Dental Pulp Mesenchymal Stem Cells Attenuate Limb Ischemia via Promoting Capillary Proliferation and Collateral Development in a Preclinical Model

Ptip is essential for tooth development via regulating Wnt pathway

OBJECTIVE

Epigenetic regulation plays important role in stem cell maintenance. Ptip was identified as epigenetic regulator, but the role in dental progenitor cells remains unclear.

SUBJECTS AND METHODS

Dental mesenchymal progenitor cells were targeted by Sp7-icre and visualized in mTmG; Sp7-icre mice. The Ptipf/f; Sp7-icre mice were generated and the phenotype of incisors and molars were shown by micro-computerized tomography, scanning electron microscope, hematoxylin & eosin staining, and immunofluorescence. Dental mesenchymal progenitor cells were sorted by fluorescence-activated cell sorting from lower incisors and RNA sequencing was performed.

RESULTS

The Sp7-icre targets dental mesenchymal progenitor cells in incisors and molars. The Ptipf/f; Sp7-icre mice showed spontaneous fractures in the cusp of upper incisors and lower incisors at 3 weeks (w), compensative overgrowth of lower incisors at 1 month (M), and overgrowth extended to the outside at 2 M. The molars showed shortened roots. The functions of odontoblasts and dental mesenchymal progenitor cells were impaired. Mechanically, loss of Ptip activates the Wnt pathway and upregulates the expression of Wls in dental mesenchymal progenitor cells. Also, the regenerative ability of lower incisors was significantly impaired.

CONCLUSION

We first demonstrated that Ptip was crucial for tooth development via regulating Wnt signaling.

Effect of Percutaneous Endovascular Angioplasty Combined with Negative Pressure Drainage on the "One-Stop" Treatment of Ischemic Diabetic Foot Ulcer

BACKGROUND

To explore the therapeutic effect, safety, and economic benefit of a "one-stop" diagnosis and treatment mode of vascular surgery for ischemic diabetic foot (DF) ulcer and to analyze the associated and independent factors that affect ulcer healing.

METHODS

In a prospective, single-center study, patients with ischemic DF ulcers from January 2017 to July 2021 were treated with either percutaneous endovascular angioplasty combined with negative pressure closed drainage (PTA-VSD) or percutaneous endovascular angioplasty combined with depuration (PTA-UD). The effectiveness and economic benefits of the 2 measures were compared, and independent factors affecting ulcer healing were explored via univariate and logistic regression analyses.

RESULTS

Fifty patients with ischemic DF ulcer (25 patients in the PTA-VSD group and 25 patients in the PTA-UD group; 40 males and 10 females) were included, with an average age of 67.74 ± 10.71 years. No difference was observed in the demographic data. The findings showed that the ulcer healing time in the PTA-VSD group was significantly shorter than that in the PTA-UD group (154.79 vs. 238.31 days), and the ulcer healing rate at 180 days post surgery was significantly greater in the PTA-VSD group (52% vs. 12%) (P = 0.002, < 0.05). The ulcer score in the PTA-VSD group decreased significantly at 3, 6, and 12 months post surgery. The duration of hospitalization in the PTA-VSD group was greater (P = 0.002, <0.05), but no significant difference in hospitalization frequency and cost was observed between the 2 groups. During follow-up, there was 1 death and 1 amputation in the PTA-UD group, but no death or amputation in the PTA-VSD group. Arterial occlusion was primarily located in the femoral-popliteal artery and the inferior knee artery in the 2 groups, and PTA intervention effectively opened the outflow tract of the affected limb. Two to three outflow tracts were opened in 41 patients. The ankle-brachial index (ABI) after surgery was significantly higher in both groups than before. Univariate and multivariate logistic regression analyses revealed that the Wagner grade and number of outflow channels and therapies (PTA-VSD) could be independent factors affecting ulcer healing.

CONCLUSIONS

The severity of DF ulcers is an important factor affecting the quality of life of patients. A multidisciplinary "one-stop" treatment strategy based on percutaneous endovascular angioplasty combined with negative pressure-sealing drainage can rapidly and effectively restore the blood flow to the affected limb and promote ulcer healing without increasing medical costs.

Botanicals and Oral Stem Cell Mediated Regeneration: A Paradigm Shift from Artificial to Biological Replacement

Stem cells are a well-known autologous pluripotent cell source, having excellent potential to develop into specialized cells, such as brain, skin, and bone marrow cells. The oral cavity is reported to be a rich source of multiple types of oral stem cells, including the dental pulp, mucosal soft tissues, periodontal ligament, and apical papilla. Oral stem cells were useful for both the regeneration of soft tissue components in the dental pulp and mineralized structure regeneration, such as bone or dentin, and can be a viable substitute for traditionally used bone marrow stem cells. In recent years, several studies have reported that plant extracts or compounds promoted the proliferation, differentiation, and survival of different oral stem cells. This review is carried out by following the PRISMA guidelines and focusing mainly on the effects of bioactive compounds on oral stem cell-mediated dental, bone, and neural regeneration. It is observed that in recent years studies were mainly focused on the utilization of oral stem cell-mediated regeneration of bone or dental mesenchymal cells, however, the utility of bioactive compounds on oral stem cell-mediated regeneration requires additional assessment beyond in vitro and in vivo studies, and requires more randomized clinical trials and case studies.

With a Little Help From My Friends: the Role of the Renal Collateral Circulation in Atherosclerotic Renovascular Disease

The collateral circulation can adapt to bypass major arteries with limited flow and serves a crucial protective role in coronary, cerebral, and peripheral arterial disease. Emerging evidence indicates that the renal collateral circulation can similarly adapt and thereby limit kidney ischemia in atherosclerotic renovascular disease. These adaptations predominantly include recruitment of preexisting microvessels for arteriogenesis, with de novo vessel formation playing a limited role. Yet, adaptations of the renal collateral circulation in renovascular disease are often insufficient to fully compensate for the limited flow within an obstructed renal artery and may be hampered by the severity of obstruction or patient comorbidities. Experimental strategies have attempted to circumvent limitations of collateral formation and improve the prognosis of patients with various ischemic vascular territories. These have included pharmacological approaches such as endothelial growth factors, renin-angiotensin-aldosterone system blockade, and If-channel-blockers, as well as interventions like preconditioning, exercise, enhanced external counter-pulsation, and low-energy shock-wave therapy. However, few of these strategies have been implemented in atherosclerotic renovascular disease. This review summarizes current understanding regarding the development of renal collateral circulation in atherosclerotic renovascular disease. Studies are needed to apply lessons learned in other vascular beds in the setting of atherosclerotic renovascular disease to develop new treatment regimens for this patient group.