Rationale, Science, and Economics of Surgical Nerve Decompression for Diabetic Neuropathy Foot Complications

Comparison of neurosensory devices in detecting cutaneous thresholds related to protective sensibility: A cross-sectional study in São Paulo, Brazil

AIMS

To quantify the static and moving cutaneous sensibility threshold of diabetic patients using a neurosensory device for quantitative pressure detection.

METHODS

Three hundred thirty-four (n = 334) patients with type 2 diabetes and no previous history of wounds on the feet were studied using the one- and two-point static (1SP;2 SP) and one- and two-point moving (1MP;2 MP) tests through the pressure-specified sensory device (PSSD) on the cutaneous territory of the dorsal first web, hallux pulp, and medial calcaneal. In addition, patients were evaluated using the Semmes-Weinstein monofilament (SWM) No. 5.07 and tuning fork (128 Hz), which were used as normality parameters to detect the loss of protective sensibility. The same examinations were used to assess the control group (228 nondiabetic).

RESULTS

Altered values were observed for the static and moving tests over the three studied nerve territories. In comparing the sensibility threshold between diabetic patients who were sensitive and nonsensitive to SWM 5.07, we observed that this filament is not the most indicated for identifying the loss of sensibility in these patients. The prevalence of patients at risk varied between 85 and 89%. The biochemical marker associated with these high rates was HbA1c (p = 0.02).

CONCLUSIONS

Numeric quantification of the pressure threshold allowed us to determine the functional deficit of nerve fibers. Our findings suggest that the neurosensory device should be used as an adjuvant tool to evaluate the degree of loss of sensation on the skin.

MicroRNA-193a Downregulates HMGB1 to Alleviate Diabetic Neuropathic Pain in a Mouse Model

BACKGROUND

Diabetic neuropathy is a serious complication for diabetic patients involving the nervous system. This disease is a quiet but painful condition caused by chronically high blood glucose levels. It is reported that high mobility group box 1 protein (HMGB1) participates in the development of neuropathic pain. This study aimed to explore the role of microRNA (miR)-193a in diabetic neuropathic pain through the regulation of HMGB1.

METHODS

A diabetic mouse model was established through the injection of streptozocin (STZ). Neuropathic pain development was shown by paw withdrawal thresholds and paw withdrawal latency. Expression levels of relative genes or miR were analyzed by qRT-PCR, while Western blot was employed to assess the protein levels. The interaction between miR-193a and HMGB1 mRNA 3'-UTR region was shown by luciferase assay. The levels of inflammation cytokines were measured by ELISA kits.

RESULTS

miR-193a expression was decreased and HMGB1 expression was upregulated in the lumbar spinal dorsal horn of STZ-induced diabetic mice. miR-193a inhibited HMGB1 expression in the lumbar spinal dorsal horn. Overexpression of miR-193a alleviated neuropathic pain in STZ-induced diabetic mice. Peripheral neuroinflammation in diabetic mice was suppressed by miR-193a overexpression.

CONCLUSION

This research illustrates that miR-193a alleviates diabetic neuropathic pain in a mouse model through the inhibition of HMGB1 expression.

The role of miR-190a-5p contributes to diabetic neuropathic pain via targeting SLC17A6

Introduction

MicroRNAs play a key role in neuropathic pain. In a previous study, miR-190a-5p was significantly downregulated in diabetic neuropathic pain (DNP). However, the role and pathological mechanism of miR-190a-5p in DNP still remain unclear.

Materials and methods

DNP model was established. The paw withdrawal thresholds were measured to assess the mechanical nociceptive response. Dual-luciferase reporter assay was used to confirm the target gene of microRNA. The expressions of microRNA, gene, and protein were detected by the quantitative real-time polymerase chain reaction or Western blot. The levels of IL-1β and IL-6 were detected with the enzyme-linked immuno sorbent assay.

Results

Compared with the control sample, the expression of miR-190a-5p was decreased and SLC17A6 was increased in the spinal tissue from those developing DNP. The bioinformatics and luciferase reporter assay demonstrated that SLC17A6 is a direct target of miR-190a-5p. Up-regulation of miR-190a-5p and inhibition of SLC17A6 could significantly weaken the painful behavior and reduce IL-1β and IL-6 level in DNP.

Conclusion

miR-190a-5p is involved in DNP via targeting SLC17A6, and miR-190a-5p and SLC17A6 may be the therapeutic targets of this disease.

Peroxisome Proliferator-Activated Receptor-γ Coactivator-1α (PGC-1α) Regulates the Expression of B-Cell Lymphoma/Leukemia-2 (Bcl-2) and Promotes the Survival of Mesenchymal Stem Cells (MSCs) via PGC-1α/ERRα Interaction in the Absence of Serum, Hypoxia, and High Glucose Conditions

BACKGROUND To study the effect of estrogen-related receptor α (ERRα) and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) on mesenchymal stem cells (MSCs) apoptosis, and further investigated its detailed molecular mechanisms in the absence of serum, hypoxia, and high glucose conditions. MATERIAL AND METHODS In our study, we first evaluated the expression rates of CD14, CD34, CD45, CD44, CD29, and Sca-1 surface markers on MSCs by flow cytometry. Then, the ability of osteogenic and fatty differentiation of MSCs was determined by osteogenic differentiation and adipogenesis reagent kit. Next, Annexin V-APC/7-AAD apoptosis kit was used for detecting the apoptosis rate of MSCs. RT-PCR and Western blotting were used for detection of mRNA expression and proteins expression, respectively. RESULTS Our data showed that the MSCs used in our study were capable of self-renewal and differentiating into many cell lineages, such as osteogenic differentiation and adipogenesis. Our results further showed that over-expression of PGC-1α could protect MSCs from apoptosis induced by rotenone. We also found that PGC-1α over-expression could enhance the expression of anti-apoptotic gene Bcl-2, and inhibit the expression of pro-apoptotic gene Bax in MSCs. In addition, our data demonstrated that PGC-1α could induce upregulation of Bcl-2 and further promote the survival of MSCs by interacting with ERRα. CONCLUSIONS In the absence of serum, hypoxia and high glucose conditions, PGC-1α can regulate the expression of Bcl-2 and promote the survival of MSCs via PGC-1α/ERRα interaction.

Evaluation of wound healing in diabetic foot ulcer using platelet-rich plasma gel: A single-arm clinical trial

The aim of the present study was to evaluate the effectiveness of using autologous platelet-rich plasma (PRP) gel for treatment of diabetic foot ulcer (DFU) during the first 4 weeks of the treatment. In this longitudinal and single-arm trial, 100 patients were randomly selected after meeting certain inclusion and exclusion criteria; of these 100 patients, 70 (70%) were enrolled in the trial. After the primary care actions such as wound debridement, the area of each wound was calculated and recorded. The PRP therapy (2mL/cm² of ulcers) was performed weekly until the healing time for each patient. We used one sample T-test for healing wounds and Bootstrap resampling approach for reporting confidence interval with 1000 Bootstrap samples. The p-value<0.05 were considered statistically significant. The mean (SD) of DFU duration was 19.71 weeks (4.94) for units sampling. The ratio of subjects who withdrew from the study was calculated to be 2 (2.8%). Average area of 71 ulcers in the mentioned number of cases was calculated to be 6.11cm² (SD: 4.37). Also, the mean, median (SD) of healing time was 8.7, 8 weeks (SD: 3.93) except for 2 mentioned cases. According to one sample T-test, wound area (cm²), on average, significantly decreased to 51.9% (CI: 46.7-57.1) through the first four weeks of therapy. Furthermore, significant correlation (0.22) was not found between area of ulcers and healing duration (p-value>0.5). According to the results, PRP could be considered as a candidate treatment for non-healing DFUs as it may prevent future complications such as amputation or death in this pathological phenomenon.