Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low-intensity pulsed ultrasound promotes mesenchymal stem cell
  transplantation-based articular cartilage regeneration by inhibiting the TNF
  signaling pathway   Mesenchymal stem cell (MSC) transplantation therapy is highly studied for the
regenerative repair of cartilage defects. Low-intensity pulsed ultrasound
(LIPUS) has the potential to promote chondrogenic differentiation of MSCs,
which is hopeful to facilitate the transplantation therapy. However, its
underlying mechanism remains unclear. Here, we investigated the promoting
effects and mechanisms of LIPUS stimulation on the chondrogenic differentiation
of human umbilical cord mesenchymal stem cells (hUC-MSCs) and further evaluated
its regenerative application value in articular cartilage defects in rats. In
vitro, the suitable sound intensity of LIPUS for differentiation promotion was
screened, and the key signal pathway of LIPUS-induced differentiation was
clarified. In vivo, defective articular cartilage rat models were established
for further validating LIPUS stimulation and hUC-MSC transplantation-based
cartilage regeneration therapy. The results showed that LIPUS stimulation with
specific parameters effectively promoted the expression of mature
cartilage-related genes and proteins, inhibited TNF-{\alpha} gene expression in
hUC-MSCs, and exhibited anti-inflammation in C28/I2 cells. In addition, the
articular cartilage defects of rats were significantly repaired after hUC-MSC
transplantation and LIPUS stimulation. Taken together, our study demonstrated
that LIPUS stimulation could realize articular cartilage regeneration due to
the inhibition of TNF signaling pathway especially TNF-{\alpha} gene expression
down-regulation, which is of clinical value for the relief of osteoarthritis.

8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th