[Research Advances on Strategies to Promote Homing and Engraftment of Hematopoietic Stem Cells--Review].

The homing and engraftment of hematopoietic stem cells (HSC) into bone marrow is the first critical step for successful clinical hematopoietic stem cell transplantation (HSCT). SDF-1 / CXCR4 is considered to be a very promising target to promote HSC homing. In recent years, with the in-depth research on the HSC homing, a variety of new strategies for promoting HSC homing and engraftment have been explored, such as nuclear hormone receptor, histone deacetylase inhibitor, prostaglandin and metabolic regulation, so as to increase the success rate of HSCT and improve the survival of patients. In this review, the recent research advances in the mechanism of HSC homing and strategies to promote HSC homing and engraftment were summarized and discussed.

[Advances in the Treatment of Glucocorticoid Resistance and Relapsed Immune Thrombocytopenia --Review].

Immune thrombocytopenia (ITP) is an immune-mediated acquired hemorrhagic autoimmune disease. At present, the first-line therapeutic drugs for ITP include glucocorticoids and intravenous immunoglobulins. However, about 1/3 of the patients had no response to the first-line treatment, or relapsed after dose reduction or withdrawal of glucocorticoids. In recent years, with the gradual deepening of the understanding on the pathogenesis of ITP, the drugs targeting different pathogenesis continually emerge, including immunomodulators, demethylating agents, spleen tyrosine kinase (SYK) inhibitors and neonatal Fc receptor (FcRn) antagonist. However, most of these drugs are in clinical trials. This review summarized briefly the recent advances in the treatment of glucocorticoids resistance and relapsed ITP, so as to provide reference for the clinical treatments.

The Protective Effect of Dexmedetomidine Against Ischemia-Reperfusion Injury after Hepatectomy: A Meta-Analysis of Randomized Controlled Trials.

Background: Hepatic inflow occlusion proceeded to reduce blood loss during hepatectomy induces ischemia-reperfusion (IR) injury in the remnant liver. Dexmedetomidine, a selective α2-adrenoceptor agonist used as an anesthetic adjuvant, has been shown to attenuate IR injury in preclinical and clinical studies. However, a meta-analysis is needed to systematically evaluate the protective effect of perioperative dexmedetomidine use on IR injury induced by hepatectomy. Methods: A prospectively registered meta-analysis following Cochrane and PRISMA guidelines concerning perioperative dexmedetomidine use on IR injury after hepatectomy was performed via searching Cochrane Library, PubMed, EMBASE, ClinicalTrials.gov, Web of Science, CNKI, WanFang, and Sinomed for eligible randomized controlled trials up to 2021.3.31. The main outcome is postoperative liver function. Risk of bias was assessed by the Cochrane Risk of Bias tool. Review Manager 5.3 and Stata12.0 were applied to perform data analyses. Results: Eight RCTs enrolling 468 participants were included. Compared with 0.9% sodium chloride, dexmedetomidine decreased serum concentration of ALT (WMD = -66.54, 95% CI: -92.10--40.98), AST (WMD= -82.96, 95% CI: -106.74--59.17), TBIL (WMD = -4.51, 95% CI: -7.32--1.71), MDA (WMD = -3.09, 95% CI: -5.17--1.01), TNF-α (WMD = -36.54, 95% CI: -61.33--11.95) and IL-6 (WMD = -165.05, 95% CI: -225.76--104.34), increased SOD activity (WMD = 24.70, 95% CI: 18.09-31.30) within postoperative one day. There was no significant difference in intraoperative or postoperative recovery parameters between groups. Conclusions: Perioperative administration of dexmedetomidine can exert a protective effect on liver IR injury after hepatectomy. Additional studies are needed to further evaluate postoperative recovery outcomes of dexmedetomidine with different dosing regimens.

[Research Advances on Ex Vivo Expansion Strategy of Hematopoietic Stem Cells--Review].

Abstract　　Hematopoietic stem cells (HSCs), as a kind of adult stem cell, is first used in clinical practice. It has been widely used in hematopoietic stem cell transplantation and has broad application prospects in the field of gene therapy. However, the shortage of HSC is still the main bottleneck restricting the clinical application of HSC transplantation, especially cord blood HSC transplantation. With the continuous improvement of the concept of HSC and the in-depth study of the molecular mechanism regulating HSC self-renewal and differentiation, it have been explored that a variety of strategies for ex vivo expansion of HSC, such as adding small molecule compounds in vitro culture system, simulating bone marrow microenvironment, regulating HSC metabolism and biomaterial-based amplification methods. In this review, recent advances in research of ex vivo expansion strategy of HSC are summarized and discussed.

Thalidomide induce response in patients with corticosteroid-resistant or relapsed ITP by upregulating Neuropilin-1 expression.

BACKGROUND: Immune thrombocytopenia (ITP) is an immune-mediated acquired autoimmune hemorrhagic disease. About one-third of patients are unresponsive to first-line therapies. Thalidomide (THD) as an immunomodulatory agent is now used to treat several autoimmune disorders. Therefore, we assessed the safety and efficacy of THD in corticosteroid-resistant or relapsed ITP patients, and preliminarily explore its mechanism. METHODS: 50 newly-diagnosed ITP patients and 47 healthy volunteers were enrolled in this study. Additionally, 17 corticosteroid-resistant or relapsed ITP patients were recruited, with 7 cases in the rhTPO + THD group and 10 cases in the THD monotherapy group. Overall response rate at 6, 12, and 24 months were assessed. Levels of Neuropilin-1(NRP-1), regulatory T cells (Tregs) and regulatory B cells (Bregs) were detected. RESULTS: Expression of NRP-1, Tregs and Bregs were reduced in newly-diagnosed ITP patients. In vitro, THD treatment upregulated expression of NRP-1and Tregs only in ITP patients. As for corticosteroid-resistant or relapsed ITP patients, overall response rate at 6, 12, and 24 months was 85.7%, 57.1% and 100% in the rhTPO + THD group and 60%, 75% and 83.3% in the THD group, respectively. Additionally, rhTPO plus THD or THD therapy significantly increased the levels of NRP-1, Tregs and Bregs in responders. CONCLUSIONS: Our study shows for the first time that NRP-1 is involved in the pathogenesis of ITP, THD could induce response in ITP patients by upregulating NRP-1 expression and restoring the proportion of Tregs and Bregs. THD might be served as a novel therapeutic agent in corticosteroid-resistant or relapsed ITP patients.

Recipient-Derived Allo-iTregs Induced by Donor DCs Effectively Inhibit the Proliferation of Donor T Cells and Reduce GVHD.

To compare the potency of recipient-derived, antigen-specific regulatory T cells induced by different dendritic cells (DCs; iTregs) and freshly isolated natural regulatory T cells (nTregs) in preventing mouse graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT). CD4+ T cells from recipient BALB/c mice were stimulated with DCs from recipient BALB/c (syn-DCs), donor B6 (allo-DCs), and third-party C3H (third-party-DCs) mice to induce different iTregs. In parallel, nTregs were isolated from spleen cells of recipient BALB/c (syn-nTregs) and donor B6 (allo-nTregs) mice using magnetic-activated cell sorting. Mixed lymphocyte reaction (MLR) assays were performed to evaluate the suppressive ability of these various regulatory T cells (Tregs). Both the iTregs and nTregs were transfused to GVHD mice on Days 0, 1, 3, and 5. Body weight, GVHD score, and survival time were monitored. Peripheral Tregs were subsequently examined on Days 7, 14, 21, and 28 after BMT, while chimerism was evaluated on Days 14 and 60. Histopathology of colon, liver, and spleen were also performed. DCs markedly induced CD25+ and Foxp3+ expression on CD4+ T cells. The allo-DC-induced Tregs (allo-iTregs) suppressed the proliferation of alloreactive T cells better than the other iTregs/nTregs in MLR assays (P < 0.05). Meanwhile, transfusion of the allo-iTregs reduced the severity of GVHD (P < 0.05), increased survival time compared with the GVHD group (P < 0.05), and enhanced the chimerism proportion. On Day 28 after BMT, the allo-iTregs group had the highest frequency of peripheral Tregs (P < 0.05). Recipient-derived allo-iTregs induced by donor DCs included predominant clones that specifically recognized donor antigens. These allo-iTregs not only prevented GVHD by suppressing the proliferation of donor-alloreactive T cells, but also promoted engraftment, and prolonged the survival of GVHD mice. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:825-836, 2019. © 2018 Wiley Periodicals, Inc.

The Neuropilin-1 Ligand, Sema3A, Acts as a Tumor Suppressor in the Pathogenesis of Acute Leukemia.

Semaphorin-3A (Sema3A) and vascular endothelial growth factor (VEGF165) are ligands of neuropilin-1 (NRP-1 or CD304) and are related to immunoregulation and tumor angiogenesis, respectively. However, possible interactions between NRP-1 and Sema3A and VEGF165 in acute leukemia remain unclear, especially whether Sema3A plays a role in acute leukemia. In this study, both of the proportion of regulatory T cells (Tregs) and their expression of NRP-1 were found to increase in acute leukemia patients compared with healthy controls. In contrast, lower mRNA and plasma levels of Sema3A were detected in the acute leukemia patients. In vitro, the addition of exogenous Sema3A inhibited the expression of NRP-1 on Tregs and it promoted apoptosis of leukemia cells. However, in the presence of anti-Sema3A antibody, the effect of rhSema3A on NRP-1 expression was reversed. These results suggest that Sema3A promotes apoptosis in leukemia cells by inhibiting expression of NRP-1, and thus, represents a tumor suppressor protein with a role in the pathogenesis of acute leukemia. Consequently, NRP-1/Sema3A signaling may represent a novel target for the treatment of acute leukemia and should be further studied. Anat Rec, 302:1127-1135, 2019. © 2018 Wiley Periodicals, Inc.

Cyclic nucleotide phosphodiesterases: potential therapeutic targets for alcohol use disorder.

Alcohol use disorder (AUD), which combines the criteria of both alcohol abuse and dependence, contributes as an important causal factor to multiple health and social problems. Given the limitation of current treatments, novel medications for AUD are needed to better control alcohol consumption and maintain abstinence. It has been well established that the intracellular signal transduction mediated by the second messengers cyclic AMP (cAMP) and cyclic GMP (cGMP) crucially underlies the genetic predisposition, rewarding properties, relapsing features, and systemic toxicity of compulsive alcohol consumption. On this basis, the upstream modulators phosphodiesterases (PDEs), which critically control intracellular levels of cyclic nucleotides by catalyzing their degradation, are proposed to play a role in modulating alcohol abuse and dependent process. Here, we highlight existing evidence that correlates cAMP and cGMP signal cascades with the regulation of alcohol-drinking behavior and discuss the possibility that PDEs may become a novel class of therapeutic targets for AUD.

Targeting Phosphodiesterases in Pharmacotherapy for Substance Dependence.

Substance dependence is a chronic relapsing brain disorder associated with adaptational changes in synaptic plasticity and neuronal functions. The high levels of substance consumption and relapse rate suggest more reliable medications are in need to better address the underlying causes of this disease. It has been well established that the intracellular second messengers cyclic AMP (cAMP) and cyclic GMP (cGMP) and their signaling systems play an important role in the molecular mechanisms of substance taking behaviors. On this basis, the phosphodiesterase (PDE) superfamily, which crucially controls cyclic nucleotide levels by catalyzing their hydrolysis, has been proposed as a novel class of therapeutic targets for substance use disorders. This chapter reviews the expression patterns of PDEs in the brain with regard to neural structures underlying the dependent process and highlights available evidence for a modulatory role of PDEs in substance dependence.

Attenuation of ethanol abstinence-induced anxiety- and depressive-like behavior by the phosphodiesterase-4 inhibitor rolipram in rodents.

RATIONALE: Withdrawal symptoms stand as a core feature of alcohol dependence. Our previous results have shown that inhibition of phosphodiesterase-4 (PDE4) decreased ethanol seeking and drinking in alcohol-preferring rodents. However, little is known about whether PDE4 is involved in ethanol abstinence-related behavior. OBJECTIVE: The objective of this study was to characterize the role of PDE4 in the development of anxiety- and depressive-like behavior induced by abstinence from ethanol exposure in different animal models. METHODS: Using three rodent models of ethanol abstinence, we examined the effects of rolipram, a prototypical, selective PDE4 inhibitor, on (1) anxiety-like behavior induced by repeated ethanol abstinence in the elevated plus maze test in fawn-hooded (FH/Wjd) rats, (2) anxiety-like behavior in the open-field test and light-dark transition test following acute ethanol abstinence in C57BL/6J mice, and (3) anxiety- and depressive-like behavior induced by protracted ethanol abstinence in the elevated plus maze, forced-swim, and tail-suspension tests in C57BL/6J mice. RESULTS: Pretreatment with rolipram (0.1 or 0.2 mg/kg) significantly increased entries and time spent in the open arms of the elevated plus maze test in rats with repeated ethanol abstinence. Similarly, in mice with acute ethanol abstinence, administration of rolipram (0.25 or 0.5 mg/kg) dose-dependently increased the crossings in the central zone of the open-field test and duration and transitions on the light side of the light-dark transition test, suggesting anxiolytic-like effects of rolipram. Consistent with these, chronic treatment with rolipram (0.1, 0.3, or 1.0 mg/kg) increased entries in the open arms of the elevated plus maze test; it also reduced the increased duration of immobility in both the forced-swim and tail-suspension tests in mice after protracted ethanol abstinence, suggesting antidepressant-like effects of rolipram. CONCLUSIONS: These results provide the first demonstration for that PDE4 plays a role in modulating the development of negative emotional reactions associated with ethanol abstinence, including anxiety and depression. PDE4 inhibitors may be a novel class of drugs for treatment of alcoholism.

Role of phosphodiesterase 4-mediated cyclic AMP signaling in pharmacotherapy for substance dependence.

The harmful effects caused by misuse of psychoactive substances have raised both medical and social problems. Substance dependence is a chronic relapsing disorder, which appears to involve neuroadaptive changes in cellular signaling and downstream gene expression. The unchanged consumption of present substances and increasing demand for new psychostimulants make the development of novel management/treatment strategies challenging. Emerging evidence has shown that the cyclic AMP (cAMP) signaling cascade plays a critical role in the initiation and development of dependence. Thus, phosphodiesterase 4 (PDE4), the primary hydrolytic enzyme for intracellular cAMP, is considered a potential target for future therapeutics dealing with prevention and intervention of substance dependence. This implication is supported by recent data from preclinical studies, and the rapid development of PDE4 inhibitors. Taken together, specific inhibitors of PDE4 and its subtypes possibly represent a novel class of pharmacotherapies for the prevention and abstinence of substance dependence. Here we discuss the modulatory role of cAMP signal transduction in the process of substance dependence and highlight recent evidence that PDE4 inhibitors might be a promising approach to substance dependence therapy.

Molecular chaperone heat shock protein 70 participates in the labile phase of the development of behavioural sensitization induced by a single morphine exposure in mice.

De-novo protein synthesis is required in the development of behavioural sensitization. A prior screening test from our laboratory has implicated heat shock protein 70 (Hsp70) as one of the proteins required in this behavioural plasticity. Thus, this study was designed to extend our understanding of the role of Hsp70 in the development of behavioural sensitization induced by a single morphine exposure in mice. First, by employing transcription inhibitor actinomycin D (AD) and protein synthesis inhibitor cycloheximide (CHX), we identified a protein synthesis-dependent labile phase (within 4 h after the first morphine injection) in the development of behavioural sensitization to a single morphine exposure. Second, Hsp70 protein expression in the nucleus accumbens correlated positively with locomotor responses of sensitized mice and, more importantly, the expression of Hsp70 increased within 1 h after the first morphine injection. Third, AD and CHX both prevented expression of Hsp70 and disrupted the development of the single morphine induced behavioural sensitization, which further implied Hsp70 was highly associated with behavioural sensitization. Finally, the selective Hsp70 inhibitor pifithrin-µ (PES) i.c.v. injected in mice prevented the development of behavioural sensitization and, critically, this inhibitory effect occurred only when PES was given within 1 h after the first morphine injection, which was within the labile phase of the development period. Taken together, we draw the conclusion that Hsp70 is crucially involved in the labile phase of the development of behavioural sensitization induced by a single morphine exposure, probably functioning as a molecular chaperone.

The phosphodiesterase-4 (PDE4) inhibitor rolipram decreases ethanol seeking and consumption in alcohol-preferring Fawn-Hooded rats.

BACKGROUND: Alcohol dependence is a complex psychiatric disorder demanding development of novel pharmacotherapies. Because the cyclic adenosine monophosphate (cAMP) signaling cascade has been implicated in mediating behavioral responses to alcohol, key components in this cascade may serve as potential treatment targets. Phosphodiesterase-4 (PDE4), an enzyme that specifically catalyzes the hydrolysis of cAMP, represents a key point in regulating intracellular cAMP levels. Thus, it was of interest to determine whether PDE4 was involved in the regulation of alcohol use and abuse. METHODS: Male Fawn-Hooded (FH/Wjd) rats were tested for 5% (v/v) ethanol (EtOH) and 10% (w/v) sucrose operant oral self-administration following treatment with the selective PDE4 inhibitor rolipram (0.0125, 0.025, or 0.05 mg/kg, subcutaneous [s.c.]); rolipram at higher doses (0.05, 0.1, and 0.2 mg/kg, s.c.) was tested to determine its impact on the intake of EtOH, sucrose, or water using the 2-bottle choice drinking paradigm. Subsequent open-field testing was performed to evaluate the influence of higher doses of rolipram on locomotor activity. RESULTS: Acute administration of rolipram dose-dependently reduced operant self-administration of 5% EtOH, but had no effect on 10% sucrose responding. Time-course assessment revealed significant decreases in EtOH consumption after rolipram (0.1, 0.2 mg/kg) treatment in continuous- and intermittent access to EtOH at 5% or 10%, respectively. Moreover, chronic rolipram treatment time-dependently decreased 5% EtOH consumption and preference during treatment days and after the termination of rolipram administration. Rolipram at the highest doses (0.1 and 0.2 mg/kg) did decrease locomotor activity, but the effect lasted only 10 and 20 minutes, respectively, which did not likely alter long-term EtOH drinking. CONCLUSIONS: These results suggest that PDE4 plays a role in alcohol seeking and consumption behavior. Drugs interfering with PDE4 may be a potential pharmacotherapy for alcohol dependence.

Tramadol induces conditioned place preference in rats: interactions with morphine and buprenorphine.

Surveys and drug surveillance have demonstrated that the abuse liability of tramadol is considerably low in the general population but appears to be higher in opiate addicts, and this difference could attribute to the poly-drug abuse of opioid addicts, although this hypothesis has not been tested in the laboratory. The present study examined the interactions between tramadol and a full µ opioid receptor agonist morphine or a partial µ opioid receptor agonist buprenorphine in a conditioned place preference (CPP) paradigm in rats. Rats were conditioned with tramadol (2-54 mg/kg, i.p.), morphine (0.125-8 mg/kg, s.c.), buprenorphine (0.01-0.316 mg/kg, s.c.) or a combination of a subeffective dose of tramadol (2mg/kg) with a subeffective dose of morphine or buprenorphine and the CPP effect was measured. The retention of CPP effect was also examined. Tramadol, morphine and buprenorphine all produced a dose-dependent and significant CPP. A smaller dose of tramadol (2mg/kg) enhanced morphine- and buprenorphine-induced CPP and shifted the dose-effect curves of both drugs leftward. In addition, the combination of tramadol with morphine or buprenorphine prolonged the retention of CPP. These findings indicate that tramadol potentiates the rewarding effects of morphine or buprenorphine largely in an additive manner and support the general contention that tramadol has relatively low abuse liability.