Retraction: Establishment of a Rabbit Model of Spinal Tuberculosis Using Mycobacterium tuberculosis Strain H37Rv

The rabbit model for spinal tuberculosis: An overview

Mycobacterium tuberculosis infection has emerged as a global public health issue, predominantly manifesting as pulmonary tuberculosis. Bone and joint tuberculosis, with spinal tuberculosis accounting for approximately 50%, represents a significant form of extrapulmonary tuberculosis. Over the past years, there has been a rise in the incidence of spinal tuberculosis, and research concerning this area has gained significant attention. At present, animal models provide a means to investigate the pathogenesis, drug resistance, and novel treatment approaches for spinal tuberculosis. New Zealand rabbits, possessing a comparable anatomical structure to humans and capable of reproducing typical pathological features of human tuberculosis, are extensively employed in spinal tuberculosis research using animal models. This article comprehensively evaluates the strengths, considerations in strain selection, various modelling approaches, and practical applications of the rabbit model in studying spinal tuberculosis based on pertinent literature to guide fundamental research in this field by providing valuable insights into appropriate animal model selection.

A comparative study of a rabbit spinal tuberculosis model constructed by local direct infection via the posterior lateral approach

The present study aims to establish a method of constructing a New Zealand rabbit spinal tuberculosis model by direct local infusion of M. tuberculosis H37Rv strain into the intervertebral disc space through the posterior lateral approach. Sixty-six New Zealand rabbits were pretreated with complete Freund's adjuvant and randomly divided into 4 group: the posterolateral approach model group (Group A, 25), ventral transverse process approach model group (Group B, 25), control group (Group C, 10), and blank group (Group D, 6). In Groups A and B, the bone holes were filled with gelatin sponge after drilling, and the local area was directly infused with 0.1 ml of M. tuberculosis H37Rv strain suspension. In Group C, the gelatin sponge was filled through the posterolateral approach and the local area was infused with 0.1 ml of normal saline suspension. In Group D, No specific treatment was performed. The general conditions of the experimental rabbits in each group were compared to those of a control group; the degree of vertebral body exposure, incision length, and complications of the two methods were compared; and the tuberculosis models were evaluated by imaging, histopathology, and bacterial culture. In Group A, the lateral side of the vertebral body was well exposed, the damage was mild, and no peritoneal rupture or gastrointestinal complications were observed. In Group B, the ventral side of the vertebral body and the intervertebral disc were exposed, and abdominal complications were more likely to occur. The survival rates of the experimental rabbits at 8 weeks after surgery were 92.0% in Group A, 88.00% in Group B, 90.0% in Group C, and 100% in Group D. MRI examinations showed that in Group A, the positive rate of radiographic bone findings was 86.9% at 4 weeks after surgery and 100% at 8 weeks after surgery; in Group B, the positive rate of radiographic bone findings was 78.2% at 4 weeks after surgery and 95.4% at 8 weeks after surgery. There was no significant difference between Groups A and B in the radiographic bone findings rate detected by the same imaging method at the same time point (P > 0.05). Eight weeks after surgery, bone destruction, paravertebral abscess, and caseous necrosis occurred in the vertebral bodies of surviving rabbits in Groups A and B. The BacT/ALERT 3D rapid culture system was used to culture the pus in the lesion, and the results showed that the positive rate of tuberculosis was 52.17% in Group A and 54.54% in Group B, and the difference was not statistically significant (P > 0.05). After pretreatment with complete Freund's adjuvant, direct infusion of the H37Rv strain of M. tuberculosis into the intervertebral disc space of New Zealand rabbits via the posterolateral approach and the ventral transverse process approach can successfully establish rabbit spinal tuberculosis models.

Vitamin D receptor activated by vitamin D administration alleviates Mycobacterium tuberculosis-induced bone destruction by inhibiting NFκB-mediated aberrant osteoclastogenesis

Clinically, bone destruction caused by Mycobacterium tuberculosis was serious especially in patients with vitamin D (VD) deficiency. However, the role of VD in M. tuberculosis-induced bone destruction remains clear. In this context, we investigate the role of VD and vitamin D receptor (VDR) in the M. tuberculosis-induced bone destruction. First, we infected RAW264.7 and bone marrow-derived macrophages (BMMs) with Mycobacterium bovis Bacillus Calmette-Guérin (M. bovis BCG) in vitro. Then, we activated VDR through VD administration. TRAP and FAK staining, bone resorption assays, immunofluorescence staining, qPCR, and western blot were carried out. In vivo, the M. tuberculosis-induced osteolytic model on the murine skull was established and the μCT and histological analyses were performed. We found that VDR and TRAP were upregulated in bone tuberculosis tissue and proved that M. tuberculosis infection promoted osteoclastogenesis in RAW264.7 and BMMs. VD could inhibit osteoclasts differentiation, fusion, and bone resorption dose-dependently. However, when VDR was knocked down, the inhibitory effect of VD on osteoclasts disappeared. In mechanism, activation of VDR inhibits the phosphorylation of IκB α, thereby inhibiting NFκB signaling pathway and alleviating osteoclastogenesis. Furthermore, in the skull osteolysis model, VD administration reduced osteolysis, but not in VDR^-/- mice. Our study, for the first time, demonstrates that activation of VDR by VD administration inhibits M. tuberculosis-induced bone destruction. Our results reveal that VD and VDR are potential therapeutic targets for M. tuberculosis-induced bone destruction, and are of great clinical significance for the development of new therapeutic strategies.

Mycobacterium tuberculosis infection increases the number of osteoclasts and inhibits osteoclast apoptosis by regulating TNF-α-mediated osteoclast autophagy

Osteoarticular tuberculosis, a chronic inflammatory disease characterized by Mycobacterium tuberculosis (M.tb) infection, has become a serious problem in China. The present study was conducted to determine the mechanism of action of tumor necrosis factor (TNF)-α in the pathogenesis of osteoarticular tuberculosis. The number of osteoclasts in osteoarticular tuberculosis tissue samples was detected by tartrate-resistant acid phosphatase staining. Autophagy and apoptosis of osteoclasts were detected by western blotting, reverse transcription-quantitative PCR, transmission electron microscopy and TUNEL staining. The results showed that autophagy and the number of osteoclasts increased in the lesions of patients with osteoarticular tuberculosis compared with osteoarthritis samples. Moreover, activation of osteoclast autophagy inhibited the apoptosis of osteoclasts infected with M.tb, and increased the expression level of TNF-α. The results showed that TNF-α enhanced the autophagic activity of M.tb-infected osteoclasts and inhibited cell apoptosis. These findings indicated that M.tb infection induced osteoclast production and inhibited osteoclast apoptosis by regulating TNF-α-mediated osteoclast autophagy, revealing a new mechanism for TNF-α in the pathogenesis of osteoarticular tuberculosis.

The wide utility of rabbits as models of human diseases

Studies using the European rabbit Oryctolagus cuniculus contributed to elucidating numerous fundamental aspects of antibody structure and diversification mechanisms and continue to be valuable for the development and testing of therapeutic humanized polyclonal and monoclonal antibodies. Additionally, during the last two decades, the use of the European rabbit as an animal model has been increasingly extended to many human diseases. This review documents the continuing wide utility of the rabbit as a reliable disease model for development of therapeutics and vaccines and studies of the cellular and molecular mechanisms underlying many human diseases. Examples include syphilis, tuberculosis, HIV-AIDS, acute hepatic failure and diseases caused by noroviruses, ocular herpes, and papillomaviruses. The use of rabbits for vaccine development studies, which began with Louis Pasteur’s rabies vaccine in 1881, continues today with targets that include the potentially blinding HSV-1 virus infection and HIV-AIDS. Additionally, two highly fatal viral diseases, rabbit hemorrhagic disease and myxomatosis, affect the European rabbit and provide unique models to understand co-evolution between a vertebrate host and viral pathogens.

Rabbits offer a powerful complement to rodents as a model for studying human immunology, disease pathology, and responses to infectious disease. A review from Pedro Esteves at the University of Porto, Portugal, Rose Mage of the National Institute of Allergy and Infectious Disease, Bethesda, USA and colleagues highlights some of the areas of research where rabbits offer an edge over rats and mice. Rabbits have a particularly sophisticated adaptive immune system, which could provide useful insights into human biology and produce valuable research and clinical reagents. They are also excellent models for studying - infectious diseases such as syphilis and tuberculosis, which produce pathology that closely resembles that of human patients. Rabbit-specific infections such as myxomatosis are giving researchers insights into how pathogens and hosts can shape each other’s evolution.

RETRACTED: The in vitro and in vivo effects of microRNA-133a on intervertebral disc destruction by targeting MMP9 in spinal tuberculosis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figure 4 A+C, which appear to have a similar phenotype as seen in many other publications, as detailed here: https://pubpeer.com/publications/0D0667F09124C7911264C51064AF20; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. The journal requested that the corresponding author comment on these concerns and provide the raw data. The authors did not respond to this request and therefore the Editor-in-Chief decided to retract the article.

Drug Release Characteristics and Tissue Distribution of Rifapentine Polylactic Acid Sustained-Release Microspheres in Rabbits after Paravertebral Implantation

BACKGROUND

Rates of drug-resistant tuberculosis (TB) and TB associated with human immunodeficiency virus (HIV) infection have increased dramatically, intensifying challenges in TB control. New formulations of TB treatment drugs that control drug release and increase local drug concentrations will have a significant impact on mitigating the toxic side effects and increasing the clinical efficacy of anti-TB drugs.

OBJECTIVES

The aim was to observe the sustained release characteristics of rifapentine polylactic acid sustained-release microspheres in vivo and the accumulation of rifapentine in other tissues following paravertebral implantation.

METHODS

This study is a basic animal experimental study that began on July 17, 2014 in the Fifth Affiliated hospital of Xinjiang Medical University. One hundred and eight New Zealand white rabbits (weighing 2.8 - 3.0 kg, male and female, China) were randomly divided into three groups of 36 rabbits each. Blood and tissue samples from the liver, lungs, kidneys, vertebrae, and paravertebral muscle were collected at different time points post-surgery. High performance liquid chromatography (HPLC) analysis with a biological internal standard was used to determine the drug concentrations in samples.

RESULTS

In group A, no significant differences in rifapentine concentrations in the liver were detected between any two time points (P > 0.05). However, the differences in rifapentine concentrations between day 10 and day 21 were statistically significant (P < 0.05); for days 21, 35, 46, and 60, the differences in rifapentine concentrations between two sequential time points were not statistically significant (P > 0.05). In group B, the differences in rifapentine concentration between days 3 and 10 in vertebral bone and in paravertebral muscles were statistically significant (P < 0.05). Rifapentine was detected in the vertebral bone tissue in the group C animals. The rifapentine concentrations between two sequential time points were statistically significant (P < 0.05). Rifapentine could not be detected in the paravertebral muscles 46 days after the operation. The differences in rifapentine concentrations between two sequential time points among days 3, 10, 21, and 35 were statistically significant (P < 0.05).

CONCLUSIONS

After paravertebral implantation of rifapentine polylactic acid sustained-release microspheres, the concentration of rifapentine in local vertebral bone tissues was maintained above the TB minimum inhibitory concentration for up to 60 days with no apparent accumulation of the drug in other tissues.

Animal models in tuberculosis research - where is the beef?

INTRODUCTION

Tuberculosis (TB) is a major global health problem, and new drugs and vaccines are urgently needed. As clinical trials in humans require tremendous resources, preclinical drug and vaccine development largely relies on valid animal models that recapitulate the pathology of human disease and the immune responses of the host as closely as possible.

AREAS COVERED

This review describes the animal models used in TB research, the most widely used being mice, guinea pigs and nonhuman primates. In addition, rabbits and cattle provide models with a disease pathology resembling that of humans. Invertebrate models, including the fruit fly and the Dictyostelium amoeba, have also been used to study mycobacterial infections. Recently, the zebrafish has emerged as a promising model for studying mycobacterial infections. The zebrafish model also facilitates the large-scale screening of drug and vaccine candidates.

EXPERT OPINION

Animal models are needed for TB research and provide valuable information on the mechanisms of the disease and on ways of preventing it. However, the data obtained in animal studies need to be carefully interpreted and evaluated before making assumptions concerning humans. With an increasing understanding of disease mechanisms, animal models can be further improved to best serve research goals.