PGC-1α activation ameliorates cancer-induced bone pain via inhibiting apoptosis of GABAergic interneurons

Cancer-induced bone pain (CIBP) stands out as one of the most challenging issues in clinical practice due to its intricate and not fully elucidated pathophysiological mechanisms. Existing evidence has pointed toward the significance of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) down-regulation in contributing to pain behaviors in various rodent models of neuropathic pain. In our current study, we aimed to investigate the role of PGC-1α in CIBP. Our results unveiled a reduction in PGC-1α expression within the spinal cord of CIBP rats, particularly in GABAergic interneurons. Notably, intrathecal administration of the PGC-1α activator ZLN005 suppressed the loss of spinal GABAergic interneurons. This suppression was achieved by inhibiting caspase-3-mediated apoptosis, ultimately leading to the alleviation of mechanical allodynia in CIBP rats. Further exploration into the mechanism revealed that PGC-1α activation played a pivotal role in mitigating ATP depletion and reactive oxygen species accumulation linked to mitochondrial dysfunction. This was achieved through the restoration of mitochondrial biogenesis and the activation of the SIRT3-SOD2 pathway. Impressively, the observed effects were prominently reversed upon the application of SR18292, a specific PGC-1α inhibitor. In conclusion, our findings strongly suggest that PGC-1α activation acts as a potent inhibitor of apoptosis in spinal GABAergic interneurons. This inhibition is mediated by the improvement of mitochondrial function, facilitated in part through the enhancement of mitochondrial biogenesis and the activation of the SIRT3-SOD2 pathway. The results of our study shed light on potential therapeutic avenues for addressing CIBP.

Matrix metalloproteinases as attractive therapeutic targets for chronic pain: A narrative review

Chronic pain constitutes an abnormal pain state that detrimentally affects the quality of life, daily activities, occupational performance, and stability of mood. Despite the prevalence of chronic pain, effective drugs with potent abirritation and minimal side effects remain elusive. Substantial studies have revealed aberrant activation of the matrix metalloproteinases (MMPs) in multiple chronic pain models. Additionally, emerging evidence has demonstrated that the downregulation of MMPs can alleviate chronic pain in diverse animal models, underscoring the unique and crucial role of MMPs in different stages and types of chronic pain. This review delves into the mechanistic insights and roles of MMPs in modulating chronic pain. The aberrant activation of MMPs has been linked to neuropathic pain through mechanisms involving myelin abnormalities in peripheral nerve and spinal dorsal horn (SDH), hyperexcitability of dorsal root ganglion (DRG) neurons, activation of N-methyl-d-aspartate receptors (NMDAR) and Ca2+-dependent signals, glial cell activation, and proinflammatory cytokines release. Different MMPs also contribute significantly to inflammatory pain and cancer pain. Furthermore, we summarized the substantial therapeutic potential of MMP pharmacological inhibitors across different types of chronic pain. Overall, our findings underscore the promising therapeutic prospects of MMPs targeting for managing chronic pain.

Targeting the JAK2/STAT3 signaling pathway for chronic pain

Chronic pain is a notable health concern because of its prevalence, persistence, and associated mental stress. Drugs targeting chronic pain with potent abirritation, and minimal side effects remain unidentified. Substantial evidence indicates that the Janus Kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway plays a distinct and critical role in different stages of chronic pain. Aberrant activation of the JAK2/STAT3 signaling pathway is evident in multiple chronic pain models. Moreover, an increasing number of studies have demonstrated that the downregulation of JAK2/STAT3 can attenuate chronic pain in different animal models. In this review, we investigated the mechanism and role of the JAK2/STAT3 signaling pathway in modulating chronic pain. The aberrant activation of JAK2/STAT3 can trigger chronic pain by interacting with microglia and astrocytes, releasing proinflammatory cytokines, inhibiting anti-inflammatory cytokines, and regulating synaptic plasticity. We also retrospectively reviewed current reports on JAK2/STAT3 pharmacological inhibitors that demonstrated their significant therapeutic potential in different types of chronic pain. In summary, our results provide strong evidence that the JAK2/STAT3 signaling pathway is a promising therapeutic target for chronic pain.

Interleukin-17: A Putative Novel Pharmacological Target for Pathological Pain

Pathological pain imposes a huge burden on the economy and the lives of patients. At present, drugs used for the treatment of pathological pain have only modest efficacy and are also plagued by adverse effects and risk for misuse and abuse. Therefore, understanding the mechanisms of pathological pain is essential for the development of novel analgesics. Several lines of evidence indicate that interleukin-17 (IL-17) is upregulated in rodent models of pathological pain in the periphery and central nervous system. Besides, the administration of IL-17 antibody alleviated pathological pain. Moreover, IL-17 administration led to mechanical allodynia which was alleviated by the IL-17 antibody. In this review, we summarized and discussed the therapeutic potential of targeting IL-17 for pathological pain. The upregulation of IL-17 promoted the development of pathological pain by promoting neuroinflammation, enhancing the excitability of dorsal root ganglion neurons, and promoting the communication of glial cells and neurons in the spinal cord. In general, the existing research shows that IL-17 is an attractive therapeutic target for pathologic pain, but the underlying mechanisms still need to be investigated.

Inhibition of Brd4 alleviates osteoarthritis pain via suppression of neuroinflammation and activation of Nrf2-mediated antioxidant signalling

BACKGROUND AND PURPOSE

Osteoarthritis (OA) pain remains a major clinical problem. It is urgent to identify novel therapeutic approaches for OA pain states. Bromodomain and extra-terminal (BET) protein inhibitors have robust anti-inflammatory effects in several pain models. However, the underlying mechanisms of these inhibitors in OA pain have not been determined. We, therefore, investigated the effects and the underlying mechanism(s) of BET inhibition on pain-related behaviours in a rat model of OA.

EXPERIMENTAL APPROACH

The OA model was established by intra-articular injection of monosodium iodoacetate (MIA) in rat knees. Pain behaviours were assessed in rats by hindlimb weight-bearing asymmetry, mechanical allodynia and thermal hyperalgesia. Possible mechanisms underlying BET inhibition were explored in the MIA-induced OA pain model in the spinal cord and dorsal root ganglia (DRG).

KEY RESULTS

Inhibiting bromodomain-containing protein 4 (Brd4) with either JQ1 or MS417, or using AAV2/9-shRNA-Brd4-EGFP-mediated knockdown of Brd4 genes, significantly attenuated MIA-induced pain behaviours. Brd4 inhibition suppressed NF-κB and NF-κB-mediated inflammatory cytokines in both the spinal cord and DRG in rats with MIA-induced OA pain. Brd4 inhibition also attenuated the oxidative stress and promoted nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent antioxidant genes in both the spinal cord and DRG in our odel of MIA-induced OA pain.

CONCLUSIONS AND IMPLICATIONS

In conclusion, Brd4 inhibition alleviated MIA-induced OA pain in rats, via suppression of neuroinflammation and activation of Nrf2-mediated antioxidant signalling. Although our model does not perfectly represent how OA develops in humans, inhibition of Brd4 may provide novel insights into possible treatments for OA pain.

[Mechanism of intestinal injury induced by WNT2B high-expressed fibroblasts in Crohn's disease]

Objective: To explore the mechanism of intestinal tissue damage induced by macrophages activated by WNT2B high-expressed fibroblasts. Methods: This study involved biological information analysis, pathological tissue research and cell experimental research. The biological information of the colon tissue from the children with inflammatory bowel disease in previous study was analyzed again with single-cell sequencing. The pathological tissues were collected by colonoscopy from 10 children with Crohn's disease treated in the Department of Gastroenterology of Guangzhou Women and Children's Medical Center from July 2022 to September 2022. According to the findings of colonoscopy, tissues with obvious inflammation or ulceration were classified as the inflammatory group, while tissues with slight inflammation and no ulceration were classified as the non-inflammatory group. HE staining was performed to observe the pathological changes of the colon tissues. Macrophage infiltration and CXCL12 expression were detected by immunofluorescence. In terms of cell experiments, fibroblasts transfected with WNT2B plasmid or empty plasmid were co-cultured with salinomycin treated or non-treated macrophages, respectively; the expression of proteins through Wnt classical pathway were detected by western blotting. Macrophages treated with SKL2001 were used as the experimental group, and those with phosphate buffer as the control group. The expression and secretion of CXCL12 in macrophages were detected by quantitative Real-time PCR and enzyme-linked immunosorbent assay (ELISA). T-test or rank sum test were used for the comparison between groups. Results: Single-cell sequencing analysis suggested that macrophages were the main cells in inflammatory bowel disease colon tissue, and there was interaction between WNT2B high-expressed fibroblasts and macrophages. HE staining of the 10 patients ((9.3±3.8) years old, 7 males and 3 females) showed that the pathological score of colon tissue in the inflammatory group was higher than that in the non-inflammatory group (4 (3, 4) vs. 2 (1, 2) points, Z=3.05, P=0.002). Tissue immunofluorescence indicated that the number of infiltrating macrophages in the inflammatory group was significantly higher than that in the non-inflammatory group under high power field of view (72.8±10.4 vs.8.4±3.5, t=25.10, P<0.001), as well as the number of cells expressing CXCL12 (14.0±3.5 vs. 4.7±1.9, t=14.68, P<0.001). In cell experiments, western blotting suggested an elevated level of glycogen synthase kinase-3β phosphorylation in macrophages co-cultured with fibroblast transfected with WNT2B plasmid, and salinmycin could reverse this change. Real-time PCR suggested that the transcription level of CXCL12 in the experimental group was higher than that in the control group (6.42±0.04 vs. 1.00±0.03, t=183.00, P<0.001), as well as the expression and secretion of CXCL12 by ELISA ((465±34) vs. (77±9) ng/L, t=13.21, P=0.006). Conclusion: WNT2B high-expressed fibroblasts can secrete WNT2B protein and activate the Wnt classical signaling pathway thus enhancing the expression and secretion of CXCL12 in macrophages, inducing the development of intestinal inflammation of Crohn's disease.

The Emerging Role of Quercetin in the Treatment of Chronic Pain

Despite much research efforts being devoted to designing alternative pharmacological interventions, chronic pain remains to be an unresolved clinical problem. Quercetin, a compound that belongs to the flavonoids family, is abundantly found in fruits and vegetables. Emerging evidence indicates that quercetin possesses anti-nociceptive effects in different rodent models of chronic pain, including inflammatory pain, neuropathic pain and cancer pain. In this review, we summarize the mechanisms underlying the analgesic effect of quercetin in preclinical studies. These studies showed that quercetin exerts potent analgesic effects against chronic pain via suppressing neuroinflammation and oxidative stress as well as modulation of synaptic plasticity, GABAergic system, and opioidergic system. Considering that the safety of quercetin is well established, it has great potential for clinical use in pain treatment.

Targeting the nitric oxide/cGMP signaling pathway to treat chronic pain

Nitric oxide (NO)/cyclic guanosine 3',5'-monophosphate (cGMP) signaling has been shown to act as a mediator involved in pain transmission and processing. In this review, we summarize and discuss the mechanisms of the NO/cGMP signaling pathway involved in chronic pain, including neuropathic pain, bone cancer pain, inflammatory pain, and morphine tolerance. The main process in the NO/cGMP signaling pathway in cells involves NO activating soluble guanylate cyclase, which leads to subsequent production of cGMP. cGMP then activates cGMP-dependent protein kinase (PKG), resulting in the activation of multiple targets such as the opening of ATP-sensitive K⁺ channels. The activation of NO/cGMP signaling in the spinal cord evidently induces upregulation of downstream molecules, as well as reactive astrogliosis and microglial polarization which participate in the process of chronic pain. In dorsal root ganglion neurons, natriuretic peptide binds to particulate guanylyl cyclase, generating and further activating the cGMP/PKG pathway, and it also contributes to the development of chronic pain. Upregulation of multiple receptors is involved in activation of the NO/cGMP signaling pathway in various pain models. Notably the NO/cGMP signaling pathway induces expression of downstream effectors, exerting both algesic and analgesic effects in neuropathic pain and inflammatory pain. These findings suggest that activation of NO/cGMP signaling plays a constituent role in the development of chronic pain, and this signaling pathway with dual effects is an interesting and promising target for chronic pain therapy.

Targeting α7 nicotinic acetylcholine receptors for chronic pain

Despite rapid advances in the field of chronic pain, it remains extremely challenging in the clinic. Pain treatment strategies have not improved for decades as opioids remain the main prescribed drugs for chronic pain management. However, long-term use of opioids often leads to detrimental side effects. Therefore, uncovering the mechanisms underlying the development and maintenance of chronic pain may aid the discovery of novel therapeutics to benefit patients with chronic pain. Substantial evidence indicates downregulation of α7 nicotinic acetylcholine receptors (α7 nAChR) in the sciatic nerve, dorsal root ganglia, and spinal cord dorsal horn in rodent models of chronic pain. Moreover, our recent study and results from other laboratories demonstrate that potentiation of α7 nAChR attenuates pain behaviors in various murine models of chronic pain. This review summarized and discussed the preclinical evidence demonstrating the therapeutic potential of α7 nAChR agonists and allosteric modulators in chronic pain. This evidence indicates that potentiation of α7 nAChR is beneficial in chronic pain, mostly by alleviating neuroinflammation. Overall, α7 nAChR-based therapy for chronic pain is an area with great promise, but more research regarding its detailed mechanisms is warranted.

Dimethyl Fumarate Attenuates Pain Behaviors in Osteoarthritis Rats via Induction of Nrf2-Mediated Mitochondrial Biogenesis

AIMS

Osteoarthritis (OA), a chronic degenerative disease, leads to pain and loss of function. Existing treatments for OA pain have limited efficacy and show significant side effects. Dimethyl fumarate, a robust nuclear factor erythroid 2-related factor 2 (Nrf2) activator, could alleviate pain behaviors in chronic pain. This study aims to investigate the role of dimethyl fumarate in a rat model of OA and its underlying mechanisms.

METHODS

We used von Frey filaments to assess the mechanical allodynia. Weight-bearing apparatus was employed to assess the hindlimb weight distribution. Western blot was employed to investigate the protein expressions of mitochondrial biogenesis markers. RT-qPCR was employed to examine the copy number of mitochondrial DNA (mtDNA).

RESULTS

Dimethyl fumarate upregulated mechanical paw withdrawal threshold (MIA + Vehicle, 1.6 ± 0.13g [mean ± SEM]; MIA + DMF, 10.5 ± 0.96g; P ＜ 0.0001). Hindlimb weight distribution was alao upregulated by dimethyl fumarate (MIA + Vehicle, 38.17 ± 0.72g; MIA + DMF, 43.59 ± 1.01g; P ＜ 0.01). Besides, activation of Nrf2 remarkably upregulated the protein levels of PGC-1α (MIA + Vehicle, 0.69 ± 0.07; MIA + DMF, 1.08 ± 0.09; P = 0.0037), NRF1 (MIA + Vehicle, 0.69 ± 0.04; MIA + DMF, 1.00 ± 0.11; P = 0.0114), TFAM (MIA + Vehicle, 0.62 ± 0.11; MIA + DMF, 1.02 ± 0.12; P = 0.0147), and the copy number of mtDNA(MIA + Vehicle, 0.52 ± 0.05; MIA + DMF, 3.81 ± 0.21; P ＜ 0.0001) Conclusions: Taken together, these results show that dimethyl fumarate alleviated pain-related behaviors in a rat model of OA through activation of Nrf2-induced mitochondrial biogenesis.

Notch signaling activation contributes to paclitaxel-induced neuropathic pain via activation of A1 astrocytes

Paclitaxel-induced neuropathic pain (PINP) is a progressive and refractory side effect of chemotherapy with few effective treatments at present. It is well-established that astrocytes activation contributes to the development of PINP. Recent reports showed astrocytes can be divided into A1 and A2 phenotypes. However, whether the transformation of astrocytes participates in PINP and the underlying mechanisms remain unknown. As Notch signaling pathway have shown to be involved in neuropathic pain, we aimed to investigate the relationship between Notch signaling pathway and A1 astrocytes in PINP. Herein we found that both A1 astrocytes and Notch signaling were markedly activated in the spinal cord of PINP rats and the downstream molecules of Notch signaling were colocalized with A1 astrocytes. DAPT (an inhibitor of Notch signaling) not only suppressed the mechanical allodynia of PINP rats, but also inhibited the activation of Notch signaling pathway and A1 astrocytes. Furthermore, Jagged1 (a ligand of Notch1 receptors) dose-dependently induced mechanical hyperalgesia in naïve rats and simultaneously led to Notch signaling activation and A1 astrocytes transformation, all of which were inhibited by DAPT. Taken together, these results demonstrate Notch signaling activation contributes to PINP via A1 astrocytes activation, which provides a promising therapeutic target for PINP.

DKK3 ameliorates neuropathic pain via inhibiting ASK-1/JNK/p-38-mediated microglia polarization and neuroinflammation

BACKGROUND

Neuropathic pain is a common and severely disabling state that affects millions of people worldwide. Microglial activation in the spinal cord plays a critical role in the pathogenesis of neuropathic pain. However, the mechanisms underlying spinal microglial activation during neuropathic pain remain incompletely understood. Here, we investigated the role of Dickkopf (DKK) 3 and its interplay with microglial activation in the spinal cord in neuropathic pain.

METHODS

In this study, we investigated the effects of intrathecal injection of recombinant DKK3 (rDKK3) on mechanical allodynia and microglial activation in the spinal cord after spared nerve injury (SNI) in rats by western blot (WB), immunofluorescence (IF), quantitative polymerase chain reaction (qPCR), and enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that SNI induced a significant decrease in the levels of DKK3, Kremen-1 and Dishevelled-1 (DVL-1) and up-regulated the expression of phosphorylated apoptosis signal-regulating kinase 1 (p-ASK1), phosphorylated c-JUN N-terminal kinase (p-JNK), phosphorylated p38 (p-p38) in the spinal cord. Moreover, our results showed that exogenous intrathecal administration of rDKK3 inhibited expression of p-ASK1, p-JNK, p-p38, promoted the transformation of microglia from M1 type to M2 type, and decreased the production of pro-inflammatory cytokines compared to the rats of SNI + Vehicle. However, these effects were reversed by intrathecal administration of Kremen-1 siRNA or Dishevelled-1 (DVL-1) siRNA.

CONCLUSIONS

These results suggest that DKK3 ameliorates neuropathic pain via inhibiting ASK-1/JNK/p-38-mediated microglia polarization and neuroinflammation, at least partly, by the Kremen-1 and DVL-1 pathways.

SIRT1: A promising therapeutic target for chronic pain

Chronic pain remains an unresolved problem. Current treatments have limited efficacy. Thus, novel therapeutic targets are urgently required for the development of more effective analgesics. An increasing number of studies have proved that sirtuin 1 (SIRT1) agonists can relieve chronic pain. In this review, we summarize recent progress in understanding the roles and mechanisms of SIRT1 in mediating chronic pain associated with peripheral nerve injury, chemotherapy‐induced peripheral neuropathy, spinal cord injury, bone cancer, and complete Freund's adjuvant injection. Emerging studies have indicated that SIRT1 activation may exert positive effects on chronic pain relief by regulating inflammation, oxidative stress, and mitochondrial dysfunction. Therefore, SIRT1 agonists may serve as potential therapeutic drugs for chronic pain.

Adipocytokines: Emerging therapeutic targets for pain management

Although pain has lower mortality rates than cancer, diabetes and stroke, pain is a predominate source of distress and disability. However, the management of pain remains an enormous problem. Many drugs used to pain treatment have more or less side effects. Therefore, the development of novel therapeutic target is critical for the treatment of pain. Notably, studies have shown that adipocytokines have a dual role in pain. Growing shreds of evidence shows that the levels of adipocytokines are upregulated or downregulated in the development of pain. In addition, substantial evidence indicates that regulation of adipocytokines levels in models of pain attenuates or promotes pain behaviors. In this review, we summarized and discussed the effect of adipocytokines in pain. These evidence indicates that adipocytokines attenuate or promote pain behaviors through interacting with their receptors, activating serotonin pathway, interacting with μ-opioid receptor, activating microglia, infiltrating macrophage and so on. Overall, adipocytokines have some potential in treating pain, but the underlying mechanisms remain unclear and need to be further studied.

β2-adrenoreceptor agonist ameliorates mechanical allodynia in paclitaxel-induced neuropathic pain via induction of mitochondrial biogenesis

Chemotherapy-induced neuropathic pain is a debilitating and common side effect of cancer treatment and so far no effective drug is available for treatment of the serious side effect. Previous studies have demonstrated β2-adrenoreceptor (ADRB2) agonists can attenuate neuropathic pain. However, the role of ADRB2 in paclitaxel -induced neuropathic pain (PINP) remains unclear. In this study, we investigated the effect of formoterol, a long-acting ADRB2 agonist, and related mechanisms in PINP. A rat model of PINP was established by intraperitoneal injection of paclitaxel (2 mg/kg) every other day with a final cumulative dose of 8 mg/kg. Hind paw withdrawal thresholds (PWTs) in response to von Frey filament stimuli were used to evaluate mechanical allodynia. Western blot was used to examine the expression of ADRB2, peroxisome proliferator-activated receptor coactivator-1α (PGC-1α), nuclear respiratory factors 1 (NRF1) and mitochondrial transcription factor A (TFAM) and the immunofluorescence was to detect the cellular localization of ADRB2 and PGC-1α in the spinal cord. Moreover, we measured mitochondrial DNA (mtDNA) copy number by qPCR. In our study, formoterol attenuated established PINP and delayed the onset of PINP. Formoterol restored ADRB2 expression as well as mtDNA copy number and PGC-1α, NRF1, and TFAM protein expression, which are major genes involved in mitochondrial biogenesis, in the spinal cord of PINP rats. Moreover, we found the analgesic effect of formoterol against PINP was partially abolished by PGC-1α inhibitor SR-18292. Collectively, these results demonstrated the activation of ADRB2 with formoterol ameliorates PINP at least partially through induction of mitochondrial biogenesis.

Nrf2 Activation Attenuates Chronic Constriction Injury-Induced Neuropathic Pain via Induction of PGC-1α-Mediated Mitochondrial Biogenesis in the Spinal Cord

BACKGROUND

Neuropathic pain is a debilitating disease with few effective treatments. Emerging evidence indicates the involvement of mitochondrial dysfunction and oxidative stress in neuropathic pain. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a potent regulator of the antioxidant response system. In this study, we investigated whether RTA-408 (RTA, a novel synthetic triterpenoid under clinical investigation) could activate Nrf2 and promote mitochondrial biogenesis (MB) to reverse neuropathic pain and the underlying mechanisms.

METHODS

Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve. Pain behaviors were measured via the von Frey test and Hargreaves plantar test. The L4-6 spinal cord was collected to examine the activation of Nrf2 and MB.

RESULTS

RTA-408 treatment significantly reversed mechanical allodynia and thermal hyperalgesia in CCI mice in a dose-dependent manner. Furthermore, RTA-408 increased the activity of Nrf2 and significantly restored MB that was impaired in CCI mice in an Nrf2-dependent manner. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1α) is the key regulator of MB. We found that the PGC-1α activator also induced a potent analgesic effect in CCI mice. Moreover, the antinociceptive effect of RTA-408 was reversed by the preinjection of the PGC-1α inhibitor.

CONCLUSIONS

Nrf2 activation attenuates chronic constriction injury-induced neuropathic pain via induction of PGC-1α-mediated mitochondrial biogenesis in the spinal cord. Our results indicate that Nrf2 may be a potential therapeutic strategy to ameliorate neuropathic pain and many other disorders with oxidative stress and mitochondrial dysfunction.

The therapeutic potential of Nrf2 inducers in chronic pain: Evidence from preclinical studies

Chronic pain remains an enormous health problem affecting approximatively 30% of the world's population. Opioids as the first line analgesics often leads to undesirable side effects when used long term. Therefore, novel therapeutic targets are urgently needed to the development of more efficacious analgesics. Substantial evidence indicates that excessive reactive oxygen species (ROS) are extremely important to the development of chronic pain. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master transcription factor regulating endogenous antioxidant defense. Emerging evidence suggests that Nrf2 and its downstream effectors are implicated in chronic inflammatory and neuropathic pain. Notably, controversial results have been reported regarding the expression of Nrf2 and its downstream targets in peripheral and central regions involved in pain transmission. However, our recent studies and results from other laboratories demonstrate that Nrf2 inducers exert potent analgesic effects in various murine models of chronic pain. In this review, we summarized and discussed the preclinical evidence demonstrating the therapeutic potential of Nrf2 inducers in chronic pain. These evidence indicates that Nrf2 activation are beneficial in chronic pain mostly by alleviating ROS-associated pathological processes. Overall, Nrf2-based therapy for chronic pain is an area with great promise, but more research regarding its detailed mechanisms is warranted.

Nrf2 activation ameliorates mechanical allodynia in paclitaxel-induced neuropathic pain

Paclitaxel-induced neuropathic pain (PINP) is refractory to currently used analgesics. Previous studies show a pivotal role of oxidative stress in PINP. Because the nuclear factor erythroid-2-related factor 2 (Nrf2) has been considered as the critical regulator of endogenous antioxidant defense, we here explored whether activation of Nrf2 could attenuate PINP. A rat model of PINP was established by intraperitoneal injection of paclitaxel (2 mg/kg) every other day with a final cumulative dose of 8 mg/kg. Hind paw withdrawal thresholds (PWTs) in response to von Frey filament stimuli were used to assess mechanical allodynia. We showed that a single dose of Nrf2 activator, oltipraz (10, 50, and 100 mg/kg), dose-dependently attenuated established mechanical allodynia, whereas repeated injection of oltipraz (100 mg· kg-1· d-1, i.p. from d 14 to d 18) almost abolished the mechanical allodynia in PINP rats. The antinociceptive effect of oltipraz was blocked by pre-injection of Nrf2 inhibitor trigonelline (20 mg/kg, i.p.). Early treatment with oltipraz (100 mg· kg-1· d-1, i.p. from d 0 to d 6) failed to prevent the development of the PINP, but delayed its onset. Western blot and immunofluorescence analysis revealed that the expression levels of Nrf2 and HO-1 were significantly upregulated in the spinal cord of PINP rats. Repeated injection of oltipraz caused further elevation of the expression levels of Nrf2 and HO-1 in the spinal cord of PINP rats, which was reversed by pre-injection of trigonelline. These results demonstrate that oltipraz ameliorates PINP via activating Nrf2/HO-1-signaling pathway in the spinal cord.

PPARγ activation mitigates mechanical allodynia in paclitaxel-induced neuropathic pain via induction of Nrf2/HO-1 signaling pathway

Paclitaxel-induced neuropathic pain (PINP) is a dose-limiting side effect and is refractory to widely used analgesic drugs. Previous studies have demonstrated a protective role of peroxisome proliferator-activated receptor gama (PPARγ) in neuropathic pain. However, whether PPARγ activation could alleviate PINP remains to be elucidated. Our previous study has validated the analgesic effect of oltipraz, an nuclear factor erythroid-2 related factor 2 (Nrf2) activator, in a rat model of PINP. In this study, we tested the hypothesis that rosiglitazone, a selective agonist of PPARγ, could attenuate PINP through induction of Nrf2/heme oxygenase-1 (HO-1) signaling pathway. Paclitaxel was injected intraperitoneally on four alternate days to induce neuropathic pain. Paw withdrawal threshold was used to evaluate mechanical allodynia. Western blot and immunofluorescence were used to examine the expression and distribution of PPARγ, Nrf2 and HO-1 in the spinal cord. Our results showed that rosiglitazone attenuated established PINP and delayed the onset of PINP via activation of PPARγ, which were reversed by PPARγ antagonist GW9662. Moreover, rosiglitazone inhibited downregulation of PPARγ in the spinal cord of PINP rats. Furthermore, the analgesic effect of rosiglitazone against PINP was abolished by trigonelline, an Nrf2 inhibitor. Finally, rosiglitazone significantly increased expression of Nrf2 and HO-1 in the spinal cord of PINP rats. Collectively, these results indicated that PPARγ activation might mitigate PINP through activating spinal Nrf2/HO-1 signaling pathway. Our results may provide an alternative option for PINP patients.

Targeting Cytokines for Morphine Tolerance: A Narrative Review

Background:

Despite its various side effects, morphine has been widely used in clinics for decades due to its powerful analgesic effect. Morphine tolerance is one of the major side effects, hindering its long-term usage for pain therapy. Currently, the thorough cellular and molecular mechanisms underlying morphine tolerance remain largely uncertain.

Methods

We searched the PubMed database with Medical subject headings (MeSH) including ‘morphine tolerance’, ‘cytokines’, ‘interleukin 1’, ‘interleukin 1 beta’, ‘interleukin 6’, ‘tumor necrosis factor alpha’, ‘interleukin 10’, ‘chemokines’. Manual searching was carried out by reviewing the reference lists of relevant studies obtained from the primary search. The searches covered the period from inception to November 1, 2017.

Results

The expression levels of certain chemokines and pro-inflammatory cytokines were significantly increased in animal models of morphine tolerance. Cytokines and cytokine receptor antagonist showed potent effect of alleviating the development of morphine tolerance.

Conclusion

Cytokines play a fundamental role in the development of morphine tolerance. Therapeutics targeting cytokines may become alternative strategies for the management of morphine tolerance.

Berberine protects against ischemia-reperfusion injury: A review of evidence from animal models and clinical studies

Ischemia-reperfusion (I/R) injury is accompanied with high morbidity and mortality and has seriously negative social and economic influences. Unfortunately, few effective therapeutic strategies are available to improve its outcome. Berberine is a natural medicine possessing multiple beneficial biological activities. Emerging evidence indicates that berberine has potential protective effects against I/R injury in brain, heart, kidney, liver, intestine and testis. However, up-to-date review focusing on the beneficial role of berberine against I/R injury is not yet available. In this paper, results from animal models and clinical studies are concisely presented and its mechanisms are discussed. We found that berberine ameliorates I/R injury in animal models via its anti-oxidant, anti-apoptotic and anti-inflammatory effects. Moreover, berberine also attenuates I/R injury by suppressing endoplasmic reticulum stress and promoting autophagy. Additionally, regulation of periphery immune system may also contributes to the beneficial effect of berberine against I/R injury. Although clinical evidence is limited, the current studies indicate that berberine may attenuate I/R injury via inhibiting excessive inflammatory response in patients. Collectively, berberine might be used as an alternative therapeutic strategy for the management of I/R injury.

Acute Toxicity and Hazardous Concentrations of Zinc to Native Freshwater Organisms Under Different pH Values in China

Zinc bioavailability to aquatic organisms varies greatly under different pH values. In the present study, five native species in China and four common international test species were selected to investigate the influence of changing pH on acute zinc toxicity. The results showed that the higher trophic levels exhibited increasing sensitivity to zinc as pH decreased. However, when the pH value was between 8 and 11, the acute toxicity of zinc was relatively constant. In addition, by using a species-sensitivity distribution (SSD) method, the short-term hazardous concentrations of zinc at different pH values (based on the 5th percentiles of the pH-specific SSDs) were determined to be 17.26 µg/L (pH 4), 48.31 µg/L (pH 5), 80.34 µg/L (pH 6) and 230.6 µg/L (pH 7), respectively. The present study provides useful information for deriving water quality criteria and assessing the risks of metals in the near future.

The Role of CXCR3 in Neurological Diseases

BACKGROUND

Neurological diseases have become an obvious challenge due to insufficient therapeutic intervention. Therefore, novel drugs for various neurological disorders are in desperate need. Recently, compelling evidence has demonstrated that chemokine receptor CXCR3, which is a G protein-coupled receptor in the CXC chemokine receptor family, may play a pivotal role in the development of neurological diseases. The aim of this review is to provide evidence for the potential of CXCR3 as a therapeutic target for neurological diseases.

METHODS

English journal articles that focused on the invovlement of CXCR3 in neurological diseases were searched via PubMed up to May 2017. Moreover, reference lists from identified articles were included for overviews.

RESULTS

The expression level of CXCR3 in T cells was significantly elevated in several neurological diseases, including multiple sclerosis (MS), glioma, Alzheimer's disease (AD), chronic pain, human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and bipolar disorder. CXCR3 antagonists showed therapeutic effects in these neurological diseases.

CONCLUSION

These studies provided hard evidence that CXCR3 plays a vital role in the pathogenesis of MS, glioma, AD, chronic pain, HAM/TSP and bipolar disorder. CXCR3 is a crucial molecule in neuroinflammatory and neurodegenerative diseases. It regulates the activation of infiltrating cells and resident immune cells. However, the exact functions of CXCR3 in neurological diseases are inconclusive. Thus, it is important to understand the topic of chemokines and the scope of their activity in neurological diseases.

[The role of poloxamer 188 for cord blood mononuclear cells into megakaryocytes cultivation and induction in three-dimensional WAVE Bioreactor]

目的

观察泊洛沙姆188（P188）对体外三维（3D）培养诱导脐血单个核细胞向巨核细胞分化的影响。

方法

将分离的脐血单个核细胞分别接种于细胞瓶和细胞培养袋中，后者采用WIGGENS摇床模拟生物反应器进行3D培养。在巨核细胞诱导培养基中加入P188体外培养14 d，观察细胞形态、计数细胞数并计算细胞存活率，采用流式细胞术观察巨核细胞表面标志表达情况。

结果

与采用传统的细胞培养瓶二维（2D）培养诱导巨核细胞相比，2D+P188培养组巨核系CD41⁺、CD41⁺/CD61⁺、CD61⁺细胞数明显增加（P值均<0.01）；在3D培养中加入P188，细胞体积变大，核形状不规则，胞质含紫红色颗粒，细胞分化更接近成熟。2D培养、3D培养及3D+P188培养组组间巨核细胞表面标志CD41、CD41/CD61、CD61表达水平差异有统计学意义（P值均<0.01）。LSD-t检验两两比较显示，与2D培养相比，3D培养诱导巨核细胞存活率及细胞数均降低（P值分别为0.018、0.027），3D+P188培养组细胞数、细胞存活率与2D和3D培养组比较差异均无统计学意义（P值均>0.05）。而3D培养组巨核细胞CD41/CD61表达水平为（36.30±1.27）%，高于2D培养组的（23.95±1.34）%（P=0.002），3D+P188培养组CD41/CD61表达水平更高[（59.45±1.20）%]。

结论

3D培养有利于巨核系祖细胞诱导分化，但细胞存活率低，加入P188，细胞生存状态好，且诱导效率更高。

Minocycline as a promising therapeutic strategy for chronic pain

Chronic pain remains to be a clinical challenge due to insufficient therapeutic strategies. Minocycline is a member of the tetracycline class of antibiotics, which has been used in clinic for decades. It is frequently reported that minocycline may has many non-antibiotic properties, among which is its anti-nociceptive effect. The results from our lab and others suggest that minocycline exerts strong analgesic effect in animal models of chronic pain including visceral pain, chemotherapy-induced periphery neuropathy, periphery injury induced neuropathic pain, diabetic neuropathic pain, spinal cord injury, inflammatory pain and bone cancer pain. In this review, we summarize the mechanisms underlying the analgesic effect of minocycline in preclinical studies. Due to a good safety record when used chronically, minocycline may become a promising therapeutic strategy for chronic pain in clinic.

The Role of Spinal GABAB Receptors in Cancer-Induced Bone Pain in Rats

Cancer-induced bone pain (CIBP) remains a major challenge in advanced cancer patients because of our lack of understanding of its mechanisms. Previous studies have shown the vital role of γ-aminobutyric acid B receptors (GABABRs) in regulating nociception and various neuropathic pain models have shown diminished activity of GABABRs. However, the role of spinal GABABRs in CIBP remains largely unknown. In this study, we investigated the specific cellular mechanisms of GABABRs in the development and maintenance of CIBP in rats. Our behavioral results show that acute as well as chronic intrathecal treatment with baclofen, a GABABR agonist, significantly attenuated CIBP-induced mechanical allodynia and ambulatory pain. The expression levels of GABABRs were significantly decreased in a time-dependent manner and colocalized mostly with neurons and a minority with astrocytes and microglia. Chronic treatment with baclofen restored the expression of GABABRs and markedly inhibited the activation of cyclic adenosine monophosphate (cAMP)-dependent protein kinase and the cAMP-response element-binding protein signaling pathway.

PERSPECTIVE

Our findings provide, to our knowledge, the first evidence that downregulation of GABABRs contribute to the development and maintenance of CIBP and restored diminished GABABRs attenuate CIBP-induced pain behaviors at least partially by inhibiting the protein kinase/cAMP-response element-binding protein signaling pathway. Therefore, spinal GABABR may become a potential therapeutic target for the management of CIBP.

PI3K/Akt Pathway: A Potential Therapeutic Target for Chronic Pain

Chronic pain is among the most disabling and costly disorders, with prevalence ranging from 10% to 55%. However, current therapeutic strategies for chronic pain are unsatisfactory due to our poor understanding of its mechanisms. Thus, novel therapeutic targets need to be found in order to improve these patients' quality of life. PI3K and its downstream Akt are widely expressed in the spinal cord, particularly in the laminae I-IV of the dorsal horn, where nociceptive C and Aδ fibers of primary afferents principally terminate. Recent studies have demonstrated their critical roles in the development and maintenance of chronic pain. In this review, we summarized the roles and mechanisms of PI3K/Akt pathway in the progression of chronic pain through sciatic nerve injury, diabetic neuropathy, spinal cord injury, bone cancer, opioid tolerance, or opioid-induced hyperalgesia.

Targeting glia for bone cancer pain

INTRODUCTION

Bone cancer pain (BCP) remains to be a clinical challenge with limited pharmaceutical interventions. Therefore, novel therapeutic targets for the management of BCP are in desperate need. Recently, a growing body of evidence has suggested that glial cells may play a pivotal role in the pathogenesis of BCP. Areas covered: This review summarizes the recent progress in the understanding of glia in BCP and reveals the potential therapeutic targets in glia for BCP treatment. Expert opinion: Pharmacological interventions inhibiting the activation of glial cells, suppressing glia-derived proinflammatory cytokines, cell surface receptors, and the intracellular signaling pathways may be beneficial for the pain management of advanced cancer patients. However, these pharmacological interventions should not disrupt the normal function of glia cells since they play a vital supportive and protective role in the central nervous system.

Genetic and epigenetic alterations induced by different levels of rye genome integration in wheat recipient

The narrow genetic variation present in common wheat (Triticum aestivum) varieties has greatly restricted the improvement of crop yield in modern breeding systems. Alien addition lines have proven to be an effective means to broaden the genetic diversity of common wheat. Wheat-rye addition lines, which are the direct bridge materials for wheat improvement, have been wildly used to produce new wheat cultivars carrying alien rye germplasm. In this study, we investigated the genetic and epigenetic alterations in two sets of wheat-rye disomic addition lines (1R-7R) and the corresponding triticales. We used expressed sequence tag-simple sequence repeat, amplified fragment length polymorphism, and methylation-sensitive amplification polymorphism analyses to analyze the effects of the introduction of alien chromosomes (either the entire genome or sub-genome) to wheat genetic background. We found obvious and diversiform variations in the genomic primary structure, as well as alterations in the extent and pattern of the genomic DNA methylation of the recipient. Meanwhile, these results also showed that introduction of different rye chromosomes could induce different genetic and epigenetic alterations in its recipient, and the genetic background of the parents is an important factor for genomic and epigenetic variation induced by alien chromosome addition.

Cross-leg repair of large soft-tissue defects in distal sites of the feet by distally based neuro-fasciocutaneous flaps with perforating vessels

The objective of this study was to introduce a method for repairing large soft-tissue defects on the foot. Distally based neuro-fasciocutaneous flaps with perforating vessels were designed along the saphenous and sural neurovascular axes. The cutaneous perforating branches of the major arteries of the lower extremities were used as pedicles, which provided a rotation arc for the cross-leg flap to cover the large-sized soft-tissue defects on the foot. We transferred 6 neurocutaneous vascular axial flaps, including 4 saphenous neurocutaneous axial flaps (ranging from 25 x 13 to 17 x 9 cm in area) with posterior tibial perforators as the pedicle, and 2 sural neurocutaneous axial flaps (ranging from 29 x 12 to 18 x 7 cm in area) supplied by the perforating branches of the peroneal vessels. These 6 cases of neuro-fasciocutaneous flaps survived with satisfactory cosmetic appearances and functional results on follow-up at 8 to 17 months post-surgery. Placing a distally based neuro-fasciocutaneous cross-leg flap with perforating vessels is an effective method for repairing large-sized soft-tissue defects on the foot.

Double-loop locking cross-stitch suture and suspension fixation for medial collateral ligament origin reconstruction

The purpose of this study was to summarize the clinical application and results of the double-loop locking cross-stitch suture and suspension fixation method for medial collateral ligament origin reconstruction. Thirty-six patients (21 males, 15 females) with an average age of 40 years (range = 17-58 years), who underwent treatment for acute fracture of the medial collateral ligament at our hospital from February 2008 to May 2009, were included in this study. All patients presented unilateral injuries (17 right-sided, 19 left-sided) and underwent repair with the double-loop locking cross-stitch suture and suspension fixation method. All incisions in this group of patients healed by first intention. Thirty-two patients were followed up for 6-20 months (average = 12 months). There were no reports of wound infection, ligament re-fracture or other complications in the follow-up period. Based on the Lysholm knee-scoring scale, the patients received a 100% excellent and good rating (20 patients - excellent score, 12 patients - good score) postoperatively. The advantages of the double-loop locking cross-stitch suture and suspension fixation method are a smaller incision, reliable fixation, and early restoration of knee joint stability. It is, therefore, an effective and low-risk method for the reconstruction of medial collateral ligament origin.

First Report of Streptomyces galilaeus Associated with Common Scab in China

During a survey of potato scab pathogens in China from 2003 to 2012, a new pathogen was found in Shanxi and Neimenggu provinces. The incidence was approximately 20% of all recovered strains. The lesions caused by the pathogen were slightly raised and similar to those caused by Streptomyces scabies (3). Lesions were excised (approximately 10 mm³) from 40 infected tubers, surface-disinfested with 0.3% NaOCl for 30 s, rinsed in sterile water three times, cut into 5 mm³, then sliced into 1-mm pieces, and plated on water agar amended with ampicillin (50 μg/ml). Plates were incubated at 28°C in the dark for 4 days. The spores of Streptomyces sp. strains growing from the tuber pieces were collected from single bacterial colonies and cultured on oatmeal agar. To fulfill Koch's postulates, one strain, CPS-2, was grown at 28°C for 10 days and the spores were washed from the plates as inoculum. One hundred milliliters of inoculum (1 × 10⁵ CFU/ml) was mixed with autoclaved soil and vermiculite (1:1) in each pot (15 cm in diameter). Cut tubers were planted in the pots (potato cv. Favorita, one plant per pot, five replicates) and grown under greenhouse conditions (22 ± 5°C). Typical common scab symptoms consisting of small, brown, raised lesions developed on potato tubers 12 weeks after planting. The same strain was re-isolated from the lesions of the new scabby tubers. Non-inoculated plants, treated as described above, but without strain CPS-2, remained healthy. The CPS-2 strain was identified based on morphological and physiological characterization and 16S rDNA sequence. On yeast-malt extract agar, the test strain produced grayish-white aerial hypha, reddish brown substrate mycelium and pigments, and loose spiral spore chains. Spores were smooth and were 0.8 to 0.9 × 1.1 to 1.2 μm in size (diameter and length). The ability of the strain to use single sources of carbon and nitrogen was verified according to the International Streptomyces project (4). The strain grew in media supplemented with L-arabinose, D-fructose, D-glucose, rhamnose, raffinose, meso-inositol, sucrose, and D-xylose, but not D-mannitol. It used L-hydroxyproline, L-methionine, and L-histidine, and produced melanin on tyrosine and peptone yeast extract agar. The strain did not grow at a pH less than 5.0 and was sensitive to streptomycin (20 μg/ml), phenol (0.1%), and crystal violet (0.5 μg/mL), but not to penicillin (10 IU/ml). The strain also produced hydrogen sulfide. The biological characteristics of strain CPS-2 were in accord with Streptomyces galilaeus. CPS-2 produced thaxtomin A in oatmeal liquid medium and the txt AB gene fragment was successfully amplified using specific primers (2). The 16S rDNA sequence of CPS-2 was amplified by PCR with primers 16S1-F: 5'-CATTCACGGAGAGTTTGATCC-3' and 16S1-R: 5'-AGAAAGGAGGTGATCCAGCC-3' (1) and sequenced. A BLAST search of the 16S rDNA sequence for CPS-2 was conducted using the NCBI GenBank database, resulting in 99.8% similarity to S. galilaeus (NR_040857). The 16S rDNA sequence for CPS-2 (1,388 bp) was deposited in GenBank (AY621378). To our knowledge, this is the first report of S. galilaeus causing common scab of potato in China. References: (1) R. A. Bukhalid et al. Appl. Environ. Microbiol. 68:738, 2002. (2) R. Flores-González et al. Plant Pathol. 57:162, 2008. (3) D. H. Lambert and R. Loria. Int. J. Syst. Bacteriol. 39:387, 1989. (4) E. B. Shirling and D. Gottlieb. Int. J. Syst. Bacteriol. 16:313, 1966.

First Report of Alternaria alternata Causing Blight on Zanthoxylum piperitum in China

Since 2009, brown leaf spot and panicle blight of Zanthoxylum piperitum (L.) DC. ("liujin," commonly known as Japanese pepper and Japanese pricklyash) has been observed on 40% of the plants in the test field of Foresty Academy of Science in Hebei Province of China. When symptoms formed on leaves, a thick yellow spot appeared, which then turned brown. When on the spikes, brown lesions were observed initially on the grain, which then spread down to fruit stem, and finally the whole spike wilted and dried up. Yield and quality losses were considerable. A fungus was isolated consistently from the diseased tissues using potato dextrose agar (PDA) (1). Three representative isolates were chosen for further characterization. All the isolates grew at 28°C on PDA and potato carrot agar (PCA) medium. Fungal colonies were initially white, then became olivaceous with some white mycelium on the top of the colony, and turned brown with age. When observed with the microscope, crineous septate hypha appeared, and conidiophore peduncles were upright or slightly curved, with a few branches, 33.0 to 75.0 μm long and 4.0 to 5.5 μm wide. Conidia were crineous short clubs or near oval in shape, 22.5 to 40.0 μm long and 8.0 to 13.5 μm wide, with a short conical beak, and had one to four longitudinal cross walls. On PCA, condia had three to seven transepta and one to five longisepta, and were produced in a branched, long chain with more than five conidia. The pathogen was identified based on morphological characteristics as Alternaria alternata (Fr.:Fr.) Keissl. (3). DNA was extracted from mycelium and PCR was performed on the internal transcribed spacer (ITS) region with primers ITS1 and ITS4. A 570-bp fragment was amplified and sequenced (GenBank Accession No. JQ973810). BLASTn analysis revealed there was 100% sequence identity with A. alternata strains (GU566303 and GQ121322). To further identify the fungus, A. alternata species-specific primers AAF2/AAR3 (2) were used to generate an amplicon which was then sequenced (JX308287). Sequence comparison showed there was 100% sequence identity with A. alternata (JQ927300 and JQ907485). Pathogenicity tests were performed by spraying with a cultured suspension (10⁶ spores/ml) of approximately 100 μl onto healthy leaves in 15-cm-diameter glass dishes containing sterilized filter paper soaked with sterilized water at room temperature. Control plants were inoculated with sterile distilled water. Ten days after inoculation, symptoms were observed in all inoculated leaves and appeared to be identical to those observed in the field. No symptoms were noted on the control leaves. Identical results were also obtained when spikes were inoculated. The fungi reisolated from symptomatic plants were A. alternata. To our knowledge, this is the first report of A. alternata causing leaf spots and panicle blight of Z. piperitum in China. References: (1) O. D. Dhingra and J. B. Sinclair. Basic Plant Pathology Methods. CRC Press, Boca Raton, FL, 1995. (2) P. Konstantinova. et al. Mycol. Res. 106:23, 2002. (3) T. Y. Zhang. China fungi records (Alternaria) (Volume 16) (in Chinese). Beijing: Science Press, 2003.

First Report of Peanut Pod Rot Caused by Neocosmospora vasinfecta in Northern China

From 2006 to 2010, peanut (Arachis hypogaea) pod rot became more prevalent in northern China, especially in the Sha River drainage area. The incidence of pod rot ranged from 30 to 100%. Typical symptoms were black rot of the pods, but no obvious morphological abnormality of the aboveground parts of infected plants was observed. Brown or black spots appeared on many pods when initially infected and then all peanut pods became black and rotten. The same fungus was isolated from 54 surface-disinfested lesions (85.2% of all lesions) on potato dextrose agar (PDA) media. One isolate, designated as HBXLb, was chosen for further characterization. In culture, both anamorph and teleomorph were present. Mycelia of the fungus grew quickly (colonies were 3.2 cm in diameter in 3 days) and became white and floccose on PDA at 28°C. The hyaline, elongated-to-cylindrical conidia aggregated on the slimy heads of conidiogenous cells that developed on undifferentiated hyphae after incubation for 3 to 4 days. Conidial sizes varied from 5 to 10 × 1.5 to 3 μm (n = 50) and were mostly single celled. Some conidia appeared slightly curved. The morphology was consistent with Acremonium spp. Numerous ascomata (perithecia) formed within 10 to 14 days when incubated at 28°C under light and dark conditions. Perithecia were orange-brown, strawberry shaped (300 to 400 μm in diameter), and ostiolate on the top. Cylindrical asci, with an average size of 90 to 110 × 7.5 to 9 μm, were present inside the ascomata with each containing eight ascospores in a row. The ascospores were brownish, spherical to ellipsoidal, and 10 to 15 × 8 to 12 μm. The cultural and morphological characteristics of isolate HBXLb matched the description of N. vasinfecta (2). The internal transcribed spacer (ITS) region of rDNA was amplified by the primer pairs ITS4/ITS5. A 525-bp amplicon (ITS4-5.8s-ITS5) was obtained and sequenced (GenBank Accession No. HM461901). The ITS sequence was a 100% match to N. vasinfecta strain N-JXLN01 (GenBank Accession No. GU213063) by BLASTn in GenBank. Pathogenicity tests were conducted on detached pods of peanut cultivar Jihua 4. Forty surface-disinfested peanut pods were soaked in a conidial suspension (10⁵ conidia per ml) for 2 min and 40 pods were soaked in sterile water as a control. Then all peanut pods were maintained in moist petri dishes under darkness for 14 days at 28°C. Brown or black spots appeared on all pods inoculated with the fungus within 10 days, while the controls remained healthy. Symptoms were similar to those originally observed in the field, and N. vasinfecta could be reisolated from all infected pods. This fungus previously has been reported as the pathogen of foot rot of peanut in South Africa (1), Taiwan (4), and Australia (3). To our knowledge, this is the first report of peanut pod rot caused by N. vasinfecta in China. References: (1) S. W. Baard et al. Phytophylactica 17:49, 1985. (2) O. A. Cornely et al. Emerg. Infect. Dis. 7:149, 2001. (3) M. F. Fuhlbohm et al. Australas. Plant Dis. Notes 2:3, 2007. (4) J. W. Huang et al. Plant Pathol. Bull. 1:203, 1992.

First Report of Neocosmospora striata Causing Peanut Pod Rot in China

In 2008, an outbreak of pod rot of peanut (Arachis hypogaea L.) occurred on most of the peanut cultivars in the Old Yellow River drainage area, the largest peanut-growing region in China. Disease incidence reached as high as 90% in some fields, causing severe yield losses. The black rot of pods and blackened, nonrotting taproots is similar to symptoms of peanut black rot caused by Cylindrocladium parasiticum, but the reddish orange perithecia of C. parasiticum were not found on the taproots close to the surface of the soil. The foliage of affected plants was generally asymptomatic, but some plants turned greener. This pod rot disease was further investigated in 2008 and 2010. Twenty-three Fusarium-like isolates were obtained from symptomatic, surface-disinfested pods with a frequency of 82%. These isolates were fast growing, with flat, thin, and grayish white colonies when cultured on potato dextrose agar (PDA) at 28°C for 3 to 4 days. The hyaline, elongated to cylindrical conidia, aggregated in slimy heads on conidiogenous cells developed from undifferentiated hyphae when observed with the light microscope. The size of conidia (single celled or one septum) varied from 3 to 9 μm long and 1.5 to 3.5 μm wide on the basis of the measurement of 50 spores. Some conidia appeared slightly curved. Ascomata formed within 10 to 14 days, with a punctate appearance on the colony. The cerebriform ascomata were dark brown, pyriform, ostiolate, glabrous, 120 to 170 × 90 to 130 μm, and with necks 30 to 50 μm long. Asci measured 60 to 90 × 6 to 10 μm, were cylindrical to cylindric-clavate, thin walled, and had an apical ring. Ascospore arrangement was obliquely uniseriate or partially biseriate, very pale yellow to hyaline, ellipsoidal, and measured 8 to 12 × 4.5 to 6 μm. Some spores had a median transverse straight or curved septum and were slightly constricted at the septum, with 6 to 10 thin, transverse, hyaline flanges. Morphological characteristics of the isolates with ascomata dark brown and ascospores with 6 to 10 transverse hyaline flanges matched the description for Neocosmospora striata (1). The internal transcribed spacer (ITS) region of rDNA was amplified from extracted template DNA with primer pairs ITS4/ITS5 and sequenced. A 591-bp amplicon (GenBank Accession No. HM461900) had 99% sequence identity with Fusarium solani (HQ607968 and HQ608009) and N. vasinfecta (GU213063), which indicated that these fungi belong to the genus Neocosmospora or Fusarium, although there is no direct sequence evidence that they are N. striata. N. striata has only been previously reported in Japan (2). This species is unique because of the dark brown ascomata and there is no comparable species (1). Koch's postulates were completed by surface-disinfesting 80 peanut pods of cv. Jihua 9813 and soaking them in conidial suspensions (10⁵ conidia/ml) for 2 min. Another 80 other pods soaked in sterile water served as controls. All peanuts were incubated in moist petri dishes under darkness at 28°C. Symptoms similar to those originally observed in the field formed within 10 days on all inoculated peanut pods and not the controls. N. striata was reisolated from all affected peanut pods. To our knowledge, this is first report of N. striata causing peanut pod rot in China and the first description of the anamorph of the fungus. References: (1) P. F. Cannon et al. Trans. Br. Mycol. Soc. 82:673, 1984. (2) S. Udagawa et al. Trans. Mycol. Soc. Jpn. 16:340, 1975.

Seedling and Slow Rusting Resistance to Leaf Rust in Chinese Wheat Cultivars

Identification of resistance genes is important for developing leaf rust resistant wheat (Triticum aestivum) cultivars. A total of 102 Chinese winter wheat cultivars and advanced lines were inoculated with 24 pathotypes of Puccinia triticina for postulation of leaf rust resistance genes effective at the seedling stage. These genotypes were also planted in the field for characterization of slow rusting responses to leaf rust in the 2006-07 and 2007-08 cropping seasons. Fourteen leaf rust resistance genes-Lr1, Lr2a, Lr3bg, Lr3ka, Lr14a, Lr16, Lr17a, Lr18, Lr20, Lr23, Lr24, Lr26, Lr34, and LrZH84-either singly or in combinations, were postulated in 65 genotypes, whereas known resistance genes were not identified in the other 37 accessions. Resistance gene Lr26 was present in 44 accessions. Genes Lr14a and Lr34 were each detected in seven entries. Lr1 and Lr3ka were each found in six cultivars, and five lines possessed Lr16. Lr17a and Lr18 were each identified in four lines. Three cultivars were postulated to possess Lr3bg. Genes Lr20, Lr24, and LrZH84 were each present in two cultivars. Each of the genes Lr2a and Lr23 may exist in one line. Fourteen genotypes showed slow leaf rusting resistance in two cropping seasons.

Visfatin stimulates production of monocyte chemotactic protein-1 and interleukin-6 in human vein umbilical endothelial cells

Monocyte chemotactic protein-1 and interleukin-6 are important inflammatory cytokines, which have close relationships with atherosclerosis. Visfatin is a novel adipokine involved in regulation of inflammatory cytokines, however, associations of visfatin with cytokines (MCP-1, IL-6) in human umbilical vein endothelial cells are unclear. The aim of this study was to determine whether visfatin has effects on the expression of MCP-1 and IL-6 in human umbilical vein endothelial cells. Enzyme-linked immunosorbent assay were used for measuring MCP-1 and IL-6 production in human umbilical vein endothelial cells. Real-time quantitative reverse-transcription polymerase chain reaction was used for determining MCP-1 and IL-6 mRNA expression. For the pathway determination following inhibitors were used: wortmannin [phosphatiylinositol 3-kinase (PI3K)], SB203580 [p38 mitogen-activated protein kinase (MAPK)], PD98059 [extracellular signal-regulated kinase (ERK) 1/2)], JNK inhibitor II [c-Jun NH 2-terminal kinase (JNK)]. We demonstrated that visfatin could obviously upregulate secretion of MCP-1and IL-6 in a dose- and time-dependent manner in human umbilical vein endothelial cells. Visfatin-induced effects were diminished by SB203580, wortmannin, and PD98059. In summary, these results suggest that visfatin-induced MCP-1 and IL-6 production involve p38 MAPK, PI3K, and ERK 1/2 pathways in human umbilical vein endothelial cells as determined by inhibition with specific inhibitors.

First Report of Potato Scab Caused by Streptomyces turgidiscabies in China

Potato scab, caused by several plant pathogenic Streptomyces species, is known to occur in potato-planting areas worldwide. Symptoms of disease on potato tubers are shallow, raised, or pitted corky lesions (2). In 1998, Streptomyces turgidiscabies was reported as a new potato scab pathogen from Hokkaido, Japan (3). Potato scab has been observed in many potato-cultivation areas in China and incidence of the disease was approximately 6 to 10% in some fields in 2006 (in our survey). To investigate the casual agent of scab disease, isolations were made from scabby potato tubers collected from different areas using oatmeal agar. Identification of an isolate from Shaanxi Province was based on morphological and physiological characterization followed by 16S rRNA confirmation. Characteristics were gray, aerial hypha, rectiflexuous spore chains, a smooth spore surface, and spores that were 0.5 to 0.7 × 1.0 to 1.2 μm. The strain did not produce melanin on tyrosine-peptone-yeast extract agar media, did not produce diffusible pigments, used all the International Streptomyces Project (ISP) sugars (4) as single carbon sources, used l-hydroxyproline, l-tyrosine, and l-histidine as single nitrogen sources but not l-methionine, grew at pH 4.5, was susceptible to streptomycin (20 μg ml^-1), phenol (0.1%), and penicillin (10 IU ml^-1) but not to crystal violet (0.5 μg ml^-1), and produced H₂S. The identification was confirmed by comparison of its 16S rRNA sequence with the GenBank database using the BLAST program. The 16S rRNA sequence was amplified by PCR with primers S1: 5'-CATTCACGGAGAGTTTGATCC-3' and S2: 5'-AGAAAGGAGGTGATCCAGCC-3' and sequenced. BLASTn analysis of the sequence obtained showed the highest similarity (99.9%) with S. turgidiscabies type strain ATCC 700248 (GenBank Accession No. AB026221). The sequence was submitted to GenBank (Accession No. AM889495). Pathogenicity of the strain was tested in the greenhouse on potato tubers of cv. Favorita grown in pots (one plant per pot, three replicates). One hundred milliliters of inoculum (1 × 10⁵ CFU ml^-1) of the strain was mixed with sterile soil and vermiculite (1:1) in each pot. Potato plants were grown at 25°C and the soil was allowed to dry between waterings. The immature potato tubers were used to evaluate scab symptoms 10 weeks after planting. All tubers inoculated with the pathogen developed typical common scab symptoms consisting of erumpent, brown, corky lesions, which is different from the symptoms caused by S. reticuliscabiei (1). The noninoculated control tubers did not show scab symptoms. S. turgidiscabies was reisolated from lesions of diseased immature tubers. The pathogenicity test indicates that S. turgidiscabies caused scab disease on potato tubers. To our knowledge, this is the first report of S. turgidiscabies causing potato scab disease in China. References: (1) K. Bouchek-Mechiche et al. Int. J. Syst. Evol. Microbiol. 56:2771, 2006. (2) R. Loria et al. Plant Dis. 81:836, 1997. (3) K. Miyajima et al. Int. J. Syst. Bacteriol. 48:495, 1998. (4) E. B. Shirling and D. Gottlieb. Int. J. Syst. Bacteriol. 16:313, 1966.

Molecular mapping of leaf rust resistance gene LrZH84 in Chinese wheat line Zhou 8425B

Leaf rust, caused by Puccinia triticina, is one of the most widespread diseases in common wheat (Triticum aestivum L.) worldwide. With the objective of identifying and mapping new genes for resistance to leaf rust, F(1), F(2) plants and F(3) lines from a cross between resistant line Zhou 8425B and susceptible line Chinese Spring were inoculated with Chinese P. triticina races THTT and MBHP in the greenhouse. A total of 793 pairs of SSR primers were used to test the parents and resistant and susceptible bulks. Seven polymorphic chromosome 1B markers were used for genotyping the F(2) and F(3) populations. Zhou 8425B carried a single dominant resistance gene, temporarily designated LrZH84, linked to SSR markers gwm582 and barc8 with genetic distances of 3.9 and 5.2 cM, respectively. The Xbarc8 allele co-segregated with Lr26 in the F(3) population. The Xgwm582 allele associated with LrZH84 was identified as a leaf rust resistance gene and shown to be present in the Predgornaia 2 parent of Zhou 8425B. The seedling reaction pattern of LrZH84 was different from those of lines with Lr26, Lr33, Lr44 and Lr46, all of which are located in chromosome 1B. It was concluded that LrZH84 is likely to be a new leaf rust resistance gene.

First Report of Cercospora concors Causing Cercospora Leaf Blotch of Potato in Inner Mongolia, North China

Cercospora leaf blotch disease of potato (Solanum tuberosum L.) caused by Cercospora concors (Casp.) Sacc (synonym Mycovellosiella concors (Casp.) Deighton) occurs worldwide but mainly has been reported in the cool and temperate climates of Europe, Asia, North America, and eastern Africa. Cercospora leaf blotch is usually a minor disease and may go unnoticed since it commonly occurs simultaneously with other potato leaf diseases such as late blight (caused by Phytophthora infestans) and early blight (caused by Alternaria solani) (2). Symptoms of Cercospora leaf blotch first appear on lower leaves as small, yellowish green, irregular blotches and later may appear on middle and upper leaves. As the leaves expand, the blotches enlarge and become purplish brown or black. Conidiophores and conidia form on the underside of the lesions, giving the lesions a mildewed appearance similar to late blight. Necrotic lesions are distinguished from those caused by the early blight pathogen A. solani by the lack of concentric rings (1). In more severe epidemics of Cercospora leaf blotch, potato leaves may be killed, stem lesions become dark and entire plants die, but no resulting yield loss from the disease has been documented. Potato tubers are not infected. From August to September of 2005, yellow-brown lesions appeared on the upper side of potato leaves (cv. Zihuabai, certified virus free) and gray mildew developed on the underside of leaves in potato field trials conducted in Jining County, 41°N, 113°E of Inner Mongolia, North China. The infections were observed mostly on lower and middle leaves of plants; 20 to 30% of plants were infected. In the laboratory, the mildew was scraped with a sterile scalpel and examined microscopically. The conidiophores were irregular in width, grayish, and highly branched. The conidia were numerous, light to dark, straight or slightly bent, cylindrical or obclavate, with conspicuous scars, and zero to six septa. The mature spores were from 16 to 59 μm long and 4 to 6 μm wide. The teleomorph of the fungus was not found. On the basis of the morphological characters, the causal agent was identified as C. concors. C. concors has been previously identified from potato leaves in the Engshi District of Hubei Province, China (3), but to our knowledge, this is the first report of the fungus causing Cercospora leaf blotch of potato in Inner Mongolia, North China. References: (1) G. D. Franc and B. I. Christ. Page 22 in: Compendium of Potato Diseases. 2nd ed. W. R. Stevenson et al., eds. American Phytopathological Society, St. Paul, MN, 2001. (2) E. R. French. Page 19 in: Compendium of Potato Diseases. 2nd ed. W. R. Stevenson et al., eds. American Phytopathological Society, St. Paul, MN, 2001. (3) S. M. Tian et al. China Potato J. 1:13, 1997.

Gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9 in rat brain after implantation of 9L rat glioma cells

The matrix metalloproteinases (MMPs) have come to be highlighted by their close relation to the cell invasion of gliomas. The inhibitors of MMPs have undergone extensive development because of its effectiveness against tumor invasion and angiogenesis. Therefore, a suitable animal model is necessary for searching new MMPs inhibitors against gliomas. In this study, we established an experimental model by implanting 9L glioma cells stereotactically into Fisher344 (F344) rat's brain, and the expression and enzymatic activity of MMP-2 and MMP-9 in 9L glioma cells and in tumor tissue was determined by means of reverse transcription polymerase chain reaction (RT-PCR), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) zymography, in situ film zymography and immunostaining. The results of RT-PCR showed that the mRNA level of MMP-2 in 9L glioma cells was higher than that of MMP-9, and the mRNA expression of MMP-9 was increased along with the growth of malignant gliomas. SDS-PAGE zymography revealed that the expression of MMP-2 and MMP-9 were significantly increased in tumor tissues, and the MMP-9 wasn't detected in normal tissue. The positive stain of MMP-2 and MMP-9 was enhanced with the growth of malignant gliomas, especially for MMP-9. The expression of active gelatinase was found in tumor tissue. In conclusion, the expression of active MMP-2 and MMP-9 was increased in 9L/F344 rat brain during the growth of malignant gliomas at different time intervals, which indicate that 9L/F344 animal model may be a prospective animal model to test new MMPs inhibitors.

Site-directed mutagenesis of gentisate 1,2-dioxygenases from Klebsiella pneumoniae M5a1 and Ralstonia sp. strain U2

Gentisate 1,2-dioxygenase (GDO, EC 1.13.11.4) is the first enzyme in gentisate pathway that catalyses the ring fission of gentisate to form maleylpyruvate. Phylogenetic tree of amino acid sequences from 11 GDOs demonstrates that the GDOs from different genus share identities between 12.1% and 64.8%. According to the alignment result, four highly conserved histidine residues in GDO from Klebsiella pneumoniae M5a1 and Ralstonia sp. strain U2 were chosen to be substituted with aspartate residues. Enzyme analysis indicated that substitution of any of these four histidine residues had resulted in the complete loss of its catalytic activity.

Recent progress in improving low-temperature stability of infrared thin-film interference filters

The degeneration of performance of an optical thin-film interference filter associated with the change of temperature is not acceptable. In this letter, we report a new progress in improving low-temperature performance of infrared narrow-band filters by using Pb(1-x)Ge(x)Te initial bulk alloy with appropriate Ge concentration x. It can be found that there exists a critical temperature for the investigated narrow-band filter, at which the temperature coefficient of filter is exactly zero. Therefore, by means of controlling the composition in (Pb(1-x)Ge(x))(1-y)Te(y) layers, the temperature coefficient of filter can be tunable at the designated low-temperature. In our present investigation, when temperature varies from 300 to 85 K, a shift of peak wavelength of 0.05935 nm.K-1 has been achieved.

Arg169 is essential for catalytic activity of 3-hydroxybenzoate 6-hydroxylase from Klebsiella pneumoniae M5a1

3-Hydroxybenzoate 6-hydroxylase from Klebsiella pneumoniae M5a1 is an enzyme that utilizes 3-hydroxybenzoate (3-HBA) as substrate yielding gentisate. Site-directed mutagenesis was carried out to define which residues may be involved in catalytic reaction. Substitution of arginine to glutamate at position 169 of the enzyme resulted in the complete loss of catalytic activity. This indicated Arg169 may play an important role in 3-HBA 6-hydroxylase catalysis.

Effects of the silanized mica surface on protein crystallization

A freshly cleaved mica surface silanized by 3-aminopropyl triethoxysilane is flat over a large area, displays a controlled degree of hydrophobicity and contains positive charges. In this paper, mica sheets silanized by this method have been used as crystallization surfaces for lysozyme, trichosanthin and three other proteins of unknown structure. Crystallization experiments have been carried out by the hanging-drop vapour-diffusion technique and the results indicate that the silanized mica surface can ameliorate the protein crystallization process considerably compared with a silanized glass cover slip control. For lysozyme on the silanized mica surface, the induction time required for crystal growth decreases markedly. For trichosanthin, the crystal size is obviously larger and the number of crystals grown is much lower. For the three proteins of unknown structure, the diffraction ability of the crystals is improved considerably.

Metabolism and disposition of gemfibrozil in Wistar and multidrug resistance-associated protein 2-deficient TR- rats

1. The roles of multidrug resistance-associated protein (Mrp) 2 deficiency and Mrp3 up-regulation were evaluated on the metabolism and disposition of gemfibrozil. 2. Results from in vitro studies in microsomes showed that the hepatic intrinsic clearance (CLint) for the oxidative metabolism of gemfibrozil was slightly higher (1.5-fold) in male TR- rats, which are deficient in Mrp2, than in wild-type Wistar rats, whereas CLint for glucuronidation was similar in both strains. 3. The biliary excretion of intravenously administered [14C]gemfibrozil was significantly impaired in TR-) rats compared with Wistar rats (22 versus 93% of the dose excreted as the acyl glucuronides over 72 h). Additionally, the extent of urinary excretion of radioactivity was much higher in TR- than in Wistar rats (78 versus 2.6% of the dose). 4. There were complex time-dependent changes in the total radioactivity levels and metabolite profiles in plasma, liver and kidney, some of which appeared to be related to the up-regulation of Mrp3. 5. Overall, it was demonstrated that alterations in the expression of the transporters Mrp2 and Mrp3 significantly affected the excretion as well as the secondary metabolism and distribution of [14C]gemfibrozil.