of GAL decreased the spontaneous firings and induced a dose-dependent hyperpolarization of LC neurons and this effect was attenuated by knockdown of Galr1, but not Galr2, confirming that mainly GALR1 mediates the inhibition effect of GAL. The inhibitory effect of GAL was also blocked by treatments of pertussis toxin (PTX), GTP-γ-s or GDP-ß-s, respectively, indicating that the functions of PTX sensitive Gi/o protein are required for GAL-induced hyperpolarization. Moreover, the blockers of GIRK (tertiapin-Q or SCH2 3390 hydrochloride) attenuated the GAL response while blocker of BK/SK/KATP channels or TASK-1/3 channels did not affect it significantly, suggesting that GIRK channels play an important role in GAL-induced hyperpolarization in LC neurons. Taken together, the inhibitory effect of GAL on LC neurons is mediated by GALR1 via PTX-sensitive Gi/o proteins, which activate GIRK channels.

Neurotransmitters and Receptors Changes in Medial Nucleus of the Trapezoid Body (MNTB) of Early-Developmental Rats with Single-Side Deafness.

BACKGROUND Congenital single-side deafness (SSD) affects sound localization even after cochlear implantation (CI) in some conditions. The medial nucleus of the trapezoid body (MNTB) plays an important role in binaural benefit and sound localization, but little is known about intrinsic molecular changes in MNTB with SSD. We aimed to observe changes in MNTB in early-developmental SSD rats, including the key neurotransmitters (GABA, Gly, Glu) and major receptors (GABAa-R/GABAb-R for GABA, Gly-R for Gly, and AMPA/NMDA for Glu). MATERIAL AND METHODS The model of early-developmental SSD was acquired by right cochlear ablation at P12 and confirmed by ABR. High-performance liquid chromatography fluorescence detection (HPLC-FLD) was performed to measure the levels of neurotransmitters in MNTB. The relative expression of neurotransmitter receptors was tested by quantitative real-time PCR analysis. RESULTS (1) The right MNTB of experimental rats had an increase in GABA, Gly, and Glu at 4 weeks after right cochlear ablation (P<0.05). (2) At 2 weeks, the left MNTB of experimental rats showed increases in GABAa-R, GABAb-R, Gly-R, and AMPA, while the right MNTB showed lower expression of NMDA (P<0.05). The higher receptors in left MNTB decreased to a level at which we found no difference at 1 week for GABAa-R and GABAb-R (P>0.05), and was even reversed for Gly-R and AMPA (P<0.05). (3) Gly level was significantly increased at 2 weeks bilaterally and continued to 4 weeks in the left MNTB (P<0.05). CONCLUSIONS Early-developmental SSD can lead to asymmetric distribution of neurotransmitters and receptors in MNTB, which can be the fundamental cause of defective sound localization after cochlear implantation.

Pokemon decreases the transcriptional activity of RARα in the absence of ligand.

Pokemon is a transcriptional repressor that belongs to the POZ and Krüppel (POK) protein family. In this study, we investigated the potential interaction between Pokemon and retinoic acid receptor alpha (RARα) and determined the role of Pokemon in regulation of RARα transcriptional activity in the absence of ligand. We found that Pokemon could directly interact with RARα. Moreover, we demonstrated that Pokemon could decrease the transcriptional activity of RARα in the absence of ligand. Furthermore, we showed that Pokemon could repress the transcriptional activity of RARα by increasing the recruitment of nuclear receptor co-repressor (NCoR) and silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) to the retinoic acid response element (RARE) element. Taken together, these data suggest that Pokemon is a novel partner of RARα that acts as a co-repressor to regulate RARα transcriptional activity in the absence of ligand.

Galanin suppresses proliferation of human U251 and T98G glioma cells via its subtype 1 receptor.

Galanin is a neuropeptide with a widespread distribution throughout the nervous and endocrine systems, and recent studies have shown an anti-proliferative effect of galanin on several types of tumors. However, whether and how galanin and its receptors are involved in the regulation of cell proliferation in glioma cells remains unclear. In this study, the roles of galanin and its subtype 1 receptor (GAL1) in the proliferation of human U251 and T98G glioma cells were investigated. We found that galanin significantly suppressed the proliferation of U251 and T98G cells as well as tumor growth in nude mice. However, galanin did not exert apoptotic or cytotoxic effects on these two cell lines. In addition, we showed that galanin decreased the proliferation of U251 and T98G cells via its GAL1 receptor. Finally, we found that the GAL1 receptor was involved in the suppressive effects of galanin by activating ERK1/2.

[Butyl alcohol extract of Baitouweng decoction inhibits Candida albicans cell membrane].

To study the inhibitory effect of butyl alcohol extract of Baitouweng decoction(BAEB) on Candida albicans cell membrane. The effects of BAEB on the activity of C. albicans were observed by Spot assay. The changes of intracellular osmotic pressure of C. albicans after BAEB intervention were detected by microtiter plate reader. The effect of BAEB on cell membrane permeability of C. albicans were observed by fluorescence microscopy. The content of ergosterol in C. albicans cell membrane was detected by high performance liquid chromatography, and the expression of ergosterol biosynthesis related genes in cell membrane was detected by qRT-PCR. The results showed that the activity of C. albicans was significantly decreased in 256, 512 and 1 024 mg•L⁻¹ BAEB group. The intracellular glycerol content of C. albicans was significantly increased in 512 and 1 024 mg•L⁻¹ BAEB group(P<0.05). The gene HOG1 associated with intracellular osmotic pressure of C. albicans was down-regulated by 9.1, 9.3 and 5.5 times, respectively. C. albicans with red fluorescent were increased significantly in 512 and 1 024 mg•L⁻¹ BAEB group. The peak area of ergosterol in the 1 024 mg•L⁻¹ BAEB group was 35.884 95, with a significant difference(P<0.05); ERG1, ERG2, ERG3, ERG4, ERG5, ERG6, ERG10, ERG11, ERG13, ERG24, ERG25, ERG251, ERG26 and UPC2 were down-regulated by 6.58, 4.89, 4.15, 9.24,3.41, 9.84, 3.08, 7.50, 5.53, 5.90, 2.45, 3.25,1.98 and 10.07 times respectively in 1 024 mg•L⁻¹ BAEB group. The study indicated that BAEB could inhibit ergosterol and its biosynthesis related genes expression in the cell membrane and inhibit the activity of C. albicans.

Pokemon (FBI-1) interacts with Smad4 to repress TGF-ß-induced transcriptional responses.

Pokemon, an important proto-oncoprotein, is a transcriptional repressor that belongs to the POK (POZ and Krüppel) family. Smad4, a key component of TGF-ß pathway, plays an essential role in TGF-ß-induced transcriptional responses. In this study, we show that Pokemon can interact directly with Smad4 both in vitro and in vivo. Overexpression of Pokemon decreases TGF-ß-induced transcriptional activities, whereas knockdown of Pokemon increases these activities. Interestingly, Pokemon does not affect activation of Smad2/3, formation of Smads complex, or DNA binding activity of Smad4. TGF-ß1 treatment increases the interaction between Pokemon and Smad4, and also enhances the recruitment of Pokemon to Smad4-DNA complex. In addition, we also find that Pokemon recruits HDAC1 to Smad4 complex but decreases the interaction between Smad4 and p300/CBP. Taken together, all these data suggest that Pokemon is a new partner of Smad4 and plays a negative role in TGF-ß pathway.

GABAergic terminals are a source of galanin to modulate cholinergic neuron development in the neonatal forebrain.

The distribution and (patho-)physiological role of neuropeptides in the adult and aging brain have been extensively studied. Galanin is an inhibitory neuropeptide that can coexist with γ-aminobutyric acid (GABA) in the adult forebrain. However, galanin's expression sites, mode of signaling, impact on neuronal morphology, and colocalization with amino acid neurotransmitters during brain development are less well understood. Here, we show that galaninergic innervation of cholinergic projection neurons, which preferentially express galanin receptor 2 (GalR2) in the neonatal mouse basal forebrain, develops by birth. Nerve growth factor (NGF), known to modulate cholinergic morphogenesis, increases GalR2 expression. GalR2 antagonism (M871) in neonates reduces the in vivo expression and axonal targeting of the vesicular acetylcholine transporter (VAChT), indispensable for cholinergic neurotransmission. During cholinergic neuritogenesis in vitro, GalR2 can recruit Rho-family GTPases to induce the extension of a VAChT-containing primary neurite, the prospective axon. In doing so, GalR2 signaling dose-dependently modulates directional filopodial growth and antagonizes NGF-induced growth cone differentiation. Galanin accumulates in GABA-containing nerve terminals in the neonatal basal forebrain, suggesting its contribution to activity-driven cholinergic development during the perinatal period. Overall, our data define the cellular specificity and molecular complexity of galanin action in the developing basal forebrain.

Activation of galanin receptor 2 stimulates large conductance Ca(2+)-dependent K(+) (BK) channels through the IP3 pathway in human embryonic kidney (HEK293) cells.

The large conductance Ca(2+)-activated K(+) (BK) channels are widely distributed in the brain, and act as intracellular calcium sensors in neurons. They play an important feedback role in controlling Ca(2+) flux and Ca(2+)-dependent processes, including neurotransmitter release and cellular excitability. In this study, the effects of the neuropeptide galanin on BK channels were examined by determining the whole-cell currents and single-channel activities in human embryonic kidney (HEK293) cells co-expressing GalR2 and the BK alpha subunit. Galanin enhanced the currents of BK channels, in a concentration-dependent and PTX-independent manner, with an ED50 value of 71.8±16.9 nM. This activation was mediated by GalR2, since its agonist AR-M1896 mimicked the effect of galanin, and since galanin did not facilitate BK currents in cells co-expressing cDNAs of BK and GalR1 or GalR3. The galanin-induced BK current persisted after replacement with Ca(2+)-free solution, suggesting that extracellular Ca(2+) is not essential. Chelating intracellular Ca(2+) by either the slow Ca(2+) buffer EGTA or the fast Ca(2+) buffer BAPTA abolished galanin-mediated activation of BK channels, indicating the important role of intracellular Ca(2+). The role of Ca(2+) efflux from the sarcoplasmic reticulum/endoplasmic reticulum (SR/ER) was confirmed by application of thapsigargin, an irreversible inhibitor that depletes Ca(2+) from SR/ER. Moreover, the inositol-1,4,5-triphosphate receptor (IP3R) was identified as the mediator responsible for increased intracellular Ca(2+) activating BK channels. Taken together, activation of GalR2 leads to elevation of intracellular Ca(2+) is due to Ca(2+) efflux from ER through IP3R sequentially opening BK channels.

TrkB signaling in parvalbumin-positive interneurons is critical for gamma-band network synchronization in hippocampus.

Although brain-derived neurotrophic factor (BDNF) is known to regulate circuit development and synaptic plasticity, its exact role in neuronal network activity remains elusive. Using mutant mice (TrkB-PV(-/-)) in which the gene for the BDNF receptor, tyrosine kinase B receptor (trkB), has been specifically deleted in parvalbumin-expressing, fast-spiking GABAergic (PV+) interneurons, we show that TrkB is structurally and functionally important for the integrity of the hippocampal network. The amplitude of glutamatergic inputs to PV+ interneurons and the frequency of GABAergic inputs to excitatory pyramidal cells were reduced in the TrkB-PV(-/-) mice. Functionally, rhythmic network activity in the gamma-frequency band (30-80 Hz) was significantly decreased in hippocampal area CA1. This decrease was caused by a desynchronization and overall reduction in frequency of action potentials generated in PV+ interneurons of TrkB-PV(-/-) mice. Our results show that the integration of PV+ interneurons into the hippocampal microcircuit is impaired in TrkB-PV(-/-) mice, resulting in decreased rhythmic network activity in the gamma-frequency band.

Reamed or unreamed intramedullary nailing for tibial fractures: a meta-analysis.

OBJECTIVE: To compare the treating effects of different intramedullary nailing methods on tibial fractures in adults. METHODS: Literature reports in both Chinese and English languages were retrieved (from the earliest available records to October 1, 2013) from the PubMed, FMJS, CNKI, Wanfang Data using randomized controlled trials (RCTs) to compare reamed and unreamed intramedullary nailing for treatment of tibial fractures. Methodological quality of the trials was critically assessed, and relevant data were extracted. Statistical software Revman 5.0 was used for data-analysis. RESULTS: A total of 12 randomized controlled trials, comprising 985 patients (475 in the unreamed group and 510 in the reamed group), were eligible for inclusion in this meta-analysis. The results of meta-analysis showed that there were no statistically significant differences between the two methods in the reported outcomes of infection (RR=0.64; 95%CI, 0.39 to 1.07; P=0.09), compartment syndrome (RR=1.44; 95%CI, 0.8 to 2.41; P=0.16), thrombosis (RR=1.29; 95%CI, 0.43 to 3.87; P=0.64), time to union (WMD=5.01; 95%CI, -1.78 to 11.80; P=0.15), delayed union (nonunion) (RR=1.56; 95%CI, 0.97 to 2.49; P=0.06), malunion (RR=1.75; 95%CI, 1.00 to 3.08; P=0.05) and knee pain (RR=0.94; 95%CI, 0.73 to 1.22; P=0.66). But there was a significantly higher fixation failure rate in the unreamed group than in the reamed group (RR=4.29; 95%CI, 2.58 to 7.14; P<0.00001). CONCLUSION: There is no significant difference in the reamed and unreamed intramedullary nailing for the treatment of tibial fractures, but our result recommends reamed nails for the treatment of closed tibial fractures for their lower fixation failure rate.

CircFgfr2 promotes osteogenic differentiation of rat dental follicle cells by targeting the miR-133a-3p/DLX3 signaling pathway.

Dental follicle cells (DFCs) promote bone regeneration in vivo and in vitro. Circular RNAs (circRNAs) play crucial roles in bone development and regeneration. Our previous study demonstrated the upregulation of circFgfr2 expression during the osteogenic differentiation of DFCs. However, the molecular mechanisms and functional roles of circFgfr2 in DFCs osteogenesis remain unclear. In this study, we aimed to investigate the subcellular localization of circFgfr2 in DFCs using fluorescence in situ hybridization. In vitro investigations demonstrated that circFgfr2 overexpression promoted osteogenic differentiation, as evidenced by real-time quantitative polymerase chain reaction. By integrating the outcomes of bioinformatics analyses, dual luciferase reporter experiments, and chromatin isolation by RNA purification, we identified circFgfr2 as a sponge for miR-133a-3p, a key regulator of osteogenic differentiation. Moreover, miR-133a-3p suppressed osteogenic differentiation by targeting DLX3 and RUNX2 in DFCs. We validated that circFgfr2 promoted the osteogenic differentiation of DFCs through the miR-133a-3p/DLX3 axis. To further investigate the therapeutic potential of circFgfr2 in bone regeneration, we conducted in vivo experiments and histological analyses. Overall, these results confirmed the crucial role of circFgfr2 in promoting osteogenesis. In summary, our findings demonstrated that the circFgfr2/miR-133a-3p/DLX3 pathway acts as a cascade, thereby identifying circFgfr2 as a promising molecular target for bone tissue engineering.