A Clinical Diagnostic Study: Fibulin-2 is a Novel Promising Biomarker for Predicting Infection

FBLN2 inhibits gastric cancer proliferation and metastasis via the TGFβ/TGIF2 pathway

Gastric cancer (GC) ranks among the most common gastrointestinal tumours and is a significant contributor to cancer mortality globally. The proliferation, metastasis, occurrence and development of GC have obvious malignant tendencies. This study is based on our previous studies. Previously, we reported that Fibulin-2 (FBLN2) can inhibit the distant metastasis of GC by promoting lost-nest apoptosis. Despite its clinical importance, the biological function of FBLN2 in GC remains inadequately understood. This study investigated the underlying molecular mechanisms of FBLN2 in the pathogenesis and progression of GC, as well as its impact on the biological behaviour of GC cells. In vivo and in vitro experiments, we demonstrated that FBLN2 overexpression resulted in a reduction in GC cell proliferation and metastasis, whereas its knockdown led to enhancement of GC proliferation and metastasis. Moreover, we used RNA-seq technology to conduct KEGG enrichment analysis of differential genes in wild-type GC cells and FBLN2 knockout GC cells and successfully confirmed that FBLN2 plays a corresponding biological role through the TGFβ/TGIF2 axis. In addition, in terms of the clinical data, we revealed a correlation between FBLN2 and TGIF2 and patient prognosis. In summary, our study revealed that FBLN2 suppressed GC proliferation, migration and invasion by downregulating the TGFβ/TGIF2 axis, suggesting that FBLN2 is a promising target for GC treatment.

Osteoporosis: Emerging targets on the classical signaling pathways of bone formation

Osteoporosis is a multifaceted skeletal disorder characterized by reduced bone mass and structural deterioration, posing a significant public health challenge, particularly in the elderly population. Treatment strategies for osteoporosis primarily focus on inhibiting bone resorption and promoting bone formation. However, the effectiveness and limitations of current therapeutic approaches underscore the need for innovative methods. This review explores emerging molecular targets within crucial signaling pathways, including wingless/integrated (WNT), bone morphogenetic protein (BMP), hedgehog (HH), and Notch signaling pathway, to understand their roles in osteogenesis regulation. The identification of crosstalk targets between these pathways further enhances our comprehension of the intricate bone metabolism cycle. In summary, unraveling the molecular complexity of osteoporosis provides insights into potential therapeutic targets beyond conventional methods, offering a promising avenue for the development of new anabolic drugs.

Fibulin-2: A potential regulator of immune dysfunction after bone trauma

OBJECTIVES

To reveal the relationship between the fibulin-2 protein and immune dysfunction after bone trauma.

METHODS

Individuals who were admitted to the study were divided into a bone trauma group, a recovered from bone trauma group and a volunteer without bone trauma group based on the reason for admission. Fibulin-2 levels in the three groups were compared. Fibulin-2-knockout (fibulin-2-/- ) mice and wild-type (WT) mice were used to detect susceptibility to infection. Hematoxylin and eosin (HE) staining and immunohistochemical staining were employed to observe pathological changes in each organ from fibulin-2-/- mice and WT mice.

RESULTS

In total, 132 patients were enrolled in this study. The fibulin-2 level in the bone trauma group was lower than that in the recovered bone trauma group (3.39 ± 1.41 vs. 4.30 ± 1.38 ng/mL, t = 2.948, p < .05) and also lower than that in the volunteers without bone trauma group (3.39 ± 1.41 vs. 4.73 ± 1.67 ng/mL, t = 4.135, p < .05). Fibulin-2-/- mice are more prone to infection. Compared with those in WT mice, spleen function and thymus function in fibulin-2-/- mice were impaired. Immunohistochemical staining revealed that compared with those in WT mice, significantly fewer CD4+ T cells, CD8+ T cells, and CD19+ B cells were noted in the spleen and thymus of fibulin-2-/- mice.

CONCLUSIONS

The plasma fibulin-2 level was lower in patients with bone trauma. Decreased fibulin-2 is associated with immune dysfunction after bone trauma.

Fibulin2: a negative regulator of BMSC osteogenic differentiation in infected bone fracture healing

Bone fracture remains a common occurrence, with a population-weighted incidence of approximately 3.21 per 1000. In addition, approximately 2% to 50% of patients with skeletal fractures will develop an infection, one of the causes of disordered bone healing. Dysfunction of bone marrow mesenchymal stem cells (BMSCs) plays a key role in disordered bone repair. However, the specific mechanisms underlying BMSC dysfunction caused by bone infection are largely unknown. In this study, we discovered that Fibulin2 expression was upregulated in infected bone tissues and that BMSCs were the source of infection-induced Fibulin2. Importantly, Fibulin2 knockout accelerated mineralized bone formation during skeletal development and inhibited inflammatory bone resorption. We demonstrated that Fibulin2 suppressed BMSC osteogenic differentiation by binding to Notch2 and inactivating the Notch2 signaling pathway. Moreover, Fibulin2 knockdown restored Notch2 pathway activation and promoted BMSC osteogenesis; these outcomes were abolished by DAPT, a Notch inhibitor. Furthermore, transplanted Fibulin2 knockdown BMSCs displayed better bone repair potential in vivo. Altogether, Fibulin2 is a negative regulator of BMSC osteogenic differentiation that inhibits osteogenesis by inactivating the Notch2 signaling pathway in infected bone.