Ulinastatin Exhibits Antinociception in Rat Models of Acute Somatic and Visceral Pain Through Inhibiting the Local and Central Inflammation

The Preventive Effect of Urinary Trypsin Inhibitor on Postoperative Cognitive Dysfunction, on the Aspect of Behavior, Evaluated by Y-Maze Test, via Modulation of Microglial Activity

This experimental study was designed to evaluate the effect of ulinastatin, a urinary trypsin inhibitor, on postoperative cognitive dysfunction (POCD) in rats under general anesthesia with isoflurane, on the aspect of behavior, as evaluated using a Y-maze test and focusing on microglial activity. Ulinastatin (50,000 U/mL) and normal saline (1 mL) were randomly (1:1) administered intraperitoneally to the ulinastatin and control groups, respectively, before general anesthesia. Anesthesia with isoflurane 1.5 volume% was maintained for 2 h. The Y-maze test was used to evaluate cognitive function. Neuronal damage using caspase-1 expression, the degree of inflammation through cytokine detection, and microglial activation with differentiation of the phenotypic expression were evaluated. Twelve rats were enrolled in the study and evenly allocated into the two groups, with no dropouts from the study. The Y-maze test showed similar results in the two groups before general anesthesia (63 ± 12% in the control group vs. 64 ± 12% in the ulinastatin group, p = 0.81). However, a significant difference was observed between the two groups after general anesthesia (17 ± 24% in the control group vs. 60 ± 12% in the ulinastatin group, p = 0.006). The ulinastatin group showed significantly lower expression of caspase-1. Pro-inflammatory cytokine levels were significantly lower in the ulinastatin group than in the control group. The ulinastatin group had a significantly lower microglial activation (41.74 ± 10.56% in the control group vs. 4.77 ± 0.56% in the ulinastatin, p < 0.001), with a significantly lower activation of M1 phenotypes (52.19 ± 7.83% in the control group vs. 5.58 ± 0.76% in the ulinastatin group, p < 0.001). Administering ulinastatin before general anesthesia prevented neuronal damage and cognitive decline after general anesthesia, in terms of the aspect of behavior, as evaluated by the Y-maze test. The protective effect of ulinastatin was associated with the inhibition of microglial activation, especially the M1 phenotype.

Role and therapeutic target of P2X2/3 receptors in visceral pain

Visceral pain (VP) is caused by internal organ disease. VP is involved in nerve conduction and related signaling molecules, but its specific pathogenesis has not yet been fully elucidated. Currently, there are no effective methods for treating VP. The role of P2X2/3 in VP has progressed. After visceral organs are subjected to noxious stimulation, cells release ATP, activate P2X2/3, enhance the sensitivity of peripheral receptors and the plasticity of neurons, enhance sensory information transmission, sensitize the central nervous system, and play an important role in the development of VP. However, antagonists possess the pharmacological effect of relieving pain. Therefore, in this review, we summarize the biological functions of P2X2/3 and discuss the intrinsic link between P2X2/3 and VP. Moreover, we focus on the pharmacological effects of P2X2/3 antagonists on VP therapy and provide a theoretical basis for its targeted therapy.

Medial and dorsal lateral septum involving social disruption stress-primed escalation in acid-induced writhes

Introduction

Stress may cause prospective escalations in abdominal pain magnitude and accumbal TRPV1 expression, while central neural circuits mediating these stress effects remain unclear.

Methods

Using retrograde tracing methods, we first demonstrated the existence of a medial septal-dorsal lateral septal -accumbal circuit very likely involving social disruption stress-primed escalations in acid-induced writhes and accumbal TRPV1 level. An intersectional viral strategy and virus-carrying hM3Dq and hM4Di DREADDs were, then, employed to selectively modulate GABAergic and cholinergic neuronal activity in medial and dorsal lateral septum.

Results

Exciting medial septal GABAergic neuron was found to prevent social disruption stress-primed escalations in acid-induced writhes and accumbal TRPV1 and PKCε expressions. Likewise, inactivating dorsal lateral septal cholinergic neurons was also effective in abolishing these stress-primed escalations. Inactivating GABAergic neuron in non-stressed animals' medial septum was found to reproduce the stress-primed effects in causing heightened acid-induced writhes and accumbal TRPV1 and PKCε levels.

Discussion

These results, taken together, prompt us to conclude that social disruption stress may produce plastic changes in a newly-identified medial septal-dorsal lateral septal-accumbal circuit. Moreover, medial septal GABAergic hypoactivity and dorsal lateral septal cholinergic hyperactivity are, at least, two likely causes reflecting such stress-produced escalations in abdominal pain magnitude and pain transduction-related protein over-expression in nucleus accumbens.

Reprogramming adipose mesenchymal stem cells into islet β-cells for the treatment of canine diabetes mellitus

BACKGROUND

Islet transplantation is an excellent method for the treatment of type I diabetes mellitus. However, due to the limited number of donors, cumbersome isolation and purification procedures, and immune rejection, the clinical application is greatly limited. The development of a simple and efficient new method to obtain islet β-cells is a key problem that urgently requires a solution for the treatment of type I diabetes mellitus.

METHODS

In this study, Pbx1, Rfx3, Pdx1, Ngn3, Pax4 and MafA were used to form a six-gene combination to efficiently reprogram aMSCs (adipose mesenchymal stem cells) into ra-βCs (reprogrammed aMSCs-derived islet β-cells), and the characteristics and immunogenicity of ra-βCs were detected. Feasibility of ra-βCs transplantation for the treatment of diabetes mellitus in model dogs and clinical dogs was detected.

RESULTS

In this study, aMSCs were efficiently reprogrammed into ra-βCs using a six-gene combination. The ra-βCs showed islet β-cell characteristics. The immunogenicity of ra-βCs was detected and remained low in vitro and increased after transplantation. The cotransplantation of ra-βCs and aMSCs in the treatment of a model and clinical cases of canine diabetes mellitus achieved ideal therapeutic effects.

CONCLUSIONS

The aMSCs were efficiently reprogrammed into ra-βCs using a six-gene combination. The cotransplantation of ra-βCs and aMSCs as a treatment for canine diabetes is feasible, which provides a theoretical basis and therapeutic method for the treatment of canine diabetes.

The analgesic effects of ulinastatin either as a single agent or in combination with sufentanil: A novel therapeutic potential for postoperative pain

Ulinastatin is a broad-spectrum protease inhibitor widely used for the treatment of various inflammation-related diseases owing to its recognized excellent anti-inflammatory and cytoprotective properties. However, whether ulinastatin can relieve postoperative pain remains unclear. In this study, we evaluated the analgesic effects of ulinastatin administered either as a single agent or in combination with sufentanil in a validated preclinical rat model of postoperative pain induced by plantar incision. We found that incisional surgery on the hind paw of these rats induced sustained ipsilateral mechanical pain hypersensitivity that lasted for at least 10 days. A single intraperitoneal (i.p.) injection of ulinastatin prevented the development and reversed the maintenance of incision-induced mechanical pain hypersensitivity in a dose-dependent manner. However, ulinastatin had no effect on the baseline nociceptive threshold. Moreover, repeated i.p. injections of ulinastatin persistently attenuated incision-induced mechanical pain hypersensitivity and promoted recovery from the surgery. The rats did not develop any analgesic tolerance over the course of repeated injections of ulinastatin. A single i.p. injection of ulinastatin was also sufficient to inhibit the initiation and maintenance of incision-induced hyperalgesic priming when the rats were subsequently challenged with an ipsilateral intraplantar prostaglandin E2 injection. Furthermore, the combined administration of ulinastatin and sufentanil significantly enhanced the analgesic effect of sufentanil on postoperative pain, which involved mechanisms other than a direct influence on opioid receptors. These findings demonstrated that ulinastatin had a significant analgesic effect on postoperative pain and might be a novel pharmacotherapeutic agent for managing postoperative pain either alone or as an adjuvant.