Thymosin Beta-4 Recombinant Adeno-associated Virus Enhances Human Nucleus Pulposus Cell Proliferation and Reduces Cell Apoptosis and Senescence

Germinal peptide eye drop promotes corneal epithelial and stromal defect healing in rabbit model

OBJECTIVE

Corneal defect is a common disease in ophthalmology caused by trauma, inflammation, drug toxicity, or surgery. To investigate the effect of germinal peptide eye drop on corneal epithelial and stromal defects after lamellar keratectomy in rabbit model.

METHODS

Eighty-five male New Zealand white rabbits were divided into five groups: Germinal Peptide eye drop at three different concentration groups, normal saline (negative control group), recombinant human epidermal growth factor (rh-EGF) eye drop (positive control group). Corneal epithelial and stromal defects of around 150-200 μm in depth were created with an 8 mm diameter trephine in the center of the right eyes of all animals.

RESULTS

Germinal peptide eye drop with the concentration of 0.001%, 0.002%, and 0.004% and rh-EGF eye drop were more effective in promoting healing, reducing opacity, and edema during the process of corneal epithelial and stromal defect regeneration compared with 0.9% normal saline. No significant difference was observed among the three different doses of germinal peptide eye drop. Compared with the saline control group, the structures of the regenerated corneas were more orderly and less inflammatory cell infiltration was observed in the germinal peptide eye drop groups and the rh-EGF eye drop group.

CONCLUSION

Germinal peptide eye drop (0.001%, 0.002%, and 0.004%) can significantly stimulate the regeneration of corneal epithelia and stroma and reduce corneal opacity and edema. Dose dependency was not observed in the current study.

Effects of Thymosin β4 on Myocardial Apoptosis in Burned Rats

The aim of this study was to investigate the effects of thymosin β4 on myocardial apoptosis following burns. Fifty healthy Sprague Dawley (SD) rats were randomly divided into the normal control group, resuscitation group the low-dose Tβ4 (thymosin β4) group (2g), the medium-dose Tβ4 group (6g), and the high-dose Tβ4 group (18g). The rats were immersed in 95°C hot water for 18 seconds, and then the model of 30% body surface area (TBSA) III° scald was established. The resuscated rats were injected with lactate Ringer's solution for antishock rehydration, while the Tβ4 treatment group was injected with lactate Ringer's solution for antishock rehydration, and the animals were sacrificed 6 h after scald. The degree of histopathological damage was observed by HE (hematoxylin and eosin) staining. Western blot was used to detect STAT1 and STAT3 protein expression levels. Real-time PCR was used to detect mRNA expressions of STAT1 and STAT3. The results showed that the apoptosis rate of the resuscitation group was significantly higher than that of the control group (P < 0.01). Compared with the resuscitation group, the apoptosis rate of thymosin β4 in the treatment group was significantly reduced (P < 0.01). Compared with the normal control group, the expression of STAT1 protein was increased and the expression of STAT3 protein was decreased in model group rats after ischemia and reperfusion. Compared with the model group, the expression of STAT1 protein decreased and the expression of STAT3 protein increased after ischemia-reperfusion in the thymosin β4 treatment group. Thymosin β4 may protect the myocardium by downregulating STAT1 and upregulating STAT3 expression and inhibiting myocardial apoptosis induced by ischemia and reperfusion after severe scald injury.

Anisodamine Maintains the Stability of Intervertebral Disc Tissue by Inhibiting the Senescence of Nucleus Pulposus Cells and Degradation of Extracellular Matrix via Interleukin-6/Janus Kinases/Signal Transducer and Activator of Transcription 3 Pathway

Objectives: Anisodamine (ANI) has been used to treat a variety of diseases. However, the study of ANI in intervertebral disc degeneration (IVDD) is unclear. This study investigated the effects of ANI on degenerative nucleus pulposus cells (NPCs) and IVDD rats, and its possible mechanisms. Methods: Human nucleus pulposus cells (HNPCs) were treated with IL-1β (20 ng/ml) to simulate IVDD, and an IVDD rat model was constructed. IL-1β-induced HNPCs were treated with different concentrations (10, 20, or 40 μM) of ANI, and IVDD rats were also treated with ANI (1 mg/kg). Results: ANI treatment significantly reduced the apoptosis, caspase-3 and SA-β-gal activities, and p53 and p21 proteins expression, while promoted telomerase activity and aggrecan and collagen II synthesis in IL-1β-induced HNPCs. Moreover, the introduction of ANI inhibited the expression of IL-6, phosphorylation of JAK and STAT3, and nuclear translocation of p-STAT3 in Degenerated HNPCs. Additionally, the application of ANI abolished the effects of IL-6 on apoptosis, SA-β-gal and telomerase activity, and the expression of p53, p21, aggrecan and collagen II proteins in degenerated HNPCs. Simultaneously, ANI treatment enhanced the effects of AG490 (inhibitor of JAK/STAT3 pathway) on IL-1β-induced apoptosis, senescence and ECM degradation in HNPCs. Furthermore, ANI treatment markedly inhibited the apoptosis and senescence in the nucleus pulposus of IVDD rats, while promoted the synthesis of aggrecan and collagen II. ANI treatment obviously inhibited JAK and STAT3 phosphorylation and inhibited nuclear translocation of p-STAT3 in IVDD rats. Conclusion: ANI inhibited the senescence and ECM degradation of NPCs by regulating the IL-6/JAK/STAT3 pathway to improve the function of NPCs in IVDD, which may provide new ideas for the treatment of IVDD.

Progress on the Function and Application of Thymosin β4

Thymosin β4 (Tβ4) is a multifunctional and widely distributed peptide that plays a pivotal role in several physiological and pathological processes in the body, namely, increasing angiogenesis and proliferation and inhibiting apoptosis and inflammation. Moreover, Tβ4 is effectively utilized for several indications in animal experiments or clinical trials, such as myocardial infarction and myocardial ischemia-reperfusion injury, xerophthalmia, liver and renal fibrosis, ulcerative colitis and colon cancer, and skin trauma. Recent studies have reported the potential application of Tβ4 and its underlying mechanisms. The present study reveals the progress regarding functions and applications of Tβ4.

The role of IL-1β and TNF-α in intervertebral disc degeneration

Low back pain (LBP), a prevalent and costly disease around the world, is predominantly caused by intervertebral disc (IVD) degeneration (IDD). LBP also presents a substantial burden to public health and the economy. IDD is mainly caused by aging, trauma, genetic susceptibility, and other factors. It is closely associated with changes in tissue structure and function, including progressive destruction of the extracellular matrix (ECM), enhanced senescence, disc cell death, and impairment of tissue biomechanical function. The inflammatory process, exacerbated by cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), are considered to be the key mediators of IDD and LBP. IL-1β and TNF-α are the most important proinflammatory cytokines, as they have powerful proinflammatory activities and can promote the secretion of a variety of proinflammatory mediators. They are also upregulated in the degenerative IVDs, and they are closely related to various pathological IDD processes, including inflammatory response, matrix destruction, cellular senescence, autophagy, apoptosis, pyroptosis, and proliferation. Therefore, anti-IL-1β and anti-TNF-α therapies may have the potential to alleviate disc degeneration and LBP. In this paper, we reviewed the expression pattern and signal transduction pathways of IL-1β and TNF-α, and we primarily focused on their similar and different roles in IDD. Because IL-1β and TNF-α inhibition have the potential to alleviate IDD, an in-depth understanding of the role of IL-1β and TNF-α in IDD will benefit the development of new treatment methods for disc degeneration with IL-1β and TNF-α at the core.

A Review of Gene Therapy Delivery Systems for Intervertebral Disc Degeneration

Background: :

Intervertebral Disc (IVD) degeneration is a major public health concern, and gene therapy seems a promising approach to delay or even reverse IVD degeneration. However, the delivery system used to transfer exogenous genes into intervertebral disc cells remains a challenge.

Methods::

The MEDLINE, Web of Science, and Scopus databases were searched for English-language articles related to gene therapy for IVD degeneration articles from 1999 to May 2019. The keywords included “gene therapy” AND “intervertebral disc”. The history of the development of different delivery systems was analysed, and the latest developments in viral and non-viral vectors for IVD degeneration treatment were reviewed.

Results: :

Gene therapy delivery systems for IVD degeneration are divided into two broad categories: viral and non-viral vectors. The most commonly used viral vectors are adenovirus, adeno-associated virus (AAV), and lentivirus. Enthusiasm for the use of adenovirus vectors has gradually declined and has been replaced by a preference for lentivirus and AAV vectors. New technologies, such as RNAi and CRISPR, have further enhanced the advantage of viral vectors. Liposomes are the classic non-viral vector, and their successors, polyplex micelles and exosomes, have more potential for use in gene therapy for IVD degeneration.

Conclusion::

Lentivirus and AAV are the conventional viral vectors used in gene therapy for IVD degeneration, and the new technologies RNAi and CRISPR have further enhanced their advantages. Nonviral vectors, such as polyplex micelles and exosomes, are promising gene therapy vectors for IVD degeneration.

Effects of thymosin β4 on neuronal apoptosis in a rat model of cerebral ischemia‑reperfusion injury

The aim of the present study was to investigate the protective effects of thymosin β4 (Tβ4) on neuronal apoptosis in rat middle cerebral artery occlusion ischemia/reperfusion (MCAO I/R) injury, and determine the mechanisms involved in this process. Forty-eight adult male Sprague-Dawley rats were randomly divided into three groups (n=16 per group): A sham control group, an ischemia/reperfusion group (I/R group), and a Tβ4 group. The focal cerebral I/R model was established by blocking the right MCA for 2 h, followed by reperfusion for 24 h. The Zea-Longa method was used to assess neurological deficits. Cerebral infarct volume was assessed using 2,3,5-triphenyltetrazolium chloride staining, and pathological changes were observed via hematoxylin and eosin staining. The terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay was used to detect apoptosis. The expression of glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), and caspase-12 (CASP12) protein was assessed using immunohistochemistry and western blotting 24 h after reperfusion. Infarct volume and neuronal damage in the I/R and Tβ4 groups were significantly greater than those observed in the sham group. The Zea-Longa score, neuronal apoptosis, and expression of GRP78, CHOP, and CASP12 in the I/R and Tβ4 groups were significantly higher than those reported in the sham group. However, the Longa score and neuronal apoptosis were lower in the Tβ4 group compared to the I/R group. The expression of GRP78 was significantly increased, whereas that of CHOP and CASP12 was significantly decreased in the Tβ4 group compared to the I/R group. The present data revealed that Tβ4 can inhibit neuronal apoptosis by upregulating GRP78 and downregulating CHOP and CASP12, thereby reducing cerebral I/R injury.

Tumor necrosis factor-α: a key contributor to intervertebral disc degeneration

Intervertebral disc (IVD) degeneration (IDD) is the most common cause leading to low back pain (LBP), which is a highly prevalent, costly, and crippling condition worldwide. Current treatments for IDD are limited to treat the symptoms and do not target the pathophysiology. Tumor necrosis factor-α (TNF-α) is one of the most potent pro-inflammatory cytokines and signals through its receptors TNFR1 and TNFR2. TNF-α is highly expressed in degenerative IVD tissues, and it is deeply involved in multiple pathological processes of disc degeneration, including matrix destruction, inflammatory responses, apoptosis, autophagy, and cell proliferation. Importantly, anti-TNF-α therapy has shown promise for mitigating disc degeneration and relieving LBP. In this review, following a brief description of TNF-α signal transduction, we mainly focus on the expression pattern and roles of TNF-α in IDD, and summarize the emerging progress regarding its inhibition as a promising biological therapeutic approach to disc degeneration and associated LBP. A better understanding will help to develop novel TNF-α-centered therapeutic interventions for degenerative disc disease.