The common marmoset (CM; Callithrix jacchus) is a small New World monkey with a high rate of pregnancy and is maintained in closed colonies as an experimental animal species. Although CMs are used for immunological research, such as studies of autoimmune disease and infectious disease, their immunological characteristics are less defined than those of other nonhuman primates. We and others have analyzed antigen recognition-related molecules, the development of hematopoietic stem cells (HSCs), and the molecules involved in the immune response. CMs systemically express Caja-G, a major histocompatibility complex class I molecule, and the ortholog of HLA-G, a suppressive nonclassical HLA class I molecule. HSCs express CD117, while CD34 is not essential for multipotency. CD117+ cells developed into all hematopoietic cell lineages, but compared with human HSCs, B cells did not extensively develop when HSCs were transplanted into an immunodeficient mouse. Although autoimmune models have been successfully established, sensitization of CMs with some bacteria induced a low protective immunity. In CMs, B cells were observed in the periphery, but IgG levels were very low compared with those in humans and mice. This evidence suggests that CM immunity is partially suppressed systemically. Such immune regulation might benefit pregnancy in CMs, which normally deliver dizygotic twins, the placentae of which are fused and the immune cells of which are mixed. In this review, we describe the CM immune system and discuss the possibility of using CMs as a model of human immunity.

It has been demonstrated that tranexamic acid (TXA), a synthetic derivative of lysine, alleviates lung damage in a trauma-hemorrhagic shock (T/HS) model. Nevertheless, the mechanism of TXA against acute lung injury (ALI) has not deeply elaborated. In this study, we generated a T/HS rat model based on previous research, and TXA (50 mg/kg and 100 mg/kg) was intravenously injected into these rats prior to or post T/HS. The results revealed that the decreased survival rate and impaired lung permeability of the rats caused by T/HS were improved by TXA pretreatment or posttreatment. T/HS-triggered over-generation of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in bronchoalveolar fluid and serum was inhibited by TXA, and the enzymatic activity of myeloperoxidase (MPO) in lung tissues was suppressed by TXA as well. Furthermore, TXA treatment deactivated the poly ADP-ribose polymerase-1 (PARP1)/nuclear factor κB (NF-κB) signaling pathway in the lungs of T/HS rats, as evidenced by increased IκBα expression, and decreased cleaved PARP1, p-p65 (Ser276), p-p65 (Ser529), p-IκBα (ser32/ser36), and intercellular adhesion molecule-1. While the expression level of total p65 did not change after T/HS, its DNA binding activity was strengthened. Both TXA pretreatment and posttreatment suppressed this effect on the DNA binding activity of NF-κB. Taken together, our results reveal that administration of TXA effectively relieves T/HS-induced ALI, at least in part, by attenuating the abnormal pulmonary inflammation.

The common marmoset (Callithrix jacchus) is a nonhuman primate that is used for preclinical research on stem cell transplantation therapies due to its similarity to human beings as well as its small size, enabling researchers to perform experiments without preparing a large number of cells. In this study, we developed a marmoset hepatic fibrosis model for regenerative medicine research. Six female marmosets aged 4–6 years were administered thioacetamide (TAA) at a dose of 2.5–40 mg/kg two or three times a week. Hepatic fibrosis was assessed by liver biopsy when blood chemistry indicated liver damage. Administration of TAA increased total bile acid, aspartate aminotransferase, and total bilirubin and decreased serum albumin levels. Following more than 11 weeks of continuous injection of TAA, histological analyses detected hepatic fibrosis in all animals. Type IV collagen 7S serum levels in animals with hepatic fibrosis were significantly higher than in normal animals as a possible marker of hepatic fibrosis in marmosets. Serial liver biopsies following the last administration of TAA revealed that induced fibrosis remained up to 11 weeks. The results suggest that continuous TAA administration induces persistent hepatic fibrosis in the common marmoset and this nonhuman primate hepatic fibrosis model have the possibility to evaluate the therapeutic effects of test samples to ameliorate hepatic fibrosis.

To achieve surgical anesthesia in animal experimentation, it is necessary to select the appropriate anesthetic protocol by considering its pharmacological properties and the surgical procedure to be performed. However, few studies have investigated the validity of anesthetic protocols under surgical conditions in small rodents. The present study aimed to clarify the pharmacological properties of 4 anesthetic protocols during the surgical procedure of castration in rats. Eight-week-old male Wistar rats were anesthetized with anesthetics, including the combination of ketamine and xylazine (K/X), the combination of medetomidine, midazolam, and butorphanol (M/M/B), isoflurane, and sevoflurane. Castration was performed under each anesthesia, and anesthetic depth and times were assessed, as were vital signs. The injectable anesthetics were investigated at standard and high doses. The concentration of inhalant anesthetics was adjusted to 1.5 minimum alveolar concentration (MAC). K/X at both doses demonstrated sufficient anesthetic depth with rapid induction and recovery. However, bradycardia and hypothermia were prominent in high-dose K/X, indicating that the standard-dose is more appropriate for surgical anesthesia in castration procedures. M/M/B demonstrated high anesthetic sensitivity variation in individual animals. In contrast to injectable anesthetics, inhalant anesthetics provided stable anesthetic depth with less cardiorespiratory influence. Sevoflurane did not lead to a significant decrease in rectal temperature during the anesthetic period. Results of the present study revealed the optimal dose and pharmacological features of several anesthetic protocols for castration, and may contribute to the standardization of surgical anesthesia in rats.

The epithelial sodium channel (ENaC) and mitogen-activated protein kinase (MAPK) pathway have been reported to be associated with the progression of acute lung injury (ALI). Oxymatrine (OMT) alone or combined with other drugs can ameliorate paraquat- or oleic acid-induced lung injury. However, the effect of OMT on lipopolysaccharide (LPS)-induced ALI remains unknown. The aim of the present study was to evaluate whether OMT can attenuate LPS-induced ALI through regulation of the ENaC and MAPK pathway using an ALI mouse model. Histological assessment of the lung and inflammatory cell counts in bronchoalveolar lavage fluid (BALF) were performed by H&E and Wright-Giemsa staining. The lung wet/dry (W/D) weight ratio and the levels of tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), ENaC subunits, and the MAPK pathway members were determined. Isolated type II rat alveolar epithelial cells were incubated with OMT 30 min before LPS stimulation to investigate the activation of ENaC and the MAPK pathway. The results showed that OMT remarkably alleviated histopathologic changes in lung and pulmonary edema, reduced inflammatory cell counts in BALF, and decreased TNF-α and CRP levels in a dose-dependent manner. OMT significantly increased the three subunits of ENaC proteins in vivo and in vitro, while it decreased p-ERK/ERK, p-p38/p38, and p-JNK/JNK ratios in vivo. However, only the JNK pathway was markedly inhibited in vitro following pretreatment with OMT. Collectively, the results suggested that OMT might alleviate LPS-induced ALI by elevating ENaC proteins and inhibiting the JNK signaling pathway.

Rabbit mesenchymal stem cells (MSCs) are important seed cells in regenerative medicine research, particularly in translational research. In the current study, we showed that rabbit subchondral bone is a reliable source of MSCs. First, we harvested subchondral bone (SCB) from the rabbit knee-joint and initiated the MSC culture by cultivating enzyme-treated SCB. Adherent fibroblast-like cells that outgrew from SCB fulfill the common immuno-phenotypic criteria for defining MSCs, but with low contamination of CD45+ hematopoietic cells. Interestingly, differentiated SCB-MSCs expressed osteogenic and chondrogenic markers at significantly higher levels than those in bone marrow cell suspension-derived MSCs (BMS-MSCs) (P<0.05). No differences in the expression of adipogenic markers between SCB-MSC and BMS-MSC (P>0.05) were observed. Moreover, the results of the colony forming unit-fibroblast assay and sphere formation assay demonstrated that the SCB-MSCs had increased self-renewal potential. SCB-MSCs expressed higher levels of the stemness markers Nanog, OCT4, and Sox-2 compared to in BMS-MSCs (P<0.05). Furthermore, the results of both the CCK-8-based assay and CFSE dilution assay showed that SCB-MSCs exhibited enhanced proliferative capacity. In addition, SCB-MSCs exhibited higher phosphorylation of extracellular signal-related kinase/mitogen-activated protein kinase signaling, which is closely related to MSC proliferation. In conclusion, we identified SCB-MSCs as a novel stem cell population that met the requirements of MSCs; the unique properties of SCB-MSC are important for the potential treatment of tissue damage resulting from disease and trauma.

The aim of this study is to investigate the changes with age on morphology and sex hormone receptor expression in the mammary glands of male Sprague-Dawley rats, focusing on male-specific cells, “oxyphilic cells”, observed after sexual maturity. The mammary glands of male rats at 14, 21, 35, 50, 75 and 100 days old were examined by gross observation, microscopic observation using whole mount specimens, histological and immunohistochemical sections. Grossly, mammary glands showed brown color at 50–100 days old. In whole mount specimens, terminal end buds (TEBs) were observed at 14–50 days old and the number of TEBs was highest at 35 days old. Histologically, the male mammary glands contained small epithelial cells with scanty cytoplasm at 14–35 days old while ductal and lobular epithelial cells were changed into oxyphilic cells with abundant cytoplasm at 50–100 days old. Immunohistochemicaly, androgen receptor (AR), estrogen receptor (ER) and progesterone receptor (PgR) expressions were found in both mammary glands found at a young age and oxyphilic cells. In oxyphilic cells, AR expression was dominant compared to ER and PgR expressions and increased with age. From these results, the development at 50–100 days old might be strongly related to AR. Ultrastructural observation of oxyphilic cells confirmed a number of lipid droplets, deformed and/or enlarged mitochondria, lysosomes and peroxisomes in their cytoplasm.

Endoplasmic reticulum (ER) stress is one of the driving forces of ischemia/reperfusion (IR)-induced acute renal failure (ARF). STF-083010, an inhibitor of the endonuclease activity of inositol-requiring enzyme-1 (IRE1), has the potential to block the initiation of a prolonged unfolded protein response (UPR) that is stimulated by ER stress and alleviates the impairments due to ER stress. In the current study, it was hypothesized that STF-083010 was capable of ameliorating ER stress-related damages in IR-induced ARF. Rats were administrated with STF-083010 and were subjected to induction of ARF using a ligation method. Then the effect of STF-083010 administration on the renal structure and function, oxidative stress, and inflammation in model rats was assessed. Furthermore, the levels of expression of UPR members and downstream effectors regulating apoptosis were detected as well. The results showed that establishment of the ARF model induced ER stress and impaired the renal structure and function. Administration of STF-083010 ameliorated impairments in the structure and function of the kidneys and the effect was associated with the suppressed oxidative stress and inflammation. At the molecular level, STF-083010 inhibited the prolonged UPR by downregulating the expressions of GRP78, p-IRE1, XBP1s, CHOP, and caspase 3, partially explaining the decreased apoptotic rate. The current study evaluated the potential of STF-083010 in treating ER stress-induced symptoms in ARF for the first time, and the findings demonstrated that STF-083010 resulted in effective treatment outcomes of ARF.

A stable and reproducible rat injury model is not currently available to study central diabetes insipidus (CDI) and the neurohypophyseal system. In addition, a system is needed to assess the severity of CDI and measure the accompanying neurobiological alterations. In the present study, a 3D-printed lesion knife with a curved head was designed to fit into the stereotaxic instrument. The neuro-anatomical features of the brain injury were determined by in vivo magnetic resonance imaging (MRI) and arginine vasopressin (AVP) immunostaining on brain sections. Rats that underwent pituitary stalk electrical lesion (PEL) exhibited a tri-phasic pattern of CDI. MRI revealed that the hyperintenseT1-weighted signal of the pituitary stalk was interrupted, and the brain sections showed an enlarged end proximal to the injury site after PEL. In addition, the number of AVP-positive cells in supraoptic nucleus (SON) and paraventricular nucleus (PVN) decreased after PEL, which confirmed the success of the CDI model. Unlike hand-made tools, the 3D-printed lesion knives were stable and reproducible. Next, we used an ordinal clustering method for staging and the k-means’ clustering method to construct a CDI index to evaluate the severity and recovery of CDI that could be used in other multiple animals, even in clinical research. In conclusion, we established a standard PEL model with a 3D-printed knife tool and proposed a CDI index that will greatly facilitate further research on CDI.