[Correlation between acupoint sensitization of body surface and pituitary adenylate cyclase activating polypeptide expression in myocardial ischemia mice]. / å¿ƒè‚Œç¼ºè¡€å°é¼ ä½“è¡¨ç©´ä½æ•åŒ–ä¸Žåž‚ä½“è ºè‹·é ¸çŽ¯åŒ–é ¶æ¿€æ´»å¤šè‚½çš„å ³ç³»ç ”ç©¶.

OBJECTIVES: To explore the relationship between sensitization points of the body surface and the expression of pituitary adenylate cyclase activating polypeptides (PACAP) in myocardial ischemia (MI) mice, so as to reveal the underlying mechanisms of acupoint sensitization from the perspective of molecular biology. METHODS: Male C57BL/6J mice were randomly divided into control and model groups (28 mice/group). The MI-induced visceral pain model was established by intraperitoneal injection of isoprenaline (ISO, 160 mg/kg). The mice of the control group received intraperitoneal injection of the same dose of normal saline. Six days after modeling, the Evans blue (EB) dye was injected into the tail vein of mice to observe the distribution and quantity of the plasma extravasated EB points at the body surface. Meanwhile, the mechanical pain threshold (MPT) was measured to evaluate the level of pain sensitivity in the activated area on their body surface and left forelimb and hindlimb, respectively. Hematoxylin-eosin (H.E.) staining was used to evaluate the morphologic and pathological changes of the heart tissue in the two groups. Then, the expressions of PACAP in the thoracic (T)1-T5 dorsal root ganglia (DRGs), spinal cord and skin in the dominant area of body surface were detected by Western blot and immunofluorescence staining, respectively. RESULTS: Compared with the control group, the heart tissue of the model group was hypertrophic and the myocardial tissue showed obvious inflammatory cell infiltration and fibrosis. In addition to these pathologic changes, the number of EB exudation points on the body surface was significantly increased (P<0.01), and was mainly distributed in the innervated region of T1-T5 segments of the spinal cord, and the MPT of these EB exudation points was lower than that of non-exudation points (P<0.01). At the same time, the MPTs of left forelimb and hindlimb were significantly decreased in the model group (P<0.001). More importantly, the level of protein and positive expression of PACAP were significantly higher in the model group than those in the control group, which was observed in the innervated body surface, spinal cord and its DRG neurons of T1-T5 segments (P<0.01, P<0.001, P<0.05). CONCLUSIONS: ISO injection resulted in histological lesions and cardiogenic referred pain on the body surface after the formation of MI in mice. The expression of PACAP in the body surface of the sensitization points, the corresponding T1-T5 segments of spinal cord and DRG neurons were significantly increased, which may partly explain the reason for acupoint sensitization in the animal model of visceral pain.

Acupuncture and related acupoint therapies for smoking cessation: An umbrella review and updated meta-analysis.

INTRODUCTION: Acupuncture and related acupoint therapies have been widely used for smoking cessation. Some relevant systematic reviews (SRs) have been published. There is a need to summarize and update the evidence to inform practice and decision-making. METHODS: Eight databases were searched from their inception to December 2023. SRs, any randomized controlled trials (RCTs) comparing acupuncture therapies with sham acupuncture, pharmacotherapy, behavioral therapy, or no treatment, were included. The primary outcome was the abstinence rate. AMSTAR-2 was employed to assess the quality of SRs. An updated meta-analysis was conducted based on SRs and RCTs. Data were synthesized using risk ratios (RR) with 95% confidence intervals (CIs). The GRADE approach was employed to assess the certainty of the updated evidence. RESULTS: Thirteen SRs and 20 RCTs outside of the SRs were identified. The SRs were of low or very low quality by AMSTAR-2. Sixteen (80%) RCTs were at high risk of performance bias. Eight acupuncture and related acupoint therapies were involved. The short-term (≤6 months) abstinence rate outcome was summarized as follows. Most SRs suggested that filiform needle acupuncture or acupressure had a better effect than sham acupuncture, but the findings were inconsistent. The updated meta-analysis also suggested that filiform needle acupuncture was more effective than sham acupuncture (RR=1.44; 95% CI: 1.02-2.02; I2 = 66%; low certainty; 9 RCTs, n=1358). Filiform needle acupuncture combined with acupressure was comparable to nicotine patches (RR=0.99; 95% CI: 0.74-1.32; low certainty; 6 RCTs, n= 524). Acupressure was superior to counseling (RR=1.46; 95% CI: 1.14-1.87; I2=5%; low certainty; 8 RCTs, n=595). No serious adverse events were reported in these SRs or RCTs. CONCLUSIONS: Low certainty evidence suggests that filiform needle acupuncture and auricular acupressure appear to be safe and effective in achieving short-term smoking cessation. However, long-term follow-up data are needed.

Zn-Shik-PEG nanoparticles alleviate inflammation and multi-organ damage in sepsis.

Sepsis is defined as a life-threatening organ dysfunction caused by excessive formation of reactive oxygen species (ROS) and dysregulated inflammatory response. Previous studies have reported that shikonin (Shik) possess prominent anti-inflammatory and antioxidant effects and holds promise as a potential therapeutic drug for sepsis. However, the poor water solubility and the relatively high toxicity of shikonin hamper its clinical application. To address this challenge, we constructed Zn2+-shikonin nanoparticles, hereafter Zn-Shik-PEG NPs, based on an organic-inorganic hybridization strategy of metal-polyphenol coordination to improve the aqueous solubility and biosafety of shikonin. Mechanistic studies suggest that Zn-Shik-PEG NPs could effectively clear intracellular ROS via regulating the Nrf2/HO-1 pathway, meanwhile Zn-Shik-PEG NPs could inhibit NLRP3 inflammasome-mediated activation of inflammation and apoptosis by regulating the AMPK/SIRT1 pathway. As a result, the Zn-Shik-PEG NPs demonstrated excellent therapeutic efficacies in lipopolysaccharide (LPS) as well as cecal ligation puncture (CLP) induced sepsis model. These findings suggest that Zn-Shik-PEG NPs may have therapeutic potential for the treatment of other ROS-associated and inflammatory diseases.

Disruption of IDO signaling pathway alleviates chronic unpredictable mild stress-induced depression-like behaviors and tumor progression in mice with breast cancer.

Women with breast cancer (BC) are often combined with psychological disorder such as depression and anxiety. Depression is associated or correlated with increased toxicity and severity of physical symptoms. However, the mechanism of BC progression related to the regulation of emotion-related circuitry remains to be further explored. The study aims to investigate indoleamine 2,3-dioxygenase (IDO) pathway mechanism underlying stress-induced progression of BC. BC cell line 4T1 was subcutaneously inoculated into BALB/c mice, and they then received daily chronic unpredictable mild stressors (CUMS) for 12 weeks. Depression-like behavior tests were conducted, including sucrose preference test (SPT), tail suspension test (TST), forced swimming test (FST), and novelty suppressed feeding test (NSF). The levels of 5-Hydroxytryptamine (5-HT) and inflammatory factors, IL-6, CXCL1, IL-10 and IL-4 were measured by enzyme linked immunosorbent assay (ELISA) of mouse serum. Immunohistochemical staining was performed to detect Ki67- or FOXP3-positive tumor cells. The status of IDO signaling pathway was assessed by immunoblotting analysis. CUMS induced depression-like behaviors, decreased the level of 5-HT, promoted tumor progression, enhanced the immunohistochemical staining of Ki-67, and promoted the activation of IDO signaling pathway in BC mice. The IDO signaling pathway was disrupted in mice by lentiviral transduction of shRAN-IDO. Lentivirus-mediated IDO knockdown attenuated CUMS-induced depression-like behaviors, increased the level of 5-HT, inhibited tumor progression, and reduced the immunohistochemical staining of Ki-67 in BC mice. The present study suggests that disruption of IDO signaling pathway alleviates CUMS-induced depression-like behaviors and inhibits tumor progression in BC mice.

[Effects of early electroacupuncture on the expression of Iba-1 and TNF-α in Parkinson's disease mice].

OBJECTIVE: To observe the effect of early electroacupuncture(EA) intervention on ionized calcium binding adapter molecule 1 (Iba-1), tyrosine hydroxylase (TH) and tumor necrosis factor-α (TNF-α) in Parkinson's disease (PD) mice, so as to explore its neuroinflammation mechanism in treating PD. METHODS: A total of 24 male C57BL/6J mice (9 weeks old) were randomly divided into control, model and EA groups, with 8 mice in each group. The PD model was established by long-term low dose subcutaneous injection of rotenone. Started at the same time with modeling, EA (2 Hz/100 Hz, 1 mA) was applied to "Shenting"(GV24), bilateral "Tianshu"(LI11), "Quchi"(ST25), and "Shangjuxu"(ST37) for 15 min, once a day for 8 weeks. The motor function was assessed by rotorod test and step length test. The expression levels of Iba-1 and TH proteins in substantia nigra pars compacta (SNpc) was detected by Western blot and immunohistochemistry. The expression level of TNF-α protein in colon tissue was examined by Western blot and immunofluorescence staining. RESULTS: Compared with the control group, the fall latency shortened at 4, 6, and 8 weeks after modeling (P<0.01) and the step length of hind limbs shortened at 5 and 7 weeks after modeling (P<0.01), the expression levels of Iba-1 in SNpc and TNF-α in colon tissue were increased (P<0.01), and the expression level of TH in SNpc was decreased (P<0.01) in the model group. Compared with the model group, the fall latency prolonged at 6 and 8 weeks after modeling (P<0.01) and the step length of hind limbs prolonged at 5 and 7 weeks after modeling (P<0.01), the expression levels of Iba-1 in SNpc and TNF-α in colon tissue were decreased (P<0.01, P<0.05), and the expression level of TH in SNpc was increased (P<0.05, P<0.01) in the EA group. CONCLUSION: Early EA intervention can delay the occurring time of motor disfunction, alleviated the loss of substantia nigra dopaminergic neurons, and exerted a good neuroprotective effect on the degenerative changes in rotenone-induced PD mice, which may be related to its effects in alleviating the intestinal inflammation, inhibiting the activation of microglia, thereby reducing the neuroinflammation.

Review of bioactivity and structure-activity relationship on baicalein (5,6,7-trihydroxyflavone) and wogonin (5,7-dihydroxy-8-methoxyflavone) derivatives: Structural modifications inspired from flavonoids in Scutellaria baicalensis.

Baicalein (5,6,7-trihydroxyflavone) and wogonin (5,7-dihydroxy-8-methoxyflavone), as typical flavonoids isolated from Scutellaria baicalensis, are well important precursors in drug discovery which produce diverse therapeutically related applications in pharmacological practices. Researches in medicinal chemistry field have synthesized baicalein and wogonin derivatives with multiple medicinal properties including antitumor, central nervous system (CNS), anti-inflammatory, antiviral, antimicrobial and hypoglycemic activities. Simultaneously, SAR (Structure-Activity Relationship) analysis has been gradually possessed, along with a great deal of derivatives have been derived for potential targets. In this article, we comprehensively summarize the biological activities and SAR for baicalein and wogonin derivatives, along with the featuring bioactive molecules reported in patents, wishing to provide an overall retrospect and prospect on baicalein and wogonin analogues.

[Effect of electroacupuncture on mood and estrogen receptor α expression in mice with polycystic ovary syndrome induced by bisphenol A exposure].

OBJECTIVE: To compare the effect of electroacupuncture (EA) on "Guanyuan" (CV4) or sensitization points in mice with polycystic ovary syndrome (PCOS), so as to explore its mechanisms underlying improvement of PCOS. METHODS: In the first part of this study, 26 female ICR mice were randomized into control group (8 mice) and model group (18 mice). The PCOS model was established by gavage of bisphenol A (BPA) at a dose of 100 mg/kg, and the control group were gavage of equal volume of corn oil, once daily, 5 days a week for 4 conse-cutive weeks. Evans blue (EB) dye (0.1 mL/10 g) was injected into the caudal vein after modeling. The size, number and distribution of EB exudation points at the skin were observed. In the second part of this study, 32 mice were randomized into control, model, EA-CV4 and EA-sensitization points groups (8 mice in each group). EA (2 Hz, 2 mA) was applied to the sensitization points or CV4 for 20 min, once daily, 5 days a week for 4 conse-cutive weeks. The body weight was measured once a week for 8 consecutive weeks. The behavior changes were evaluated by open field test and elevated plus maze test. H.E. staining was used to observe the histopathologic changes of the ovary tissue. Serum level of estradiol (E2) was measured by ELISA. The expressions of estrogen receptor α (ER-α) in ovarian and uterine tissues were detected by Western blot and immunofluorescence. RESULTS: (1) In PCOS mice, the EB exudation points were found to overlap the lower abdomen, lumbosacral, chest, back and lower limbs regions, and the number of EB points was significantly more than that of the control group (P<0.01). (2) After the intervention and compared with the control group, the ovaries showed polycystic changes and an increase of atresia follicles with a larger diameter, the activity time in the central area, the total distance of movement, the times of open-arm entries, the duration in open-arm, the serum E2 content and the expression of ER-α in ovarian tissue were significantly decreased (P<0.01, P<0.05), while the mice's body weight and the expression of ER-α in uterine tissue were increased (P<0.05) in the model group. After the intervention and compared with the model group, a small number of normal follicles and corpus luteum were observed under microscope, the activity time in the central area, the total distance of movement, the times of open-arm entries, the duration in open-arm, the serum E2 content and the expression of ER-α in ovarian tissue were significantly increased (P<0.05, P<0.01), while the mice's body weight and the expression of ER-α in uterine tissue was decreased (P<0.05) in both EA-CV4 and EA-sensitization points groups. CONCLUSION: EA at sensitization points and CV4 can regulate the expression of estrogen and ER-α in PCOS mice, and improve the anxiety like behavior. EB exudation points on the body surface can not only reflect the functional changes of organs, but also treat diseases through body surface stimulation, suggesting a dual role in diagnosis and treatment.

NAc-VTA circuit underlies emotional stress-induced anxiety-like behavior in the three-chamber vicarious social defeat stress mouse model.

Emotional stress is considered a severe pathogenetic factor of psychiatric disorders. However, the circuit mechanisms remain largely unclear. Using a three-chamber vicarious social defeat stress (3C-VSDS) model in mice, we here show that chronic emotional stress (CES) induces anxiety-like behavior and transient social interaction changes. Dopaminergic neurons of ventral tegmental area (VTA) are required to control this behavioral deficit. VTA dopaminergic neuron hyperactivity induced by CES is involved in the anxiety-like behavior in the innate anxiogenic environment. Chemogenetic activation of VTA dopaminergic neurons directly triggers anxiety-like behavior, while chemogenetic inhibition of these neurons promotes resilience to the CES-induced anxiety-like behavior. Moreover, VTA dopaminergic neurons receiving nucleus accumbens (NAc) projections are activated in CES mice. Bidirectional modulation of the NAc-VTA circuit mimics or reverses the CES-induced anxiety-like behavior. In conclusion, we propose that a NAc-VTA circuit critically establishes and regulates the CES-induced anxiety-like behavior. This study not only characterizes a preclinical model that is representative of the nuanced aspect of CES, but also provides insight to the circuit-level neuronal processes that underlie empathy-like behavior.

Research progress in biological activities of succinimide derivatives.

Succinimides are well recognized heterocyclic compounds in drug discovery which produce diverse therapeutically related applications in pharmacological practices. Researches in medicinal chemistry field have isolated and synthesized succinimide derivatives with multiple medicinal properties including anticonvulsant, anti-inflammatory, antitumor and antimicrobial agents, 5-HT receptor ligands and enzyme inhibitors. Simultaneously, SAR (Structure-Activity Relationship) analysis has been gradually possessed, along with a great deal of derivatives have been derived for potential targets. In this article, we comprehensively summarize the biological activities and SAR for succinimide derivatives, along with the featuring bioactive molecules reported in patents, wishing to provide an overall retrospect and prospect on the succinimide analogues.

Research progress in biological activities of isochroman derivatives.

Isochromans are well recognized heterocyclic compounds in drug discovery which produce diverse therapeutically related applications in pharmacological practices. Medicinal chemistry investigators have synthesized drug-like isochroman candidates with multiple medicinal features including central nervous system (CNS), antioxidant, antimicrobial, antihypertensive, antitumor and anti-inflammatory agents. Simultaneously, SAR (Structure-Activity Relationship) analysis has drawn attentions among medicinal chemists, along with a great deal of derivatives have been derived for potential targets. In this article, we thoroughly summarize the biological activities and part of typical SAR for isochroman derivatives reported on existing literatures and patents, wishing to provide an overall retrospect and prospect on the isochroman analogues.

Region-specific inhibition of 14-3-3 proteins induces psychomotor behaviors in mice.

The 14-3-3 family of proteins is genetically linked to several psychiatric disorders, including schizophrenia. Our 14-3-3 functional knockout (FKO) mice, as well as other 14-3-3 knockout models, have been shown to exhibit behavioral endophenotypes related to schizophrenia. While specific forebrain regions, such as the prefrontal cortex (PFC) and hippocampus (HP), have been implicated in schizophrenic pathophysiology, the role of these brain regions in the top-down control of specific schizophrenia-associated behaviors has not been examined. Here, we used an adeno-associated virus (AAV) delivered shRNA to knock down the expression of the 14-3-3-inhibitor transgene, thus selectively restoring the function of 14-3-3 in the forebrain of the 14-3-3 FKO mice, we found that injection of the AAV-shRNA into both the PFC and the HP is necessary to attenuate psychomotor activity of the 14-3-3 FKO mice. Furthermore, we found that acute inhibition of 14-3-3, through the delivery of an AAV expressing the 14-3-3 inhibitor to both the PFC and HP, can trigger psychomotor agitation. Interestingly, when assessing the two brain regions separately, we determined that AAV-mediated expression of the 14-3-3 inhibitor specifically within the HP alone is sufficient to induce several behavioral deficits including hyperactivity, impaired associative learning and memory, and reduced sensorimotor gating. In addition, we show that post-synaptic NMDA receptor levels are regulated by acute 14-3-3 manipulations. Taken together, findings from this study directly link 14-3-3 inhibition in specific forebrain regions to certain schizophrenia-associated endophenotypes.

Motile axonal mitochondria contribute to the variability of presynaptic strength.

One of the most notable characteristics of synaptic transmission is the wide variation in synaptic strength in response to identical stimulation. In hippocampal neurons, approximately one-third of axonal mitochondria are highly motile, and some dynamically pass through presynaptic boutons. This raises a fundamental question: can motile mitochondria contribute to the pulse-to-pulse variability of presynaptic strength? Recently, we identified syntaphilin as an axonal mitochondrial-docking protein. Using hippocampal neurons and slices of syntaphilin knockout mice, we demonstrate that the motility of axonal mitochondria correlates with presynaptic variability. Enhancing mitochondrial motility increases the pulse-to-pulse variability, whereas immobilizing mitochondria reduces the variability. By dual-color live imaging at single-bouton levels, we further show that motile mitochondria passing through boutons dynamically influence synaptic vesicle release, mainly by altering ATP homeostasis in axons. Thus, our study provides insight into the fundamental properties of the CNS to ensure the plasticity and reliability of synaptic transmission.

Liuwei Dihuang decoction facilitates the induction of long-term potentiation (LTP) in senescence accelerated mouse/prone 8 (SAMP8) hippocampal slices by inhibiting voltage-dependent calcium channels (VDCCs) and promoting N-methyl-d-aspartate receptor (NMDA) receptors.

ETHNOPHARMACOLOGICAL RELEVANCE: Liuwei Dihuang decoction (LW) is a typical traditional Chinese medicine (TCM) prescription and consists of six herbs including Rehmannia glutinosa Libosch. (family: Scrophulariaceae), Cornus officinalis Sieb. (family: Cornaceae), Dioscorea opposite Thunb. (family: Dioscoreaceae), Alisma orientale (G. Samuelsson) Juz (family: Alismataceae), Poria cocos (Schw.)Wolf (family: Polyporaceae) and Paeonia suffruticosa Andrews (family: Paeoniaceae). It has long been used clinically in treatment of many kinds of diseases with the sign of Yin insufficiency of kidney. AIM OF THE STUDY: Our previous pharmacological studies demonstrated that LW possesses effect of ameliorating the decline of the learning and memory in senescence accelerated mouse/prone 8 (SAMP8), but the mechanism has not been well established. LW-containing serum (LWCS) is used in the current study to elucidate the possible mechanisms. MATERIALS AND METHODS: 6-month-old SAMP8 was used in this study to investigate the effect of LWCS on the induction of long-term potentiation (LTP). Primary cultured hippocampal neurons were used in this study to investigate the effects of LWCS on [Ca(2+)](i), I(Ca) and N-Methyl-d-aspartate (NMDA)-evoked currents. [Ca(2+)](i) was imaged using Fluo-3 and whole-cell patch recordings were applied to study the I(Ca) and NMDA-evoked currents. RESULTS: We find that LWCS facilitates the induction of LTP in hippocampal slices of 6-month-old SAMP8. In primary cultured hippocampal neurons, LWCS increases intracellular [Ca(2+)](i), the I(Ca) is suppressed by LWCS, and NMDA-evoked currents are promoted. CONCLUSION: These results indicate that LW improves the synaptic plasticity by inhibiting voltage-dependent calciumchannels (VDCCs) and promoting the function of NMDA receptors. This improvement might be one of the mechanisms contributing to cognitive improvement effect of LW.

Snapin-regulated late endosomal transport is critical for efficient autophagy-lysosomal function in neurons.

Neuron maintenance and survival require late endocytic transport from distal processes to the soma where lysosomes are predominantly localized. Here, we report a role for Snapin in attaching dynein to late endosomes through its intermediate chain (DIC). snapin(-/-) neurons exhibit aberrant accumulation of immature lysosomes, clustering and impaired retrograde transport of late endosomes along processes, reduced lysosomal proteolysis due to impaired delivery of internalized proteins and hydrolase precursors from late endosomes to lysosomes, and impaired clearance of autolysosomes, combined with reduced neuron viability and neurodegeneration. The phenotypes are rescued by expressing the snapin transgene, but not the DIC-binding-defective Snapin-L99K mutant. Snapin overexpression in wild-type neurons enhances late endocytic transport and lysosomal function, whereas expressing the mutant defective in Snapin-DIC coupling shows a dominant-negative effect. Altogether, our study highlights new mechanistic insights into how Snapin-DIC coordinates retrograde transport and late endosomal-lysosomal trafficking critical for autophagy-lysosomal function, and thus neuronal homeostasis.

Characterization of neuronal Src kinase purified from a bacterial expression system.

Neuronal Src (n-Src) is an alternative isoform of Src kinase containing a 6-amino acid insert in the SH3 domain that is highly expressed in neurons of the central nervous system (CNS). To investigate the function of n-Src, wild-type n-Src, constitutively active n-Src in which the C-tail tyrosine 535 was mutated to phenylalanine (n-Src/Y535F) and inactive n-Src in which the lysine 303 was mutated to arginine in addition to the mutation of Y535F (n-Src/K303R/Y535F), were expressed and purified from Escherichia coli BL21(DE3) cells. We found that all three types of n-Src constructs expressed at very high yields (∼500 mg/L) at 37°C, but formed inclusion bodies. In the presence of 8M urea these proteins could be solubilized, purified under denaturing conditions, and subsequently refolded in the presence of arginine (0.5M). These Src proteins were enzymatically active except for the n-Src/K303R/Y535F mutant. n-Src proteins expressed at 18°C were soluble, albeit at lower yields (∼10-20 mg/L). The lowest yields were for n-Src/Y535F (∼10 mg/L) and the highest for n-Src/K303R/Y535F (∼20 mg/L). We characterized the purified n-Src proteins expressed at 18°C. We found that altering n-Src enzyme activity either pharmacologically (e.g., application of ATP or a Src inhibitor) or genetically (mutation of Y535 or K303) was consistently associated with changes in n-Src stability: an increase in n-Src activity was coupled with a decrease in n-Src stability and vice versa. These findings, therefore, indicate that n-Src activity and stability are interdependent. Finally, the successful production of functionally active n-Src in this study indicates that the bacterial expression system may be a useful protein source in future investigations of n-Src regulation and function.

Generation of insulin-producing cells from PDX-1 gene-modified human mesenchymal stem cells.

Islet cell replacement is considered as the optimal treatment for type I diabetes. However, the availability of human pancreatic islets for transplantation is limited. Here, we show that human bone marrow-derived mesenchymal stem cells (hMSCs) could be induced to differentiate into functional insulin-producing cells by introduction of the pancreatic duodenal homeobox-1 (PDX-1). Recombinant adenoviral vector was used to deliver PDX-1 gene into hMSCs. After being infected with Ad-PDX-1, hMSCs were successfully induced to differentiate into insulin-secreting cells. The differentiated PDX-1+ hMSCs expressed multiple islet-cell genes including neurogenin3 (Ngn3), insulin, GK, Glut2, and glucagon, produced and released insulin/C-peptide in a weak glucose-regulated manner. After the differentiated PDX-1+ hMSCs were transplanted into STZ-induced diabetic mice, euglycemia can be obtained within 2 weeks and maintained for at least 42 days. These findings validate the hMSCs model system as a potential basis for enrichment of human beta cells or their precursors, and a possible source for cell replacement therapy in diabetes.

SO-3, a new O-superfamily conopeptide derived from Conus striatus, selectively inhibits N-type calcium currents in cultured hippocampal neurons.

Whole-cell currents in cultured hippocampal neurons were recorded to investigate the effects of SO-3, a new O-superfamily conopeptide derived from Conus striatus, on voltage-sensitive channels. SO-3 had no effect on voltage-sensitive sodium currents, delayed rectifier potassium currents, and transient outward potassium currents. Similar to the selective N-type calcium channel blocker omega-conotoxin MVIIA (MVIIA), SO-3 could concentration-dependently inhibit the high voltage-activated (HVA) calcium currents (I(Ca)). MVIIA(3 microM), 10 microM nimodipine, and 0.5 microM omega-agatoxin IVA (Aga) could selectively block the N-, L-, and P/Q-type I(Ca), which contributed approximately 32, approximately 38, and approximately 21% of the HVA currents in hippocampal neurons, respectively. About 31% of the total HVA currents were inhibited by 3 microM SO-3. SO-3 (3 microM) and 3 microM MVIIA inhibited the overlapping components of HVA currents, whereas no overlapping component was inhibited by 3 microM SO-3 and 10 microM nimodipine, or by 3 microM SO-3 and 0.5 microM Aga. Also, 3 microM SO-3 had no effect on R-type currents. SO-3 had less inhibitory effects on non-N-type HVA currents than MVIIA at higher concentrations (30 and 100 microM). The inhibitory effects of SO-3 and MVIIA on HVA currents were almost fully reversible. However, the recovery from block by MVIIA was more rapid than recovery from block by SO-3. It is concluded that SO-3 is a new omega-conotoxin selectively targeting N-type voltage-sensitive calcium channels. Considering the significance of N-type calcium channels for pain transduction, SO-3 may have therapeutic potential as a novel analgesic agent.